From 471945c3483591a8c3868289de8e9b7510d26c37 Mon Sep 17 00:00:00 2001
From: Sam Lijin <sam@boundaryml.com>
Date: Sat, 26 Sep 2026 13:39:53 -0700
Subject: [PATCH] Embed SDK bytecode as a single-line blob decoded natively by
 bridges
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Generated SDKs embed the compiled program as one string literal: base64
of an LZ4 frame (`baml_artifact::encode_embedded`). The host language
never decodes it: generated code hands the literal (or its bytes) to the
runtime entry point, renamed from `initialize_runtime_from_bytecode` to
`initialize_runtime_from_blob` (`initializeRuntimeFromBlob` /
`InitializeRuntimeFromBlob` in the bridges), and `bridge_cffi` decodes it
natively (`baml_artifact::decode_embedded`). Raw artifacts, recognized by
their `BAMLART` magic, still pass through, so the Rust SDK's
`include_bytes!` `.bin` and the C#/C++ carriers are unchanged.

- Python embeds `BYTECODE: bytes = b"…"`, Go a `const bytecode`, Swift a
  single-line `bytecodeBase64`, Java the same text in `inlinedbaml.b64`.
- TypeScript embeds `export const BYTECODE = "…"`; the Node and web
  `initializeRuntimeFromBlob` also accept a string.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../workflows/verify-rust-sdk.reusable.yaml   |  2 +-
 baml_language/Cargo.lock                      |  7 +-
 baml_language/Cargo.toml                      |  2 +
 baml_language/crates/baml_artifact/Cargo.toml |  2 +
 baml_language/crates/baml_artifact/src/lib.rs | 94 ++++++++++++++++++-
 .../crates/baml_sdkgen_types/Cargo.toml       |  1 +
 .../src/embedded_bytecode.rs                  | 15 +++
 .../crates/baml_sdkgen_types/src/lib.rs       |  2 +
 baml_language/crates/bridge_cffi/Cargo.toml   |  1 +
 .../crates/bridge_cffi/cbindgen.toml          |  4 +-
 .../crates/bridge_cffi/include/baml_cffi.h    | 19 ++--
 baml_language/crates/bridge_cffi/src/api.rs   | 28 +++---
 .../crates/bridge_cffi/src/ffi/runtime.rs     | 16 ++--
 baml_language/crates/bridge_cffi/src/lib.rs   | 26 +++--
 .../crates/bridge_cffi/src/lib_native.rs      |  4 +-
 .../crates/bridge_cffi/tests/abi_assertions.h | 12 +--
 .../crates/bridge_cffi/tests/abi_layout.c     |  4 +-
 .../crates/bridge_cffi/tests/abi_layout.rs    |  4 +-
 .../crates/bridge_cffi/tests/abi_smoke.c      |  2 +-
 .../crates/bridge_cffi/tests/bytecode_skew.rs | 41 +++++---
 .../ruby_sorbet/test/native/bridge_fixture.c  |  8 +-
 .../customizable/host_callables.test.ts       |  6 +-
 .../customizable/bridge_surface.test.ts       |  2 +-
 .../sdk_tests/harness_runner/src/lib.rs       | 19 ++--
 .../bridge-ref/ref-java-examples.md           |  9 +-
 .../bridge-ref/ref-java-type-mappings.md      |  4 +-
 .../bridge_cpp/include/baml/detail/loader.h   |  4 +-
 .../cpp/bridge_cpp/include/baml/runtime.h     | 11 +--
 .../cpp/bridge_cpp/tests/runtime_smoke.cc     |  2 +-
 baml_language/sdks/cpp/sdkgen_cpp/src/lib.rs  |  8 +-
 .../bridge_csharp/src/Cffi/NativeApi.cs       |  8 +-
 .../bridge_csharp/src/Cffi/NativeTypes.cs     |  6 +-
 .../Baml.Bridge.AbiLifetimeProbe/Program.cs   | 12 +--
 .../tests/Baml.Bridge.AbiProbe/Program.cs     |  4 +-
 .../NativeBytecodeInitializer.cs              |  8 +-
 .../NativeBridge.cs                           |  8 +-
 .../tests/Baml.Bridge.Tests/Program.cs        | 12 +--
 .../tests/native_fixtures/table_diagnostics.c |  2 +-
 .../baml_go/internal/cffi/include/baml_cffi.h | 19 ++--
 baml_language/sdks/go/baml_go/native_unix.go  | 10 +-
 .../sdks/go/baml_go/native_windows.go         | 10 +-
 baml_language/sdks/go/sdkgen_go/src/lib.rs    | 29 +++---
 .../sdks/java/bridge_java/src/lib.rs          |  7 +-
 .../sdks/java/sdkgen_java/src/lib.rs          | 58 +++---------
 .../src/baml_core/baml_py/__init__.pyi        |  2 +-
 .../python/rust/bridge_python/src/runtime.rs  |  7 +-
 .../rust/sdkgen_python_pydantic2/src/lib.rs   | 46 +++------
 .../sdks/python/src/baml_bridge/baml_py.pyi   |  2 +-
 .../sdks/python/tests/test_engine.py          |  2 +-
 .../bridge_ruby/lib/baml/bridge/native.rb     | 10 +-
 .../sdks/rust/bridge_rust/src/capi.rs         | 24 ++---
 .../sdks/rust/bridge_rust/src/runtime.rs      |  4 +-
 .../sdks/swift/Sources/BamlBridge/Api.swift   |  6 +-
 .../swift/Sources/BamlBridge/Runtime.swift    |  4 +-
 .../Sources/CBamlBridge/include/baml_cffi.h   | 19 ++--
 .../sdks/swift/rust/sdkgen_swift/Cargo.toml   |  2 +-
 .../sdks/swift/rust/sdkgen_swift/src/lib.rs   | 59 ++++++------
 .../bridge_typescript/dist/index.d.ts         |  2 +-
 .../bridge_typescript/dist/index.d.ts.map     |  2 +-
 .../bridge_typescript/dist/index.js           |  6 +-
 .../bridge_typescript/dist/index.js.map       |  2 +-
 .../bridge_typescript/dist/native.d.ts        |  8 +-
 .../bridge_typescript/src/runtime.rs          | 19 ++--
 .../bridge_typescript/typescript_src/index.ts |  9 +-
 .../typescript_src/native.d.ts                |  8 +-
 .../bridge_typescript_web/src/runtime.rs      | 13 ++-
 .../tests/runtime_errors.test.ts              |  2 +-
 .../typescript_src/index.ts                   |  4 +-
 .../typescript_src/native.ts                  |  2 +-
 .../typescript_src/wasm/bridge_web_core.d.ts  |  9 +-
 .../sdkgen_typescript_shared/Cargo.toml       |  4 +-
 .../sdkgen_typescript_shared/src/leaf.rs      | 16 ++--
 .../sdkgen_typescript_shared/src/lib.rs       | 87 +++++++----------
 release/bridge-cffi-public-exports.txt        |  4 +-
 74 files changed, 513 insertions(+), 423 deletions(-)
 create mode 100644 baml_language/crates/baml_sdkgen_types/src/embedded_bytecode.rs

diff --git a/.github/workflows/verify-rust-sdk.reusable.yaml b/.github/workflows/verify-rust-sdk.reusable.yaml
index b0371f91e77..4010d0f7b05 100644
--- a/.github/workflows/verify-rust-sdk.reusable.yaml
+++ b/.github/workflows/verify-rust-sdk.reusable.yaml
@@ -276,7 +276,7 @@ jobs:
           # GNU/Linux invocation; on macOS the functional smokes above already
           # prove the ABI (the consumer calls through every symbol).
           if [[ "$RUNNER_OS" == "Linux" ]]; then
-            for sym in version free_buffer create_baml_runtime initialize_runtime_from_bytecode \
+            for sym in version free_buffer create_baml_runtime initialize_runtime_from_blob \
                        register_callback new_function_call call_function; do
               nm -D "${{ steps.art.outputs.dylib }}" | grep -qw "$sym" || {
                 echo "::error::dylib missing exported symbol $sym"; exit 1; }
diff --git a/baml_language/Cargo.lock b/baml_language/Cargo.lock
index 17ccf4be18c..37e3e545877 100644
--- a/baml_language/Cargo.lock
+++ b/baml_language/Cargo.lock
@@ -597,8 +597,10 @@ name = "baml_artifact"
 version = "0.0.0-beta"
 dependencies = [
  "baml_version",
+ "base64",
  "borsh",
  "log",
+ "lz4_flex",
  "sha2",
  "thiserror 2.0.18",
 ]
@@ -1091,6 +1093,7 @@ dependencies = [
 name = "baml_sdkgen_types"
 version = "0.0.0-beta"
 dependencies = [
+ "baml_artifact",
  "baml_base",
  "baml_type",
  "fs2",
@@ -6680,19 +6683,19 @@ dependencies = [
 name = "sdkgen_swift"
 version = "0.0.0-beta"
 dependencies = [
+ "baml_artifact",
  "baml_base",
  "baml_sdkgen_types",
  "baml_version",
- "base64",
 ]
 
 [[package]]
 name = "sdkgen_typescript_shared"
 version = "0.0.0-beta"
 dependencies = [
+ "baml_artifact",
  "baml_base",
  "baml_sdkgen_types",
- "base64",
 ]
 
 [[package]]
diff --git a/baml_language/Cargo.toml b/baml_language/Cargo.toml
index 03a4ebc826e..8e247be9a0a 100644
--- a/baml_language/Cargo.toml
+++ b/baml_language/Cargo.toml
@@ -233,6 +233,8 @@ fancy-regex = { version = "0.19" }
 # gitignore-aware directory walking (workspace project discovery in the LSP)
 ignore = { version = "0.4" }
 base64 = "0.22"
+# LZ4 frames compress the bytecode that generated SDKs embed.
+lz4_flex = { version = "0.13" }
 mime_guess = "2"
 bytecount = "0.6"
 reqwest = { version = "0.13.1", default-features = false, features = [
diff --git a/baml_language/crates/baml_artifact/Cargo.toml b/baml_language/crates/baml_artifact/Cargo.toml
index 7e5f4dc13f4..5b0faf8d35f 100644
--- a/baml_language/crates/baml_artifact/Cargo.toml
+++ b/baml_language/crates/baml_artifact/Cargo.toml
@@ -23,7 +23,9 @@ workspace = true
 
 [dependencies]
 baml_version = { workspace = true }
+base64 = { workspace = true }
 borsh = { workspace = true }
 log = { workspace = true }
+lz4_flex = { workspace = true }
 sha2 = { workspace = true }
 thiserror = { workspace = true }
diff --git a/baml_language/crates/baml_artifact/src/lib.rs b/baml_language/crates/baml_artifact/src/lib.rs
index 96608c859fa..26a425f6aa1 100644
--- a/baml_language/crates/baml_artifact/src/lib.rs
+++ b/baml_language/crates/baml_artifact/src/lib.rs
@@ -5,8 +5,12 @@
 //! the release metadata check at bridge startup useful while adding an ABI
 //! check that runs even when generated metadata is unavailable.
 
-use std::fmt;
+use std::{
+    fmt,
+    io::{Read as _, Write as _},
+};
 
+use base64::{Engine as _, engine::general_purpose::STANDARD as BASE64};
 use borsh::{BorshDeserialize, BorshSerialize};
 use sha2::{Digest, Sha256};
 
@@ -171,6 +175,54 @@ pub enum Error {
     Encode { kind: ArtifactKind, message: String },
     #[error("failed to decode {kind}: {message}")]
     Decode { kind: ArtifactKind, message: String },
+    #[error("failed to decode embedded {kind}: {message}")]
+    Embedded { kind: ArtifactKind, message: String },
+}
+
+/// Encode an artifact for embedding as a single-line string literal in
+/// generated SDK source: an LZ4 frame, then standard padded base64.
+/// [`decode_embedded`] reverses this; bridges call it so host languages never
+/// decode the payload themselves. The encoding cannot begin with [`MAGIC`], so
+/// bridges can accept either form.
+pub fn encode_embedded(artifact: &[u8]) -> String {
+    let mut encoder = lz4_flex::frame::FrameEncoder::new(Vec::new());
+    encoder
+        .write_all(artifact)
+        .expect("writing to a Vec cannot fail");
+    BASE64.encode(encoder.finish().expect("writing to a Vec cannot fail"))
+}
+
+/// Largest artifact [`decode_embedded`] will inflate. Generated programs are a
+/// few MB; the cap keeps a malformed, highly compressible payload from
+/// allocating unbounded memory before artifact validation can reject it.
+pub const MAX_EMBEDDED_ARTIFACT_BYTES: u64 = 512 * 1024 * 1024;
+
+/// Decode an [`encode_embedded`] payload back into the artifact bytes.
+pub fn decode_embedded(kind: ArtifactKind, encoded: &[u8]) -> Result<Vec<u8>, Error> {
+    decode_embedded_within(kind, encoded, MAX_EMBEDDED_ARTIFACT_BYTES)
+}
+
+fn decode_embedded_within(
+    kind: ArtifactKind,
+    encoded: &[u8],
+    max_artifact_bytes: u64,
+) -> Result<Vec<u8>, Error> {
+    let embedded_error = |message: String| Error::Embedded { kind, message };
+    let compressed = BASE64
+        .decode(encoded)
+        .map_err(|error| embedded_error(format!("invalid base64: {error}")))?;
+    let mut artifact = Vec::new();
+    // Read one byte past the cap so an oversized artifact is detectable.
+    lz4_flex::frame::FrameDecoder::new(compressed.as_slice())
+        .take(max_artifact_bytes.saturating_add(1))
+        .read_to_end(&mut artifact)
+        .map_err(|error| embedded_error(format!("invalid LZ4 frame: {error}")))?;
+    if artifact.len() as u64 > max_artifact_bytes {
+        return Err(embedded_error(format!(
+            "decoded artifact exceeds {max_artifact_bytes} bytes"
+        )));
+    }
+    Ok(artifact)
 }
 
 /// Serialize `value` and wrap it in a versioned artifact envelope.
@@ -366,6 +418,46 @@ pub fn decode_payload(kind: ArtifactKind, bytes: &[u8]) -> Result<&[u8], Error>
 mod tests {
     use super::*;
 
+    #[test]
+    fn embedded_encoding_round_trips() {
+        let artifact = encode(ArtifactKind::Program, &vec![7_u32; 1024]).unwrap();
+        let encoded = encode_embedded(&artifact);
+        assert!(encoded.len() < artifact.len());
+        assert!(!encoded.contains('\n'));
+        assert!(!encoded.as_bytes().starts_with(MAGIC));
+        let restored = decode_embedded(ArtifactKind::Program, encoded.as_bytes()).unwrap();
+        assert_eq!(restored, artifact);
+        let decoded: Vec<u32> = decode(ArtifactKind::Program, &restored).unwrap();
+        assert_eq!(decoded, vec![7_u32; 1024]);
+    }
+
+    #[test]
+    fn oversized_embedded_artifacts_are_rejected() {
+        let artifact = encode(ArtifactKind::Program, &vec![0_u8; 4096]).unwrap();
+        let encoded = encode_embedded(&artifact);
+        let limit = artifact.len() as u64;
+        assert_eq!(
+            decode_embedded_within(ArtifactKind::Program, encoded.as_bytes(), limit).unwrap(),
+            artifact
+        );
+        let error = decode_embedded_within(ArtifactKind::Program, encoded.as_bytes(), limit - 1)
+            .unwrap_err();
+        assert!(
+            matches!(&error, Error::Embedded { message, .. } if message.contains("exceeds")),
+            "{error}"
+        );
+    }
+
+    #[test]
+    fn corrupt_embedded_payloads_are_embedded_errors() {
+        let encoded = encode_embedded(&encode(ArtifactKind::Program, &vec![1_u32; 64]).unwrap());
+        for corrupt in ["not base64!", &encoded[..(encoded.len() / 2) & !3]] {
+            let corrupt = corrupt.as_bytes();
+            let error = decode_embedded(ArtifactKind::Program, corrupt).unwrap_err();
+            assert!(matches!(error, Error::Embedded { .. }), "{error}");
+        }
+    }
+
     #[test]
     fn round_trips_payload() {
         let artifact = encode(ArtifactKind::Program, &vec![1_u32, 2, 3]).unwrap();
diff --git a/baml_language/crates/baml_sdkgen_types/Cargo.toml b/baml_language/crates/baml_sdkgen_types/Cargo.toml
index cfe69b44f77..8ba16df70e7 100644
--- a/baml_language/crates/baml_sdkgen_types/Cargo.toml
+++ b/baml_language/crates/baml_sdkgen_types/Cargo.toml
@@ -17,6 +17,7 @@ doctest = false
 workspace = true
 
 [dependencies]
+baml_artifact = { workspace = true }
 baml_base = { workspace = true }
 baml_type = { workspace = true }
 serde = { workspace = true }
diff --git a/baml_language/crates/baml_sdkgen_types/src/embedded_bytecode.rs b/baml_language/crates/baml_sdkgen_types/src/embedded_bytecode.rs
new file mode 100644
index 00000000000..96ac34776eb
--- /dev/null
+++ b/baml_language/crates/baml_sdkgen_types/src/embedded_bytecode.rs
@@ -0,0 +1,15 @@
+//! The bytecode payload that generated SDKs embed in source.
+
+/// Encode compiled BAML bytecode for embedding as a single-line string
+/// literal (see [`baml_artifact::encode_embedded`]). Generated SDKs hand the
+/// string to their bridge's embedded-bytecode initializer unchanged; decoding
+/// happens natively, never in the host language.
+///
+/// Empty bytecode stays empty so the bridge still reports a missing payload
+/// rather than a corrupt one.
+pub fn embedded_bytecode_base64(bytecode: &[u8]) -> String {
+    if bytecode.is_empty() {
+        return String::new();
+    }
+    baml_artifact::encode_embedded(bytecode)
+}
diff --git a/baml_language/crates/baml_sdkgen_types/src/lib.rs b/baml_language/crates/baml_sdkgen_types/src/lib.rs
index 835d3928910..4397660b46b 100644
--- a/baml_language/crates/baml_sdkgen_types/src/lib.rs
+++ b/baml_language/crates/baml_sdkgen_types/src/lib.rs
@@ -2,6 +2,7 @@
 //! Attributes "don't exist"
 //! Union / Optional / Null invariance guaranteed
 
+mod embedded_bytecode;
 mod errors;
 mod generator_fields;
 mod output_writer;
@@ -10,6 +11,7 @@ mod string_literal;
 mod symbols;
 mod ty;
 mod type_queries;
+pub use embedded_bytecode::embedded_bytecode_base64;
 pub use errors::*;
 pub use generator_fields::*;
 pub use output_writer::*;
diff --git a/baml_language/crates/bridge_cffi/Cargo.toml b/baml_language/crates/bridge_cffi/Cargo.toml
index 5d68d1b16a4..2665191c856 100644
--- a/baml_language/crates/bridge_cffi/Cargo.toml
+++ b/baml_language/crates/bridge_cffi/Cargo.toml
@@ -21,6 +21,7 @@ rustls = [ "sys_native/rustls" ]
 bundle-http = [ "sys_native/bundle-http" ]
 
 [dependencies]
+baml_artifact = { workspace = true }
 baml_version = { workspace = true }
 bex_project = { workspace = true }
 bridge_ctypes = { workspace = true }
diff --git a/baml_language/crates/bridge_cffi/cbindgen.toml b/baml_language/crates/bridge_cffi/cbindgen.toml
index 8f08a14de4a..e2b60870b7a 100644
--- a/baml_language/crates/bridge_cffi/cbindgen.toml
+++ b/baml_language/crates/bridge_cffi/cbindgen.toml
@@ -73,7 +73,7 @@ include = [
   "BamlHostReleaseCallback",
   "BamlUnhandledSpawnErrorCallback",
   "BamlVersionFn",
-  "BamlInitializeRuntimeFromBytecodeFn",
+  "BamlInitializeRuntimeFromBlobFn",
   "BamlFreeBufferFn",
   "BamlRegisterCallbackFn",
   "BamlCallFunctionFn",
@@ -118,7 +118,7 @@ exclude = [
   "flush_events",
   "version",
   "create_baml_runtime",
-  "initialize_runtime_from_bytecode",
+  "initialize_runtime_from_blob",
   "destroy_baml_runtime",
   "invoke_runtime_cli",
 ]
diff --git a/baml_language/crates/bridge_cffi/include/baml_cffi.h b/baml_language/crates/bridge_cffi/include/baml_cffi.h
index 5a3209a3964..70785791c30 100644
--- a/baml_language/crates/bridge_cffi/include/baml_cffi.h
+++ b/baml_language/crates/bridge_cffi/include/baml_cffi.h
@@ -178,8 +178,7 @@ typedef struct BamlBuffer {
 
 typedef struct BamlBuffer (*BamlVersionFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeFn)(const uint8_t *bytecode,
-                                                                 size_t length);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobFn)(const uint8_t *bytecode, size_t length);
 
 typedef void (*BamlFreeBufferFn)(struct BamlBuffer buffer);
 
@@ -298,9 +297,9 @@ typedef void (*BamlRegisterUnhandledSpawnErrorCallbackFn)(BamlUnhandledSpawnErro
 
 typedef struct BamlBuffer (*BamlShutdownRuntimeFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeWithMetadataFn)(const uint8_t *bytecode,
-                                                                             size_t length,
-                                                                             const char *baml_toml);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobWithMetadataFn)(const uint8_t *bytecode,
+                                                                         size_t length,
+                                                                         const char *baml_toml);
 
 /**
  * First version of the shared BAML C API.
@@ -350,7 +349,7 @@ typedef struct BamlApiV1 {
    * calls are serialized only while replacing the global runtime; calls
    * already in progress retain their previous runtime instance.
    */
-  BamlInitializeRuntimeFromBytecodeFn initialize_runtime_from_bytecode;
+  BamlInitializeRuntimeFromBlobFn initialize_runtime_from_blob;
   /**
    * Release exactly one runtime-owned buffer returned through this table.
    *
@@ -483,7 +482,7 @@ typedef struct BamlApiV1 {
   /**
    * Replace the runtime from bytecode after validating embedded generation metadata.
    */
-  BamlInitializeRuntimeFromBytecodeWithMetadataFn initialize_runtime_from_bytecode_with_metadata;
+  BamlInitializeRuntimeFromBlobWithMetadataFn initialize_runtime_from_blob_with_metadata;
 } BamlApiV1;
 
 typedef const struct BamlApiV1 *(*BamlGetApiV1Fn)(void);
@@ -515,9 +514,9 @@ BamlCffiStatus __testonly_seed_heap_handle(uint64_t slab_key,
  * Initialize generated bytecode after validating its embedded `baml.toml`.
  */
 BAML_CFFI_API
-struct BamlBuffer initialize_runtime_from_bytecode_with_metadata(const uint8_t *bytecode,
-                                                                 size_t length,
-                                                                 const char *baml_toml);
+struct BamlBuffer initialize_runtime_from_blob_with_metadata(const uint8_t *bytecode,
+                                                             size_t length,
+                                                             const char *baml_toml);
 
