diff --git a/src/ml/imf/registry.ts b/src/ml/imf/registry.ts
index 7d69e7b..596f915 100644
--- a/src/ml/imf/registry.ts
+++ b/src/ml/imf/registry.ts
@@ -16,7 +16,7 @@
 import { load as loadYaml } from "js-yaml"
 
 export const DEFAULT_INDEX_URL =
-  "https://github.com/interscript/interscript-models/releases/download/index-v10/models-index.yaml"
+  "https://github.com/interscript/interscript-models/releases/download/index-v12/models-index.yaml"
 
 export interface Part {
   url: string
diff --git a/test/client-work.test.ts b/test/client-work.test.ts
index 16905c6..c00d372 100644
--- a/test/client-work.test.ts
+++ b/test/client-work.test.ts
@@ -145,9 +145,9 @@ describe("CORS asset rewrite (13)", () => {
   it("rewrites canonical interscript-models release URLs too", () => {
     expect(
       corsAssetUrl(
-        "https://github.com/interscript/interscript-models/releases/download/index-v10/models-index.yaml",
+        "https://github.com/interscript/interscript-models/releases/download/index-v12/models-index.yaml",
       ),
-    ).toBe("https://api.interscript.org/v1/assets/index-v10/models-index.yaml")
+    ).toBe("https://api.interscript.org/v1/assets/index-v12/models-index.yaml")
   })
   it("leaves other hosts and schemes untouched", () => {
     expect(corsAssetUrl("https://example.com/x.zip")).toBe("https://example.com/x.zip")
diff --git a/test/conformance.test.ts b/test/conformance.test.ts
new file mode 100644
index 0000000..bd760dd
--- /dev/null
+++ b/test/conformance.test.ts
@@ -0,0 +1,45 @@
+/**
+ * Frozen conformance fixtures (interscript-models/conformance/) — the
+ * TypeScript runtime must reproduce the vectors byte-exactly under the
+ * declared decode mode, or the change does not merge.
+ *
+ * Gated on env: SECRYST_E2E_ZIP (the artifact) + CONFORMANCE_VECTORS
+ * (the fixture file), so CI runs without downloads.
+ */
+
+import { readFileSync } from "node:fs"
+import { describe, expect, it } from "vitest"
+import { IMFModel } from "../src/ml/imf/index.js"
+
+const e2eZip = process.env["SECRYST_E2E_ZIP"]
+const conformanceVectors = process.env["CONFORMANCE_VECTORS"]
+
+describe("frozen conformance fixtures", () => {
+  it.skipIf(!e2eZip || !conformanceVectors)(
+    "reproduces the vectors byte-exactly (single-row-greedy)",
+    async () => {
+      const vectors = JSON.parse(
+        readFileSync(conformanceVectors!, "utf-8"),
+      ) as {
+        model: string
+        decode: { mode: string }
+        vectors: { src: string; out: string }[]
+      }
+      expect(vectors.decode.mode).toBe("single-row-greedy")
+      const model = await IMFModel.load(e2eZip!)
+      const failures: string[] = []
+      for (const v of vectors.vectors) {
+        const got = await model.translate(v.src, 256)
+        if (got !== v.out) {
+          failures.push(`${v.src} -> ${got} (expected ${v.out})`)
+        }
+      }
+      await model.dispose()
+      expect(
+        failures,
+        `${vectors.model}: ${failures.length}/${vectors.vectors.length} mismatched`,
+      ).toEqual([])
+    },
+    600_000,
+  )
+})