diff --git a/open-sse/config/kiroConstants.js b/open-sse/config/kiroConstants.js
index 3ff6acbbfa..cbc104bcc4 100644
--- a/open-sse/config/kiroConstants.js
+++ b/open-sse/config/kiroConstants.js
@@ -38,6 +38,46 @@ export function resolveDefaultProfileArn(authMethod) {
   return social ? KIRO_DEFAULT_PROFILE_ARNS.social : KIRO_DEFAULT_PROFILE_ARNS["builder-id"];
 }
 
+// ─── Regional CodeWhisperer endpoints ───────────────────────────────────────
+// Kiro historically assumed us-east-1 everywhere. IAM Identity Center (IdC)
+// accounts can be homed in another region (e.g. eu-central-1); their token is
+// rejected with 403 "bearer token invalid" by the us-east-1 endpoints, and
+// their CodeWhisperer profile is only visible from the regional Amazon Q host.
+// These helpers thread `providerSpecificData.region` through, defaulting to
+// us-east-1 so existing Builder ID / social accounts are unaffected.
+
+export const KIRO_DEFAULT_REGION = "us-east-1";
+
+/** Normalize a Kiro region, falling back to us-east-1. */
+export function resolveKiroRegion(region) {
+  const r = typeof region === "string" ? region.trim() : "";
+  return r || KIRO_DEFAULT_REGION;
+}
+
+/**
+ * Data-plane (generateAssistantResponse) URL for a region.
+ * Returns null for us-east-1 so callers keep the historical registry baseUrls
+ * (runtime.kiro.dev → codewhisperer → q). Other regions use the regional
+ * Amazon Q endpoint, the only host that resolves + accepts their token.
+ */
+export function resolveKiroDataPlaneUrl(region) {
+  const r = resolveKiroRegion(region);
+  if (r === KIRO_DEFAULT_REGION) return null;
+  return `https://q.${r}.amazonaws.com/generateAssistantResponse`;
+}
+
+/**
+ * Control-plane host (ListAvailableProfiles / GetUsageLimits) for a region.
+ * us-east-1 keeps the historical codewhisperer host; other regions use the
+ * regional Amazon Q host.
+ */
+export function resolveKiroControlPlaneHost(region) {
+  const r = resolveKiroRegion(region);
+  return r === KIRO_DEFAULT_REGION
+    ? "https://codewhisperer.us-east-1.amazonaws.com"
+    : `https://q.${r}.amazonaws.com`;
+}
+
 export const KIRO_THINKING_BUDGET_DEFAULT = 16000;
 
 export const KIRO_AGENTIC_SYSTEM_PROMPT = `
diff --git a/open-sse/executors/kiro.js b/open-sse/executors/kiro.js
index 3034f725f9..bd7a9ce894 100644
--- a/open-sse/executors/kiro.js
+++ b/open-sse/executors/kiro.js
@@ -2,6 +2,7 @@ import { BaseExecutor } from "./base.js";
 import { PROVIDERS } from "../config/providers.js";
 import { v4 as uuidv4 } from "uuid";
 import { refreshKiroToken } from "../services/tokenRefresh.js";
+import { resolveKiroDataPlaneUrl } from "../config/kiroConstants.js";
 import { SSE_DONE, SSE_HEADERS } from "../utils/sseConstants.js";
 
 /**
@@ -51,6 +52,13 @@ export class KiroExecutor extends BaseExecutor {
    * (kiro.dev first) since its token is what that gateway accepts.
    */
   getOrderedBaseUrls(credentials) {
+    // IAM Identity Center accounts can be homed outside us-east-1. Their token is
+    // rejected by the hardcoded us-east-1 registry baseUrls (403 "bearer token
+    // invalid"), so route to the account's regional Amazon Q endpoint. us-east-1
+    // (Builder ID / social / unset) keeps the registry baseUrls + 429 rotation.
+    const regional = resolveKiroDataPlaneUrl(credentials?.providerSpecificData?.region);
+    if (regional) return [regional];
+
     const baseUrls = this.getBaseUrls();
     const isApiKey = credentials?.providerSpecificData?.authMethod === "api_key";
     if (!isApiKey) return baseUrls;
diff --git a/open-sse/services/tokenRefresh/providers.js b/open-sse/services/tokenRefresh/providers.js
index b8352156bb..8929cc1a33 100644
--- a/open-sse/services/tokenRefresh/providers.js
+++ b/open-sse/services/tokenRefresh/providers.js
@@ -296,7 +296,7 @@ async function resolveKiroProfileArnPatch(providerSpecificData, accessToken, ref
   let profileArn = refreshedArn?.trim?.() || null;
   if (!profileArn) {
     const { fetchKiroProfileArn } = await import("../../../src/lib/oauth/providers.js");
-    profileArn = await fetchKiroProfileArn(accessToken);
+    profileArn = await fetchKiroProfileArn(accessToken, providerSpecificData?.region);
   }
   return profileArn ? { providerSpecificData: { profileArn } } : {};
 }
diff --git a/open-sse/services/usage/kiro.js b/open-sse/services/usage/kiro.js
index fb22156567..e2d2399ff9 100644
--- a/open-sse/services/usage/kiro.js
+++ b/open-sse/services/usage/kiro.js
@@ -3,7 +3,7 @@
  */
 
 import { proxyAwareFetch } from "../../utils/proxyFetch.js";
-import { resolveDefaultProfileArn } from "../../config/kiroConstants.js";
+import { resolveDefaultProfileArn, resolveKiroRegion, resolveKiroControlPlaneHost, KIRO_DEFAULT_REGION } from "../../config/kiroConstants.js";
 import { U, parseResetTime } from "./shared.js";
 