 #ifdef __cplusplus
 }  // extern "C"
diff --git a/baml_language/crates/bridge_cffi/src/api.rs b/baml_language/crates/bridge_cffi/src/api.rs
index af5fff6067d..8485a57a024 100644
--- a/baml_language/crates/bridge_cffi/src/api.rs
+++ b/baml_language/crates/bridge_cffi/src/api.rs
@@ -95,9 +95,9 @@ pub type BamlUnhandledSpawnErrorCallback =
     extern "C" fn(content: *const i8, length: usize, cancelled: i32);
 
 pub type BamlVersionFn = extern "C" fn() -> Buffer;
-pub type BamlInitializeRuntimeFromBytecodeFn =
+pub type BamlInitializeRuntimeFromBlobFn =
     extern "C" fn(bytecode: *const u8, length: usize) -> Buffer;
-pub type BamlInitializeRuntimeFromBytecodeWithMetadataFn =
+pub type BamlInitializeRuntimeFromBlobWithMetadataFn =
     extern "C" fn(bytecode: *const u8, length: usize, baml_toml: *const libc::c_char) -> Buffer;
 pub type BamlFreeBufferFn = extern "C" fn(buffer: Buffer);
 pub type BamlRegisterCallbackFn = extern "C" fn(callback: BamlResultCallback);
@@ -167,7 +167,7 @@ pub struct BamlApiV1 {
     /// failure and must always be passed once to `free_buffer`. Concurrent
     /// calls are serialized only while replacing the global runtime; calls
     /// already in progress retain their previous runtime instance.
-    pub initialize_runtime_from_bytecode: BamlInitializeRuntimeFromBytecodeFn,
+    pub initialize_runtime_from_blob: BamlInitializeRuntimeFromBlobFn,
     /// Release exactly one runtime-owned buffer returned through this table.
     ///
     /// Do not use a different library instance's function, release a copied
@@ -258,15 +258,14 @@ pub struct BamlApiV1 {
     /// Wait for spawned work, report unreachable errors, and release the runtime.
     pub shutdown_runtime: BamlShutdownRuntimeFn,
     /// Replace the runtime from bytecode after validating embedded generation metadata.
-    pub initialize_runtime_from_bytecode_with_metadata:
-        BamlInitializeRuntimeFromBytecodeWithMetadataFn,
+    pub initialize_runtime_from_blob_with_metadata: BamlInitializeRuntimeFromBlobWithMetadataFn,
 }
 
 static BAML_API_V1: BamlApiV1 = BamlApiV1 {
     abi_version: BAML_API_V1_ABI_VERSION,
     struct_size: std::mem::size_of::<BamlApiV1>(),
     version: crate::version,
-    initialize_runtime_from_bytecode: crate::initialize_runtime_from_bytecode_ffi,
+    initialize_runtime_from_blob: crate::initialize_runtime_from_blob_ffi,
     free_buffer: crate::free_buffer,
     register_callback: crate::register_callback,
     call_function: crate::call_function,
@@ -287,8 +286,7 @@ static BAML_API_V1: BamlApiV1 = BamlApiV1 {
     register_bridge: crate::register_bridge_ffi,
     register_unhandled_spawn_error_callback: crate::register_unhandled_spawn_error_callback,
     shutdown_runtime: crate::shutdown_runtime_ffi,
-    initialize_runtime_from_bytecode_with_metadata:
-        crate::initialize_runtime_from_bytecode_with_metadata,
+    initialize_runtime_from_blob_with_metadata: crate::initialize_runtime_from_blob_with_metadata,
 };
 
 /// Return the immutable version-1 BAML C API function table.
@@ -328,8 +326,8 @@ mod tests {
         let api = unsafe { &*baml_get_api_v1() };
         assert_same_function!(api.version, crate::version);
         assert_same_function!(
-            api.initialize_runtime_from_bytecode,
-            crate::initialize_runtime_from_bytecode_ffi
+            api.initialize_runtime_from_blob,
+            crate::initialize_runtime_from_blob_ffi
         );
         assert_same_function!(api.free_buffer, crate::free_buffer);
         assert_same_function!(api.register_callback, crate::register_callback);
@@ -361,8 +359,8 @@ mod tests {
         );
         assert_same_function!(api.shutdown_runtime, crate::shutdown_runtime_ffi);
         assert_same_function!(
-            api.initialize_runtime_from_bytecode_with_metadata,
-            crate::initialize_runtime_from_bytecode_with_metadata
+            api.initialize_runtime_from_blob_with_metadata,
+            crate::initialize_runtime_from_blob_with_metadata
         );
     }
 
@@ -370,7 +368,7 @@ mod tests {
     fn every_v1_field_retains_its_declared_function_type() {
         let api = unsafe { &*baml_get_api_v1() };
         let _: BamlVersionFn = api.version;
-        let _: BamlInitializeRuntimeFromBytecodeFn = api.initialize_runtime_from_bytecode;
+        let _: BamlInitializeRuntimeFromBlobFn = api.initialize_runtime_from_blob;
         let _: BamlFreeBufferFn = api.free_buffer;
         let _: BamlRegisterCallbackFn = api.register_callback;
         let _: BamlCallFunctionFn = api.call_function;
@@ -392,8 +390,8 @@ mod tests {
         let _: BamlRegisterUnhandledSpawnErrorCallbackFn =
             api.register_unhandled_spawn_error_callback;
         let _: BamlShutdownRuntimeFn = api.shutdown_runtime;
-        let _: BamlInitializeRuntimeFromBytecodeWithMetadataFn =
-            api.initialize_runtime_from_bytecode_with_metadata;
+        let _: BamlInitializeRuntimeFromBlobWithMetadataFn =
+            api.initialize_runtime_from_blob_with_metadata;
         let _: BamlGetApiV1Fn = baml_get_api_v1;
     }
 
diff --git a/baml_language/crates/bridge_cffi/src/ffi/runtime.rs b/baml_language/crates/bridge_cffi/src/ffi/runtime.rs
index 4c5f6ca6530..b0b53bdd6e1 100644
--- a/baml_language/crates/bridge_cffi/src/ffi/runtime.rs
+++ b/baml_language/crates/bridge_cffi/src/ffi/runtime.rs
@@ -5,7 +5,7 @@ use std::{collections::HashMap, ffi::CStr, panic::AssertUnwindSafe};
 use super::super::panic::ffi_safe_ptr;
 use crate::{
     BridgeInfo, BridgeLanguage, Buffer, initialize_runtime,
-    initialize_runtime_from_bytecode as initialize_runtime_from_bytecode_impl, register_bridge,
+    initialize_runtime_from_blob as initialize_runtime_from_blob_impl, register_bridge,
 };
 
 /// Returns the BAML version as a Buffer containing raw UTF-8 bytes.
@@ -185,20 +185,20 @@ pub extern "C" fn create_baml_runtime(
 /// it with [`crate::free_buffer`].
 #[allow(clippy::not_unsafe_ptr_arg_deref)]
 #[unsafe(no_mangle)]
-pub extern "C" fn initialize_runtime_from_bytecode(bytecode: *const u8, length: usize) -> Buffer {
+pub extern "C" fn initialize_runtime_from_blob(bytecode: *const u8, length: usize) -> Buffer {
     if bytecode.is_null() && length != 0 {
         return Buffer::from(b"bytecode pointer is null but length is nonzero".to_vec());
     }
     if let Some(error) = bytecode_preflight_failure(length) {
         return error;
     }
-    initialize_runtime_from_bytecode_inner(bytecode, length, None)
+    initialize_runtime_from_blob_inner(bytecode, length, None)
 }
 
 /// Initialize generated bytecode after validating its embedded `baml.toml`.
 #[allow(clippy::not_unsafe_ptr_arg_deref)]
 #[unsafe(no_mangle)]
-pub extern "C" fn initialize_runtime_from_bytecode_with_metadata(
+pub extern "C" fn initialize_runtime_from_blob_with_metadata(
     bytecode: *const u8,
     length: usize,
     baml_toml: *const libc::c_char,
@@ -224,7 +224,7 @@ pub extern "C" fn initialize_runtime_from_bytecode_with_metadata(
             }
         }
     };
-    initialize_runtime_from_bytecode_inner(bytecode, length, manifest)
+    initialize_runtime_from_blob_inner(bytecode, length, manifest)
 }
 
 fn bytecode_preflight_failure(length: usize) -> Option<Buffer> {
@@ -233,7 +233,7 @@ fn bytecode_preflight_failure(length: usize) -> Option<Buffer> {
         .map(|error| Buffer::from(error.to_string().into_bytes()))
 }
 
-fn initialize_runtime_from_bytecode_inner(
+fn initialize_runtime_from_blob_inner(
     bytecode: *const u8,
     length: usize,
     embedded_baml_toml: Option<&str>,
@@ -248,7 +248,7 @@ fn initialize_runtime_from_bytecode_inner(
         } else {
             unsafe { std::slice::from_raw_parts(bytecode, length) }
         };
-        initialize_runtime_from_bytecode_impl(bytecode, embedded_baml_toml)
+        initialize_runtime_from_blob_impl(bytecode, embedded_baml_toml)
             .map(|_| ())
             .map_err(|error| error.to_string())
     }));
@@ -409,7 +409,7 @@ mod tests {
 
     #[test]
     fn bytecode_initializer_rejects_null_pointer_with_nonzero_length() {
-        let buffer = initialize_runtime_from_bytecode(std::ptr::null(), 1);
+        let buffer = initialize_runtime_from_blob(std::ptr::null(), 1);
         let message = unsafe { std::slice::from_raw_parts(buffer.ptr.cast::<u8>(), buffer.len) };
         assert_eq!(
             std::str::from_utf8(message).unwrap(),
diff --git a/baml_language/crates/bridge_cffi/src/lib.rs b/baml_language/crates/bridge_cffi/src/lib.rs
index e57ac7c1481..8bfc3472f8e 100644
--- a/baml_language/crates/bridge_cffi/src/lib.rs
+++ b/baml_language/crates/bridge_cffi/src/lib.rs
@@ -156,12 +156,15 @@ pub fn get_runtime() -> Result<Arc<dyn Bex>, BridgeError> {
 
 /// Initialize the global runtime from serialized BAML bytecode.
 ///
-/// The payload is a versioned artifact containing `bex_vm_types::Program`.
-/// Validation, decoding, and engine construction live behind
+/// The payload is a versioned artifact containing `bex_vm_types::Program`,
+/// either raw or in the embedded encoding generated SDKs carry
+/// (`baml_artifact::encode_embedded`), which is decoded here so host languages
+/// pass it through untouched. Validation, decoding, and engine construction
+/// live behind
 /// `bex_project::new_from_bytecode` so the bridge stays on the `bex_project`
 /// surface rather than reaching into bex internals. Artifact validation runs
 /// even when the optional generated `baml.toml` metadata is absent.
-pub fn initialize_runtime_from_bytecode_with_sys_ops(
+pub fn initialize_runtime_from_blob_with_sys_ops(
     bytecode: &[u8],
     embedded_baml_toml: Option<&str>,
     sys_ops: sys_ops::SysOps,
@@ -171,7 +174,7 @@ pub fn initialize_runtime_from_bytecode_with_sys_ops(
     let generated_toolchain_version = embedded_baml_toml
         .map(|manifest| validate_generated_metadata(manifest, bridge))
         .transpose()?;
-    let runtime: Arc<dyn Bex> = bex_project::new_from_bytecode(bytecode, sys_ops).map_err(|error| {
+    let load_error = |error: &dyn std::fmt::Display| {
         let generated = generated_toolchain_version
             .as_deref()
             .map(|version| format!(" generated using BAML toolchain {version},"))
@@ -180,7 +183,16 @@ pub fn initialize_runtime_from_bytecode_with_sys_ops(
             "BAML startup failed: generated SDK bytecode could not be loaded.\n\n`baml_sdk`{generated} could not be loaded by {} {}: {error}",
             bridge.bridge_runtime_name, bridge.bridge_runtime_version,
         ))
-    })?;
+    };
+    let bytecode: std::borrow::Cow<'_, [u8]> = if bytecode.starts_with(baml_artifact::MAGIC) {
+        bytecode.into()
+    } else {
+        baml_artifact::decode_embedded(baml_artifact::ArtifactKind::Program, bytecode)
+            .map_err(|error| load_error(&error))?
+            .into()
+    };
+    let runtime: Arc<dyn Bex> =
+        bex_project::new_from_bytecode(&bytecode, sys_ops).map_err(|error| load_error(&error))?;
     install_unhandled_spawn_error_handler(&runtime);
     platform::replace_runtime(runtime.clone())?;
     Ok(runtime)
@@ -374,13 +386,13 @@ pub async fn shutdown_runtime() -> Result<(), BridgeError> {
 
 /// Initialize the native process-global runtime from serialized BAML bytecode.
 #[cfg(not(target_arch = "wasm32"))]
-pub fn initialize_runtime_from_bytecode(
+pub fn initialize_runtime_from_blob(
     bytecode: &[u8],
     embedded_baml_toml: Option<&str>,
 ) -> Result<Arc<dyn Bex>, BridgeError> {
     use sys_native::SysOpsExt as _;
 
-    initialize_runtime_from_bytecode_with_sys_ops(
+    initialize_runtime_from_blob_with_sys_ops(
         bytecode,
         embedded_baml_toml,
         sys_ops::SysOps::native(),
diff --git a/baml_language/crates/bridge_cffi/src/lib_native.rs b/baml_language/crates/bridge_cffi/src/lib_native.rs
index 3e893f542d2..92ae4137654 100644
--- a/baml_language/crates/bridge_cffi/src/lib_native.rs
+++ b/baml_language/crates/bridge_cffi/src/lib_native.rs
@@ -43,8 +43,8 @@ pub use ffi::{
     objects::flush_events,
     runtime::{
         BamlBridgeInfoV1, create_baml_runtime, destroy_baml_runtime,
-        initialize_runtime_from_bytecode as initialize_runtime_from_bytecode_ffi,
-        initialize_runtime_from_bytecode_with_metadata, invoke_runtime_cli, register_bridge_ffi,
+        initialize_runtime_from_blob as initialize_runtime_from_blob_ffi,
+        initialize_runtime_from_blob_with_metadata, invoke_runtime_cli, register_bridge_ffi,
         shutdown_runtime as shutdown_runtime_ffi, version,
     },
     unhandled_spawn::register_unhandled_spawn_error_callback,
diff --git a/baml_language/crates/bridge_cffi/tests/abi_assertions.h b/baml_language/crates/bridge_cffi/tests/abi_assertions.h
index d3d55235f0a..b121802a5b0 100644
--- a/baml_language/crates/bridge_cffi/tests/abi_assertions.h
+++ b/baml_language/crates/bridge_cffi/tests/abi_assertions.h
@@ -112,8 +112,8 @@ BAML_STATIC_ASSERT(
 BAML_STATIC_ASSERT(offsetof(BamlApiV1, abi_version) == 0, "ABI version must be first");
 BAML_ASSERT_AFTER(abi_version, struct_size);
 BAML_ASSERT_AFTER(struct_size, version);
-BAML_ASSERT_AFTER(version, initialize_runtime_from_bytecode);
-BAML_ASSERT_AFTER(initialize_runtime_from_bytecode, free_buffer);
+BAML_ASSERT_AFTER(version, initialize_runtime_from_blob);
+BAML_ASSERT_AFTER(initialize_runtime_from_blob, free_buffer);
 BAML_ASSERT_AFTER(free_buffer, register_callback);
 BAML_ASSERT_AFTER(register_callback, call_function);
 BAML_ASSERT_AFTER(call_function, new_function_call);
@@ -133,13 +133,13 @@ BAML_ASSERT_AFTER(media_base64, media_mime_type);
 BAML_ASSERT_AFTER(media_mime_type, register_bridge);
 BAML_ASSERT_AFTER(register_bridge, register_unhandled_spawn_error_callback);
 BAML_ASSERT_AFTER(register_unhandled_spawn_error_callback, shutdown_runtime);
-BAML_ASSERT_AFTER(shutdown_runtime, initialize_runtime_from_bytecode_with_metadata);
+BAML_ASSERT_AFTER(shutdown_runtime, initialize_runtime_from_blob_with_metadata);
 BAML_STATIC_ASSERT(
     BAML_API_V1_MIN_SIZE == offsetof(BamlApiV1, register_unhandled_spawn_error_callback),
     "the appended lifecycle fields must follow the original V1 prefix");
 
 BAML_ASSERT_FIELD_TYPE(version, BamlVersionFn)
-BAML_ASSERT_FIELD_TYPE(initialize_runtime_from_bytecode, BamlInitializeRuntimeFromBytecodeFn)
+BAML_ASSERT_FIELD_TYPE(initialize_runtime_from_blob, BamlInitializeRuntimeFromBlobFn)
 BAML_ASSERT_FIELD_TYPE(free_buffer, BamlFreeBufferFn)
 BAML_ASSERT_FIELD_TYPE(register_callback, BamlRegisterCallbackFn)
 BAML_ASSERT_FIELD_TYPE(call_function, BamlCallFunctionFn)
@@ -161,7 +161,7 @@ BAML_ASSERT_FIELD_TYPE(register_bridge, BamlRegisterBridgeFn)
 BAML_ASSERT_FIELD_TYPE(register_unhandled_spawn_error_callback,
                        BamlRegisterUnhandledSpawnErrorCallbackFn)
 BAML_ASSERT_FIELD_TYPE(shutdown_runtime, BamlShutdownRuntimeFn)
-BAML_ASSERT_FIELD_TYPE(initialize_runtime_from_bytecode_with_metadata,
-                       BamlInitializeRuntimeFromBytecodeWithMetadataFn)
+BAML_ASSERT_FIELD_TYPE(initialize_runtime_from_blob_with_metadata,
+                       BamlInitializeRuntimeFromBlobWithMetadataFn)
 
 #endif /* BAML_CFFI_TEST_ABI_ASSERTIONS_H */
diff --git a/baml_language/crates/bridge_cffi/tests/abi_layout.c b/baml_language/crates/bridge_cffi/tests/abi_layout.c
index 6491138da91..950fda1ebb7 100644
--- a/baml_language/crates/bridge_cffi/tests/abi_layout.c
+++ b/baml_language/crates/bridge_cffi/tests/abi_layout.c
@@ -69,7 +69,7 @@ int main(void) {
   PRINT_OFFSET(BamlApiV1, abi_version);
   PRINT_OFFSET(BamlApiV1, struct_size);
   PRINT_OFFSET(BamlApiV1, version);
-  PRINT_OFFSET(BamlApiV1, initialize_runtime_from_bytecode);
+  PRINT_OFFSET(BamlApiV1, initialize_runtime_from_blob);
   PRINT_OFFSET(BamlApiV1, free_buffer);
   PRINT_OFFSET(BamlApiV1, register_callback);
   PRINT_OFFSET(BamlApiV1, call_function);
@@ -90,6 +90,6 @@ int main(void) {
   PRINT_OFFSET(BamlApiV1, register_bridge);
   PRINT_OFFSET(BamlApiV1, register_unhandled_spawn_error_callback);
   PRINT_OFFSET(BamlApiV1, shutdown_runtime);
-  PRINT_OFFSET(BamlApiV1, initialize_runtime_from_bytecode_with_metadata);
+  PRINT_OFFSET(BamlApiV1, initialize_runtime_from_blob_with_metadata);
   return 0;
 }
diff --git a/baml_language/crates/bridge_cffi/tests/abi_layout.rs b/baml_language/crates/bridge_cffi/tests/abi_layout.rs
index 40417819a4b..50dbe2f0e12 100644
--- a/baml_language/crates/bridge_cffi/tests/abi_layout.rs
+++ b/baml_language/crates/bridge_cffi/tests/abi_layout.rs
@@ -250,7 +250,7 @@ fn rust_c_and_cpp_agree_on_the_complete_v1_abi() {
     field!("BamlApiV1", BamlApiV1, abi_version);
     field!("BamlApiV1", BamlApiV1, struct_size);
     field!("BamlApiV1", BamlApiV1, version);
-    field!("BamlApiV1", BamlApiV1, initialize_runtime_from_bytecode);
+    field!("BamlApiV1", BamlApiV1, initialize_runtime_from_blob);
     field!("BamlApiV1", BamlApiV1, free_buffer);
     field!("BamlApiV1", BamlApiV1, register_callback);
     field!("BamlApiV1", BamlApiV1, call_function);
@@ -278,7 +278,7 @@ fn rust_c_and_cpp_agree_on_the_complete_v1_abi() {
     field!(
         "BamlApiV1",
         BamlApiV1,
-        initialize_runtime_from_bytecode_with_metadata
+        initialize_runtime_from_blob_with_metadata
     );
 
     assert_eq!(actual, expected, "C and Rust ABI layouts differ");
diff --git a/baml_language/crates/bridge_cffi/tests/abi_smoke.c b/baml_language/crates/bridge_cffi/tests/abi_smoke.c
index 649c7066842..a4431a55745 100644
--- a/baml_language/crates/bridge_cffi/tests/abi_smoke.c
+++ b/baml_language/crates/bridge_cffi/tests/abi_smoke.c
@@ -53,7 +53,7 @@ static void baml_close_library(BamlLibrary library) {
 #endif
 
 static int baml_required_functions_exist(const BamlApiV1 *api) {
-  return api->version != NULL && api->initialize_runtime_from_bytecode != NULL &&
+  return api->version != NULL && api->initialize_runtime_from_blob != NULL &&
          api->free_buffer != NULL && api->register_callback != NULL &&
          api->call_function != NULL && api->new_function_call != NULL &&
          api->cancel_function_call != NULL && api->register_host_dispatch_callback != NULL &&
diff --git a/baml_language/crates/bridge_cffi/tests/bytecode_skew.rs b/baml_language/crates/bridge_cffi/tests/bytecode_skew.rs
index 9c073a6a153..fe317a0ee91 100644
--- a/baml_language/crates/bridge_cffi/tests/bytecode_skew.rs
+++ b/baml_language/crates/bridge_cffi/tests/bytecode_skew.rs
@@ -15,18 +15,35 @@ fn bridge_surfaces_bytecode_skew_without_generated_metadata() {
     )
     .unwrap();
 
