diff --git a/src/adapters/kiro.ts b/src/adapters/kiro.ts
index 8d022c2d7..1f093b391 100644
--- a/src/adapters/kiro.ts
+++ b/src/adapters/kiro.ts
@@ -52,6 +52,24 @@ const AMZ_TARGET = "AmazonCodeWhispererStreamingService.GenerateAssistantRespons
 const SDK_VERSION = "1.0.27";
 const NODE_VERSION = "22.21.1";
 const KIRO_IDE_VERSION = "1.0.0";
+type KiroWireClient = "ide" | "cli";
+
+function kiroCliPlatform(): "linux" | "macos" | "windows" {
+  return process.platform === "win32" ? "windows" : process.platform === "darwin" ? "macos" : "linux";
+}
+
+function kiroCliUserAgent(includeAppVersion: boolean): string {
+  return [
+    "aws-sdk-rust/1.3.15",
+    "ua/2.1",
+    "api/codewhispererstreaming/0.1.17975",
+    `os/${kiroCliPlatform()}`,
+    "lang/rust/1.92.0",
+    ...(includeAppVersion ? ["md/appVersion-2.14.2"] : []),
+    "m/F",
+    "app/AmazonQ-For-CLI",
+  ].join(" ");
+}
 
 // Payload construction (conversationState)
 interface KiroToolUse {
@@ -68,7 +86,10 @@ interface KiroUserInputMessage {
   content: string;
   modelId?: string;
   origin?: string;
-  userInputMessageContext?: { tools?: unknown[]; toolResults?: KiroToolResult[] };
+  userInputMessageContext?: {
+    tools?: unknown[];
+    toolResults?: KiroToolResult[];
+  };
   images?: KiroImage[];
 }
 interface KiroHistoryEntry {
@@ -385,6 +406,7 @@ export function buildKiroPayload(
   parsed: OcxParsedRequest,
   profileArn: string | undefined,
   forcedCompletionMode?: KiroCompletionMode,
+  wireClient: KiroWireClient = "ide",
 ): {
   payload: Record<string, unknown>;
   nameMap: Map<string, string>;
@@ -509,7 +531,7 @@ export function buildKiroPayload(
         userInputMessage: {
           content: turn.content,
           modelId,
-          origin: "AI_EDITOR",
+          origin: wireClient === "cli" ? "KIRO_CLI" : "AI_EDITOR",
           ...(turn.images.length > 0 ? { images: turn.images } : {}),
           ...(turn.toolResults.length > 0 ? { userInputMessageContext: { toolResults: turn.toolResults } } : {}),
         },
@@ -539,6 +561,10 @@ export function buildKiroPayload(
   const payload: Record<string, unknown> = {
     conversationState: {
       chatTriggerType: "MANUAL",
+      ...(wireClient === "cli" ? {
+        agentContinuationId: crypto.randomUUID(),
+        agentTaskType: "vibe",
+      } : {}),
       conversationId,
       currentMessage: { userInputMessage: currentUim },
       ...(history.length > 0 ? { history } : {}),
@@ -1446,9 +1472,25 @@ export function createKiroAdapter(provider: OcxProviderConfig): ProviderAdapter
       throw new Error("kiro token missing — run ocx login kiro");
     }
     const region = resolveKiroApiRegion(parsed._kiroAuthContext);
-    const profileArn = resolveKiroProfileArn(parsed._kiroAuthContext);
+    const resolvedProfileArn = resolveKiroProfileArn(parsed._kiroAuthContext);
+    const isApiKey = provider.apiKey.trim().startsWith("ksk_");
+    const profileArn = isApiKey ? undefined : resolvedProfileArn;
+    // Builder ID and Kiro API keys have no profile ARN and are accepted only on Kiro's CLI
+    // request path. Enterprise profiles retain the existing IDE-shaped request.
+    const wireClient: KiroWireClient = isApiKey || !profileArn ? "cli" : "ide";
     const fp = fingerprint().slice(0, 64);
-    const headers: Record<string, string> = {
+    const headers: Record<string, string> = wireClient === "cli" ? {
+      authorization: `Bearer ${provider.apiKey}`,
+      "content-type": "application/x-amz-json-1.0",
+      accept: "*/*",
+      "x-amz-target": AMZ_TARGET,
+      "user-agent": kiroCliUserAgent(true),
+      "x-amz-user-agent": kiroCliUserAgent(false),
+      "x-amzn-codewhisperer-optout": "true",
+      "amz-sdk-request": "attempt=1; max=3",
+      "amz-sdk-invocation-id": invocationId(),
+      ...(isApiKey ? { tokentype: "API_KEY" } : {}),
+    } : {
       authorization: `Bearer ${provider.apiKey}`,
       "content-type": "application/x-amz-json-1.0",
       accept: "application/vnd.amazon.eventstream",
@@ -1460,7 +1502,7 @@ export function createKiroAdapter(provider: OcxProviderConfig): ProviderAdapter
       "amz-sdk-invocation-id": invocationId(),
     };
     if (profileArn) headers["x-amzn-kiro-profile-arn"] = profileArn;
-    const built = buildKiroPayload(parsed, profileArn, forcedCompletionMode);
+    const built = buildKiroPayload(parsed, profileArn, forcedCompletionMode, wireClient);
     await normalizeKiroImages(built.payload);
     const contextInputEstimate = estimateKiroPayloadInputTokens(built.payload, parsed.modelId);
     const body = JSON.stringify(built.payload);
@@ -1472,6 +1514,7 @@ export function createKiroAdapter(provider: OcxProviderConfig): ProviderAdapter
       messageCount: kiroPayloadMessages(parsed).length,
       toolCount: parsed.context.tools?.length ?? 0,
       hasProfileArn: Boolean(profileArn),
+      wireClient,
       hasPreviousResponseId: Boolean(parsed.previousResponseId),
     });
     return {
diff --git a/tests/kiro-adapter.test.ts b/tests/kiro-adapter.test.ts
index 62e578279..b2ad63731 100644
--- a/tests/kiro-adapter.test.ts
+++ b/tests/kiro-adapter.test.ts
@@ -73,14 +73,53 @@ describe("kiro adapter — buildRequest", () => {
     }
   });
 