 /**
@@ -70,12 +70,20 @@ export async function getKiroUsage(accessToken, providerSpecificData, proxyOptio
     resourceType: "AGENTIC_REQUEST",
   });
 
+  // Region-aware usage hosts. us-east-1 keeps the historical codewhisperer/q
+  // hosts from the registry; other regions (IdC accounts) use the regional
+  // Amazon Q host so the GetUsageLimits call isn't rejected with 403.
+  const isDefaultRegion = resolveKiroRegion(providerSpecificData?.region) === KIRO_DEFAULT_REGION;
+  const cwHost = isDefaultRegion ? U("kiro").cwHost : resolveKiroControlPlaneHost(providerSpecificData?.region);
+  const qHost = isDefaultRegion ? U("kiro").qHost : resolveKiroControlPlaneHost(providerSpecificData?.region);
+  const limitsPath = U("kiro").limitsPath;
+
   // For compatibility, try multiple known Kiro usage endpoints
   const attempts = [
     {
       name: "codewhisperer-get",
       run: async () => proxyAwareFetch(
-        `${U("kiro").cwHost}${U("kiro").limitsPath}?${getUsageParams.toString()}`,
+        `${cwHost}${limitsPath}?${getUsageParams.toString()}`,
         {
           method: "GET",
           headers: {
@@ -91,7 +99,7 @@ export async function getKiroUsage(accessToken, providerSpecificData, proxyOptio
     },
     {
       name: "codewhisperer-post",
-      run: async () => proxyAwareFetch(U("kiro").cwHost, {
+      run: async () => proxyAwareFetch(cwHost, {
         method: "POST",
         headers: {
           "Authorization": `Bearer ${accessToken}`,
@@ -115,7 +123,7 @@ export async function getKiroUsage(accessToken, providerSpecificData, proxyOptio
           ...(profileArn ? { profileArn } : {}),
           resourceType: "AGENTIC_REQUEST",
         });
-        return proxyAwareFetch(`${U("kiro").qHost}${U("kiro").limitsPath}?${params}`, {
+        return proxyAwareFetch(`${qHost}${limitsPath}?${params}`, {
           method: "GET",
           headers: {
             "Authorization": `Bearer ${accessToken}`,
diff --git a/src/lib/oauth/providerHelpers.js b/src/lib/oauth/providerHelpers.js
index 0cb46933b5..1f2cef4e6c 100644
--- a/src/lib/oauth/providerHelpers.js
+++ b/src/lib/oauth/providerHelpers.js
@@ -50,10 +50,17 @@ function extractEmailFromAccessToken(accessToken) {
   return payload.email || payload.preferred_username || payload.sub || undefined;
 }
 