-    let Err(error) = bridge_cffi::initialize_runtime_from_bytecode(&bytecode, None) else {
-        panic!("format-skewed bytecode must fail");
+    // Raw artifacts and the embedded encoding generated SDKs carry decode to
+    // the same program, so both surface the same skew.
+    let embedded = baml_artifact::encode_embedded(&bytecode);
+    for payload in [bytecode.as_slice(), embedded.as_bytes()] {
+        let Err(error) = bridge_cffi::initialize_runtime_from_blob(payload, None) else {
+            panic!("format-skewed bytecode must fail");
+        };
+        assert_eq!(error.to_string(), expected_skew_error());
+    }
+
+    let Err(error) = bridge_cffi::initialize_runtime_from_blob(b"not an embedded program", None)
+    else {
+        panic!("corrupt embedded bytecode must fail");
     };
-    assert_eq!(
-        error.to_string(),
-        format!(
-            "BAML startup failed: generated SDK bytecode could not be loaded.\n\n`baml_sdk` could not be loaded by baml-bridge-test {}: Failed to deserialize BAML bytecode: generated bytecode: toolchain {} / format {}; this runtime: {} / format {} — regenerate baml_sdk and rebuild the bridge from the same commit",
-            baml_version::CANONICAL_VERSION,
-            baml_artifact::BUILD_FINGERPRINT,
-            baml_artifact::FORMAT_VERSION + 1,
-            baml_artifact::BUILD_FINGERPRINT,
-            baml_artifact::FORMAT_VERSION,
-        )
+    assert!(
+        error
+            .to_string()
+            .contains("failed to decode embedded generated bytecode: invalid base64"),
+        "{error}"
     );
 }
+
+fn expected_skew_error() -> String {
+    format!(
+        "BAML startup failed: generated SDK bytecode could not be loaded.\n\n`baml_sdk` could not be loaded by baml-bridge-test {}: Failed to deserialize BAML bytecode: generated bytecode: toolchain {} / format {}; this runtime: {} / format {} — regenerate baml_sdk and rebuild the bridge from the same commit",
+        baml_version::CANONICAL_VERSION,
+        baml_artifact::BUILD_FINGERPRINT,
+        baml_artifact::FORMAT_VERSION + 1,
+        baml_artifact::BUILD_FINGERPRINT,
+        baml_artifact::FORMAT_VERSION,
+    )
+}
diff --git a/baml_language/sdk_tests/crates/ruby_sorbet/test/native/bridge_fixture.c b/baml_language/sdk_tests/crates/ruby_sorbet/test/native/bridge_fixture.c
index 48c812f2875..f1c91f0edd1 100644
--- a/baml_language/sdk_tests/crates/ruby_sorbet/test/native/bridge_fixture.c
+++ b/baml_language/sdk_tests/crates/ruby_sorbet/test/native/bridge_fixture.c
@@ -215,7 +215,7 @@ static const BamlApiV1 default_api = {
     .abi_version = BAML_API_V1_ABI_VERSION,
     .struct_size = sizeof(BamlApiV1),
     .version = probe_version,
-    .initialize_runtime_from_bytecode = probe_initialize,
+    .initialize_runtime_from_blob = probe_initialize,
     .free_buffer = probe_free,
     .register_callback = probe_register_result,
     .call_function = probe_call,
@@ -236,7 +236,7 @@ static const BamlApiV1 default_api = {
     .register_bridge = probe_register_bridge,
     .register_unhandled_spawn_error_callback = probe_register_unhandled_spawn_error,
     .shutdown_runtime = probe_shutdown_runtime,
-    .initialize_runtime_from_bytecode_with_metadata = probe_initialize_with_metadata,
+    .initialize_runtime_from_blob_with_metadata = probe_initialize_with_metadata,
 };
 
 static BamlApiV1 probe_api;
@@ -252,7 +252,7 @@ static void null_requested_field(const char *field) {
     return;
   }
   NULL_FIELD(version)
-  NULL_FIELD(initialize_runtime_from_bytecode)
+  NULL_FIELD(initialize_runtime_from_blob)
   NULL_FIELD(free_buffer)
   NULL_FIELD(register_callback)
   NULL_FIELD(call_function)
@@ -273,7 +273,7 @@ static void null_requested_field(const char *field) {
   NULL_FIELD(register_bridge)
   NULL_FIELD(register_unhandled_spawn_error_callback)
   NULL_FIELD(shutdown_runtime)
-  NULL_FIELD(initialize_runtime_from_bytecode_with_metadata)
+  NULL_FIELD(initialize_runtime_from_blob_with_metadata)
 }
 
 BAML_CFFI_API const BamlApiV1 *baml_get_api_v1(void) {
diff --git a/baml_language/sdk_tests/crates/typescript/function_calls/customizable/host_callables.test.ts b/baml_language/sdk_tests/crates/typescript/function_calls/customizable/host_callables.test.ts
index 19f70f4a48c..060ec8c578f 100644
--- a/baml_language/sdk_tests/crates/typescript/function_calls/customizable/host_callables.test.ts
+++ b/baml_language/sdk_tests/crates/typescript/function_calls/customizable/host_callables.test.ts
@@ -1,5 +1,5 @@
 import "./baml_sdk/index.js";
-import { BamlAbortError, BamlCallContext, BamlError, BamlPanic, initializeRuntimeFromBytecode } from "@boundaryml/baml-bridge";
+import { BamlAbortError, BamlCallContext, BamlError, BamlPanic, initializeRuntimeFromBlob } from "@boundaryml/baml-bridge";
 import { describe, expect, it } from "vitest";
 import { BYTECODE } from "./baml_sdk/_inlinedbaml.js";
 import {
@@ -227,7 +227,7 @@ describe("function_calls — generated SDK host callables", () => {
 
     const pending = call_with_callback_async(callback, 9);
     await wasDispatched;
-    initializeRuntimeFromBytecode(BYTECODE);
+    initializeRuntimeFromBlob(BYTECODE);
     resolveResult("after-replacement");
     await expect(pending).resolves.toBe("after-replacement");
   });
@@ -263,7 +263,7 @@ describe("function_calls — generated SDK host callables", () => {
 
     const pending = call_with_callback_async(callback, 12, { $ctx: ctx });
     await wasDispatched;
-    initializeRuntimeFromBytecode(BYTECODE);
+    initializeRuntimeFromBlob(BYTECODE);
     ctx.abort();
     await expect(pending).rejects.toBeInstanceOf(BamlAbortError);
     settle("late after replacement");
diff --git a/baml_language/sdk_tests/crates/typescript/type_shapes/customizable/bridge_surface.test.ts b/baml_language/sdk_tests/crates/typescript/type_shapes/customizable/bridge_surface.test.ts
index 9321c59407a..817a97882cc 100644
--- a/baml_language/sdk_tests/crates/typescript/type_shapes/customizable/bridge_surface.test.ts
+++ b/baml_language/sdk_tests/crates/typescript/type_shapes/customizable/bridge_surface.test.ts
@@ -41,7 +41,7 @@ const packageRootExports = [
   "getTypeMap",
   "getVersion",
   "initializeRuntime",
-  "initializeRuntimeFromBytecode",
+  "initializeRuntimeFromBlob",
   "lowerTypeToWireTy",
   "newFunctionCall",
   "reflectType",
diff --git a/baml_language/sdk_tests/harness_runner/src/lib.rs b/baml_language/sdk_tests/harness_runner/src/lib.rs
index 7d1eded7c44..188ef4b7730 100644
--- a/baml_language/sdk_tests/harness_runner/src/lib.rs
+++ b/baml_language/sdk_tests/harness_runner/src/lib.rs
@@ -437,23 +437,20 @@ pub fn assert_typescript_web_generated_esm(fixture: &str, runtime_dir: &str) {
     );
     let inlined_bytecode = fs::read_to_string(generated.join("baml_sdk/_inlinedbaml.ts"))
         .unwrap_or_else(|e| panic!("{fixture}: read generated bytecode module: {e}"));
-    // The bytecode is emitted as base64 lines joined into one string; an empty
-    // program would still emit the export, so non-emptiness means at least one
-    // populated payload line.
-    let has_bytecode_payload = inlined_bytecode
-        .lines()
-        .any(|line| line.starts_with("  \"") && line.ends_with("\",") && line.len() > 5);
+    // The bytecode is emitted as a single string literal; an empty program
+    // would still emit the export, so non-emptiness means a populated literal.
+    let has_bytecode_payload = inlined_bytecode.lines().any(|line| {
+        line.starts_with("export const BYTECODE = \"")
+            && line.len() > "export const BYTECODE = \"\";".len()
+    });
     assert!(
-        inlined_bytecode.contains("export const BYTECODE = decodeBytecode(BYTECODE_BASE64);")
-            && has_bytecode_payload,
+        has_bytecode_payload,
         "{fixture}: generated SDK must contain non-empty BAML bytecode"
     );
     let root = fs::read_to_string(generated.join("baml_sdk/index.ts"))
         .unwrap_or_else(|e| panic!("{fixture}: read generated SDK root: {e}"));
     assert!(
-        root.contains(
-            "initializeRuntimeFromBytecode(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML)"
-        ),
+        root.contains("initializeRuntimeFromBlob(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML)"),
         "{fixture}: generated SDK root must initialize the web runtime from emitted bytecode and metadata"
     );
 }
diff --git a/baml_language/sdks/agent-docs/bridge-ref/ref-java-examples.md b/baml_language/sdks/agent-docs/bridge-ref/ref-java-examples.md
index 87639fa5e3a..1a731197a48 100644
--- a/baml_language/sdks/agent-docs/bridge-ref/ref-java-examples.md
+++ b/baml_language/sdks/agent-docs/bridge-ref/ref-java-examples.md
@@ -111,8 +111,7 @@ public final class Baml {
             if (in == null) {
                 throw new IllegalStateException("baml_sdk/inlinedbaml.b64 not found on the classpath — …");
             }
-            byte[] b64 = in.readAllBytes();
-            byte[] bytecode = java.util.Base64.getMimeDecoder().decode(b64);
+            byte[] bytecode = in.readAllBytes();
             baml_bridge.BamlFfi.initFromBytecode(bytecode);
         } catch (java.io.IOException e) {
             throw new java.io.UncheckedIOException("failed to read embedded BAML bytecode", e);
@@ -900,9 +899,9 @@ conditionally-always via `__traceback__`). The generated `Person` /
 
 The generated Java SDK root includes:
 
-- **`inlinedbaml.b64`** — the compiler-produced bytecode as a base64 classpath
-  resource, decoded in `Baml.java`'s static initializer via
-  `Base64.getMimeDecoder()` (`lib.rs:11-13,320-326`; `Baml.java:450-460`);
+- **`inlinedbaml.b64`** — the compiler-produced bytecode as a base64-encoded LZ4
+  classpath resource, which `Baml.java`'s static initializer passes unchanged to
+  `BamlFfi.initFromBytecode` for native decoding;
 - **`Baml.java`** — the runtime anchor whose `static {}` block registers the type
   map (`registerClass` / `registerEnum` / `registerUnion`, carrying field
   declaration order + per-field decode descriptors) and calls
diff --git a/baml_language/sdks/agent-docs/bridge-ref/ref-java-type-mappings.md b/baml_language/sdks/agent-docs/bridge-ref/ref-java-type-mappings.md
index 02c6c52ddb7..ceb2c7b7c1f 100644
--- a/baml_language/sdks/agent-docs/bridge-ref/ref-java-type-mappings.md
+++ b/baml_language/sdks/agent-docs/bridge-ref/ref-java-type-mappings.md
@@ -329,8 +329,8 @@ Notes:
   expression is a fully-qualified name, the import-collection machinery the TS emitter needs
   (`TranslatedType { expr, imports }`) collapses to a plain `String` (translate_ty.rs:1–7).
 - **Runtime init via a root-holder static initializer.** Loading any generated class triggers
-  idempotent runtime initialization from **embedded bytecode** (base64/MIME-embedded, decoded with
-  `java.util.Base64.getMimeDecoder()`), the Java analog of Python's root-package import side effect
+  idempotent runtime initialization from **embedded bytecode** (a base64-encoded LZ4 resource whose
+  raw bytes go to `BamlFfi.initFromBytecode`, which decodes them natively), the Java analog of Python's root-package import side effect
   (conventions doc:84–87). There is no `_inlinedbaml.py` / `_typemap.py` / `py.typed` triplet; the
   BAML source and the FQN⇄class map live in `TypeRegistry` registrations run at init.
 - **Free functions → static methods on a per-namespace `Fns` holder** (`baml_sdk.<ns>.Fns.<fn>()`;
diff --git a/baml_language/sdks/cpp/bridge_cpp/include/baml/detail/loader.h b/baml_language/sdks/cpp/bridge_cpp/include/baml/detail/loader.h
index 8e88899eea7..36879972f35 100644
--- a/baml_language/sdks/cpp/bridge_cpp/include/baml/detail/loader.h
+++ b/baml_language/sdks/cpp/bridge_cpp/include/baml/detail/loader.h
@@ -307,7 +307,7 @@ inline const loaded_api& load_api() {
                               " bytes from " + chosen);
     }
     if (table->version == nullptr ||
-        table->initialize_runtime_from_bytecode == nullptr ||
+        table->initialize_runtime_from_blob == nullptr ||
         table->free_buffer == nullptr || table->register_callback == nullptr ||
         table->call_function == nullptr ||
         table->new_function_call == nullptr ||
@@ -323,7 +323,7 @@ inline const loaded_api& load_api() {
         table->register_bridge == nullptr ||
         table->register_unhandled_spawn_error_callback == nullptr ||
         table->shutdown_runtime == nullptr ||
-        table->initialize_runtime_from_bytecode_with_metadata == nullptr) {
+        table->initialize_runtime_from_blob_with_metadata == nullptr) {
       throw runtime_error(
           "BAML_RUNTIME_ABI_MISMATCH",
           "runtime ABI table contains a null required operation");
diff --git a/baml_language/sdks/cpp/bridge_cpp/include/baml/runtime.h b/baml_language/sdks/cpp/bridge_cpp/include/baml/runtime.h
index 34216feceb9..33908951627 100644
--- a/baml_language/sdks/cpp/bridge_cpp/include/baml/runtime.h
+++ b/baml_language/sdks/cpp/bridge_cpp/include/baml/runtime.h
@@ -88,9 +88,8 @@ inline std::string version() {
 // payload generated SDKs embed). Registers this bridge (language + SDK
 // canonical version) first -- the contract-required ordering -- then boots.
 // Replaces any previously initialized runtime.
-inline void initialize_runtime_from_bytecode(const uint8_t* bytecode,
-                                             size_t length,
-                                             const char* sdk_version) {
+inline void initialize_runtime_from_blob(const uint8_t* bytecode, size_t length,
+                                         const char* sdk_version) {
   static_cast<void>(sdk_version);
   detail::ensure_registered(toolchain_version(), kBridgeRuntimeName,
                             bridge_runtime_version());
@@ -98,13 +97,13 @@ inline void initialize_runtime_from_bytecode(const uint8_t* bytecode,
       baml_cpp_unhandled_spawn_error_trampoline);
   install_shutdown_hook();
   detail::owned_buffer failure{
-      detail::api().initialize_runtime_from_bytecode(bytecode, length)};
+      detail::api().initialize_runtime_from_blob(bytecode, length)};
   if (!failure.empty()) {
     throw error(failure.to_string());
   }
 }
 
-inline void initialize_runtime_from_bytecode_with_metadata(
+inline void initialize_runtime_from_blob_with_metadata(
     const uint8_t* bytecode, size_t length, const char* embedded_baml_toml) {
   detail::ensure_registered(toolchain_version(), kBridgeRuntimeName,
                             bridge_runtime_version());
@@ -112,7 +111,7 @@ inline void initialize_runtime_from_bytecode_with_metadata(
       baml_cpp_unhandled_spawn_error_trampoline);
   install_shutdown_hook();
   detail::owned_buffer failure{
-      detail::api().initialize_runtime_from_bytecode_with_metadata(
+      detail::api().initialize_runtime_from_blob_with_metadata(
           bytecode, length, embedded_baml_toml)};
   if (!failure.empty()) {
     throw error(failure.to_string());
diff --git a/baml_language/sdks/cpp/bridge_cpp/tests/runtime_smoke.cc b/baml_language/sdks/cpp/bridge_cpp/tests/runtime_smoke.cc
index df8084f86e9..402aaca10ab 100644
--- a/baml_language/sdks/cpp/bridge_cpp/tests/runtime_smoke.cc
+++ b/baml_language/sdks/cpp/bridge_cpp/tests/runtime_smoke.cc
@@ -31,7 +31,7 @@ static void TestBytecodeInitRejectsGarbage() {
   bool threw = false;
   try {
     const std::string v = baml::version();
-    baml::initialize_runtime_from_bytecode(garbage, sizeof(garbage), v.c_str());
+    baml::initialize_runtime_from_blob(garbage, sizeof(garbage), v.c_str());
   } catch (const baml::error&) {
     threw = true;
   }
diff --git a/baml_language/sdks/cpp/sdkgen_cpp/src/lib.rs b/baml_language/sdks/cpp/sdkgen_cpp/src/lib.rs
index 402b5454203..5fd958171ea 100644
--- a/baml_language/sdks/cpp/sdkgen_cpp/src/lib.rs
+++ b/baml_language/sdks/cpp/sdkgen_cpp/src/lib.rs
@@ -2444,7 +2444,7 @@ fn render_inlinedbaml(
          for (const BamlBytecodeChunk& chunk : kBamlBytecodeChunks) {{\n      \
          bytecode.append(chunk.data, chunk.len);\n    \
          }}\n    \
-         ::baml::initialize_runtime_from_bytecode(\n        \
+         ::baml::initialize_runtime_from_blob(\n        \
          reinterpret_cast<const uint8_t*>(bytecode.data()), bytecode.size(),\n        \
          \"{version}\");\n  \
          }});\n\
@@ -2453,12 +2453,12 @@ fn render_inlinedbaml(
     );
     if embedded_baml_toml.is_some() {
         let legacy_call = format!(
-            "::baml::initialize_runtime_from_bytecode(\n        reinterpret_cast<const uint8_t*>(bytecode.data()), bytecode.size(),\n        \"{}\");",
+            "::baml::initialize_runtime_from_blob(\n        reinterpret_cast<const uint8_t*>(bytecode.data()), bytecode.size(),\n        \"{}\");",
             baml_version::CANONICAL_VERSION
         );
         buf = buf.replace(
             &legacy_call,
-            "::baml::initialize_runtime_from_bytecode_with_metadata(\n        reinterpret_cast<const uint8_t*>(bytecode.data()), bytecode.size(),\n        kEmbeddedBamlToml);",
+            "::baml::initialize_runtime_from_blob_with_metadata(\n        reinterpret_cast<const uint8_t*>(bytecode.data()), bytecode.size(),\n        kEmbeddedBamlToml);",
         );
     }
     let _ = writeln!(buf, "}}  // namespace {detail}");
@@ -2485,7 +2485,7 @@ mod bytecode_escape_tests {
         );
 
         assert!(output.contains("const char kEmbeddedBamlToml[]"));
-        assert!(output.contains("initialize_runtime_from_bytecode_with_metadata("));
+        assert!(output.contains("initialize_runtime_from_blob_with_metadata("));
         assert!(output.contains("kEmbeddedBamlToml);"));
     }
 
diff --git a/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeApi.cs b/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeApi.cs
index 3f58cacf87a..7fe0cfba5db 100644
--- a/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeApi.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeApi.cs
@@ -65,8 +65,8 @@ internal void InitializeRuntime(ReadOnlySpan<byte> bytecode, string? embeddedBam
             fixed (byte* manifestPointer = manifest)
             {
                 status = embeddedBamlToml is null
-                    ? table->InitializeRuntimeFromBytecode(pointer, (nuint)bytecode.Length)
-                    : table->InitializeRuntimeFromBytecodeWithMetadata(
+                    ? table->InitializeRuntimeFromBlob(pointer, (nuint)bytecode.Length)
+                    : table->InitializeRuntimeFromBlobWithMetadata(
                         pointer,
                         (nuint)bytecode.Length,
                         manifestPointer);
@@ -263,8 +263,8 @@ internal static void ValidateTable(BamlApiV1* api)
         }
 