-  test("headers carry Bearer token + CW targets", async () => {
-    const { url, method, headers } = await createKiroAdapter(provider).buildRequest(parsedWith([{ role: "user", content: "hi" }]));
+  test("Builder ID requests without a profile ARN use the Kiro CLI wire contract", async () => {
+    const { url, method, headers, body } = await createKiroAdapter(provider).buildRequest(parsedWith([{ role: "user", content: "hi" }]));
+    const payload = JSON.parse(body) as {
+      profileArn?: string;
+      conversationState: {
+        agentContinuationId?: string;
+        agentTaskType?: string;
+        currentMessage: { userInputMessage: Record<string, unknown> };
+      };
+    };
     expect(url).toBe("https://runtime.us-east-1.kiro.dev/");
     expect(method).toBe("POST");
     expect(headers.authorization).toBe("Bearer tok-123");
     expect(headers["x-amz-target"]).toBe("AmazonCodeWhispererStreamingService.GenerateAssistantResponse");
-    expect(headers.accept).toBe("application/vnd.amazon.eventstream");
-    expect(headers["x-amzn-kiro-agent-mode"]).toBe("vibe");
+    expect(headers.accept).toBe("*/*");
+    expect(headers["user-agent"]).toContain("app/AmazonQ-For-CLI");
+    expect(headers["x-amzn-kiro-agent-mode"]).toBeUndefined();
+    expect(headers["x-amzn-kiro-profile-arn"]).toBeUndefined();
+    expect(headers["x-amzn-codewhisperer-optout"]).toBe("true");
+    expect(headers.tokentype).toBeUndefined();
+    expect(payload.profileArn).toBeUndefined();
+    expect(payload.conversationState.agentTaskType).toBe("vibe");
+    expect(payload.conversationState.agentContinuationId).toMatch(/^[0-9a-f-]{36}$/);
+    expect(payload.conversationState.currentMessage.userInputMessage).toMatchObject({
+      content: "hi",
+      origin: "KIRO_CLI",
+    });
+    expect(payload.conversationState.currentMessage.userInputMessage).not.toHaveProperty("userInputMessageContext.envState");
+  });
+
+  test("Kiro API keys force the CLI token type and ignore unrelated profile metadata", async () => {
+    const apiKeyProvider = { ...provider, authMode: "key", apiKey: "ksk_example" } as unknown as OcxProviderConfig;
+    const parsed = parsedWith([{ role: "user", content: "hi" }]);
+    parsed._kiroAuthContext = {
+      profileArn: "arn:aws:codewhisperer:us-east-1:123456789012:profile/unrelated",
+    };
+    const request = await createKiroAdapter(apiKeyProvider).buildRequest(parsed);
+    const body = JSON.parse(request.body) as {
+      profileArn?: string;
+      conversationState: { currentMessage: { userInputMessage: { origin?: string } } };
+    };
+
+    expect(request.headers.authorization).toBe("Bearer ksk_example");
+    expect(request.headers.tokentype).toBe("API_KEY");
+    expect(request.headers["x-amzn-kiro-profile-arn"]).toBeUndefined();
+    expect(body.profileArn).toBeUndefined();
+    expect(body.conversationState.currentMessage.userInputMessage.origin).toBe("KIRO_CLI");
   });
 
   test("runtime URL uses KIRO_API_REGION separately from auth region", async () => {
@@ -104,6 +143,8 @@ describe("kiro adapter — buildRequest", () => {
 
     expect(request.url).toBe("https://runtime.eu-central-1.kiro.dev/");
     expect(request.headers["x-amzn-kiro-profile-arn"]).toBe(parsed._kiroAuthContext.profileArn);
+    expect(request.headers.accept).toBe("application/vnd.amazon.eventstream");
+    expect(request.headers["x-amzn-kiro-agent-mode"]).toBe("vibe");
     expect(body.profileArn).toBe(parsed._kiroAuthContext.profileArn);
   });
 
@@ -668,7 +709,7 @@ describe("kiro adapter — buildRequest", () => {
     ];
     const cs = JSON.parse((await createKiroAdapter(provider).buildRequest(parsedWith(messages))).body).conversationState;
     expect(cs.history).toEqual([
-      { userInputMessage: { content: "first\n\nsecond", modelId: "claude-sonnet-4.5", origin: "AI_EDITOR" } },
+      { userInputMessage: { content: "first\n\nsecond", modelId: "claude-sonnet-4.5", origin: "KIRO_CLI" } },
       { assistantResponseMessage: { content: "one\n\ntwo" } },
     ]);
     expect(cs.currentMessage.userInputMessage.content).toBe("third");