fix(providers): encode Mythos adaptive requests

vincentkoc · vincentkoc · commit 6b0f718b9a4b · 2026-06-11T11:11:21.000+09:00
diff --git a/docs/providers/bedrock-mantle.md b/docs/providers/bedrock-mantle.md
@@ -38,6 +38,18 @@ Choose your preferred auth method and follow the setup steps.
         export AWS_REGION="us-west-2"
         ```
       </Step>
+      <Step title="Opt in to provider data sharing for Claude Fable 5">
+        Claude Fable 5 and Claude Mythos-class Bedrock models require the Mantle Data Retention API mode `provider_data_share` before invocation. This opt-in allows Bedrock to share prompts and completions with Anthropic and retain them for up to 30 days for trust and safety review.
+
+        ```bash
+        curl -X PUT https://bedrock-mantle.us-east-1.api.aws/v1/data_retention \
+          -H "Authorization: Bearer $AWS_BEARER_TOKEN_BEDROCK" \
+          -H "Content-Type: application/json" \
+          -d '{ "mode": "provider_data_share" }'
+        ```
+
+        Use another Bedrock model in the config if you cannot accept that retention mode.
+      </Step>
       <Step title="Verify models are discovered">
         ```bash
         openclaw models list
diff --git a/docs/providers/bedrock.md b/docs/providers/bedrock.md
@@ -38,18 +38,6 @@ Choose your preferred auth method and follow the setup steps.
         export AWS_BEARER_TOKEN_BEDROCK="..."
         ```
       </Step>
-      <Step title="Opt in to provider data sharing for Claude Fable 5">
-        Claude Fable 5 and Claude Mythos-class Bedrock models require the Bedrock Data Retention API mode `provider_data_share` before invocation. This opt-in allows Bedrock to share prompts and completions with Anthropic and retain them for up to 30 days for trust and safety review.
-
-        ```bash
-        curl -X PUT https://bedrock-mantle.us-east-1.api.aws/v1/data_retention \
-          -H "x-api-key: $BEDROCK_API_KEY" \
-          -H "Content-Type: application/json" \
-          -d '{ "mode": "provider_data_share" }'
-        ```
-
-        Use another Bedrock model in the config if you cannot accept that retention mode.
-      </Step>
       <Step title="Add a Bedrock provider and model to your config">
         No `apiKey` is required. Configure the provider with `auth: "aws-sdk"`:
 
diff --git a/extensions/amazon-bedrock/stream.runtime.test.ts b/extensions/amazon-bedrock/stream.runtime.test.ts
@@ -182,6 +182,21 @@ describe("Bedrock thinking effort mapping", () => {
     });
   });
 
+  it("forces adaptive thinking for Bedrock Mythos Preview when callers omit reasoning", () => {
+    const model = bedrockModel({
+      id: "us.anthropic.claude-mythos-preview",
+      name: "US Claude Mythos Preview",
+      reasoning: true,
+    });
+    const options = testing.resolveSimpleBedrockOptions(model, {});
+
+    expect(options.reasoning).toBe("high");
+    expect(testing.buildAdditionalModelRequestFields(model, options)).toEqual({
+      thinking: { type: "adaptive", display: "summarized" },
+      output_config: { effort: "high" },
+    });
+  });
+
   it("clamps max effort for Claude models without native max support", () => {
     expect(
       testing.mapThinkingLevelToEffort(
diff --git a/extensions/amazon-bedrock/stream.runtime.ts b/extensions/amazon-bedrock/stream.runtime.ts
@@ -563,23 +563,39 @@ function resolveClaudeProfileNameModelId(modelName?: string): string | undefined
   if (!normalized.includes("claude")) {
     return undefined;
   }
-  const family = /(?:fable-5|opus-4-(?:6|7|8)|sonnet-4-6)(?:$|-)/.exec(normalized)?.[0];
+  const family = /(?:fable-5|mythos-preview|opus-4-(?:6|7|8)|sonnet-4-6)(?:$|-)/.exec(
+    normalized,
+  )?.[0];
   return family ? `claude-${family.replace(/-$/, "")}` : undefined;
 }
 