         Require(api->Version is not null, "version");
-        Require(api->InitializeRuntimeFromBytecode is not null, "initialize_runtime_from_bytecode");
-        Require(api->InitializeRuntimeFromBytecodeWithMetadata is not null, "initialize_runtime_from_bytecode_with_metadata");
+        Require(api->InitializeRuntimeFromBlob is not null, "initialize_runtime_from_blob");
+        Require(api->InitializeRuntimeFromBlobWithMetadata is not null, "initialize_runtime_from_blob_with_metadata");
         Require(api->FreeBuffer is not null, "free_buffer");
         Require(api->RegisterCallback is not null, "register_callback");
         Require(api->CallFunction is not null, "call_function");
diff --git a/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeTypes.cs b/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeTypes.cs
index 36583d95e99..af402f31bd6 100644
--- a/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeTypes.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/src/Cffi/NativeTypes.cs
@@ -39,7 +39,7 @@ internal unsafe struct BamlApiV1
     internal uint AbiVersion;
     internal nuint StructSize;
     internal delegate* unmanaged[Cdecl]<BamlBuffer> Version;
-    internal delegate* unmanaged[Cdecl]<byte*, nuint, BamlBuffer> InitializeRuntimeFromBytecode;
+    internal delegate* unmanaged[Cdecl]<byte*, nuint, BamlBuffer> InitializeRuntimeFromBlob;
     internal delegate* unmanaged[Cdecl]<BamlBuffer, void> FreeBuffer;
     internal delegate* unmanaged[Cdecl]<delegate* unmanaged[Cdecl]<uint, byte*, nuint, void>, void> RegisterCallback;
     internal delegate* unmanaged[Cdecl]<byte*, nuint, uint, void> CallFunction;
@@ -60,12 +60,12 @@ internal unsafe struct BamlApiV1
     internal delegate* unmanaged[Cdecl]<BamlBridgeInfoV1*, BamlBuffer> RegisterBridge;
     internal delegate* unmanaged[Cdecl]<delegate* unmanaged[Cdecl]<sbyte*, nuint, int, void>, void> RegisterUnhandledSpawnErrorCallback;
     internal delegate* unmanaged[Cdecl]<BamlBuffer> ShutdownRuntime;
-    internal delegate* unmanaged[Cdecl]<byte*, nuint, byte*, BamlBuffer> InitializeRuntimeFromBytecodeWithMetadata;
+    internal delegate* unmanaged[Cdecl]<byte*, nuint, byte*, BamlBuffer> InitializeRuntimeFromBlobWithMetadata;
 }
 
 internal static unsafe class BamlApiV1Layout
 {
-    internal static readonly nuint RequiredPrefixSize = EndOf(nameof(BamlApiV1.InitializeRuntimeFromBytecodeWithMetadata));
+    internal static readonly nuint RequiredPrefixSize = EndOf(nameof(BamlApiV1.InitializeRuntimeFromBlobWithMetadata));
 
     private static nuint EndOf(string field) =>
         checked((nuint)Marshal.OffsetOf<BamlApiV1>(field) + (nuint)IntPtr.Size);
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiLifetimeProbe/Program.cs b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiLifetimeProbe/Program.cs
index e4b75269500..c52efb3db5e 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiLifetimeProbe/Program.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiLifetimeProbe/Program.cs
@@ -103,7 +103,7 @@ public static int Main(string[] args)
 
         string emptyBytecodeDiagnostic = ConsumeUtf8Buffer(
             api,
-            api->InitializeRuntimeFromBytecode(null, 0));
+            api->InitializeRuntimeFromBlob(null, 0));
         Require(
             emptyBytecodeDiagnostic.Length > 0,
             "empty bytecode unexpectedly initialized the runtime");
@@ -113,7 +113,7 @@ public static int Main(string[] args)
         {
             string diagnostic = ConsumeUtf8Buffer(
                 api,
-                api->InitializeRuntimeFromBytecode(
+                api->InitializeRuntimeFromBlob(
                     invalid,
                     (nuint)invalidBytecode.Length));
             Require(
@@ -126,7 +126,7 @@ public static int Main(string[] args)
         {
             string diagnostic = ConsumeUtf8Buffer(
                 api,
-                api->InitializeRuntimeFromBytecode(
+                api->InitializeRuntimeFromBlob(
                     bytes,
                     (nuint)bytecode.Length));
             Require(
@@ -854,8 +854,8 @@ private static void ValidateRequiredFunctions(BamlApiV1* api)
     {
         Require(api->Version is not null, "version is null");
         Require(
-            api->InitializeRuntimeFromBytecode is not null,
-            "initialize_runtime_from_bytecode is null");
+            api->InitializeRuntimeFromBlob is not null,
+            "initialize_runtime_from_blob is null");
         Require(api->FreeBuffer is not null, "free_buffer is null");
         Require(api->RegisterCallback is not null, "register_callback is null");
         Require(api->CallFunction is not null, "call_function is null");
@@ -1035,7 +1035,7 @@ private readonly struct BamlApiV1
         public readonly delegate* unmanaged[Cdecl]<
             byte*,
             nuint,
-            BamlBuffer> InitializeRuntimeFromBytecode;
+            BamlBuffer> InitializeRuntimeFromBlob;
         public readonly delegate* unmanaged[Cdecl]<BamlBuffer, void> FreeBuffer;
         public readonly delegate* unmanaged[Cdecl]<
             delegate* unmanaged[Cdecl]<uint, byte*, nuint, void>,
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiProbe/Program.cs b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiProbe/Program.cs
index f15c4224660..06a9abefe02 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiProbe/Program.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.AbiProbe/Program.cs
@@ -92,7 +92,7 @@ private static string ConsumeBuffer(BamlApiV1* api, BamlBuffer buffer)
     private static void ValidateRequiredFunctions(BamlApiV1* api)
     {
         Require(api->Version is not null, "version is null");
-        Require(api->InitializeRuntimeFromBytecode is not null, "initialize_runtime_from_bytecode is null");
+        Require(api->InitializeRuntimeFromBlob is not null, "initialize_runtime_from_blob is null");
         Require(api->FreeBuffer is not null, "free_buffer is null");
         Require(api->RegisterCallback is not null, "register_callback is null");
         Require(api->CallFunction is not null, "call_function is null");
@@ -143,7 +143,7 @@ private readonly struct BamlApiV1
         public readonly uint AbiVersion;
         public readonly nuint StructSize;
         public readonly delegate* unmanaged[Cdecl]<BamlBuffer> Version;
-        public readonly delegate* unmanaged[Cdecl]<byte*, nuint, BamlBuffer> InitializeRuntimeFromBytecode;
+        public readonly delegate* unmanaged[Cdecl]<byte*, nuint, BamlBuffer> InitializeRuntimeFromBlob;
         public readonly delegate* unmanaged[Cdecl]<BamlBuffer, void> FreeBuffer;
         public readonly delegate* unmanaged[Cdecl]<delegate* unmanaged[Cdecl]<uint, byte*, nuint, void>, void> RegisterCallback;
         public readonly delegate* unmanaged[Cdecl]<byte*, nuint, uint, void> CallFunction;
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.ProgramBootstrapProbe/NativeBytecodeInitializer.cs b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.ProgramBootstrapProbe/NativeBytecodeInitializer.cs
index acb188da646..bcabe3ab704 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.ProgramBootstrapProbe/NativeBytecodeInitializer.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.ProgramBootstrapProbe/NativeBytecodeInitializer.cs
@@ -52,8 +52,8 @@ internal NativeBytecodeInitializer(string? nativeLibraryPath)
             $"truncated API table {api->StructSize}");
         Require(api->Version is not null, "version is null");
         Require(
-            api->InitializeRuntimeFromBytecode is not null,
-            "initialize_runtime_from_bytecode is null");
+            api->InitializeRuntimeFromBlob is not null,
+            "initialize_runtime_from_blob is null");
         Require(api->FreeBuffer is not null, "free_buffer is null");
         ProductVersion = Consume(api->Version());
     }
@@ -74,7 +74,7 @@ internal string Initialize(byte[] bytes)
         fixed (byte* pointer = bytes)
         {
             return Consume(
-                api->InitializeRuntimeFromBytecode(
+                api->InitializeRuntimeFromBlob(
                     pointer,
                     (nuint)bytes.Length));
         }
@@ -132,7 +132,7 @@ private readonly struct BamlApiPrefix
         public readonly delegate* unmanaged[Cdecl]<
             byte*,
             nuint,
-            BamlBuffer> InitializeRuntimeFromBytecode;
+            BamlBuffer> InitializeRuntimeFromBlob;
         public readonly delegate* unmanaged[Cdecl]<BamlBuffer, void> FreeBuffer;
     }
 
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.StreamMediaAbiProbe/NativeBridge.cs b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.StreamMediaAbiProbe/NativeBridge.cs
index ad2fc49b993..7a1f14e3372 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.StreamMediaAbiProbe/NativeBridge.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.StreamMediaAbiProbe/NativeBridge.cs
@@ -89,7 +89,7 @@ public NativeBridge(
         fixed (byte* pointer = bytes)
         {
             string diagnostic = ConsumeUtf8(
-                api->InitializeRuntimeFromBytecode(
+                api->InitializeRuntimeFromBlob(
                     pointer,
                     (nuint)bytes.Length));
             Require(
@@ -418,8 +418,8 @@ private static void ValidateRequiredFunctions(BamlApiV1* api)
     {
         Require(api->Version is not null, "version is null");
         Require(
-            api->InitializeRuntimeFromBytecode is not null,
-            "initialize_runtime_from_bytecode is null");
+            api->InitializeRuntimeFromBlob is not null,
+            "initialize_runtime_from_blob is null");
         Require(api->FreeBuffer is not null, "free_buffer is null");
         Require(api->RegisterCallback is not null, "register_callback is null");
         Require(api->CallFunction is not null, "call_function is null");
@@ -539,7 +539,7 @@ private readonly struct BamlApiV1
         public readonly delegate* unmanaged[Cdecl]<
             byte*,
             nuint,
-            BamlBuffer> InitializeRuntimeFromBytecode;
+            BamlBuffer> InitializeRuntimeFromBlob;
         public readonly delegate* unmanaged[Cdecl]<BamlBuffer, void> FreeBuffer;
         public readonly delegate* unmanaged[Cdecl]<
             delegate* unmanaged[Cdecl]<uint, byte*, nuint, void>,
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.Tests/Program.cs b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.Tests/Program.cs
index aedab4029d2..1a4900fe5b6 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.Tests/Program.cs
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/Baml.Bridge.Tests/Program.cs
@@ -1245,7 +1245,7 @@ private static void VerifyNativeAbiLayoutAndValidation()
             (nameof(BamlApiV1.AbiVersion), 0),
             (nameof(BamlApiV1.StructSize), 8),
             (nameof(BamlApiV1.Version), 16),
-            (nameof(BamlApiV1.InitializeRuntimeFromBytecode), 24),
+            (nameof(BamlApiV1.InitializeRuntimeFromBlob), 24),
             (nameof(BamlApiV1.FreeBuffer), 32),
             (nameof(BamlApiV1.RegisterCallback), 40),
             (nameof(BamlApiV1.CallFunction), 48),
@@ -1266,7 +1266,7 @@ private static void VerifyNativeAbiLayoutAndValidation()
             (nameof(BamlApiV1.RegisterBridge), 168),
             (nameof(BamlApiV1.RegisterUnhandledSpawnErrorCallback), 176),
             (nameof(BamlApiV1.ShutdownRuntime), 184),
-            (nameof(BamlApiV1.InitializeRuntimeFromBytecodeWithMetadata), 192),
+            (nameof(BamlApiV1.InitializeRuntimeFromBlobWithMetadata), 192),
         ];
         foreach ((string field, int offset) in layout)
         {
@@ -2719,7 +2719,7 @@ private static BamlOutboundResult MediaHandleResult(
         AbiVersion = 2,
         StructSize = (nuint)sizeof(BamlApiV1),
         Version = &Version,
-        InitializeRuntimeFromBytecode = &Initialize,
+        InitializeRuntimeFromBlob = &Initialize,
         FreeBuffer = &FreeBuffer,
         RegisterCallback = &RegisterResult,
         CallFunction = &Call,
@@ -2740,7 +2740,7 @@ private static BamlOutboundResult MediaHandleResult(
         RegisterBridge = &RegisterBridge,
         RegisterUnhandledSpawnErrorCallback = &RegisterUnhandledSpawnError,
         ShutdownRuntime = &Shutdown,
-        InitializeRuntimeFromBytecodeWithMetadata = &InitializeWithMetadata,
+        InitializeRuntimeFromBlobWithMetadata = &InitializeWithMetadata,
     };
 
     private static void ExpectInvalidTable(BamlApiV1 table, bool passNull = false)
@@ -2762,7 +2762,7 @@ private static void ClearRequiredFunction(ref BamlApiV1 table, int field)
         switch (field)
         {
             case 0: table.Version = null; break;
-            case 1: table.InitializeRuntimeFromBytecode = null; break;
+            case 1: table.InitializeRuntimeFromBlob = null; break;
             case 2: table.FreeBuffer = null; break;
             case 3: table.RegisterCallback = null; break;
             case 4: table.CallFunction = null; break;
@@ -2783,7 +2783,7 @@ private static void ClearRequiredFunction(ref BamlApiV1 table, int field)
             case 19: table.RegisterBridge = null; break;
             case 20: table.RegisterUnhandledSpawnErrorCallback = null; break;
             case 21: table.ShutdownRuntime = null; break;
-            case 22: table.InitializeRuntimeFromBytecodeWithMetadata = null; break;
+            case 22: table.InitializeRuntimeFromBlobWithMetadata = null; break;
             default: throw new ArgumentOutOfRangeException(nameof(field));
         }
     }
diff --git a/baml_language/sdks/csharp/bridge_csharp/tests/native_fixtures/table_diagnostics.c b/baml_language/sdks/csharp/bridge_csharp/tests/native_fixtures/table_diagnostics.c
index 1c83889738a..eb67f9c6726 100644
--- a/baml_language/sdks/csharp/bridge_csharp/tests/native_fixtures/table_diagnostics.c
+++ b/baml_language/sdks/csharp/bridge_csharp/tests/native_fixtures/table_diagnostics.c
@@ -110,7 +110,7 @@ static BamlApiV1 probe_api = {
     .abi_version = BAML_API_V1_ABI_VERSION,
     .struct_size = sizeof(BamlApiV1),
     .version = probe_version,
-    .initialize_runtime_from_bytecode = probe_initialize,
+    .initialize_runtime_from_blob = probe_initialize,
     .free_buffer = probe_free,
     .register_callback = probe_register_result,
     .call_function = probe_call,
diff --git a/baml_language/sdks/go/baml_go/internal/cffi/include/baml_cffi.h b/baml_language/sdks/go/baml_go/internal/cffi/include/baml_cffi.h
index 5a3209a3964..70785791c30 100644
--- a/baml_language/sdks/go/baml_go/internal/cffi/include/baml_cffi.h
+++ b/baml_language/sdks/go/baml_go/internal/cffi/include/baml_cffi.h
@@ -178,8 +178,7 @@ typedef struct BamlBuffer {
 
 typedef struct BamlBuffer (*BamlVersionFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeFn)(const uint8_t *bytecode,
-                                                                 size_t length);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobFn)(const uint8_t *bytecode, size_t length);
 
 typedef void (*BamlFreeBufferFn)(struct BamlBuffer buffer);
 
@@ -298,9 +297,9 @@ typedef void (*BamlRegisterUnhandledSpawnErrorCallbackFn)(BamlUnhandledSpawnErro
 
 typedef struct BamlBuffer (*BamlShutdownRuntimeFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeWithMetadataFn)(const uint8_t *bytecode,
-                                                                             size_t length,
-                                                                             const char *baml_toml);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobWithMetadataFn)(const uint8_t *bytecode,
+                                                                         size_t length,
+                                                                         const char *baml_toml);
 
 /**
  * First version of the shared BAML C API.
@@ -350,7 +349,7 @@ typedef struct BamlApiV1 {
    * calls are serialized only while replacing the global runtime; calls
    * already in progress retain their previous runtime instance.
    */
-  BamlInitializeRuntimeFromBytecodeFn initialize_runtime_from_bytecode;
+  BamlInitializeRuntimeFromBlobFn initialize_runtime_from_blob;
   /**
    * Release exactly one runtime-owned buffer returned through this table.
    *
@@ -483,7 +482,7 @@ typedef struct BamlApiV1 {
   /**
    * Replace the runtime from bytecode after validating embedded generation metadata.
    */
-  BamlInitializeRuntimeFromBytecodeWithMetadataFn initialize_runtime_from_bytecode_with_metadata;
+  BamlInitializeRuntimeFromBlobWithMetadataFn initialize_runtime_from_blob_with_metadata;
 } BamlApiV1;
 
 typedef const struct BamlApiV1 *(*BamlGetApiV1Fn)(void);
@@ -515,9 +514,9 @@ BamlCffiStatus __testonly_seed_heap_handle(uint64_t slab_key,
  * Initialize generated bytecode after validating its embedded `baml.toml`.
  */
 BAML_CFFI_API
-struct BamlBuffer initialize_runtime_from_bytecode_with_metadata(const uint8_t *bytecode,
-                                                                 size_t length,
-                                                                 const char *baml_toml);
+struct BamlBuffer initialize_runtime_from_blob_with_metadata(const uint8_t *bytecode,
+                                                             size_t length,
+                                                             const char *baml_toml);
 
 #ifdef __cplusplus
 }  // extern "C"
diff --git a/baml_language/sdks/go/baml_go/native_unix.go b/baml_language/sdks/go/baml_go/native_unix.go
index 6f106839f0b..ef223a1418b 100644
--- a/baml_language/sdks/go/baml_go/native_unix.go
+++ b/baml_language/sdks/go/baml_go/native_unix.go
@@ -81,13 +81,13 @@ static const char *baml_open_library(const char *path) {
 		dlclose(handle);
 		return baml_loader_error;
 	}
-	const size_t required_size = offsetof(BamlApiV1, initialize_runtime_from_bytecode_with_metadata) + sizeof(api->initialize_runtime_from_bytecode_with_metadata);
+	const size_t required_size = offsetof(BamlApiV1, initialize_runtime_from_blob_with_metadata) + sizeof(api->initialize_runtime_from_blob_with_metadata);
 	if (api->struct_size < required_size) {
 		snprintf(baml_loader_error, sizeof(baml_loader_error), "truncated BAML ABI v1 table: got %zu bytes, need at least %zu", api->struct_size, required_size);
 		dlclose(handle);
 		return baml_loader_error;
 	}
-	if (api->version == NULL || api->initialize_runtime_from_bytecode == NULL ||
+	if (api->version == NULL || api->initialize_runtime_from_blob == NULL ||
 		api->free_buffer == NULL || api->register_callback == NULL ||
 		api->call_function == NULL || api->new_function_call == NULL ||
 		api->cancel_function_call == NULL ||
@@ -101,7 +101,7 @@ static const char *baml_open_library(const char *path) {
 		api->register_bridge == NULL ||
 		api->register_unhandled_spawn_error_callback == NULL ||
 		api->shutdown_runtime == NULL ||
-		api->initialize_runtime_from_bytecode_with_metadata == NULL) {
+		api->initialize_runtime_from_blob_with_metadata == NULL) {
 		snprintf(baml_loader_error, sizeof(baml_loader_error), "BAML ABI v1 table contains a NULL required function");
 		dlclose(handle);
 		return baml_loader_error;
@@ -135,10 +135,10 @@ static BamlBuffer baml_register_go_bridge(const uint8_t *runtime_name, size_t ru
 	return baml_api->register_bridge(&info);
 }
 static BamlBuffer baml_initialize(const uint8_t *bytecode, size_t length) {
-	return baml_api->initialize_runtime_from_bytecode(bytecode, length);
+	return baml_api->initialize_runtime_from_blob(bytecode, length);
 }
 static BamlBuffer baml_initialize_with_metadata(const uint8_t *bytecode, size_t length, const char *baml_toml) {
-	return baml_api->initialize_runtime_from_bytecode_with_metadata(bytecode, length, baml_toml);
+	return baml_api->initialize_runtime_from_blob_with_metadata(bytecode, length, baml_toml);
 }
 static void baml_free_buffer(BamlBuffer buffer) { baml_api->free_buffer(buffer); }
 static void baml_register_go_callback(void) {
diff --git a/baml_language/sdks/go/baml_go/native_windows.go b/baml_language/sdks/go/baml_go/native_windows.go
index 973018f28a4..74e9685cffa 100644
--- a/baml_language/sdks/go/baml_go/native_windows.go
+++ b/baml_language/sdks/go/baml_go/native_windows.go
@@ -59,13 +59,13 @@ static const char *baml_open_library(const wchar_t *path) {
 		FreeLibrary(handle);
 		return baml_loader_error;
 	}
-	const size_t required_size = offsetof(BamlApiV1, initialize_runtime_from_bytecode_with_metadata) + sizeof(api->initialize_runtime_from_bytecode_with_metadata);
+	const size_t required_size = offsetof(BamlApiV1, initialize_runtime_from_blob_with_metadata) + sizeof(api->initialize_runtime_from_blob_with_metadata);
 	if (api->struct_size < required_size) {
 		snprintf(baml_loader_error, sizeof(baml_loader_error), "truncated BAML ABI v1 table: got %zu bytes, need at least %zu", api->struct_size, required_size);
 		FreeLibrary(handle);
 		return baml_loader_error;
 	}
-	if (api->version == NULL || api->initialize_runtime_from_bytecode == NULL ||
+	if (api->version == NULL || api->initialize_runtime_from_blob == NULL ||
 		api->free_buffer == NULL || api->register_callback == NULL ||
 		api->call_function == NULL || api->new_function_call == NULL ||
 		api->cancel_function_call == NULL ||
@@ -79,7 +79,7 @@ static const char *baml_open_library(const wchar_t *path) {
 		api->register_bridge == NULL ||
 		api->register_unhandled_spawn_error_callback == NULL ||
 		api->shutdown_runtime == NULL ||
-		api->initialize_runtime_from_bytecode_with_metadata == NULL) {
+		api->initialize_runtime_from_blob_with_metadata == NULL) {
 		snprintf(baml_loader_error, sizeof(baml_loader_error), "BAML ABI v1 table contains a NULL required function");
 		FreeLibrary(handle);
 		return baml_loader_error;
@@ -109,8 +109,8 @@ static BamlBuffer baml_register_go_bridge(const uint8_t *runtime_name, size_t ru
 	};
 	return baml_api->register_bridge(&info);
 }
-static BamlBuffer baml_initialize(const uint8_t *bytecode, size_t length) { return baml_api->initialize_runtime_from_bytecode(bytecode, length); }
-static BamlBuffer baml_initialize_with_metadata(const uint8_t *bytecode, size_t length, const char *baml_toml) { return baml_api->initialize_runtime_from_bytecode_with_metadata(bytecode, length, baml_toml); }
+static BamlBuffer baml_initialize(const uint8_t *bytecode, size_t length) { return baml_api->initialize_runtime_from_blob(bytecode, length); }
+static BamlBuffer baml_initialize_with_metadata(const uint8_t *bytecode, size_t length, const char *baml_toml) { return baml_api->initialize_runtime_from_blob_with_metadata(bytecode, length, baml_toml); }
 static void baml_free_buffer(BamlBuffer buffer) { baml_api->free_buffer(buffer); }
 static void baml_register_go_callback(void) {
 	baml_api->register_callback(baml_go_result_callback);
diff --git a/baml_language/sdks/go/sdkgen_go/src/lib.rs b/baml_language/sdks/go/sdkgen_go/src/lib.rs
index a2bef8522db..88263933c83 100644
--- a/baml_language/sdks/go/sdkgen_go/src/lib.rs
+++ b/baml_language/sdks/go/sdkgen_go/src/lib.rs
@@ -5032,24 +5032,23 @@ fn render_bootstrap(bytecode: &[u8], embedded_baml_toml: Option<&str>) -> String
     out.push_str("import (\n\t\"sync\"\n\n");
     let _ = writeln!(out, "\t\"{BAML_GO_MODULE}\"\n)\n");
     out.push_str("var (\n\tonce          sync.Once\n\tinitializeErr error\n)\n\n");
-    out.push_str("var bytecode = []byte{\n");
-    for chunk in bytecode.chunks(20) {
-        let line = chunk
-            .iter()
-            .map(u8::to_string)
-            .collect::<Vec<_>>()
-            .join(", ");
-        let _ = writeln!(out, "\t{line},");
-    }
-    out.push_str("}\n\n");
+    // One line of encoded bytecode, passed to the runtime as bytes; the
+    // bridge decodes it natively.
+    let _ = writeln!(
+        out,
+        "const bytecode = \"{}\"\n",
+        baml_sdkgen_types::embedded_bytecode_base64(bytecode)
+    );
     if let Some(embedded_baml_toml) = embedded_baml_toml {
         let _ = writeln!(out, "const embeddedBamlToml = {embedded_baml_toml:?}\n");
     }
     out.push_str("func Ensure() error {\n");
     if embedded_baml_toml.is_some() {
-        out.push_str("\tonce.Do(func() { initializeErr = baml_go.InitializeWithMetadata(bytecode, embeddedBamlToml) })\n");
+        out.push_str("\tonce.Do(func() { initializeErr = baml_go.InitializeWithMetadata([]byte(bytecode), embeddedBamlToml) })\n");
     } else {
-        out.push_str("\tonce.Do(func() { initializeErr = baml_go.Initialize(bytecode) })\n");
+        out.push_str(
+            "\tonce.Do(func() { initializeErr = baml_go.Initialize([]byte(bytecode)) })\n",
+        );
     }
     out.push_str("\treturn initializeErr\n}\n");
     out
@@ -5323,8 +5322,10 @@ mod tests {
         assert!(functions.contains("\"user.echo_text\""));
         assert!(functions.contains("baml_go.String(value)"));
         assert!(
-            files[&PathBuf::from("internal/bootstrap/bootstrap.go")]
-                .contains("var bytecode = []byte{\n\t1, 2, 3,")
+            files[&PathBuf::from("internal/bootstrap/bootstrap.go")].contains(&format!(
+                "const bytecode = \"{}\"\n",
+                baml_sdkgen_types::embedded_bytecode_base64(&[1, 2, 3])
+            ))
         );
     }
 
