From 6ac482ca63c6e0d289cd64f3e3a3be8d79826666 Mon Sep 17 00:00:00 2001
From: Shakker <shakkerdroid@gmail.com>
Date: Sun, 12 Apr 2026 05:27:03 +0100
Subject: [PATCH] fix: allow bedrock signed thinking replay under anthropic
 policy

---
 src/agents/transcript-policy.test.ts | 32 +++++++++++++++++++++++-----
 src/agents/transcript-policy.ts      | 13 ++++++-----
 2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/src/agents/transcript-policy.test.ts b/src/agents/transcript-policy.test.ts
index 8ad1509771e..32fedb9adc5 100644
--- a/src/agents/transcript-policy.test.ts
+++ b/src/agents/transcript-policy.test.ts
@@ -4,6 +4,9 @@ vi.mock("../plugins/provider-runtime.js", async () => {
   const actual = await vi.importActual<typeof import("../plugins/provider-runtime.js")>(
     "../plugins/provider-runtime.js",
   );
+  const replayHelpers = await vi.importActual<
+    typeof import("../plugins/provider-replay-helpers.js")
+  >("../plugins/provider-replay-helpers.js");
   return {
     ...actual,
     resolveProviderRuntimePlugin: vi.fn(({ provider }: { provider?: string }) => {
@@ -51,7 +54,10 @@ vi.mock("../plugins/provider-runtime.js", async () => {
                 repairToolUseResultPairing: true,
                 validateAnthropicTurns: true,
                 allowSyntheticToolResults: true,
-                ...(modelId.includes("claude") ? { dropThinkingBlocks: true } : {}),
+                ...(modelId.includes("claude") &&
+                !replayHelpers.shouldPreserveThinkingBlocks(modelId)
+                  ? { dropThinkingBlocks: true }
+                  : {}),
               };
             case "minimax":
             case "minimax-portal":
@@ -71,7 +77,10 @@ vi.mock("../plugins/provider-runtime.js", async () => {
                     repairToolUseResultPairing: true,
                     validateAnthropicTurns: true,
                     allowSyntheticToolResults: true,
-                    ...(modelId.includes("claude") ? { dropThinkingBlocks: true } : {}),
+                    ...(modelId.includes("claude") &&
+                    !replayHelpers.shouldPreserveThinkingBlocks(modelId)
+                      ? { dropThinkingBlocks: true }
+                      : {}),
                   };
             case "moonshot":
             case "ollama":
@@ -182,9 +191,8 @@ let shouldAllowProviderOwnedThinkingReplay: typeof import("./transcript-policy.j
 
 describe("resolveTranscriptPolicy", () => {
   beforeAll(async () => {
-    ({ resolveTranscriptPolicy, shouldAllowProviderOwnedThinkingReplay } = await import(
-      "./transcript-policy.js"
-    ));
+    ({ resolveTranscriptPolicy, shouldAllowProviderOwnedThinkingReplay } =
+      await import("./transcript-policy.js"));
   });
 
   beforeEach(() => {
@@ -421,6 +429,20 @@ describe("resolveTranscriptPolicy", () => {
     ).toBe(true);
   });
 
+  it("allows immutable provider-owned thinking replay for bedrock claude replay policies", () => {
+    const policy = resolveTranscriptPolicy({
+      provider: "amazon-bedrock",
+      modelId: "us.anthropic.claude-opus-4-6-v1",
+      modelApi: "bedrock-converse-stream",
+    });
+    expect(
+      shouldAllowProviderOwnedThinkingReplay({
+        modelApi: "bedrock-converse-stream",
+        policy,
+      }),
+    ).toBe(true);
+  });
+
   it("does not allow immutable provider-owned thinking replay for strict openai-compatible replay", () => {
     const policy = resolveTranscriptPolicy({
       provider: "vllm",
diff --git a/src/agents/transcript-policy.ts b/src/agents/transcript-policy.ts
index 3185c8823e9..00c1411fb16 100644
--- a/src/agents/transcript-policy.ts
+++ b/src/agents/transcript-policy.ts
@@ -31,13 +31,16 @@ export type TranscriptPolicy = {
 
 export function shouldAllowProviderOwnedThinkingReplay(params: {
   modelApi?: string | null;
-  policy: Pick<TranscriptPolicy, "validateAnthropicTurns" | "preserveSignatures" | "dropThinkingBlocks">;
+  policy: Pick<
+    TranscriptPolicy,
+    "validateAnthropicTurns" | "preserveSignatures" | "dropThinkingBlocks"
+  >;
 }): boolean {
   return (
-    params.modelApi === "anthropic-messages" &&
-    params.policy.validateAnthropicTurns === true &&
-    params.policy.preserveSignatures === true &&
-    params.policy.dropThinkingBlocks !== true
+    isAnthropicApi(params.modelApi) &&
+    params.policy.validateAnthropicTurns &&
+    params.policy.preserveSignatures &&
+    !params.policy.dropThinkingBlocks
   );
 }