fix(providers): disable Bedrock prompt caching for non-Anthropic models (#20866) (thanks @pierreeurope)

src/agents/pi-embedded-runner-extraparams.test.ts

@@ -151,6 +151,42 @@ describe("applyExtraParamsToAgent", () => {
     });
   });
 
+  it("disables prompt caching for non-Anthropic Bedrock models", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+
+    applyExtraParamsToAgent(agent, undefined, "amazon-bedrock", "amazon.nova-micro-v1");
+
+    const model = {
+      api: "openai-completions",
+      provider: "amazon-bedrock",
+      id: "amazon.nova-micro-v1",
+    } as Model<"openai-completions">;
+    const context: Context = { messages: [] };
+
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.cacheRetention).toBe("none");
+  });
+
+  it("keeps Anthropic Bedrock models eligible for provider-side caching", () => {
+    const { calls, agent } = createOptionsCaptureAgent();
+
+    applyExtraParamsToAgent(agent, undefined, "amazon-bedrock", "us.anthropic.claude-sonnet-4-5");
+
+    const model = {
+      api: "openai-completions",
+      provider: "amazon-bedrock",
+      id: "us.anthropic.claude-sonnet-4-5",
+    } as Model<"openai-completions">;
+    const context: Context = { messages: [] };
+
+    void agent.streamFn?.(model, context, {});
+
+    expect(calls).toHaveLength(1);
+    expect(calls[0]?.cacheRetention).toBeUndefined();
+  });
+
   it("adds Anthropic 1M beta header when context1m is enabled for Opus/Sonnet", () => {
     const { calls, agent } = createOptionsCaptureAgent();
     const cfg = buildAnthropicModelConfig("anthropic/claude-opus-4-6", { context1m: true });

src/agents/pi-embedded-runner/extra-params.ts

@@ -137,6 +137,20 @@ function createStreamFnWithExtraParams(
   return wrappedStreamFn;
 }
 
+function isAnthropicBedrockModel(modelId: string): boolean {
+  const normalized = modelId.toLowerCase();
+  return normalized.includes("anthropic.claude") || normalized.includes("anthropic/claude");
+}
+
+function createBedrockNoCacheWrapper(baseStreamFn: StreamFn | undefined): StreamFn {
+  const underlying = baseStreamFn ?? streamSimple;
+  return (model, context, options) =>
+    underlying(model, context, {
+      ...options,
+      cacheRetention: "none",
+    });
+}
+
 function isDirectOpenAIBaseUrl(baseUrl: unknown): boolean {
   if (typeof baseUrl !== "string" || !baseUrl.trim()) {
     return true;
@@ -501,6 +515,11 @@ export function applyExtraParamsToAgent(
     agent.streamFn = createOpenRouterSystemCacheWrapper(agent.streamFn);
   }
 
+  if (provider === "amazon-bedrock" && !isAnthropicBedrockModel(modelId)) {
+    log.debug(`disabling prompt caching for non-Anthropic Bedrock model ${provider}/${modelId}`);
+    agent.streamFn = createBedrockNoCacheWrapper(agent.streamFn);
+  }
+
   // Enable Z.AI tool_stream for real-time tool call streaming.
   // Enabled by default for Z.AI provider, can be disabled via params.tool_stream: false
   if (provider === "zai" || provider === "z-ai") {