diff --git a/baml_language/sdks/java/bridge_java/src/lib.rs b/baml_language/sdks/java/bridge_java/src/lib.rs
index b5500f98017..00befac87e4 100644
--- a/baml_language/sdks/java/bridge_java/src/lib.rs
+++ b/baml_language/sdks/java/bridge_java/src/lib.rs
@@ -55,12 +55,12 @@ fn call_sync_to_bytes(args_proto: &[u8]) -> Vec<u8> {
 /// `baml_bridge.BamlFfi.nativeInitFromBytecode(byte[] bytecode, String metadata, String runtimeVersion, String toolchainVersion)`.
 ///
 /// Initialize the process-global runtime from serialized BAML bytecode
-/// (`bridge_cffi::initialize_runtime_from_bytecode`, the same path
+/// (`bridge_cffi::initialize_runtime_from_blob`, the same path
 /// `bridge_python` uses). Idempotent in the same sense as Python: the
 /// single-slot singleton is replaced, so a second call swaps the runtime.
 /// A setup failure is thrown as an unchecked `RuntimeException` (this is a
 /// handle-returning site with no envelope to ride, like Python's
-/// `initialize_runtime_from_bytecode` raising).
+/// `initialize_runtime_from_blob` raising).
 #[unsafe(no_mangle)]
 pub extern "system" fn Java_baml_1bridge_BamlFfi_nativeInitFromBytecode(
     mut env: JNIEnv<'_>,
@@ -142,8 +142,7 @@ pub extern "system" fn Java_baml_1bridge_BamlFfi_nativeInitFromBytecode(
         }
     };
 
-    if let Err(e) =
-        bridge_cffi::initialize_runtime_from_bytecode(&bytes, embedded_baml_toml.as_deref())
+    if let Err(e) = bridge_cffi::initialize_runtime_from_blob(&bytes, embedded_baml_toml.as_deref())
     {
         throw_runtime_exception_exact(&mut env, &e.to_string());
     }
diff --git a/baml_language/sdks/java/sdkgen_java/src/lib.rs b/baml_language/sdks/java/sdkgen_java/src/lib.rs
index f5d310b55be..27b86130625 100644
--- a/baml_language/sdks/java/sdkgen_java/src/lib.rs
+++ b/baml_language/sdks/java/sdkgen_java/src/lib.rs
@@ -8,7 +8,7 @@
 //! file), a per-package `Fns` holder binding free functions to the
 //! `baml_bridge.BamlFfi` runtime entry points, minted sealed-union
 //! types, a root `Baml.java` runtime anchor, and the compiled BAML
-//! bytecode as a base64 classpath resource (`inlinedbaml.b64` — Java
+//! bytecode as a base64 LZ4 classpath resource (`inlinedbaml.b64` — Java
 //! caps a static initializer at 64KB of JVM bytecode, so a
 //! `new byte[]{...}` literal like TS's `_inlinedbaml.ts` cannot work).
 //!
@@ -394,7 +394,7 @@ fn to_source_code_internal(
         ));
     }
     let anchor_body = format!(
-        "/**\n * Runtime anchor for the generated SDK: loading this class registers\n * the type map (BAML FQN \u{2194} generated class, with field declaration\n * order) and initializes the BAML runtime from the embedded bytecode\n * resource (idempotent) \u{2014} the Java analog of Python's root-package\n * import side effect. Every generated binding holder forces this via\n * {{@link #ensure()}}.\n */\npublic final class {anchor_ident} {{\n    private {anchor_ident}() {{}}\n\n    static {{\n{registrations}        try (java.io.InputStream in = {anchor_ident}.class.getResourceAsStream(\"/baml_sdk/inlinedbaml.b64\")) {{\n            if (in == null) {{\n                throw new IllegalStateException(\n                        \"baml_sdk/inlinedbaml.b64 not found on the classpath \u{2014} is the generated resource root registered?\");\n            }}\n            byte[] b64 = in.readAllBytes();\n            byte[] bytecode = java.util.Base64.getMimeDecoder().decode(b64);\n            baml_bridge.BamlFfi.initFromBytecode(bytecode);\n        }} catch (java.io.IOException e) {{\n            throw new java.io.UncheckedIOException(\"failed to read embedded BAML bytecode\", e);\n        }}\n    }}\n\n    /** Forces class initialization (and thus runtime init). No-op afterwards. */\n    public static void ensure() {{}}\n}}\n"
+        "/**\n * Runtime anchor for the generated SDK: loading this class registers\n * the type map (BAML FQN \u{2194} generated class, with field declaration\n * order) and initializes the BAML runtime from the embedded bytecode\n * resource (idempotent) \u{2014} the Java analog of Python's root-package\n * import side effect. Every generated binding holder forces this via\n * {{@link #ensure()}}.\n */\npublic final class {anchor_ident} {{\n    private {anchor_ident}() {{}}\n\n    static {{\n{registrations}        try (java.io.InputStream in = {anchor_ident}.class.getResourceAsStream(\"/baml_sdk/inlinedbaml.b64\")) {{\n            if (in == null) {{\n                throw new IllegalStateException(\n                        \"baml_sdk/inlinedbaml.b64 not found on the classpath \u{2014} is the generated resource root registered?\");\n            }}\n            byte[] bytecode = in.readAllBytes();\n            baml_bridge.BamlFfi.initFromBytecode(bytecode);\n        }} catch (java.io.IOException e) {{\n            throw new java.io.UncheckedIOException(\"failed to read embedded BAML bytecode\", e);\n        }}\n    }}\n\n    /** Forces class initialization (and thus runtime init). No-op afterwards. */\n    public static void ensure() {{}}\n}}\n"
     );
     let anchor_body = if embedded_baml_toml.is_some() {
         anchor_body.replace(
@@ -411,13 +411,15 @@ fn to_source_code_internal(
         with_package(&root, &anchor_body),
     );
 
-    // Compiled BAML bytecode as a base64 text resource. Base64 keeps
-    // the emitter's `HashMap<PathBuf, String>` contract (raw bytecode
-    // is not valid UTF-8) and dodges Java's 64KB static-initializer /
-    // constant-pool limits that rule out a byte-array literal.
+    // Compiled BAML bytecode as an embedded-bytecode text resource (base64
+    // of an LZ4 frame), passed to the bridge as raw bytes and decoded
+    // natively. Text keeps the emitter's
+    // `HashMap<PathBuf, String>` contract (raw bytecode is not valid
+    // UTF-8) and dodges Java's 64KB static-initializer / constant-pool
+    // limits that rule out a byte-array literal.
     out.insert(
         PathBuf::from("inlinedbaml.b64"),
-        base64_encode(baml_bytecode),
+        baml_sdkgen_types::embedded_bytecode_base64(baml_bytecode),
     );
     if let Some(embedded_baml_toml) = embedded_baml_toml {
         out.insert(
@@ -603,35 +605,6 @@ fn with_package(pkg: &PackagePath, body: &str) -> String {
     format!("package {};\n\n{body}", pkg.java_package())
 }
 
-/// Standard-alphabet base64 with padding, dependency-free. The
-/// bytecode payload is written once per fixture at build time, so
-/// encoder throughput is irrelevant.
-fn base64_encode(data: &[u8]) -> String {
-    const ALPHABET: &[u8; 64] = b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
-    let mut out = String::with_capacity(data.len().div_ceil(3) * 4);
-    for chunk in data.chunks(3) {
-        let b = [
-            chunk[0],
-            chunk.get(1).copied().unwrap_or(0),
-            chunk.get(2).copied().unwrap_or(0),
-        ];
-        let n = (u32::from(b[0]) << 16) | (u32::from(b[1]) << 8) | u32::from(b[2]);
-        out.push(ALPHABET[(n >> 18) as usize & 63] as char);
-        out.push(ALPHABET[(n >> 12) as usize & 63] as char);
-        out.push(if chunk.len() > 1 {
-            ALPHABET[(n >> 6) as usize & 63] as char
-        } else {
-            '='
-        });
-        out.push(if chunk.len() > 2 {
-            ALPHABET[n as usize & 63] as char
-        } else {
-            '='
-        });
-    }
-    out
-}
-
 #[cfg(test)]
 mod tests {
     use baml_base::Name as BaseName;
@@ -1668,15 +1641,10 @@ mod tests {
             &[0, 1, 2, 253, 254, 255],
             NamingConvention::PreserveCase,
         );
-        assert_eq!(out[&PathBuf::from("inlinedbaml.b64")], "AAEC/f7/");
-    }
-
-    #[test]
-    fn base64_padding() {
-        assert_eq!(base64_encode(b""), "");
-        assert_eq!(base64_encode(b"f"), "Zg==");
-        assert_eq!(base64_encode(b"fo"), "Zm8=");
-        assert_eq!(base64_encode(b"foo"), "Zm9v");
+        assert_eq!(
+            out[&PathBuf::from("inlinedbaml.b64")],
+            baml_sdkgen_types::embedded_bytecode_base64(&[0, 1, 2, 253, 254, 255])
+        );
     }
 
     // -- explicit generics: emitter surface ----------------------------------
diff --git a/baml_language/sdks/python/rust/bridge_python/src/baml_core/baml_py/__init__.pyi b/baml_language/sdks/python/rust/bridge_python/src/baml_core/baml_py/__init__.pyi
index 1552e1a4c0c..ea2010286dc 100644
--- a/baml_language/sdks/python/rust/bridge_python/src/baml_core/baml_py/__init__.pyi
+++ b/baml_language/sdks/python/rust/bridge_python/src/baml_core/baml_py/__init__.pyi
@@ -179,7 +179,7 @@ class BamlRuntime:
         * `files` - Map of filename to file content
         """
     @staticmethod
-    def initialize_runtime_from_bytecode(bytecode: bytes, embedded_baml_toml: typing.Optional[builtins.str] = None) -> BamlRuntime:
+    def initialize_runtime_from_blob(bytecode: bytes, embedded_baml_toml: typing.Optional[builtins.str] = None) -> BamlRuntime:
         r"""
         Initialize the process-global runtime from serialized BAML bytecode.
         """
diff --git a/baml_language/sdks/python/rust/bridge_python/src/runtime.rs b/baml_language/sdks/python/rust/bridge_python/src/runtime.rs
index 13e64e7a523..dd316e0e3fa 100644
--- a/baml_language/sdks/python/rust/bridge_python/src/runtime.rs
+++ b/baml_language/sdks/python/rust/bridge_python/src/runtime.rs
@@ -57,14 +57,11 @@ impl BamlRuntime {
     /// * `bytecode` - borsh-encoded BAML bytecode program
     #[staticmethod]
     #[pyo3(signature = (bytecode, embedded_baml_toml=None))]
-    fn initialize_runtime_from_bytecode(
+    fn initialize_runtime_from_blob(
         bytecode: Vec<u8>,
         embedded_baml_toml: Option<String>,
     ) -> PyResult<Self> {
-        match bridge_cffi::initialize_runtime_from_bytecode(
-            &bytecode,
-            embedded_baml_toml.as_deref(),
-        ) {
+        match bridge_cffi::initialize_runtime_from_blob(&bytecode, embedded_baml_toml.as_deref()) {
             Ok(_bex) => Ok(BamlRuntime),
             Err(e) => Err(crate::errors::bridge_error_to_initialization_error(e)),
         }
diff --git a/baml_language/sdks/python/rust/sdkgen_python_pydantic2/src/lib.rs b/baml_language/sdks/python/rust/sdkgen_python_pydantic2/src/lib.rs
index 15b82c56d65..cafc72e2d33 100644
--- a/baml_language/sdks/python/rust/sdkgen_python_pydantic2/src/lib.rs
+++ b/baml_language/sdks/python/rust/sdkgen_python_pydantic2/src/lib.rs
@@ -613,7 +613,7 @@ fn render_root_init(top_children: &BTreeSet<String>, use_bytecode: bool) -> Stri
     out.push_str("from . import _inlinedbaml\n");
     out.push_str("from ._typemap import _TYPE_MAP\n\n");
     if use_bytecode {
-        out.push_str("BamlRuntime.initialize_runtime_from_bytecode(_inlinedbaml.BYTECODE, _inlinedbaml.EMBEDDED_BAML_TOML)\n\n");
+        out.push_str("BamlRuntime.initialize_runtime_from_blob(_inlinedbaml.BYTECODE, _inlinedbaml.EMBEDDED_BAML_TOML)\n\n");
     } else {
         out.push_str("BamlRuntime.initialize_runtime(\n");
         out.push_str("    \"baml_src\", _inlinedbaml.FILES\n");
@@ -736,9 +736,11 @@ fn render_baml_source_files(files: &[UserBamlFile]) -> String {
 }
 
 fn render_inlinedbaml_bytecode(bytecode: &[u8], embedded_baml_toml: Option<&str>) -> String {
-    let mut out = String::from("from __future__ import annotations\n\nBYTECODE: bytes = ");
-    out.push_str(&py_bytes(bytecode));
-    out.push_str("\nEMBEDDED_BAML_TOML: str | None = ");
+    // One line of encoded bytecode (ASCII), passed to the bridge as bytes; the
+    // bridge decodes it natively.
+    let mut out = String::from("from __future__ import annotations\n\nBYTECODE: bytes = b\"");
+    out.push_str(&baml_sdkgen_types::embedded_bytecode_base64(bytecode));
+    out.push_str("\"\nEMBEDDED_BAML_TOML: str | None = ");
     out.push_str(
         &embedded_baml_toml
             .map(py_string)
@@ -753,32 +755,6 @@ fn render_inlinedbaml_bytecode(bytecode: &[u8], embedded_baml_toml: Option<&str>
 /// round-trips through `ast.literal_eval` and is byte-identical.
 pub(crate) use baml_sdkgen_types::quoted_string as py_string;
 
-/// Render bytes as adjacent Python bytes literals. Chunking keeps generated
-/// lines manageable without adding any runtime decode step.
-pub(crate) fn py_bytes(bytes: &[u8]) -> String {
-    const CHUNK_SIZE: usize = 80;
-
-    if bytes.is_empty() {
-        return "b\"\"".to_string();
-    }
-
-    let mut out = String::from("(\n");
-    for chunk in bytes.chunks(CHUNK_SIZE) {
-        out.push_str("    b\"");
-        for &byte in chunk {
-            match byte {
-                b'\\' => out.push_str("\\\\"),
-                b'"' => out.push_str("\\\""),
-                0x20..=0x7e => out.push(byte as char),
-                _ => write!(out, "\\x{byte:02x}").unwrap(),
-            }
-        }
-        out.push_str("\"\n");
-    }
-    out.push(')');
-    out
-}
-
 /// Return the `cg::Name` that keys a given symbol in the pool. Not
 /// load-bearing today (we iterate `pool.keys()` directly), but kept
 /// near the emitter for symmetry with `SymbolPool`.
@@ -1773,15 +1749,17 @@ mod tests {
 
         let root = &out[&PathBuf::from("__init__.py")];
         assert!(
-            root.contains("BamlRuntime.initialize_runtime_from_bytecode(_inlinedbaml.BYTECODE, _inlinedbaml.EMBEDDED_BAML_TOML)")
+            root.contains("BamlRuntime.initialize_runtime_from_blob(_inlinedbaml.BYTECODE, _inlinedbaml.EMBEDDED_BAML_TOML)")
         );
         assert!(!root.contains("BamlRuntime.initialize_runtime("));
         assert!(root.contains("def get_baml_source_files() -> dict[str, str]:"));
 
         let inl = &out[&PathBuf::from("_inlinedbaml.py")];
         assert!(inl.starts_with(HEADER));
-        assert!(inl.contains("BYTECODE: bytes = ("));
-        assert!(inl.contains("b\"\\x00BAML\\\"\\x0a\\xff\""));
+        assert!(inl.contains(&format!(
+            "BYTECODE: bytes = b\"{}\"\n",
+            baml_sdkgen_types::embedded_bytecode_base64(bytecode)
+        )));
         assert!(!inl.contains("FILES: dict[str, str]"));
 
         let sources = &out[&PathBuf::from("_baml_sources.py")];
@@ -1810,7 +1788,7 @@ mod tests {
         );
 
         let inlined = &out[&PathBuf::from("_inlinedbaml.py")];
-        assert!(inlined.contains("BYTECODE: bytes = ("));
+        assert!(inlined.contains("BYTECODE: bytes = b\""));
         assert!(inlined.contains("EMBEDDED_BAML_TOML: str | None = "));
         assert!(!inlined.contains("function a()"));
 
diff --git a/baml_language/sdks/python/src/baml_bridge/baml_py.pyi b/baml_language/sdks/python/src/baml_bridge/baml_py.pyi
index 2401232687b..1558abcfb5e 100644
--- a/baml_language/sdks/python/src/baml_bridge/baml_py.pyi
+++ b/baml_language/sdks/python/src/baml_bridge/baml_py.pyi
@@ -179,7 +179,7 @@ class BamlRuntime:
         * `files` - Map of filename to file content
         """
     @staticmethod
-    def initialize_runtime_from_bytecode(bytecode: typing.Sequence[builtins.int], embedded_baml_toml: typing.Optional[builtins.str] = None) -> BamlRuntime:
+    def initialize_runtime_from_blob(bytecode: typing.Sequence[builtins.int], embedded_baml_toml: typing.Optional[builtins.str] = None) -> BamlRuntime:
         r"""
         Initialize the process-global runtime from serialized BAML bytecode.
 
diff --git a/baml_language/sdks/python/tests/test_engine.py b/baml_language/sdks/python/tests/test_engine.py
index bb34a6e0251..e323cbbbb34 100644
--- a/baml_language/sdks/python/tests/test_engine.py
+++ b/baml_language/sdks/python/tests/test_engine.py
@@ -185,7 +185,7 @@ def test_generated_bytecode_version_skew_fails_before_deserialization(self):
 """
 
         with pytest.raises(RuntimeError) as exc_info:
-            BamlRuntime.initialize_runtime_from_bytecode(
+            BamlRuntime.initialize_runtime_from_blob(
                 b"\x00", embedded_baml_toml
             )
 
diff --git a/baml_language/sdks/ruby/bridge_ruby/lib/baml/bridge/native.rb b/baml_language/sdks/ruby/bridge_ruby/lib/baml/bridge/native.rb
index 5b13a194d19..3bf3724e586 100644
--- a/baml_language/sdks/ruby/bridge_ruby/lib/baml/bridge/native.rb
+++ b/baml_language/sdks/ruby/bridge_ruby/lib/baml/bridge/native.rb
@@ -30,7 +30,7 @@ class BridgeInfoV1 < FFI::Struct
       class ApiV1 < FFI::Struct
         FUNCTION_FIELDS = %i[
           version
-          initialize_runtime_from_bytecode
+          initialize_runtime_from_blob
           free_buffer
           register_callback
           call_function
@@ -51,7 +51,7 @@ class ApiV1 < FFI::Struct
           register_bridge
           register_unhandled_spawn_error_callback
           shutdown_runtime
-          initialize_runtime_from_bytecode_with_metadata
+          initialize_runtime_from_blob_with_metadata
         ].freeze
 
         layout :abi_version, :uint32,
@@ -61,7 +61,7 @@ class ApiV1 < FFI::Struct
 
       FUNCTION_SIGNATURES = {
         version: [Buffer.by_value, []],
-        initialize_runtime_from_bytecode: [
+        initialize_runtime_from_blob: [
           Buffer.by_value,
           %i[pointer size_t],
           { blocking: true }
@@ -97,8 +97,8 @@ def register_result_callback(callback)
         def initialize_runtime(bytecode)
           pointer = memory_for(bytecode)
           diagnostic = read_owned_utf8(
-            function(:initialize_runtime_from_bytecode).call(pointer, bytecode.bytesize),
-            "initialize_runtime_from_bytecode"
+            function(:initialize_runtime_from_blob).call(pointer, bytecode.bytesize),
+            "initialize_runtime_from_blob"
           )
           return if diagnostic.empty?
 
