[Bug] Double URL encoding in OAuth MCP server authentication

[HerbCaudill]

Bug Description
it looks like claude code is double-encoding some url as part of the oath process to authenticate to an mcp server?

Environment Info

• Platform: darwin
• Terminal: vscode
• Version: 2.1.6
• Feedback ID: c0357945-1d5d-4c07-9fa8-ed7209ee41d8

Errors

[{"error":"Error: Plugin path not found: /Users/herbcaudill/.claude/plugins/marketplaces/claude-plugins-official/plugins/code-review\n    at p57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:6240)\n    at d57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:5802)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:14659","timestamp":"2026-01-18T21:15:51.711Z"},{"error":"Error: Plugin path not found: /Users/herbcaudill/.claude/plugins/marketplaces/claude-plugins-official/plugins/code-simplifier\n    at p57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:6240)\n    at d57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:5802)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:14659","timestamp":"2026-01-18T21:15:51.712Z"},{"error":"Error: Plugin path not found: /Users/herbcaudill/.claude/plugins/marketplaces/claude-plugins-official/plugins/frontend-design\n    at p57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:6240)\n    at d57 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:5802)\n    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3265:14659","timestamp":"2026-01-18T21:15:51.744Z"},{"error":"MaxFileReadTokenExceededError: File content (93214 tokens) exceeds maximum allowed tokens (25000). Please use offset and limit parameters to read specific portions of the file, or use the GrepTool to search for specific content.\n    at PA2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1681:13298)\n    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)\n    at async Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1690:996)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3218:1513","timestamp":"2026-01-18T21:17:10.965Z"},{"error":"MaxFileReadTokenExceededError: File content (66415 tokens) exceeds maximum allowed tokens (25000). Please use offset and limit parameters to read specific portions of the file, or use the GrepTool to search for specific content.\n    at PA2 (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1681:13298)\n    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)\n    at async Object.call (file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:1690:996)\n    at async file:///opt/homebrew/lib/node_modules/@anthropic-ai/claude-code/cli.js:3218:1513","timestamp":"2026-01-18T21:17:11.417Z"}]

[github-actions]

Found 1 possible duplicate issue:

1. [BUG] OAuth redirect_uri contains space causing authorization failure #17176

This issue will be automatically closed as a duplicate in 3 days.

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🤖 Generated with Claude Code

[github-actions]

This issue has been automatically closed as a duplicate of #17176.

If this is incorrect, please re-open this issue or create a new one.

🤖 Generated with Claude Code

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.