-export async function fetchKiroProfileArn(accessToken) {
+export async function fetchKiroProfileArn(accessToken, region) {
   if (!accessToken) return null;
+  // IdC accounts homed outside us-east-1 only expose their CodeWhisperer profile
+  // via the regional Amazon Q host; us-east-1 returns an empty profile list for
+  // them. Default to the historical us-east-1 codewhisperer host.
+  const normalizedRegion = typeof region === "string" && region.trim() ? region.trim() : "us-east-1";
+  const host = normalizedRegion === "us-east-1"
+    ? "https://codewhisperer.us-east-1.amazonaws.com"
+    : `https://q.${normalizedRegion}.amazonaws.com`;
   try {
-    const response = await fetch("https://codewhisperer.us-east-1.amazonaws.com/ListAvailableProfiles", {
+    const response = await fetch(`${host}/ListAvailableProfiles`, {
       method: "POST",
       headers: {
         "Content-Type": "application/json",
diff --git a/src/lib/oauth/providers.js b/src/lib/oauth/providers.js
index c66d25bbdc..e567ce3cdf 100644
--- a/src/lib/oauth/providers.js
+++ b/src/lib/oauth/providers.js
@@ -1362,7 +1362,7 @@ export async function pollForToken(providerName, deviceCode, codeVerifier, extra
       const tokens = provider.mapTokens(result.data, extra);
       // Kiro IDC/Builder-ID tokens lack profileArn; resolve it to avoid 403
       if (providerName === "kiro" && !tokens.providerSpecificData?.profileArn) {
-        const profileArn = await fetchKiroProfileArn(tokens.accessToken);
+        const profileArn = await fetchKiroProfileArn(tokens.accessToken, tokens.providerSpecificData?.region);
         if (profileArn) tokens.providerSpecificData.profileArn = profileArn;
       }
       return { success: true, tokens };
diff --git a/tests/unit/kiro-region.test.js b/tests/unit/kiro-region.test.js
new file mode 100644
index 0000000000..084a632c97
--- /dev/null
+++ b/tests/unit/kiro-region.test.js
@@ -0,0 +1,91 @@
+import { describe, it, expect, vi, afterEach } from "vitest";
+import {
+  resolveKiroRegion,
+  resolveKiroDataPlaneUrl,
+  resolveKiroControlPlaneHost,
+  KIRO_DEFAULT_REGION,
+} from "../../open-sse/config/kiroConstants.js";
+import { KiroExecutor } from "../../open-sse/executors/kiro.js";
+import { fetchKiroProfileArn } from "../../src/lib/oauth/providerHelpers.js";
+
+/**
+ * Regression tests for multi-region Kiro / CodeWhisperer support.
+ *
+ * Background: Kiro assumed us-east-1 for the data plane, profile resolution and
+ * usage. IAM Identity Center accounts homed elsewhere (e.g. eu-central-1) are
+ * rejected with 403 "bearer token invalid" by the us-east-1 hosts, and their
+ * CodeWhisperer profile is only visible from the regional Amazon Q endpoint.
+ * The region (stored in providerSpecificData.region by the IdC device flow) now
+ * drives those endpoints, defaulting to us-east-1 for existing accounts.
+ */
+describe("kiro region helpers", () => {
+  it("defaults to us-east-1 and trims input", () => {
+    expect(resolveKiroRegion()).toBe(KIRO_DEFAULT_REGION);
+    expect(resolveKiroRegion("")).toBe("us-east-1");
+    expect(resolveKiroRegion("  eu-central-1  ")).toBe("eu-central-1");
+  });
+
+  it("returns null data-plane URL for us-east-1 (keep registry baseUrls)", () => {
+    expect(resolveKiroDataPlaneUrl()).toBeNull();
+    expect(resolveKiroDataPlaneUrl("us-east-1")).toBeNull();
+  });
+
+  it("returns the regional Amazon Q data-plane URL for other regions", () => {
+    expect(resolveKiroDataPlaneUrl("eu-central-1")).toBe(
+      "https://q.eu-central-1.amazonaws.com/generateAssistantResponse"
+    );
+  });
+
+  it("resolves the control-plane host per region", () => {
+    expect(resolveKiroControlPlaneHost("us-east-1")).toBe(
+      "https://codewhisperer.us-east-1.amazonaws.com"
+    );
+    expect(resolveKiroControlPlaneHost("eu-central-1")).toBe(
+      "https://q.eu-central-1.amazonaws.com"
+    );
+  });
+});
+
+describe("KiroExecutor.buildUrl region routing", () => {
+  it("keeps the us-east-1 registry baseUrl when no/default region", () => {
+    const ex = new KiroExecutor();
+    const url = ex.buildUrl("claude-sonnet-4.5", true, 0, { providerSpecificData: {} });
+    expect(url).toBe("https://runtime.us-east-1.kiro.dev/generateAssistantResponse");
+  });
+
+  it("routes to the regional Amazon Q endpoint for a non-default region", () => {
+    const ex = new KiroExecutor();
+    const url = ex.buildUrl("claude-opus-4.8", true, 0, {
+      providerSpecificData: { region: "eu-central-1" },
+    });
+    expect(url).toBe("https://q.eu-central-1.amazonaws.com/generateAssistantResponse");
+  });
+});
+
+describe("fetchKiroProfileArn region host", () => {
+  afterEach(() => vi.restoreAllMocks());
+
+  it("queries us-east-1 codewhisperer by default", async () => {
+    const fetchMock = vi.spyOn(globalThis, "fetch").mockResolvedValue({
+      ok: true,
+      json: async () => ({ profiles: [{ arn: "arn:aws:codewhisperer:us-east-1:1:profile/X" }] }),
+    });
+    const arn = await fetchKiroProfileArn("token");
+    expect(arn).toBe("arn:aws:codewhisperer:us-east-1:1:profile/X");
+    expect(fetchMock.mock.calls[0][0]).toBe(
+      "https://codewhisperer.us-east-1.amazonaws.com/ListAvailableProfiles"
+    );
+  });
+
+  it("queries the regional Amazon Q host for a non-default region", async () => {
+    const fetchMock = vi.spyOn(globalThis, "fetch").mockResolvedValue({
+      ok: true,
+      json: async () => ({ profiles: [{ arn: "arn:aws:codewhisperer:eu-central-1:2:profile/Y" }] }),
+    });
+    const arn = await fetchKiroProfileArn("token", "eu-central-1");
+    expect(arn).toBe("arn:aws:codewhisperer:eu-central-1:2:profile/Y");
+    expect(fetchMock.mock.calls[0][0]).toBe(
+      "https://q.eu-central-1.amazonaws.com/ListAvailableProfiles"
+    );
+  });
+});