diff --git a/baml_language/sdks/rust/bridge_rust/src/capi.rs b/baml_language/sdks/rust/bridge_rust/src/capi.rs
index 91ce5a2570a..e9262ca66dc 100644
--- a/baml_language/sdks/rust/bridge_rust/src/capi.rs
+++ b/baml_language/sdks/rust/bridge_rust/src/capi.rs
@@ -45,8 +45,8 @@ pub(crate) struct Api {
         unsafe extern "C" fn(*const c_char, *const c_char) -> *const c_void,
     /// Returns a status buffer: empty on success, otherwise a UTF-8 error
     /// message. Read it with [`Api::take_status`].
-    pub(crate) initialize_runtime_from_bytecode: unsafe extern "C" fn(*const u8, usize) -> Buffer,
-    pub(crate) initialize_runtime_from_bytecode_with_metadata:
+    pub(crate) initialize_runtime_from_blob: unsafe extern "C" fn(*const u8, usize) -> Buffer,
+    pub(crate) initialize_runtime_from_blob_with_metadata:
         unsafe extern "C" fn(*const u8, usize, *const c_char) -> Buffer,
     pub(crate) register_callback: unsafe extern "C" fn(CallbackFn),
     pub(crate) new_function_call: unsafe extern "C" fn() -> u64,
@@ -139,7 +139,7 @@ struct BamlApiV1 {
     abi_version: u32,
     struct_size: usize,
     version: Option<unsafe extern "C" fn() -> Buffer>,
-    initialize_runtime_from_bytecode: Option<unsafe extern "C" fn(*const u8, usize) -> Buffer>,
+    initialize_runtime_from_blob: Option<unsafe extern "C" fn(*const u8, usize) -> Buffer>,
     free_buffer: Option<unsafe extern "C" fn(Buffer)>,
     register_callback: Option<unsafe extern "C" fn(CallbackFn)>,
     call_function: Option<unsafe extern "C" fn(*const u8, usize, u32)>,
@@ -166,7 +166,7 @@ struct BamlApiV1 {
     register_unhandled_spawn_error_callback:
         Option<unsafe extern "C" fn(extern "C" fn(*const c_char, usize, i32))>,
     shutdown_runtime: Option<unsafe extern "C" fn() -> Buffer>,
-    initialize_runtime_from_bytecode_with_metadata:
+    initialize_runtime_from_blob_with_metadata:
         Option<unsafe extern "C" fn(*const u8, usize, *const c_char) -> Buffer>,
 }
 
@@ -241,14 +241,14 @@ fn load_inner(env: &loader::LoaderEnv) -> Result<Api, LoaderError> {
     }
 
     let version = required_slot(table.version, "version", &path)?;
-    let initialize_runtime_from_bytecode = required_slot(
-        table.initialize_runtime_from_bytecode,
-        "initialize_runtime_from_bytecode",
+    let initialize_runtime_from_blob = required_slot(
+        table.initialize_runtime_from_blob,
+        "initialize_runtime_from_blob",
         &path,
     )?;
-    let initialize_runtime_from_bytecode_with_metadata = required_slot(
-        table.initialize_runtime_from_bytecode_with_metadata,
-        "initialize_runtime_from_bytecode_with_metadata",
+    let initialize_runtime_from_blob_with_metadata = required_slot(
+        table.initialize_runtime_from_blob_with_metadata,
+        "initialize_runtime_from_blob_with_metadata",
         &path,
     )?;
     let free_buffer = required_slot(table.free_buffer, "free_buffer", &path)?;
@@ -287,8 +287,8 @@ fn load_inner(env: &loader::LoaderEnv) -> Result<Api, LoaderError> {
     let api = Api {
         // Not part of BamlApiV1 (a legacy direct export); resolved directly.
         create_baml_runtime: sym(&library, b"create_baml_runtime\0")?,
-        initialize_runtime_from_bytecode,
-        initialize_runtime_from_bytecode_with_metadata,
+        initialize_runtime_from_blob,
+        initialize_runtime_from_blob_with_metadata,
         register_callback,
         new_function_call,
         call_function,
diff --git a/baml_language/sdks/rust/bridge_rust/src/runtime.rs b/baml_language/sdks/rust/bridge_rust/src/runtime.rs
index 74cc3cbfb3a..4bd4b1ffd24 100644
--- a/baml_language/sdks/rust/bridge_rust/src/runtime.rs
+++ b/baml_language/sdks/rust/bridge_rust/src/runtime.rs
@@ -37,12 +37,12 @@ pub fn initialize_from_bytecode_with_metadata(
     #[expect(unsafe_code)]
     let status = unsafe {
         match manifest.as_ref() {
-            Some(manifest) => (api.initialize_runtime_from_bytecode_with_metadata)(
+            Some(manifest) => (api.initialize_runtime_from_blob_with_metadata)(
                 bytecode.as_ptr(),
                 bytecode.len(),
                 manifest.as_ptr(),
             ),
-            None => (api.initialize_runtime_from_bytecode)(bytecode.as_ptr(), bytecode.len()),
+            None => (api.initialize_runtime_from_blob)(bytecode.as_ptr(), bytecode.len()),
         }
     };
     api.take_status(status).map_err(SdkError::new)
diff --git a/baml_language/sdks/swift/Sources/BamlBridge/Api.swift b/baml_language/sdks/swift/Sources/BamlBridge/Api.swift
index 73238b37d89..d78922ea5b8 100644
--- a/baml_language/sdks/swift/Sources/BamlBridge/Api.swift
+++ b/baml_language/sdks/swift/Sources/BamlBridge/Api.swift
@@ -28,7 +28,7 @@ enum BamlApi {
     }()
 
     static let version = v1.version!
-    static let initializeRuntimeFromBytecode = v1.initialize_runtime_from_bytecode!
+    static let initializeRuntimeFromBlob = v1.initialize_runtime_from_blob!
     static let freeBuffer = v1.free_buffer!
     static let registerCallback = v1.register_callback!
     static let callFunction = v1.call_function!
@@ -49,8 +49,8 @@ enum BamlApi {
     static let registerBridge = v1.register_bridge!
     static let registerUnhandledSpawnErrorCallback = v1.register_unhandled_spawn_error_callback!
     static let shutdownRuntime = v1.shutdown_runtime!
-    static let initializeRuntimeFromBytecodeWithMetadata =
-        v1.initialize_runtime_from_bytecode_with_metadata!
+    static let initializeRuntimeFromBlobWithMetadata =
+        v1.initialize_runtime_from_blob_with_metadata!
 
     /// Copy a runtime-owned buffer to a `Data` and release it exactly
     /// once via the table's `free_buffer`. A zero-length buffer may have
diff --git a/baml_language/sdks/swift/Sources/BamlBridge/Runtime.swift b/baml_language/sdks/swift/Sources/BamlBridge/Runtime.swift
index 437450885fb..217c36865b7 100644
--- a/baml_language/sdks/swift/Sources/BamlBridge/Runtime.swift
+++ b/baml_language/sdks/swift/Sources/BamlBridge/Runtime.swift
@@ -133,14 +133,14 @@ public final class BamlRuntime: @unchecked Sendable {
         let errorBuffer = bytecode.withUnsafeBytes { buf -> BamlBuffer in
             if let embeddedBamlToml {
                 return embeddedBamlToml.withCString { manifest in
-                    BamlApi.initializeRuntimeFromBytecodeWithMetadata(
+                    BamlApi.initializeRuntimeFromBlobWithMetadata(
                         buf.baseAddress?.assumingMemoryBound(to: UInt8.self),
                         buf.count,
                         manifest
                     )
                 }
             }
-            return BamlApi.initializeRuntimeFromBytecode(
+            return BamlApi.initializeRuntimeFromBlob(
                 buf.baseAddress?.assumingMemoryBound(to: UInt8.self), buf.count)
         }
         let initError = String(decoding: BamlApi.takeBuffer(errorBuffer), as: UTF8.self)
diff --git a/baml_language/sdks/swift/Sources/CBamlBridge/include/baml_cffi.h b/baml_language/sdks/swift/Sources/CBamlBridge/include/baml_cffi.h
index 5a3209a3964..70785791c30 100644
--- a/baml_language/sdks/swift/Sources/CBamlBridge/include/baml_cffi.h
+++ b/baml_language/sdks/swift/Sources/CBamlBridge/include/baml_cffi.h
@@ -178,8 +178,7 @@ typedef struct BamlBuffer {
 
 typedef struct BamlBuffer (*BamlVersionFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeFn)(const uint8_t *bytecode,
-                                                                 size_t length);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobFn)(const uint8_t *bytecode, size_t length);
 
 typedef void (*BamlFreeBufferFn)(struct BamlBuffer buffer);
 
@@ -298,9 +297,9 @@ typedef void (*BamlRegisterUnhandledSpawnErrorCallbackFn)(BamlUnhandledSpawnErro
 
 typedef struct BamlBuffer (*BamlShutdownRuntimeFn)(void);
 
-typedef struct BamlBuffer (*BamlInitializeRuntimeFromBytecodeWithMetadataFn)(const uint8_t *bytecode,
-                                                                             size_t length,
-                                                                             const char *baml_toml);
+typedef struct BamlBuffer (*BamlInitializeRuntimeFromBlobWithMetadataFn)(const uint8_t *bytecode,
+                                                                         size_t length,
+                                                                         const char *baml_toml);
 
 /**
  * First version of the shared BAML C API.
@@ -350,7 +349,7 @@ typedef struct BamlApiV1 {
    * calls are serialized only while replacing the global runtime; calls
    * already in progress retain their previous runtime instance.
    */
-  BamlInitializeRuntimeFromBytecodeFn initialize_runtime_from_bytecode;
+  BamlInitializeRuntimeFromBlobFn initialize_runtime_from_blob;
   /**
    * Release exactly one runtime-owned buffer returned through this table.
    *
@@ -483,7 +482,7 @@ typedef struct BamlApiV1 {
   /**
    * Replace the runtime from bytecode after validating embedded generation metadata.
    */
-  BamlInitializeRuntimeFromBytecodeWithMetadataFn initialize_runtime_from_bytecode_with_metadata;
+  BamlInitializeRuntimeFromBlobWithMetadataFn initialize_runtime_from_blob_with_metadata;
 } BamlApiV1;
 
 typedef const struct BamlApiV1 *(*BamlGetApiV1Fn)(void);
@@ -515,9 +514,9 @@ BamlCffiStatus __testonly_seed_heap_handle(uint64_t slab_key,
  * Initialize generated bytecode after validating its embedded `baml.toml`.
  */
 BAML_CFFI_API
-struct BamlBuffer initialize_runtime_from_bytecode_with_metadata(const uint8_t *bytecode,
-                                                                 size_t length,
-                                                                 const char *baml_toml);
+struct BamlBuffer initialize_runtime_from_blob_with_metadata(const uint8_t *bytecode,
+                                                             size_t length,
+                                                             const char *baml_toml);
 
 #ifdef __cplusplus
 }  // extern "C"
diff --git a/baml_language/sdks/swift/rust/sdkgen_swift/Cargo.toml b/baml_language/sdks/swift/rust/sdkgen_swift/Cargo.toml
index 24a57d49b66..8859fb740ec 100644
--- a/baml_language/sdks/swift/rust/sdkgen_swift/Cargo.toml
+++ b/baml_language/sdks/swift/rust/sdkgen_swift/Cargo.toml
@@ -14,7 +14,6 @@ license = { workspace = true }
 baml_base = { workspace = true }
 baml_sdkgen_types = { workspace = true }
 baml_version = { workspace = true }
-base64 = { workspace = true }
 
 [lib]
 doctest = false
@@ -23,3 +22,4 @@ doctest = false
 workspace = true
 
 [dev-dependencies]
+baml_artifact = { workspace = true }
diff --git a/baml_language/sdks/swift/rust/sdkgen_swift/src/lib.rs b/baml_language/sdks/swift/rust/sdkgen_swift/src/lib.rs
index b1bc37ad510..9dc58c261fd 100644
--- a/baml_language/sdks/swift/rust/sdkgen_swift/src/lib.rs
+++ b/baml_language/sdks/swift/rust/sdkgen_swift/src/lib.rs
@@ -37,7 +37,6 @@ use std::{
 use baml_base::qualified_name::AI_STREAM_STREAM;
 use baml_sdkgen_types::{Class, Name, Symbol, SymbolPool, Ty, TypeAlias};
 pub use baml_sdkgen_types::{NamingConvention, OutputType};
-use base64::Engine as _;
 use emit::{
     FnKind, RenderedField, indent_lines, render_callable, render_class, render_enum,
     render_type_alias, sort_key,
@@ -691,36 +690,30 @@ fn render_ns_enum(
     out
 }
 
-/// The borsh bytecode payload, base64-encoded, as ONE multiline string
-/// literal. Two rejected alternatives, both fatal at engine sizes: a
-/// `[UInt8]` literal type-checks element-by-element, and a `"…" + "…"`
-/// chunk chain builds a `+` expression whose type-check is
-/// super-linear in the number of chunks (observed: 55+ minutes for a
-/// multi-MB payload). A `"""…"""` literal is a single token — instant —
-/// and the embedded newlines are skipped by the base64 decoder via
-/// `.ignoreUnknownCharacters`.
+/// The bytecode payload (base64 of an LZ4 frame, which the bridge decodes
+/// natively) as ONE single-line string literal, handed to the bridge as its
+/// UTF-8 bytes. Two rejected alternatives, both fatal at engine sizes: a
+/// `[UInt8]` literal type-checks element-by-element, and a `"…" + "…"` chunk
+/// chain builds a `+` expression whose type-check is super-linear in the
+/// number of chunks (observed: 55+ minutes for a multi-MB payload). A single
+/// literal is a single token — instant.
 fn render_inlined_baml(baml_bytecode: &[u8], embedded_baml_toml: Option<&str>) -> String {
-    // Fixed-width lines inside the literal for editor/diff friendliness.
-    const CHUNK: usize = 96;
-    let b64 = base64::engine::general_purpose::STANDARD.encode(baml_bytecode);
     let mut out = String::from(
         "// Generated by BAML. DO NOT EDIT.\n\
          import Foundation\n\n\
-         enum _BamlInlined {\n    static let bytecodeBase64: String = \"\"\"\n",
+         enum _BamlInlined {\n",
+    );
+    let _ = writeln!(
+        out,
+        "    static let bytecodeBase64: String = \"{}\"",
+        baml_sdkgen_types::embedded_bytecode_base64(baml_bytecode)
     );
-    for chunk in b64.as_bytes().chunks(CHUNK) {
-        out.push_str("        ");
-        out.push_str(std::str::from_utf8(chunk).expect("base64 is ascii"));
-        out.push('\n');
-    }
-    out.push_str("        \"\"\"\n");
     let manifest = embedded_baml_toml
         .map(|manifest| format!("Optional.some({manifest:?})"))
         .unwrap_or_else(|| "Optional.none".to_string());
     let _ = writeln!(out, "    static let embeddedBamlToml: String? = {manifest}");
     out.push_str(
-        "\n    static var bytecode: Data {\n        \
-         Data(base64Encoded: bytecodeBase64, options: .ignoreUnknownCharacters)!\n    }\n}\n",
+        "\n    static var bytecode: Data {\n        Data(bytecodeBase64.utf8)\n    }\n}\n",
     );
     out
 }
@@ -730,23 +723,25 @@ mod tests {
     use super::*;
 
     #[test]
-    fn bytecode_payload_round_trips_via_base64() {
+    fn bytecode_payload_round_trips_through_embedded_encoding() {
         let pool = SymbolPool::default();
         let bytecode = vec![0u8, 1, 2, 250, 251, 252];
         let files = to_source_code_with_bytecode(&pool, &bytecode, NamingConvention::PreserveCase);
 
         let inlined = &files[&PathBuf::from("_InlinedBaml.swift")];
-        // Collect the bare base64 lines between the `"""` delimiters.
-        let b64: String = inlined
+        let encoded = inlined
             .lines()
-            .skip_while(|l| !l.contains("\"\"\""))
-            .skip(1)
-            .take_while(|l| !l.contains("\"\"\""))
-            .map(str::trim)
-            .collect();
-        let decoded = base64::engine::general_purpose::STANDARD
-            .decode(b64)
-            .expect("valid base64");
+            .find_map(|l| {
+                l.trim()
+                    .strip_prefix("static let bytecodeBase64: String = \"")
+            })
+            .and_then(|l| l.strip_suffix('"'))
+            .expect("single-line bytecode literal");
+        let decoded = baml_artifact::decode_embedded(
+            baml_artifact::ArtifactKind::Program,
+            encoded.as_bytes(),
+        )
+        .expect("valid embedded bytecode");
         assert_eq!(decoded, bytecode);
 
