diff --git a/src/auth/oauth-provider.test.ts b/src/auth/oauth-provider.test.ts
index 32126a9f..4fb12e76 100644
--- a/src/auth/oauth-provider.test.ts
+++ b/src/auth/oauth-provider.test.ts
@@ -1985,7 +1985,7 @@ describe('ExternalOAuthProvider', () => {
       await provider.handleCallback(mockReq, mockRes);
 
       expect(mockRes.status).toHaveBeenCalledWith(500);
-      expect(mockRes.send).toHaveBeenCalledWith('Internal Server Error during token exchange');
+      expect(mockRes.send).toHaveBeenCalledWith(expect.stringMatching(/^Internal Server Error during token exchange \(correlation ID: [a-f0-9-]+\)$/));
     });
   });
 
diff --git a/src/auth/oauth-provider.ts b/src/auth/oauth-provider.ts
index 981e4aad..a66da933 100644
--- a/src/auth/oauth-provider.ts
+++ b/src/auth/oauth-provider.ts
@@ -36,6 +36,7 @@ import {
   PROXY_CREDENTIALS,
 } from '../core/constants.js';
 import { escapeHtmlSafe } from '../validation/validation-utils.js';
+import { generateCorrelationId } from '../core/errors.js';
 import { SSRFValidator } from '../security/ssrf-validator.js';
 import { parseOAuthMetadataEndpoints } from './oauth-metadata.js';
 import { InMemoryClientsStore } from './client-store/in-memory-clients-store.js';
@@ -867,8 +868,9 @@ export class ExternalOAuthProvider implements OAuthServerProvider {
         res.redirect(clientUrl.toString());
 
     } catch (err) {
-        this.logger.error('Callback handling failed', err as Error);
-        res.status(500).send('Internal Server Error during token exchange');
+        const correlationId = generateCorrelationId();
+        this.logger.error('Callback handling failed', err as Error, { correlationId });
+        res.status(500).send(`Internal Server Error during token exchange (correlation ID: ${correlationId})`);
     }
   }
 
diff --git a/src/transport/http-transport.test.ts b/src/transport/http-transport.test.ts
index f14646e1..d68f6575 100644
--- a/src/transport/http-transport.test.ts
+++ b/src/transport/http-transport.test.ts
@@ -2340,7 +2340,7 @@ describeIfListen('HttpTransport', () => {
         .query({ code: 'test-code' });
 
       expect(response.status).toBe(500);
-      expect(response.text).toBe('OAuth callback failed');
+      expect(response.text).toMatch(/^OAuth callback failed \(correlation ID: [a-f0-9-]+\)$/);
     });
   });
 
diff --git a/src/transport/http-transport.ts b/src/transport/http-transport.ts
index 263fea71..096f8b1f 100644
--- a/src/transport/http-transport.ts
+++ b/src/transport/http-transport.ts
@@ -1814,8 +1814,9 @@ export class HttpTransport {
 
       await profileState.oauthProvider.authorize(client, params, res);
     } catch (error) {
-      this.logger.error('OAuth authorize error', error instanceof Error ? error : new Error(String(error)));
-      res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send('OAuth authorization failed');
+      const correlationId = generateCorrelationId();
+      this.logger.error('OAuth authorize error', error instanceof Error ? error : new Error(String(error)), { correlationId });
+      res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send(`OAuth authorization failed (correlation ID: ${correlationId})`);
     }
   }
 
@@ -2077,9 +2078,10 @@ export class HttpTransport {
 
       await profileState.oauthProvider.handleCallback(req, res);
     } catch (error) {
-      this.logger.error('OAuth callback error', error instanceof Error ? error : new Error(String(error)));
+      const correlationId = generateCorrelationId();
+      this.logger.error('OAuth callback error', error instanceof Error ? error : new Error(String(error)), { correlationId });
       if (!res.headersSent) {
-        res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send('OAuth callback failed');
+        res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send(`OAuth callback failed (correlation ID: ${correlationId})`);
       }
     }
   }
@@ -2113,8 +2115,9 @@ export class HttpTransport {
       };
       res.json(buildAuthorizationServerMetadata(metadata, profileState.context.enterpriseAuthorization));
     } catch (error) {
-      this.logger.error('OAuth authorization server metadata error', error instanceof Error ? error : new Error(String(error)));
-      res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send('OAuth metadata failed');
+      const correlationId = generateCorrelationId();
+      this.logger.error('OAuth authorization server metadata error', error instanceof Error ? error : new Error(String(error)), { correlationId });
+      res.status(HTTP_STATUS.INTERNAL_SERVER_ERROR).send(`OAuth metadata failed (correlation ID: ${correlationId})`);
     }
   }