diff --git a/changelog.d/added-adr-0026-sync.md b/changelog.d/added-adr-0026-sync.md
new file mode 100644
index 0000000..425d9a4
--- /dev/null
+++ b/changelog.d/added-adr-0026-sync.md
@@ -0,0 +1 @@
+- Sync Hive ADR 0026 (sandbox runtime selection) to the docs site and list it in the ADR nav (#550).
diff --git a/scripts/sync-hive-docs.main.test.ts b/scripts/sync-hive-docs.main.test.ts
index 45bc9fa..1f241ea 100644
--- a/scripts/sync-hive-docs.main.test.ts
+++ b/scripts/sync-hive-docs.main.test.ts
@@ -65,7 +65,7 @@ async function runSync(): Promise<{ out: string; err: string }> {
     () => {
       const done =
         exitSpy.mock.calls.length > 0 ||
-        joinCalls(logSpy).includes("adr/0025-central-stage-engine.md");
+        joinCalls(logSpy).includes("adr/0026-sandbox-runtime-selection.md");
       if (!done) throw new Error("sync still running");
     },
     { timeout: 5_000, interval: 5 }
diff --git a/scripts/sync-hive-docs.test.ts b/scripts/sync-hive-docs.test.ts
index d7593d7..59104f4 100644
--- a/scripts/sync-hive-docs.test.ts
+++ b/scripts/sync-hive-docs.test.ts
@@ -40,6 +40,12 @@ describe("rewriteLinkTarget — Case 1: in-tree synced docs -> site route", () =
     ).toBe("/docs/hive/adr/0001-record-architecture-decisions");
   });
 
+  it("rewrites ADR-0026 sandbox runtime selection link from adr/README.md to its adr/ route", () => {
+    expect(
+      rewriteLinkTarget("0026-sandbox-runtime-selection.md", ADR_README)
+    ).toBe("/docs/hive/adr/0026-sandbox-runtime-selection");
+  });
+
   it("preserves an #anchor on an in-tree link", () => {
     expect(rewriteLinkTarget("architecture.md#the-governor-loop", README)).toBe(
       "/docs/hive/architecture#the-governor-loop"
diff --git a/scripts/sync-hive-docs.ts b/scripts/sync-hive-docs.ts
index 4944538..2f22515 100644
--- a/scripts/sync-hive-docs.ts
+++ b/scripts/sync-hive-docs.ts
@@ -91,6 +91,7 @@ const files: Array<{ source: string; target?: string; route?: string }> = [
   { source: "adr/0023-trusted-author-automerge.md" },
   { source: "adr/0024-provider-credential-lifecycle.md" },
   { source: "adr/0025-central-stage-engine.md" },
+  { source: "adr/0026-sandbox-runtime-selection.md" },
 ];
 
 // Hive pages authored in this repo (docs/content/hive/) rather than synced,
diff --git a/src/app/docs/page-map.ts b/src/app/docs/page-map.ts
index 382ed10..a7eeb93 100644
--- a/src/app/docs/page-map.ts
+++ b/src/app/docs/page-map.ts
@@ -192,6 +192,7 @@ const NAV_STRUCTURE_HIVE: Array<{ title: string; items: NavItem[] }> = [
         { '0023 Trusted-author automerge': 'adr/0023-trusted-author-automerge.md' },
         { '0024 Provider credential lifecycle': 'adr/0024-provider-credential-lifecycle.md' },
         { '0025 Central stage engine': 'adr/0025-central-stage-engine.md' },
+        { '0026 Sandbox runtime selection': 'adr/0026-sandbox-runtime-selection.md' },
       ] },
       { 'Environment variable reference': 'env-vars.md' },
     ]