         assert!(files[&PathBuf::from("BamlRoot.swift")].contains("public enum Baml"));
diff --git a/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts b/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts
index 230e939ad14..d7a7f72d0c8 100644
--- a/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts
+++ b/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts
@@ -31,7 +31,7 @@ export declare function initializeRuntime(srcDir: string, files: Record<string,
  * Free-function runtime initializer used by generated `baml_sdk/index.ts` when
  * codegen embeds precompiled BAML bytecode.
  */
-export declare function initializeRuntimeFromBytecode(bytecode: Buffer | Uint8Array, embeddedBamlToml?: string): void;
+export declare function initializeRuntimeFromBlob(bytecode: string | Buffer | Uint8Array, embeddedBamlToml?: string): void;
 export { BamlAbortError, BamlError, BamlInvalidArgumentError, BamlClientError, BamlCancelledError, BamlPanic, wrapNativeError, } from './errors.js';
 export declare function newFunctionCall(): bigint;
 export declare function cancelFunctionCall(callId: bigint): boolean;
diff --git a/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts.map b/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts.map
index ea114098d14..561bcab622d 100644
--- a/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts.map
+++ b/baml_language/sdks/typescript/bridge_typescript/dist/index.d.ts.map
@@ -1 +1 @@
-{"version":3,"file":"index.d.ts","sourceRoot":"","sources":["../typescript_src/index.ts"],"names":[],"mappings":"AAEA,OAAO,EACH,WAAW,EAEX,eAAe,EACf,eAAe,EAGlB,MAAM,aAAa,CAAC;AAMrB,OAAO,EACH,WAAW,EACX,eAAe,EACf,UAAU,EACV,eAAe,EACf,UAAU,EACV,uBAAuB,EACvB,mBAAmB,EACnB,UAAU,EACV,WAAW,GACd,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,sBAAsB,EAAE,uBAAuB,EAAE,MAAM,aAAa,CAAC;AAG9E,OAAO,EAAE,SAAS,EAAE,SAAS,EAAE,SAAS,EAAE,OAAO,EAAE,MAAM,aAAa,CAAC;AAEvE,OAAO,EAAE,UAAU,EAAE,MAAM,aAAa,CAAC;AACzC,OAAO,EAAE,gBAAgB,EAAE,MAAM,oBAAoB,CAAC;AACtD,YAAY,EAAE,mCAAmC,EAAE,2BAA2B,EAAE,MAAM,oBAAoB,CAAC;AAC3G,OAAO,EAAE,UAAU,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAC1E,YAAY,EAAE,qBAAqB,EAAE,iBAAiB,EAAE,MAAM,YAAY,CAAC;AAC3E,OAAO,EAAE,UAAU,EAAE,MAAM,kBAAkB,CAAC;AAE9C,OAAO,EAAE,WAAW,EAAE,UAAU,EAAE,UAAU,EAAE,MAAM,cAAc,CAAC;AAEnE,OAAO,EAAE,cAAc,EAAE,sBAAsB,EAAE,KAAK,EAAE,MAAM,sBAAsB,CAAC;AACrF,YAAY,EAAE,aAAa,EAAE,MAAM,sBAAsB,CAAC;AAE1D,OAAO,EAAE,QAAQ,EAAE,KAAK,EAAE,iBAAiB,EAAE,WAAW,EAAE,MAAM,cAAc,CAAC;AAC/E,YAAY,EAAE,gBAAgB,EAAE,aAAa,EAAE,kBAAkB,EAAE,aAAa,EAAE,kBAAkB,EAAE,MAAM,cAAc,CAAC;AAE3H;;;;;GAKG;AACH,wBAAgB,iBAAiB,CAAC,MAAM,EAAE,MAAM,EAAE,KAAK,EAAE,MAAM,CAAC,MAAM,EAAE,MAAM,CAAC,GAAG,IAAI,CAErF;AAED;;;GAGG;AACH,wBAAgB,6BAA6B,CAAC,QAAQ,EAAE,MAAM,GAAG,UAAU,EAAE,gBAAgB,CAAC,EAAE,MAAM,GAAG,IAAI,CAE5G;AACD,OAAO,EACH,cAAc,EACd,SAAS,EACT,wBAAwB,EACxB,eAAe,EACf,kBAAkB,EAClB,SAAS,EACT,eAAe,GAClB,MAAM,aAAa,CAAC;AAErB,wBAAgB,eAAe,IAAI,MAAM,CAExC;AAED,wBAAgB,kBAAkB,CAAC,MAAM,EAAE,MAAM,GAAG,OAAO,CAE1D;AAED,OAAO,sBAAsB,CAAC;AAE9B,qBAAa,cAAc;IACvB,OAAO,CAAC,MAAM,CAAU;gBAEZ,KAAK,EAAE,OAAO;IAI1B,MAAM,IAAI,OAAO;IAIjB,QAAQ,IAAI,MAAM;CAGrB;AAED,wBAAgB,gBAAgB,CAC5B,EAAE,EAAE,WAAW,EACf,YAAY,EAAE,MAAM,EACpB,MAAM,EAAE,MAAM,CAAC,MAAM,EAAE,OAAO,CAAC,EAC/B,GAAG,CAAC,EAAE,eAAe,EACrB,OAAO,CAAC,EAAE,eAAe,GAC1B,cAAc,CAwBhB;AAED,wBAAsB,YAAY,CAC9B,EAAE,EAAE,WAAW,EACf,YAAY,EAAE,MAAM,EACpB,MAAM,EAAE,MAAM,CAAC,MAAM,EAAE,OAAO,CAAC,EAC/B,GAAG,CAAC,EAAE,eAAe,EACrB,OAAO,CAAC,EAAE,eAAe,GAC1B,OAAO,CAAC,cAAc,CAAC,CAoBzB"}
\ No newline at end of file
+{"version":3,"file":"index.d.ts","sourceRoot":"","sources":["../typescript_src/index.ts"],"names":[],"mappings":"AAEA,OAAO,EACH,WAAW,EAEX,eAAe,EACf,eAAe,EAGlB,MAAM,aAAa,CAAC;AAMrB,OAAO,EACH,WAAW,EACX,eAAe,EACf,UAAU,EACV,eAAe,EACf,UAAU,EACV,uBAAuB,EACvB,mBAAmB,EACnB,UAAU,EACV,WAAW,GACd,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,sBAAsB,EAAE,uBAAuB,EAAE,MAAM,aAAa,CAAC;AAG9E,OAAO,EAAE,SAAS,EAAE,SAAS,EAAE,SAAS,EAAE,OAAO,EAAE,MAAM,aAAa,CAAC;AAEvE,OAAO,EAAE,UAAU,EAAE,MAAM,aAAa,CAAC;AACzC,OAAO,EAAE,gBAAgB,EAAE,MAAM,oBAAoB,CAAC;AACtD,YAAY,EAAE,mCAAmC,EAAE,2BAA2B,EAAE,MAAM,oBAAoB,CAAC;AAC3G,OAAO,EAAE,UAAU,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAC1E,YAAY,EAAE,qBAAqB,EAAE,iBAAiB,EAAE,MAAM,YAAY,CAAC;AAC3E,OAAO,EAAE,UAAU,EAAE,MAAM,kBAAkB,CAAC;AAE9C,OAAO,EAAE,WAAW,EAAE,UAAU,EAAE,UAAU,EAAE,MAAM,cAAc,CAAC;AAEnE,OAAO,EAAE,cAAc,EAAE,sBAAsB,EAAE,KAAK,EAAE,MAAM,sBAAsB,CAAC;AACrF,YAAY,EAAE,aAAa,EAAE,MAAM,sBAAsB,CAAC;AAE1D,OAAO,EAAE,QAAQ,EAAE,KAAK,EAAE,iBAAiB,EAAE,WAAW,EAAE,MAAM,cAAc,CAAC;AAC/E,YAAY,EAAE,gBAAgB,EAAE,aAAa,EAAE,kBAAkB,EAAE,aAAa,EAAE,kBAAkB,EAAE,MAAM,cAAc,CAAC;AAE3H;;;;;GAKG;AACH,wBAAgB,iBAAiB,CAAC,MAAM,EAAE,MAAM,EAAE,KAAK,EAAE,MAAM,CAAC,MAAM,EAAE,MAAM,CAAC,GAAG,IAAI,CAErF;AAED;;;GAGG;AACH,wBAAgB,yBAAyB,CAAC,QAAQ,EAAE,MAAM,GAAG,MAAM,GAAG,UAAU,EAAE,gBAAgB,CAAC,EAAE,MAAM,GAAG,IAAI,CAOjH;AACD,OAAO,EACH,cAAc,EACd,SAAS,EACT,wBAAwB,EACxB,eAAe,EACf,kBAAkB,EAClB,SAAS,EACT,eAAe,GAClB,MAAM,aAAa,CAAC;AAErB,wBAAgB,eAAe,IAAI,MAAM,CAExC;AAED,wBAAgB,kBAAkB,CAAC,MAAM,EAAE,MAAM,GAAG,OAAO,CAE1D;AAED,OAAO,sBAAsB,CAAC;AAE9B,qBAAa,cAAc;IACvB,OAAO,CAAC,MAAM,CAAU;gBAEZ,KAAK,EAAE,OAAO;IAI1B,MAAM,IAAI,OAAO;IAIjB,QAAQ,IAAI,MAAM;CAGrB;AAED,wBAAgB,gBAAgB,CAC5B,EAAE,EAAE,WAAW,EACf,YAAY,EAAE,MAAM,EACpB,MAAM,EAAE,MAAM,CAAC,MAAM,EAAE,OAAO,CAAC,EAC/B,GAAG,CAAC,EAAE,eAAe,EACrB,OAAO,CAAC,EAAE,eAAe,GAC1B,cAAc,CAwBhB;AAED,wBAAsB,YAAY,CAC9B,EAAE,EAAE,WAAW,EACf,YAAY,EAAE,MAAM,EACpB,MAAM,EAAE,MAAM,CAAC,MAAM,EAAE,OAAO,CAAC,EAC/B,GAAG,CAAC,EAAE,eAAe,EACrB,OAAO,CAAC,EAAE,eAAe,GAC1B,OAAO,CAAC,cAAc,CAAC,CAoBzB"}
\ No newline at end of file
diff --git a/baml_language/sdks/typescript/bridge_typescript/dist/index.js b/baml_language/sdks/typescript/bridge_typescript/dist/index.js
index 3328adda06f..ec2f22a3115 100644
--- a/baml_language/sdks/typescript/bridge_typescript/dist/index.js
+++ b/baml_language/sdks/typescript/bridge_typescript/dist/index.js
@@ -40,8 +40,10 @@ export function initializeRuntime(srcDir, files) {
  * Free-function runtime initializer used by generated `baml_sdk/index.ts` when
  * codegen embeds precompiled BAML bytecode.
  */
-export function initializeRuntimeFromBytecode(bytecode, embeddedBamlToml) {
-    BamlRuntime.initializeRuntimeFromBytecode(Buffer.from(bytecode), embeddedBamlToml);
+export function initializeRuntimeFromBlob(bytecode, embeddedBamlToml) {
+    // Generated SDKs pass their embedded bytecode string through untouched;
+    // the native bridge decodes it.
+    BamlRuntime.initializeRuntimeFromBlob(typeof bytecode === "string" ? bytecode : Buffer.from(bytecode), embeddedBamlToml);
 }
 export { BamlAbortError, BamlError, BamlInvalidArgumentError, BamlClientError, BamlCancelledError, BamlPanic, wrapNativeError, } from './errors.js';
 export function newFunctionCall() {
diff --git a/baml_language/sdks/typescript/bridge_typescript/dist/index.js.map b/baml_language/sdks/typescript/bridge_typescript/dist/index.js.map
index 93f344d4ca3..db0c5434580 100644
--- a/baml_language/sdks/typescript/bridge_typescript/dist/index.js.map
+++ b/baml_language/sdks/typescript/bridge_typescript/dist/index.js.map
@@ -1 +1 @@
-{"version":3,"file":"index.js","sourceRoot":"","sources":["../typescript_src/index.ts"],"names":[],"mappings":"AAAA,kEAAkE;AAElE,OAAO,EACH,WAAW,EAIX,kBAAkB,IAAI,wBAAwB,EAC9C,eAAe,IAAI,qBAAqB,GAC3C,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAC9D,OAAO,EAAE,kBAAkB,EAAE,MAAM,gBAAgB,CAAC;AACpD,OAAO,EAAE,eAAe,EAAE,MAAM,aAAa,CAAC;AAC9C,OAAO,EAAE,iBAAiB,EAAE,MAAM,mBAAmB,CAAC;AAEtD,OAAO,EACH,WAAW,EACX,eAAe,EACf,UAAU,EACV,eAAe,EACf,UAAU,EACV,uBAAuB,EACvB,mBAAmB,EACnB,UAAU,EACV,WAAW,GACd,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,sBAAsB,EAAE,uBAAuB,EAAE,MAAM,aAAa,CAAC;AAC9E,+EAA+E;AAC/E,8DAA8D;AAC9D,OAAO,EAAE,SAAS,EAAE,SAAS,EAAE,SAAS,EAAE,OAAO,EAAE,MAAM,aAAa,CAAC;AACvE,4EAA4E;AAC5E,OAAO,EAAE,UAAU,EAAE,MAAM,aAAa,CAAC;AACzC,OAAO,EAAE,gBAAgB,EAAE,MAAM,oBAAoB,CAAC;AAEtD,OAAO,EAAE,UAAU,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAE1E,OAAO,EAAE,UAAU,EAAE,MAAM,kBAAkB,CAAC;AAC9C,8EAA8E;AAC9E,OAAO,EAAE,WAAW,EAAE,UAAU,EAAE,UAAU,EAAE,MAAM,cAAc,CAAC;AACnE,6EAA6E;AAC7E,OAAO,EAAE,cAAc,EAAE,sBAAsB,EAAE,KAAK,EAAE,MAAM,sBAAsB,CAAC;AAErF,0EAA0E;AAC1E,OAAO,EAAE,QAAQ,EAAE,KAAK,EAAE,iBAAiB,EAAE,WAAW,EAAE,MAAM,cAAc,CAAC;AAG/E;;;;;GAKG;AACH,MAAM,UAAU,iBAAiB,CAAC,MAAc,EAAE,KAA6B;IAC3E,WAAW,CAAC,iBAAiB,CAAC,MAAM,EAAE,KAAK,CAAC,CAAC;AACjD,CAAC;AAED;;;GAGG;AACH,MAAM,UAAU,6BAA6B,CAAC,QAA6B,EAAE,gBAAyB;IAClG,WAAW,CAAC,6BAA6B,CAAC,MAAM,CAAC,IAAI,CAAC,QAAQ,CAAC,EAAE,gBAAgB,CAAC,CAAC;AACvF,CAAC;AACD,OAAO,EACH,cAAc,EACd,SAAS,EACT,wBAAwB,EACxB,eAAe,EACf,kBAAkB,EAClB,SAAS,EACT,eAAe,GAClB,MAAM,aAAa,CAAC;AAErB,MAAM,UAAU,eAAe;IAC3B,OAAO,MAAM,CAAC,qBAAqB,EAAE,CAAC,CAAC;AAC3C,CAAC;AAED,MAAM,UAAU,kBAAkB,CAAC,MAAc;IAC7C,OAAO,wBAAwB,CAAC,MAAM,CAAC,QAAQ,EAAE,CAAC,CAAC;AACvD,CAAC;AAED,OAAO,sBAAsB,CAAC;AAE9B,MAAM,OAAO,cAAc;IACf,MAAM,CAAU;IAExB,YAAY,KAAc;QACtB,IAAI,CAAC,MAAM,GAAG,KAAK,CAAC;IACxB,CAAC;IAED,MAAM;QACF,OAAO,IAAI,CAAC,MAAM,CAAC;IACvB,CAAC;IAED,QAAQ;QACJ,OAAO,kBAAkB,IAAI,CAAC,SAAS,CAAC,IAAI,CAAC,MAAM,CAAC,GAAG,CAAC;IAC5D,CAAC;CACJ;AAED,MAAM,UAAU,gBAAgB,CAC5B,EAAe,EACf,YAAoB,EACpB,MAA+B,EAC/B,GAAqB,EACrB,OAAyB;IAEzB,kEAAkE;IAClE,sEAAsE;IACtE,mEAAmE;IACnE,kDAAkD;IAClD,MAAM,MAAM,GAAG,eAAe,EAAE,CAAC;IACjC,MAAM,SAAS,GAAG,cAAc,CAAC,MAAM,EAAE,EAAE,QAAQ,EAAE,IAAI,EAAE,MAAM,EAAE,YAAY,EAAE,CAAC,CAAC;IACnF,MAAM,cAAc,GAAG,iBAAiB,CAAC,OAAO,EAAE,MAAM,CAAC,CAAC;IAC1D,kEAAkE;IAClE,gEAAgE;IAChE,8DAA8D;IAC9D,iEAAiE;IACjE,+DAA+D;IAC/D,IAAI,CAAC;QACD,IAAI,WAAmB,CAAC;QACxB,IAAI,CAAC;YACD,WAAW,GAAG,EAAE,CAAC,gBAAgB,CAAC,SAAS,EAAE,GAAG,IAAI,IAAI,CAAC,CAAC;QAC9D,CAAC;QAAC,OAAO,GAAG,EAAE,CAAC;YACX,MAAM,eAAe,CAAC,GAAG,CAAC,CAAC;QAC/B,CAAC;QACD,OAAO,IAAI,cAAc,CAAC,gBAAgB,CAAC,WAAW,CAAC,CAAC,CAAC;IAC7D,CAAC;YAAS,CAAC;QACP,cAAc,CAAC,MAAM,EAAE,CAAC;IAC5B,CAAC;AACL,CAAC;AAED,MAAM,CAAC,KAAK,UAAU,YAAY,CAC9B,EAAe,EACf,YAAoB,EACpB,MAA+B,EAC/B,GAAqB,EACrB,OAAyB;IAEzB,MAAM,MAAM,GAAG,eAAe,EAAE,CAAC;IACjC,MAAM,SAAS,GAAG,cAAc,CAAC,MAAM,EAAE,EAAE,MAAM,EAAE,YAAY,EAAE,CAAC,CAAC;IACnE,MAAM,cAAc,GAAG,iBAAiB,CAAC,OAAO,EAAE,MAAM,CAAC,CAAC;IAC1D,kEAAkE;IAClE,gEAAgE;IAChE,8DAA8D;IAC9D,iEAAiE;IACjE,+DAA+D;IAC/D,IAAI,CAAC;QACD,IAAI,WAAmB,CAAC;QACxB,IAAI,CAAC;YACD,WAAW,GAAG,MAAM,EAAE,CAAC,YAAY,CAAC,SAAS,EAAE,GAAG,IAAI,IAAI,CAAC,CAAC;QAChE,CAAC;QAAC,OAAO,GAAG,EAAE,CAAC;YACX,MAAM,eAAe,CAAC,GAAG,CAAC,CAAC;QAC/B,CAAC;QACD,OAAO,IAAI,cAAc,CAAC,gBAAgB,CAAC,WAAW,CAAC,CAAC,CAAC;IAC7D,CAAC;YAAS,CAAC;QACP,cAAc,CAAC,MAAM,EAAE,CAAC;IAC5B,CAAC;AACL,CAAC;AAED,0EAA0E;AAC1E,kBAAkB,EAAE,CAAC"}
\ No newline at end of file
+{"version":3,"file":"index.js","sourceRoot":"","sources":["../typescript_src/index.ts"],"names":[],"mappings":"AAAA,kEAAkE;AAElE,OAAO,EACH,WAAW,EAIX,kBAAkB,IAAI,wBAAwB,EAC9C,eAAe,IAAI,qBAAqB,GAC3C,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAC9D,OAAO,EAAE,kBAAkB,EAAE,MAAM,gBAAgB,CAAC;AACpD,OAAO,EAAE,eAAe,EAAE,MAAM,aAAa,CAAC;AAC9C,OAAO,EAAE,iBAAiB,EAAE,MAAM,mBAAmB,CAAC;AAEtD,OAAO,EACH,WAAW,EACX,eAAe,EACf,UAAU,EACV,eAAe,EACf,UAAU,EACV,uBAAuB,EACvB,mBAAmB,EACnB,UAAU,EACV,WAAW,GACd,MAAM,aAAa,CAAC;AACrB,OAAO,EAAE,sBAAsB,EAAE,uBAAuB,EAAE,MAAM,aAAa,CAAC;AAC9E,+EAA+E;AAC/E,8DAA8D;AAC9D,OAAO,EAAE,SAAS,EAAE,SAAS,EAAE,SAAS,EAAE,OAAO,EAAE,MAAM,aAAa,CAAC;AACvE,4EAA4E;AAC5E,OAAO,EAAE,UAAU,EAAE,MAAM,aAAa,CAAC;AACzC,OAAO,EAAE,gBAAgB,EAAE,MAAM,oBAAoB,CAAC;AAEtD,OAAO,EAAE,UAAU,EAAE,cAAc,EAAE,gBAAgB,EAAE,MAAM,YAAY,CAAC;AAE1E,OAAO,EAAE,UAAU,EAAE,MAAM,kBAAkB,CAAC;AAC9C,8EAA8E;AAC9E,OAAO,EAAE,WAAW,EAAE,UAAU,EAAE,UAAU,EAAE,MAAM,cAAc,CAAC;AACnE,6EAA6E;AAC7E,OAAO,EAAE,cAAc,EAAE,sBAAsB,EAAE,KAAK,EAAE,MAAM,sBAAsB,CAAC;AAErF,0EAA0E;AAC1E,OAAO,EAAE,QAAQ,EAAE,KAAK,EAAE,iBAAiB,EAAE,WAAW,EAAE,MAAM,cAAc,CAAC;AAG/E;;;;;GAKG;AACH,MAAM,UAAU,iBAAiB,CAAC,MAAc,EAAE,KAA6B;IAC3E,WAAW,CAAC,iBAAiB,CAAC,MAAM,EAAE,KAAK,CAAC,CAAC;AACjD,CAAC;AAED;;;GAGG;AACH,MAAM,UAAU,yBAAyB,CAAC,QAAsC,EAAE,gBAAyB;IACvG,wEAAwE;IACxE,gCAAgC;IAChC,WAAW,CAAC,yBAAyB,CACjC,OAAO,QAAQ,KAAK,QAAQ,CAAC,CAAC,CAAC,QAAQ,CAAC,CAAC,CAAC,MAAM,CAAC,IAAI,CAAC,QAAQ,CAAC,EAC/D,gBAAgB,CACnB,CAAC;AACN,CAAC;AACD,OAAO,EACH,cAAc,EACd,SAAS,EACT,wBAAwB,EACxB,eAAe,EACf,kBAAkB,EAClB,SAAS,EACT,eAAe,GAClB,MAAM,aAAa,CAAC;AAErB,MAAM,UAAU,eAAe;IAC3B,OAAO,MAAM,CAAC,qBAAqB,EAAE,CAAC,CAAC;AAC3C,CAAC;AAED,MAAM,UAAU,kBAAkB,CAAC,MAAc;IAC7C,OAAO,wBAAwB,CAAC,MAAM,CAAC,QAAQ,EAAE,CAAC,CAAC;AACvD,CAAC;AAED,OAAO,sBAAsB,CAAC;AAE9B,MAAM,OAAO,cAAc;IACf,MAAM,CAAU;IAExB,YAAY,KAAc;QACtB,IAAI,CAAC,MAAM,GAAG,KAAK,CAAC;IACxB,CAAC;IAED,MAAM;QACF,OAAO,IAAI,CAAC,MAAM,CAAC;IACvB,CAAC;IAED,QAAQ;QACJ,OAAO,kBAAkB,IAAI,CAAC,SAAS,CAAC,IAAI,CAAC,MAAM,CAAC,GAAG,CAAC;IAC5D,CAAC;CACJ;AAED,MAAM,UAAU,gBAAgB,CAC5B,EAAe,EACf,YAAoB,EACpB,MAA+B,EAC/B,GAAqB,EACrB,OAAyB;IAEzB,kEAAkE;IAClE,sEAAsE;IACtE,mEAAmE;IACnE,kDAAkD;IAClD,MAAM,MAAM,GAAG,eAAe,EAAE,CAAC;IACjC,MAAM,SAAS,GAAG,cAAc,CAAC,MAAM,EAAE,EAAE,QAAQ,EAAE,IAAI,EAAE,MAAM,EAAE,YAAY,EAAE,CAAC,CAAC;IACnF,MAAM,cAAc,GAAG,iBAAiB,CAAC,OAAO,EAAE,MAAM,CAAC,CAAC;IAC1D,kEAAkE;IAClE,gEAAgE;IAChE,8DAA8D;IAC9D,iEAAiE;IACjE,+DAA+D;IAC/D,IAAI,CAAC;QACD,IAAI,WAAmB,CAAC;QACxB,IAAI,CAAC;YACD,WAAW,GAAG,EAAE,CAAC,gBAAgB,CAAC,SAAS,EAAE,GAAG,IAAI,IAAI,CAAC,CAAC;QAC9D,CAAC;QAAC,OAAO,GAAG,EAAE,CAAC;YACX,MAAM,eAAe,CAAC,GAAG,CAAC,CAAC;QAC/B,CAAC;QACD,OAAO,IAAI,cAAc,CAAC,gBAAgB,CAAC,WAAW,CAAC,CAAC,CAAC;IAC7D,CAAC;YAAS,CAAC;QACP,cAAc,CAAC,MAAM,EAAE,CAAC;IAC5B,CAAC;AACL,CAAC;AAED,MAAM,CAAC,KAAK,UAAU,YAAY,CAC9B,EAAe,EACf,YAAoB,EACpB,MAA+B,EAC/B,GAAqB,EACrB,OAAyB;IAEzB,MAAM,MAAM,GAAG,eAAe,EAAE,CAAC;IACjC,MAAM,SAAS,GAAG,cAAc,CAAC,MAAM,EAAE,EAAE,MAAM,EAAE,YAAY,EAAE,CAAC,CAAC;IACnE,MAAM,cAAc,GAAG,iBAAiB,CAAC,OAAO,EAAE,MAAM,CAAC,CAAC;IAC1D,kEAAkE;IAClE,gEAAgE;IAChE,8DAA8D;IAC9D,iEAAiE;IACjE,+DAA+D;IAC/D,IAAI,CAAC;QACD,IAAI,WAAmB,CAAC;QACxB,IAAI,CAAC;YACD,WAAW,GAAG,MAAM,EAAE,CAAC,YAAY,CAAC,SAAS,EAAE,GAAG,IAAI,IAAI,CAAC,CAAC;QAChE,CAAC;QAAC,OAAO,GAAG,EAAE,CAAC;YACX,MAAM,eAAe,CAAC,GAAG,CAAC,CAAC;QAC/B,CAAC;QACD,OAAO,IAAI,cAAc,CAAC,gBAAgB,CAAC,WAAW,CAAC,CAAC,CAAC;IAC7D,CAAC;YAAS,CAAC;QACP,cAAc,CAAC,MAAM,EAAE,CAAC;IAC5B,CAAC;AACL,CAAC;AAED,0EAA0E;AAC1E,kBAAkB,EAAE,CAAC"}
\ No newline at end of file
diff --git a/baml_language/sdks/typescript/bridge_typescript/dist/native.d.ts b/baml_language/sdks/typescript/bridge_typescript/dist/native.d.ts
index c9d92b5ceb9..b4fac05b1c2 100644
--- a/baml_language/sdks/typescript/bridge_typescript/dist/native.d.ts
+++ b/baml_language/sdks/typescript/bridge_typescript/dist/native.d.ts
@@ -107,8 +107,12 @@ export declare class BamlRuntime {
    * the `initializeRuntime(...)` import the spec docs use.
    */
   static initializeRuntime(rootPath: string, files: Record<string, string>): BamlRuntime
-  /** Initialize the process-global runtime from precompiled BAML bytecode. */
-  static initializeRuntimeFromBytecode(bytecode: Buffer, embeddedBamlToml?: string | undefined | null): BamlRuntime
+  /**
+   * Initialize the process-global runtime from precompiled BAML bytecode:
+   * a raw artifact, or the encoded string generated SDKs embed (decoded
+   * natively, never in JavaScript).
+   */
+  static initializeRuntimeFromBlob(bytecode: string | Buffer, embeddedBamlToml?: string | undefined | null): BamlRuntime
   /** Call a BAML function synchronously (blocking). */
   callFunctionSync(argsProto: Buffer, ctx?: HostSpanManager | undefined | null): Buffer
   /** Call a BAML function asynchronously. */
diff --git a/baml_language/sdks/typescript/bridge_typescript/src/runtime.rs b/baml_language/sdks/typescript/bridge_typescript/src/runtime.rs
index ef89d372fdc..051fe3116fd 100644
--- a/baml_language/sdks/typescript/bridge_typescript/src/runtime.rs
+++ b/baml_language/sdks/typescript/bridge_typescript/src/runtime.rs
@@ -35,16 +35,19 @@ impl BamlRuntime {
         }
     }
 
