Remove legacy Jinja prompt support

baml_language/Cargo.toml

@@ -105,8 +105,6 @@ bex_cache = { path = "crates/bex_cache", default-features = false }
 bex_project = { path = "crates/bex_project", default-features = false }
 bex_engine = { path = "crates/bex_engine", default-features = false }
 sys_glob = { path = "crates/sys_glob" }
-sys_jinja = { path = "crates/sys_jinja" }
-sys_jinja_types = { path = "crates/sys_jinja_types" }
 sys_llm = { path = "crates/sys_llm", default-features = false }
 sys_ops = { path = "crates/sys_ops", default-features = false }
 sys_types = { path = "crates/sys_types" }
@@ -135,16 +133,6 @@ bex_resource_types = { path = "crates/bex_resource_types" }
 darwin-kperf = "0.1.0"
 darwin-kperf-events = "0.1.0"
 
-# External dependency for sys_llm jinja module
-minijinja = { git = "https://github.com/boundaryml/minijinja.git", branch = "value-cmp", default-features = false, features = [
-  "macros",
-  "builtins",
-  "debug",
-  "preserve_order",
-  "serde",
-  "unstable_machinery",
-] }
-minijinja-contrib = { git = "https://github.com/boundaryml/minijinja.git", branch = "value-cmp", features = [ "pycompat" ] }
 baml_workspace = { path = "crates/baml_workspace" }
 
 #  External dependencies

baml_language/crates/baml_base/src/dedent.rs

@@ -1,22 +1,15 @@
-//! Template-string dedenting.
+//! Backtick-string dedenting.
 //!
-//! Shared with `sys_llm::jinja::render::preprocess_template`; both implement the
-//! same algorithm and should remain in lockstep until that callsite migrates to
-//! this one.
-//!
-//! Algorithm (BEP-049 §12, Kotlin `trimIndent` rule):
+//! Algorithm (BEP-049 section 12, Kotlin `trimIndent` rule):
 //! 1. Compute the longest common leading-whitespace *prefix* across all non-blank
 //!    lines, compared character-by-character. Tabs and spaces don't mix: a
 //!    tab-indented line and a space-indented line share no common prefix, so the
-//!    strip column drops to zero (§12 Rule 2).
+//!    strip column drops to zero (section 12, rule 2).
 //! 2. Strip that common prefix from every line that has it; otherwise keep the
 //!    line as-is (its content is whitespace-only).
 //! 3. Trim leading/trailing whitespace from the overall result.
 //!
-//! Used by BEP-049 backtick string literals (multi-line auto-dedent, §12). The
-//! legacy Jinja prompt pipeline (`sys_llm::preprocess_template`) keeps the older
-//! byte-count-min variant until that path is removed (M6) — they intentionally
-//! diverge on mixed tab/space indentation, which only the new backtick form specs.
+//! Used by BEP-049 backtick string literals for multi-line auto-dedent.
 // Walk leading whitespace by *char* so we never split a multi-byte
 // Unicode whitespace codepoint (NBSP U+00A0 = 2 bytes, LINE SEPARATOR
 // U+2028 = 3 bytes, etc.). A naive `line.len() - line.trim_start().len()`

baml_language/crates/baml_builtins2/keyword_docs/baml_keywords.yaml

@@ -320,13 +320,6 @@ testset:
 
     Every leaf gets a canonical ID beginning with `root` (or `root.<namespace>`) and using `::` for testset nesting. For example, the first test above is `root::math suite::adds`. Run `baml test --list` to discover IDs and `baml test --help` for selectors and profiles.
 
-template_string:
-  summary: "Defines a reusable prompt template with Jinja2 syntax."
-  syntax: |
-    template_string Greeting(name: string) #"
-      Hello, {{ name }}! How can I help you?
-    "#
-
 retry_policy:
   summary: "Configures automatic retry behavior for LLM calls."
   syntax: |

baml_language/crates/baml_compiler2_ast/src/ast.rs

@@ -1623,7 +1623,6 @@ pub enum BuiltinKind {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct LlmBodyDef {
     pub client: Option<Name>,
-    pub prompt: Option<RawPrompt>,
     /// Pre-lowered companion bodies keyed by target name. The single-path
     /// world stashes exactly one: `"spec"` — the `<Fn>$spec` body, built in
     /// `lower_cst` while the CST backtick is still in hand (the AST must stay
@@ -1645,15 +1644,6 @@ pub struct LlmBodyDef {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct RawPrompt {
     pub text: std::string::String,
-    /// Interpolation locations within the template.
-    pub interpolations: Vec<Interpolation>,
-    pub span: TextRange,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Interpolation {
-    pub content: std::string::String,
-    /// Span of the full interpolation, including delimiters.
     pub span: TextRange,
 }
 

baml_language/crates/baml_compiler2_ast/src/companions.rs

@@ -62,6 +62,22 @@ fn own_params(parent: &FunctionDef) -> Vec<Param> {
         .collect()
 }
 
