Kong/insomnia · error · MCPAuthError

Authentication failed

Error message

Authentication failed

What it means

Error "Authentication failed" thrown in Kong/insomnia.

Source

Thrown at packages/insomnia/src/main/mcp/transport-streamable-http.ts:269

      if (authResult === 'REDIRECT') {
        // Wait for oauth authorization flow to complete in default browser
        const authorizationCode = await redirectPromise;
        // Exchange authorization code for tokens
        authResult = await auth(authProvider, {
          serverUrl: url,
          resourceMetadataUrl,
          scope,
          authorizationCode,
          fetchFn: authFetchFn,
        });
      }
      if (authResult !== 'AUTHORIZED') {
        throw new UnauthorizedError();
      }
    } catch (e) {
      console.error('Authentication failed', e);
      // Wrap and throw MCPAuthError for better identification, some of the errors thrown by sdk are generic Error which is hard to identify
      throw new MCPAuthError(e.message || 'Authentication failed', { cause: e });
    } finally {
      // Close the oauth authorization modal after authorization is complete
      BrowserWindow.getAllWindows().forEach(window => {
        window.webContents.send('hide-oauth-authorization-modal');
      });
      // cleanup the oauth client provider listener
      unsubscribe();
    }
    return await wrappedFetch(url, init, context, authProvider, true);
  }
  return response;
};

View on GitHub (pinned to d9bb2b0142)

When it happens

Trigger: Thrown at packages/insomnia/src/main/mcp/transport-streamable-http.ts:269 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

• Authentication and authorization failures — expired tokens, bad credentials, and missing scopes.

AI-assisted analysis of Kong/insomnia@d9bb2b0142 (2026-08-26). Data as JSON: /api/errors/f717e62195c10f22. Report an issue: GitHub.