-    /// Initialize the process-global runtime from precompiled BAML bytecode.
-    #[napi(factory, js_name = "initializeRuntimeFromBytecode")]
-    pub fn initialize_runtime_from_bytecode(
-        bytecode: Buffer,
+    /// Initialize the process-global runtime from precompiled BAML bytecode:
+    /// a raw artifact, or the encoded string generated SDKs embed (decoded
+    /// natively, never in JavaScript).
+    #[napi(factory, js_name = "initializeRuntimeFromBlob")]
+    pub fn initialize_runtime_from_blob(
+        bytecode: Either<String, Buffer>,
         embedded_baml_toml: Option<String>,
     ) -> napi::Result<Self> {
-        match bridge_cffi::initialize_runtime_from_bytecode(
-            bytecode.as_ref(),
-            embedded_baml_toml.as_deref(),
-        ) {
+        let bytecode: &[u8] = match &bytecode {
+            Either::A(encoded) => encoded.as_bytes(),
+            Either::B(bytes) => bytes.as_ref(),
+        };
+        match bridge_cffi::initialize_runtime_from_blob(bytecode, embedded_baml_toml.as_deref()) {
             Ok(_bex) => Ok(BamlRuntime {}),
             Err(e) => Err(bridge_error_to_napi(e)),
         }
diff --git a/baml_language/sdks/typescript/bridge_typescript/typescript_src/index.ts b/baml_language/sdks/typescript/bridge_typescript/typescript_src/index.ts
index 2f53cdce8c8..7973ca8e339 100644
--- a/baml_language/sdks/typescript/bridge_typescript/typescript_src/index.ts
+++ b/baml_language/sdks/typescript/bridge_typescript/typescript_src/index.ts
@@ -58,8 +58,13 @@ export function initializeRuntime(srcDir: string, files: Record<string, string>)
  * Free-function runtime initializer used by generated `baml_sdk/index.ts` when
  * codegen embeds precompiled BAML bytecode.
  */
-export function initializeRuntimeFromBytecode(bytecode: Buffer | Uint8Array, embeddedBamlToml?: string): void {
-    BamlRuntime.initializeRuntimeFromBytecode(Buffer.from(bytecode), embeddedBamlToml);
+export function initializeRuntimeFromBlob(bytecode: string | Buffer | Uint8Array, embeddedBamlToml?: string): void {
+    // Generated SDKs pass their embedded bytecode string through untouched;
+    // the native bridge decodes it.
+    BamlRuntime.initializeRuntimeFromBlob(
+        typeof bytecode === "string" ? bytecode : Buffer.from(bytecode),
+        embeddedBamlToml,
+    );
 }
 export {
     BamlAbortError,
diff --git a/baml_language/sdks/typescript/bridge_typescript/typescript_src/native.d.ts b/baml_language/sdks/typescript/bridge_typescript/typescript_src/native.d.ts
index 6d64d13e648..c69f7e6f1aa 100644
--- a/baml_language/sdks/typescript/bridge_typescript/typescript_src/native.d.ts
+++ b/baml_language/sdks/typescript/bridge_typescript/typescript_src/native.d.ts
@@ -100,8 +100,12 @@ export declare class BamlRuntime {
    * the `initializeRuntime(...)` import the spec docs use.
    */
   static initializeRuntime(rootPath: string, files: Record<string, string>): BamlRuntime
-  /** Initialize the process-global runtime from precompiled BAML bytecode. */
-  static initializeRuntimeFromBytecode(bytecode: Buffer, embeddedBamlToml?: string | undefined | null): BamlRuntime
+  /**
+   * Initialize the process-global runtime from precompiled BAML bytecode:
+   * a raw artifact, or the encoded string generated SDKs embed (decoded
+   * natively, never in JavaScript).
+   */
+  static initializeRuntimeFromBlob(bytecode: string | Buffer, embeddedBamlToml?: string | undefined | null): BamlRuntime
   /** Call a BAML function synchronously (blocking). */
   callFunctionSync(argsProto: Buffer, ctx?: HostSpanManager | undefined | null): Buffer
   /** Call a BAML function asynchronously. */
diff --git a/baml_language/sdks/typescript/bridge_typescript_web/src/runtime.rs b/baml_language/sdks/typescript/bridge_typescript_web/src/runtime.rs
index d32f546ef12..521f0071ebc 100644
--- a/baml_language/sdks/typescript/bridge_typescript_web/src/runtime.rs
+++ b/baml_language/sdks/typescript/bridge_typescript_web/src/runtime.rs
@@ -4,16 +4,23 @@ use std::collections::HashMap;
 
 use wasm_bindgen::prelude::*;
 
+/// Stage a runtime from precompiled BAML bytecode: a raw artifact
+/// (`Uint8Array`), or the encoded string generated SDKs embed (decoded
+/// natively, never in JavaScript).
 #[wasm_bindgen(js_name = stageRuntimeBytecode)]
 #[allow(clippy::needless_pass_by_value)] // wasm-bindgen requires an owned optional string at the JS boundary.
 pub fn stage_runtime_bytecode(
-    bytecode: &[u8],
+    bytecode: JsValue,
     embedded_baml_toml: Option<String>,
 ) -> Result<(), JsValue> {
+    let bytecode = match bytecode.as_string() {
+        Some(encoded) => encoded.into_bytes(),
+        None => js_sys::Uint8Array::new(&bytecode).to_vec(),
+    };
     let sys_ops = sys_wasm::build()
         .map_err(|error| crate::errors::setup_error(crate::errors::CLIENT, error))?;
-    bridge_cffi::initialize_runtime_from_bytecode_with_sys_ops(
-        bytecode,
+    bridge_cffi::initialize_runtime_from_blob_with_sys_ops(
+        &bytecode,
         embedded_baml_toml.as_deref(),
         sys_ops,
     )
diff --git a/baml_language/sdks/typescript/bridge_typescript_web/tests/runtime_errors.test.ts b/baml_language/sdks/typescript/bridge_typescript_web/tests/runtime_errors.test.ts
index 6077fd8d499..8c2b067b19d 100644
--- a/baml_language/sdks/typescript/bridge_typescript_web/tests/runtime_errors.test.ts
+++ b/baml_language/sdks/typescript/bridge_typescript_web/tests/runtime_errors.test.ts
@@ -63,7 +63,7 @@ describe("Web runtime and setup errors", () => {
     expect((rawError as Error & { code?: string }).code).toBe("invalid_argument");
 
     expect(() => BamlRuntime.initializeRuntime(".", { "": SOURCE_A })).toThrow(BamlInvalidArgumentError);
-    expect(() => BamlRuntime.initializeRuntimeFromBytecode(new Uint8Array([1, 2, 3]))).toThrow(/Failed to deserialize BAML bytecode/);
+    expect(() => BamlRuntime.initializeRuntimeFromBlob(new Uint8Array([1, 2, 3]))).toThrow(/Failed to deserialize BAML bytecode/);
   });
 
   it("initializes from sources and replaces the singleton atomically", async () => {
diff --git a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/index.ts b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/index.ts
index 1fee901e4e0..0bab3fad16c 100644
--- a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/index.ts
+++ b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/index.ts
@@ -18,8 +18,8 @@ export { BamlAbortError, BamlCancelledError, BamlClientError, BamlError, BamlInv
 export { BamlPrompt, decodeCallResult, encodeCallArgs } from "./shared/proto.js";
 export type { BamlPromptCallOptions, BamlPromptMessage } from "./shared/proto.js";
 
-export function initializeRuntimeFromBytecode(bytecode: Uint8Array, embeddedBamlToml?: string): void {
-  BamlRuntime.initializeRuntimeFromBytecode(bytecode, embeddedBamlToml);
+export function initializeRuntimeFromBlob(bytecode: string | Uint8Array, embeddedBamlToml?: string): void {
+  BamlRuntime.initializeRuntimeFromBlob(bytecode, embeddedBamlToml);
 }
 
 export function initializeRuntime(srcDir: string, files: Record<string, string>): void {
diff --git a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/native.ts b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/native.ts
index 6677e3ac0bc..164ea4221ce 100644
--- a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/native.ts
+++ b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/native.ts
@@ -377,7 +377,7 @@ export class HostSpanManager {
 }
 
 export class BamlRuntime {
-  static initializeRuntimeFromBytecode(bytecode: Uint8Array, embeddedBamlToml?: string): BamlRuntime {
+  static initializeRuntimeFromBlob(bytecode: string | Uint8Array, embeddedBamlToml?: string): BamlRuntime {
     ensureWebSysopsConfigured();
     try {
       stageRuntimeBytecode(bytecode, embeddedBamlToml);
diff --git a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/wasm/bridge_web_core.d.ts b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/wasm/bridge_web_core.d.ts
index 3ce75312222..a0eff38ada4 100644
--- a/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/wasm/bridge_web_core.d.ts
+++ b/baml_language/sdks/typescript/bridge_typescript_web/typescript_src/wasm/bridge_web_core.d.ts
@@ -125,7 +125,12 @@ export function seedFunctionRefHandle(global_index: number): bigint;
 
 export function seedGenericMediaHandle(): bigint;
 
-export function stageRuntimeBytecode(bytecode: Uint8Array, embedded_baml_toml?: string | null): void;
+/**
+ * Stage a runtime from precompiled BAML bytecode: a raw artifact
+ * (`Uint8Array`), or the encoded string generated SDKs embed (decoded
+ * natively, never in JavaScript).
+ */
+export function stageRuntimeBytecode(bytecode: any, embedded_baml_toml?: string | null): void;
 
 export function stageRuntimeSources(root_path: string, files: any): void;
 
@@ -154,7 +159,7 @@ export interface InitOutput {
     readonly mediaUrl: (a: bigint, b: number) => [number, number, number, number];
     readonly callFunction: (a: number, b: number) => any;
     readonly callFunctionSync: (a: number, b: number) => [number, number];
-    readonly stageRuntimeBytecode: (a: number, b: number, c: number, d: number) => [number, number];
+    readonly stageRuntimeBytecode: (a: any, b: number, c: number) => [number, number];
     readonly stageRuntimeSources: (a: number, b: number, c: any) => [number, number];
     readonly _testHandleTableEntryCount: () => [number, number, number];
     readonly cloneHandle: (a: bigint) => [bigint, number, number];
diff --git a/baml_language/sdks/typescript/sdkgen_typescript_shared/Cargo.toml b/baml_language/sdks/typescript/sdkgen_typescript_shared/Cargo.toml
index 540692f9d2d..50670bdbcd3 100644
--- a/baml_language/sdks/typescript/sdkgen_typescript_shared/Cargo.toml
+++ b/baml_language/sdks/typescript/sdkgen_typescript_shared/Cargo.toml
@@ -13,10 +13,12 @@ license = { workspace = true }
 [dependencies]
 baml_base = { workspace = true }
 baml_sdkgen_types = { workspace = true }
-base64 = { workspace = true }
 
 [lib]
 doctest = false
 
 [lints]
 workspace = true
+
+[dev-dependencies]
+baml_artifact = { workspace = true }
diff --git a/baml_language/sdks/typescript/sdkgen_typescript_shared/src/leaf.rs b/baml_language/sdks/typescript/sdkgen_typescript_shared/src/leaf.rs
index ecbcc61f773..44c99fc74ea 100644
--- a/baml_language/sdks/typescript/sdkgen_typescript_shared/src/leaf.rs
+++ b/baml_language/sdks/typescript/sdkgen_typescript_shared/src/leaf.rs
@@ -599,16 +599,14 @@ fn write_preamble_ts(
     if is_root {
         out.push_str(&runtime_import_line(
             state,
-            &["initializeRuntimeFromBytecode", "setTypeMap"],
+            &["initializeRuntimeFromBlob", "setTypeMap"],
             runtime_package,
         ));
         out.push_str("import * as _inlinedbaml from \"./_inlinedbaml.js\";\n");
         out.push_str("import { _TYPE_MAP } from \"./_typemap.js\";\n");
         out.push_str(&cross_leaf_imports(state, &body.leaf));
         out.push('\n');
-        out.push_str(
-            "initializeRuntimeFromBytecode(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);\n",
-        );
+        out.push_str("initializeRuntimeFromBlob(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);\n");
         out.push_str("setTypeMap(_TYPE_MAP);\n");
         if !kids.is_empty() {
             out.push('\n');
@@ -1373,12 +1371,14 @@ mod tests {
         let mut kids = BTreeSet::new();
         kids.insert("lorem".to_string());
         let ts = render_index_ts(&b, &kids, true, TEST_RUNTIME_PACKAGE);
-        assert!(ts.contains(
-            "initializeRuntimeFromBytecode(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);"
-        ));
+        assert!(
+            ts.contains(
+                "initializeRuntimeFromBlob(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);"
+            )
+        );
         assert!(ts.contains("setTypeMap(_TYPE_MAP);"));
         assert!(ts.contains("export * as lorem from \"./lorem/index.js\";"));
         assert!(ts.contains("export const make_foo = defineFunction("));
-        assert!(ts.contains("import { defineFunction, initializeRuntimeFromBytecode, setTypeMap, type BamlCallContext } from \"@boundaryml/baml-bridge\";"));
+        assert!(ts.contains("import { defineFunction, initializeRuntimeFromBlob, setTypeMap, type BamlCallContext } from \"@boundaryml/baml-bridge\";"));
     }
 }
diff --git a/baml_language/sdks/typescript/sdkgen_typescript_shared/src/lib.rs b/baml_language/sdks/typescript/sdkgen_typescript_shared/src/lib.rs
index 8c1ab888f00..434ae644a69 100644
--- a/baml_language/sdks/typescript/sdkgen_typescript_shared/src/lib.rs
+++ b/baml_language/sdks/typescript/sdkgen_typescript_shared/src/lib.rs
@@ -32,7 +32,6 @@ use std::{
 
 use baml_sdkgen_types::{Name, SymbolPool, public_interface_tokens};
 pub use baml_sdkgen_types::{NamingConvention, OutputType};
-use base64::{Engine as _, engine::general_purpose::STANDARD as BASE64_STANDARD};
 
 use crate::{
     emit::{build_emitted, typemap_file::render_typemap_module},
@@ -221,43 +220,21 @@ fn init_ts_path(dir: &[String]) -> PathBuf {
     path
 }
 
-/// Base64 characters per emitted source line. Long enough that the line count
-/// stays small, short enough that the file is still diffable.
-const BYTECODE_BASE64_LINE: usize = 4096;
-
 fn render_inlinedbaml(bytecode: &[u8], embedded_baml_toml: Option<&str>) -> String {
-    // The bytecode ships as base64 rather than a decimal `new Uint8Array([...])`
-    // literal. That literal cost up to 5 source characters per byte (~3.8 on
-    // average, measured); base64 costs 1.33, which shrinks this module by ~65%.
+    // The bytecode ships as one line of encoded bytecode (see
+    // `baml_sdkgen_types::embedded_bytecode_base64`) rather than a decimal
+    // `new Uint8Array([...])` literal, which cost up to 5 source characters
+    // per byte (~3.8 on average, measured). BYTECODE is passed to
+    // `initializeRuntimeFromBlob` as a string, and the bridge decodes it
+    // natively.
     //
     // Size matters here beyond disk: bundlers and the Cloudflare Workers test
     // pool move this module around as a unit, and workerd caps a single
     // WebSocket message at 1 MiB — a large enough program made the pool drop
     // the connection with a 1009 "Message is too large".
-    //
-    // `atob` is the one decoder available everywhere this runs: browsers,
-    // Workers, and Node (global since 16). BYTECODE stays a Uint8Array, so
-    // `initializeRuntimeFromBytecode` is unaffected.
-    let encoded = BASE64_STANDARD.encode(bytecode);
-    let mut out = String::with_capacity(encoded.len() + encoded.len() / 256 + 512);
-    out.push_str("const BYTECODE_BASE64 = [\n");
-    for chunk in encoded.as_bytes().chunks(BYTECODE_BASE64_LINE) {
-        out.push_str("  \"");
-        // base64 output is ASCII, so the chunk is always valid UTF-8 and needs
-        // no escaping.
-        out.push_str(std::str::from_utf8(chunk).expect("base64 output is ASCII"));
-        out.push_str("\",\n");
-    }
-    out.push_str("].join(\"\");\n\n");
-    out.push_str("function decodeBytecode(encoded: string): Uint8Array {\n");
-    out.push_str("  const binary = atob(encoded);\n");
-    out.push_str("  const bytes = new Uint8Array(binary.length);\n");
-    out.push_str("  for (let i = 0; i < binary.length; i += 1) {\n");
-    out.push_str("    bytes[i] = binary.charCodeAt(i);\n");
-    out.push_str("  }\n");
-    out.push_str("  return bytes;\n");
-    out.push_str("}\n\n");
-    out.push_str("export const BYTECODE = decodeBytecode(BYTECODE_BASE64);\n");
+    let encoded = baml_sdkgen_types::embedded_bytecode_base64(bytecode);
+    let mut out = String::with_capacity(encoded.len() + 512);
+    let _ = writeln!(out, "export const BYTECODE = \"{encoded}\";");
     let manifest = embedded_baml_toml
         .map(ts_string)
         .unwrap_or_else(|| "undefined".to_string());
@@ -365,9 +342,11 @@ mod tests {
         assert!(!out.keys().any(|p| p.to_string_lossy().ends_with(".d.ts")));
         let root = &out[&PathBuf::from("index.ts")];
         assert!(root.contains(HEADER_LEN_MARKER));
-        assert!(root.contains(
-            "initializeRuntimeFromBytecode(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);"
-        ));
+        assert!(
+            root.contains(
+                "initializeRuntimeFromBlob(_inlinedbaml.BYTECODE, _inlinedbaml.BAML_TOML);"
+            )
+        );
         assert!(root.contains("setTypeMap(_TYPE_MAP);"));
         assert!(root.contains("export * as baml from \"./baml/index.js\";"));
         assert!(!root.contains("export const b"));
@@ -469,25 +448,23 @@ mod tests {
             GeneratorConfig::new("@boundaryml/baml-bridge"),
         );
         let inlined = &out[&PathBuf::from("_inlinedbaml.ts")];
-        assert!(inlined.contains("export const BYTECODE = decodeBytecode(BYTECODE_BASE64);"));
-        // The exact base64 for those six bytes, so a change to the encoding
+        // The exact payload for those six bytes, so a change to the encoding
         // fails here rather than at runtime in a generated SDK.
         assert!(
             inlined.contains(&format!(
-                "  \"{}\",\n",
-                BASE64_STANDARD.encode([0, 1, 2, 253, 254, 255])
+                "export const BYTECODE = \"{}\";\n",
+                baml_sdkgen_types::embedded_bytecode_base64(&[0, 1, 2, 253, 254, 255])
             )),
             "{inlined}"
         );
-        // The decoder must be self-contained: no import, and byte-exact.
-        assert!(inlined.contains("const binary = atob(encoded);"));
+        // Decoding is the bridge's job, never the generated module's.
+        assert!(!inlined.contains("atob"));
     }
 
     #[test]
-    fn inlinedbaml_base64_round_trips_and_wraps_long_bytecode() {
-        // Enough bytes to span several emitted lines, with every byte value
-        // represented so a mangled alphabet or a bad chunk boundary shows up.
-        let bytecode: Vec<u8> = (0..(BYTECODE_BASE64_LINE * 3))
+    fn inlinedbaml_payload_is_one_line_that_round_trips() {
+        // Every byte value represented so a mangled alphabet shows up.
+        let bytecode: Vec<u8> = (0..(3 * 4096))
             .map(|i| u8::try_from(i % 256).expect("i % 256 fits in u8"))
             .collect();
         let out = to_source_code(
@@ -498,17 +475,23 @@ mod tests {
         );
         let inlined = &out[&PathBuf::from("_inlinedbaml.ts")];
 
-        let joined: String = inlined
+        let payloads: Vec<&str> = inlined
             .lines()
-            .filter(|l| l.starts_with("  \"") && l.ends_with("\","))
-            .map(|l| &l[3..l.len() - 2])
+            .filter_map(|l| l.strip_prefix("export const BYTECODE = \""))
+            .map(|l| {
+                l.strip_suffix("\";")
+                    .expect("payload line ends the literal")
+            })
             .collect();
+        assert_eq!(payloads.len(), 1, "{inlined}");
         assert_eq!(
-            BASE64_STANDARD
-                .decode(joined)
-                .expect("emitted base64 decodes"),
+            baml_artifact::decode_embedded(
+                baml_artifact::ArtifactKind::Program,
+                payloads[0].as_bytes()
+            )
+            .expect("emitted payload decodes"),
             bytecode,
-            "emitted base64 must round-trip to the original bytecode"
+            "emitted payload must round-trip to the original bytecode"
         );
     }
 
diff --git a/release/bridge-cffi-public-exports.txt b/release/bridge-cffi-public-exports.txt
index 93613172f44..7d62377f63c 100644
--- a/release/bridge-cffi-public-exports.txt
+++ b/release/bridge-cffi-public-exports.txt
@@ -18,8 +18,8 @@ create_baml_runtime
 destroy_baml_runtime
 flush_events
 free_buffer
-initialize_runtime_from_bytecode
-initialize_runtime_from_bytecode_with_metadata
+initialize_runtime_from_blob
+initialize_runtime_from_blob_with_metadata
 invoke_runtime_cli
 new_function_call
 register_callback