+fn generic_type_args(parent: &FunctionDef) -> Vec<crate::ast::TypeExpr> {
+    parent
+        .generic_params
+        .iter()
+        .map(|param| {
+            TypeExprKind::Path {
+                segments: vec![param.name.clone()],
+                generic_args: vec![],
+                associated_type_bindings: vec![],
+                attrs: vec![],
+            }
+            .at(parent.span)
+        })
+        .collect()
+}
+
 fn companion_def(
     parent: &FunctionDef,
     name: Name,
@@ -126,6 +142,7 @@ fn llm_render_prompt(parent: &FunctionDef) -> Option<FunctionDef> {
     let body = lower_expr_body::synthesize_spec_render_prompt_body(
         parent.name.as_str(),
         &param_names,
+        generic_type_args(parent),
         Some(out),
         parent.span,
     );

baml_language/crates/baml_compiler2_ast/src/lower_cst.rs

@@ -17,8 +17,8 @@ use crate::{
     ast::{
         AssociatedTypeBindingDef, AssociatedTypeDef, BuiltinKind, CallArg, EnumDef, Expr, ExprId,
         FieldDef, FunctionBodyDef, FunctionDef, FunctionDefaults, ImplementsBlockDef,
-        ImplementsForDef, InterfaceDef, InterfaceFieldLinkDef, Interpolation, Item, LambdaDef,
-        LambdaKind, LlmBodyDef, MethodSigDef, Param, RawAttribute, RawAttributeArg, RawPrompt,
+        ImplementsForDef, InterfaceDef, InterfaceFieldLinkDef, Item, LambdaDef, LambdaKind,
+        LlmBodyDef, MethodSigDef, Param, RawAttribute, RawAttributeArg, RawPrompt,
         TemplateStringDef, TestArgValue, TestDef, TypeAliasDef, TypeExpr, TypeExprKind, VariantDef,
     },
     companions::expand_companions,
@@ -156,6 +156,9 @@ pub fn lower_file_with_path_and_test_owner(
                 diags.push(lower_generator_deprecation(&child));
             }
             baml_compiler_syntax::SyntaxKind::TEMPLATE_STRING_DEF => {
+                diags.push(LoweringDiagnostic::TemplateStringRemoved {
+                    span: child.span_range(),
+                });
                 if let Some(ts) = lower_template_string(&child, &mut diags) {
                     items.push(Item::TemplateString(ts));
                 }
@@ -343,10 +346,9 @@ fn lower_function(
 
         // Jinja prompts are removed: the single-path world renders prompts as
         // plain backtick templates through the spec.
-        if llm.prompt_field().and_then(|pf| pf.raw_string()).is_some() {
+        if let Some(raw_prompt) = llm.prompt_field().and_then(|pf| pf.raw_string()) {
             diags.push(LoweringDiagnostic::LlmJinjaPromptRemoved {
-                function_name: name.as_str().to_string(),
-                span: llm_body_def.span,
+                span: raw_prompt.syntax().span_range(),
             });
         }
 
@@ -397,9 +399,22 @@ fn lower_function(
             .iter()
             .any(|(t, _)| t == "spec")
         {
+            let spec_type_args = generic_params
+                .iter()
+                .map(|param| {
+                    crate::ast::TypeExprKind::Path {
+                        segments: vec![param.name.clone()],
+                        generic_args: vec![],
+                        associated_type_bindings: vec![],
+                        attrs: vec![],
+                    }
+                    .at(llm_body_def.span)
+                })
+                .collect();
             let (expr_body, source_map) = lower_expr_body::synthesize_spec_agent_run_body(
                 name.as_str(),
                 &param_names,
+                spec_type_args,
                 return_type.clone(),
                 llm_body_def.span,
             );
@@ -693,14 +708,8 @@ fn lower_llm_body(llm_body: &ast::LlmFunctionBody) -> LlmBodyDef {
         .and_then(|cf| cf.value())
         .map(|name| Name::new(&name));
 
