OAuth Callback Failure: Localhost Port Unreachable on Safari

[mfazekas]

Bug Description Trying to register linear MCP SSE server.

[DEBUG] MCP server "linear": Authorization URL: https://mcp.linear.app/authorize?response_type=code&client_id=Awe5h3&code_challenge=-F2bFsuA_lilJk&code_challenge_method=S256&redirect_uri=http%3A%2F%2Flocalhost%3A45123%2Fcallback

MCP server "linear" Error: Unauthorized [DEBUG] MCP server "linear": Authentication required for SSE server

Then browser is opened and it tries to redirect to:

http://localhost:45123/callback?code=6f909992-

But Safari Can't Connect to the Server. Safari cannot open the page "localhost:45123/..." because safari can't connect to server "localhost"

Environment Info

• Platform: macos
• Terminal: vscode
• Version: 1.0.9
• Feedback ID: 0b55da21-ab72-4e90-a5c9-a86f7ebddc82

Errors

[{"error":"SyntaxError: Unexpected token } in JSON at position 50\n    at JSON.parse (<anonymous>)\n    at s5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:557:9977)\n    at jp9 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:307)\n    at mH (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:995)\n    at l8 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:1336)\n    at q50 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:643:6202)\n    at file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:693:1493\n    at Q (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:526:17069)\n    at hF5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2298:17523)\n    at file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2302:6238","timestamp":"2025-06-03T11:00:44.635Z"},{"error":"Error: Invalid managed settings: [\n  {\n    \"code\": \"invalid_type\",\n    \"expected\": \"object\",\n    \"received\": \"null\",\n    \"path\": [],\n    \"message\": \"Expected object, received null\"\n  }\n]\n    at jp9 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:356)\n    at mH (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:995)\n    at l8 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:1336)\n    at q50 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:643:6202)\n    at file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:693:1493\n    at Q (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:526:17069)\n    at hF5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2298:17523)\n    at file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2302:6238","timestamp":"2025-06-03T11:00:44.638Z"},{"error":"SyntaxError: Unexpected token } in JSON at position 50\n    at JSON.parse (<anonymous>)\n    at s5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:557:9977)\n    at jp9 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:307)\n    at mH (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:995)\n    at Ks1 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1406:1489)\n    at LF2 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1406:1450)\n    at fF5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2298:14429)\n    at W1A.<anonymous> (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2298:20806)\n    at async W1A.parseAsync (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:517:4184)\n    at async dF5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2302:5972)","timestamp":"2025-06-03T11:00:44.733Z"},{"error":"Error: Invalid managed settings: [\n  {\n    \"code\": \"invalid_type\",\n    \"expected\": \"object\",\n    \"received\": \"null\",\n    \"path\": [],\n    \"message\": \"Expected object, received null\"\n  }\n]\n    at jp9 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:356)\n    at mH (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:562:995)\n    at Ks1 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1406:1489)\n    at LF2 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:1406:1450)\n    at fF5 (file:///Users/boga/.claude/local/node_modules/@anthropic-ai/claude-code/cli.js:2298:14429)\n    at W1A.<anonymous> (file:///Users/boga/.claude/l

Note: Error logs were truncated.

[arnis71]

Same here, very annoying. But for me it is Arc browser

[arnis71]

It is not working in the latest version

[dionoid]

Same here, using the Edge browser on macOS. Note that I'm using a streamable-http MCP server.

[koistya]

Maybe integrate OAuth Callback to make the auth flow in the CLI console smoother?

[github-actions[bot]]

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