diff --git a/packages/ai/src/utils/oauth/openai-codex.ts b/packages/ai/src/utils/oauth/openai-codex.ts
index 0bc705a5..62c4c352 100644
--- a/packages/ai/src/utils/oauth/openai-codex.ts
+++ b/packages/ai/src/utils/oauth/openai-codex.ts
@@ -30,7 +30,7 @@ const SCOPE = "openid profile email offline_access";
 const JWT_CLAIM_PATH = "https://api.openai.com/auth";
 
 type TokenSuccess = { type: "success"; access: string; refresh: string; expires: number };
-type TokenFailure = { type: "failed" };
+type TokenFailure = { type: "failed"; message: string; status?: number };
 type TokenResult = TokenSuccess | TokenFailure;
 
 type JwtPayload = {
@@ -108,8 +108,11 @@ async function exchangeAuthorizationCode(
 
 	if (!response.ok) {
 		const text = await response.text().catch(() => "");
-		console.error("[openai-codex] code->token failed:", response.status, text);
-		return { type: "failed" };
+		return {
+			type: "failed",
+			status: response.status,
+			message: `OpenAI Codex token exchange failed (${response.status}): ${text || response.statusText}`,
+		};
 	}
 
 	const json = (await response.json()) as {
@@ -119,8 +122,10 @@ async function exchangeAuthorizationCode(
 	};
 
 	if (!json.access_token || !json.refresh_token || typeof json.expires_in !== "number") {
-		console.error("[openai-codex] token response missing fields:", json);
-		return { type: "failed" };
+		return {
+			type: "failed",
+			message: `OpenAI Codex token exchange response missing fields: ${JSON.stringify(json)}`,
+		};
 	}
 
 	return {
@@ -145,8 +150,11 @@ async function refreshAccessToken(refreshToken: string): Promise<TokenResult> {
 
 		if (!response.ok) {
 			const text = await response.text().catch(() => "");
-			console.error("[openai-codex] Token refresh failed:", response.status, text);
-			return { type: "failed" };
+			return {
+				type: "failed",
+				status: response.status,
+				message: `OpenAI Codex token refresh failed (${response.status}): ${text || response.statusText}`,
+			};
 		}
 
 		const json = (await response.json()) as {
@@ -156,8 +164,10 @@ async function refreshAccessToken(refreshToken: string): Promise<TokenResult> {
 		};
 
 		if (!json.access_token || !json.refresh_token || typeof json.expires_in !== "number") {
-			console.error("[openai-codex] Token refresh response missing fields:", json);
-			return { type: "failed" };
+			return {
+				type: "failed",
+				message: `OpenAI Codex token refresh response missing fields: ${JSON.stringify(json)}`,
+			};
 		}
 
 		return {
@@ -167,8 +177,10 @@ async function refreshAccessToken(refreshToken: string): Promise<TokenResult> {
 			expires: Date.now() + json.expires_in * 1000,
 		};
 	} catch (error) {
-		console.error("[openai-codex] Token refresh error:", error);
-		return { type: "failed" };
+		return {
+			type: "failed",
+			message: `OpenAI Codex token refresh error: ${error instanceof Error ? error.message : String(error)}`,
+		};
 	}
 }
 
@@ -258,12 +270,7 @@ function startLocalOAuthServer(state: string): Promise<OAuthServerInfo> {
 					waitForCode: () => waitForCodePromise,
 				});
 			})
-			.on("error", (err: NodeJS.ErrnoException) => {
-				console.error(
-					`[openai-codex] Failed to bind http://${CALLBACK_HOST}:1455 (`,
-					err.code,
-					") Falling back to manual paste.",
-				);
+			.on("error", (_err: NodeJS.ErrnoException) => {
 				settleWait?.(null);
 				resolve({
 					close: () => {
@@ -386,7 +393,7 @@ export async function loginOpenAICodex(options: {
 
 		const tokenResult = await exchangeAuthorizationCode(code, verifier);
 		if (tokenResult.type !== "success") {
-			throw new Error("Token exchange failed");
+			throw new Error(tokenResult.message);
 		}
 
 		const accountId = getAccountId(tokenResult.access);
@@ -411,7 +418,7 @@ export async function loginOpenAICodex(options: {
 export async function refreshOpenAICodexToken(refreshToken: string): Promise<OAuthCredentials> {
 	const result = await refreshAccessToken(refreshToken);
 	if (result.type !== "success") {
-		throw new Error("Failed to refresh OpenAI Codex token");
+		throw new Error(result.message);
 	}
 
 	const accountId = getAccountId(result.access);
diff --git a/packages/ai/test/openai-codex-oauth.test.ts b/packages/ai/test/openai-codex-oauth.test.ts
new file mode 100644
index 00000000..276abe1b
--- /dev/null
+++ b/packages/ai/test/openai-codex-oauth.test.ts
@@ -0,0 +1,32 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { refreshOpenAICodexToken } from "../src/utils/oauth/openai-codex.js";
+
+describe("OpenAI Codex OAuth", () => {
+	afterEach(() => {
+		vi.restoreAllMocks();
+		vi.unstubAllGlobals();
+	});
+
+	it("does not write token refresh failures to stderr", async () => {
+		const consoleError = vi.spyOn(console, "error").mockImplementation(() => {});
+		vi.stubGlobal(
+			"fetch",
+			vi.fn(async (): Promise<Response> => {
+				return new Response(
+					JSON.stringify({
+						error: {
+							message: "Could not validate your token. Please try signing in again.",
+							type: "invalid_request_error",
+						},
+					}),
+					{ status: 401, statusText: "Unauthorized", headers: { "Content-Type": "application/json" } },
+				);
+			}),
+		);
+
+		await expect(refreshOpenAICodexToken("invalid-refresh-token")).rejects.toThrow(
+			/OpenAI Codex token refresh failed \(401\).*Could not validate your token/,
+		);
+		expect(consoleError).not.toHaveBeenCalled();
+	});
+});