+function isClaudeMythosPreviewModelId(modelId?: string): boolean {
+  return /(?:^|-)claude-mythos-preview(?=$|[^a-z0-9])/.test(
+    modelId
+      ?.trim()
+      .toLowerCase()
+      .replace(/[\s_.:]+/g, "-") ?? "",
+  );
+}
+
 /** Check canonical metadata and profile names for adaptive Claude support. */
 function supportsAdaptiveThinking(model: Model<"bedrock-converse-stream">): boolean {
   const profileModelId = resolveClaudeProfileNameModelId(model.name);
   return (
-    supportsClaudeAdaptiveThinking(model) || supportsClaudeAdaptiveThinking({ id: profileModelId })
+    supportsClaudeAdaptiveThinking(model) ||
+    supportsClaudeAdaptiveThinking({ id: profileModelId }) ||
+    isClaudeMythosPreviewModelId(resolveClaudeModelIdentity(model)) ||
+    isClaudeMythosPreviewModelId(profileModelId)
   );
 }
 
 function requiresMandatoryAdaptiveThinking(model: Model<"bedrock-converse-stream">): boolean {
   const profileModelId = resolveClaudeProfileNameModelId(model.name);
   return (
     isClaudeAdaptiveThinkingDefaultModelId(resolveClaudeModelIdentity(model)) ||
-    (profileModelId ? isClaudeAdaptiveThinkingDefaultModelId(profileModelId) : false)
+    (profileModelId ? isClaudeAdaptiveThinkingDefaultModelId(profileModelId) : false) ||
+    isClaudeMythosPreviewModelId(resolveClaudeModelIdentity(model)) ||
+    isClaudeMythosPreviewModelId(profileModelId)
   );
 }
 
diff --git a/src/llm/providers/anthropic.test.ts b/src/llm/providers/anthropic.test.ts
@@ -535,6 +535,36 @@ describe("Anthropic provider", () => {
     });
   });
 
+  it("uses adaptive thinking for Foundry Mythos Preview without native max metadata", async () => {
+    let capturedPayload: unknown;
+    const stream = streamSimpleAnthropic(
+      makeAnthropicModel({
+        id: "prod-mythos-preview",
+        name: "claude-mythos-preview",
+        provider: "microsoft-foundry",
+        reasoning: true,
+      }),
+      {
+        messages: [{ role: "user", content: "hello", timestamp: 0 }],
+      },
+      {
+        apiKey: "sk-ant-provider",
+        reasoning: "high",
+        onPayload: (payload) => {
+          capturedPayload = payload;
+          throw new Error("stop before network");
+        },
+      },
+    );
+
+    await stream.result();
+
+    expect(capturedPayload).toMatchObject({
+      thinking: { type: "adaptive" },
+      output_config: { effort: "high" },
+    });
+  });
+
   it.each([
     {
       id: "prod-primary",
diff --git a/src/llm/providers/anthropic.ts b/src/llm/providers/anthropic.ts
@@ -807,7 +807,24 @@ function normalizeAnthropicToolChoice(
  * Check if a model supports adaptive thinking (Fable 5, Opus 4.6+, Sonnet 4.6).
  */
 function supportsAdaptiveThinking(model: Model<"anthropic-messages">): boolean {
-  return supportsClaudeAdaptiveThinking(model) || model.thinkingLevelMap?.max === "max";
+  return (
+    supportsClaudeAdaptiveThinking(model) ||
+    model.thinkingLevelMap?.max === "max" ||
+    isClaudeMythosPreviewModel(model)
+  );
+}
+
+function isClaudeMythosPreviewModel(model: Model<"anthropic-messages">): boolean {
+  return [model.id, model.name, model.params?.canonicalModelId]
+    .filter((value): value is string => typeof value === "string")
+    .some((value) =>
+      /(?:^|-)claude-mythos-preview(?=$|[^a-z0-9])/.test(
+        value
+          .trim()
+          .toLowerCase()
+          .replace(/[\s_.:]+/g, "-"),
+      ),
+    );
 }
 
 function supportsNativeXhighEffort(model: Model<"anthropic-messages">): boolean {