-    let prompt = llm_body
-        .prompt_field()
-        .and_then(|pf| pf.raw_string())
-        .map(|raw_str| lower_raw_prompt(&raw_str));
-
     LlmBodyDef {
         client,
-        prompt,
         // Filled in by the LLM-function branch once param names are known.
         companion_bodies: Vec::new(),
         has_tools: llm_tools_present(llm_body),
@@ -828,46 +837,10 @@ fn tools_value_element(
 }
 
 fn lower_raw_prompt(raw_string: &ast::RawStringLiteral) -> RawPrompt {
-    use baml_compiler_syntax::{
-        SyntaxKind,
-        ast::{JinjaExpression, JinjaStatement, PromptText},
-    };
-
-    let mut text = String::new();
-    let mut interpolations = Vec::new();
     let prompt_span = raw_string.syntax().span_range();
-
-    for child in raw_string.syntax().children() {
-        match child.kind() {
-            SyntaxKind::PROMPT_TEXT => {
-                if let Some(prompt_text) = PromptText::cast(child.clone()) {
-                    text.push_str(&prompt_text.text());
-                }
-            }
-            SyntaxKind::TEMPLATE_INTERPOLATION => {
-                if let Some(jinja_expr) = JinjaExpression::cast(child.clone()) {
-                    let inner = jinja_expr.inner_text();
-                    let full = jinja_expr.full_text();
-                    let span = child.span_range();
-                    interpolations.push(Interpolation {
-                        content: inner,
-                        span,
-                    });
-                    text.push_str(&full);
-                }
-            }
-            SyntaxKind::TEMPLATE_CONTROL => {
-                if let Some(jinja_stmt) = JinjaStatement::cast(child.clone()) {
-                    text.push_str(&jinja_stmt.full_text());
-                }
-            }
-            _ => {}
-        }
-    }
-
     RawPrompt {
-        text,
-        interpolations,
+        text: crate::parse_string_attr_value(&raw_string.syntax().text().to_string())
+            .unwrap_or_default(),
         span: prompt_span,
     }
 }

baml_language/crates/baml_compiler2_ast/src/lower_expr_body.rs

@@ -618,6 +618,7 @@ pub(crate) fn synthesize_llm_spec_body(
 pub(crate) fn synthesize_spec_render_prompt_body(
     function_name: &str,
     param_names: &[Name],
+    spec_type_args: Vec<crate::ast::TypeExpr>,
     out_type: Option<crate::ast::TypeExpr>,
     span: TextRange,
 ) -> (ExprBody, AstSourceMap) {
@@ -636,7 +637,7 @@ pub(crate) fn synthesize_spec_render_prompt_body(
     let spec_call = ctx.alloc_expr(
         Expr::Call {
             callee: spec_callee,
-            type_args: vec![],
+            type_args: spec_type_args,
             args: spec_args,
         },
         span,
@@ -733,6 +734,7 @@ pub(crate) fn synthesize_spec_parse_body(
 pub(crate) fn synthesize_spec_agent_run_body(
     function_name: &str,
     param_names: &[Name],
+    spec_type_args: Vec<crate::ast::TypeExpr>,
     out_type: Option<crate::ast::TypeExpr>,
     span: TextRange,
 ) -> (ExprBody, AstSourceMap) {
@@ -755,7 +757,7 @@ pub(crate) fn synthesize_spec_agent_run_body(
     let spec_call = ctx.alloc_expr(
         Expr::Call {
             callee: spec_callee,
-            type_args: vec![],
+            type_args: spec_type_args,
             args: spec_args,
         },
         span,
@@ -825,6 +827,7 @@ pub(crate) fn synthesize_spec_agent_run_body(
 pub fn synthesize_spec_stream_body(
     function_name: &str,
     param_names: &[Name],
+    spec_type_args: Vec<crate::ast::TypeExpr>,
     type_args: Vec<crate::ast::TypeExpr>,
     span: TextRange,
 ) -> (ExprBody, AstSourceMap) {
@@ -847,7 +850,7 @@ pub fn synthesize_spec_stream_body(
     let spec_call = ctx.alloc_expr(
         Expr::Call {
             callee: spec_callee,
-            type_args: vec![],
+            type_args: spec_type_args,
             args: spec_args,
         },
         span,