What this error means

MCP OAuth: Claude Code re-runs DCR on every authenticate, orphaning the previously-issued client_id and its refresh_token is a Claude Code failure pattern reported for developers trying to fix claude code mcp oauth authentication loop where dynamic client registration (dcr) runs repeatedly instead of reusing cached credentials, causing orphaned client ids and stale refresh tokens. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub Issue #59460 on anthropics/claude-code opened May 16 2026 by aria-inboxia. Labels: area:auth, area:mcp, bug, has repro, platform:macos. Open with 2 comments. Regresses authentication flows for users integrating MCP servers via OAuth. Directly impacts paid Claude Code Max plan users who rely on MCP integrations.

Common causes

  • GitHub Issue #59460 on anthropics/claude-code opened May 16 2026 by aria-inboxia. Labels: area:auth, area:mcp, bug, has repro, platform:macos. Open with 2 comments. Regresses authentication flows for users integrating MCP servers via OAuth. Directly impacts paid Claude Code Max plan users who rely on MCP integrations.

Quick fixes

  1. Confirm the exact error signature matches MCP OAuth: Claude Code re-runs DCR on every authenticate, orphaning the previously-issued client_id and its refresh_token.
  2. Check the Claude Code account, local tool state, and provider configuration involved in the failing workflow.
  3. Verify the account session, API key, provider settings, and environment where the failing tool is running.

Platform/tool-specific checks

  • Verify the command, editor, extension, or API client that produced the error.
  • Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
  • Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

  1. Capture the exact error message and the command, editor action, or request that triggered it.
  2. Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
  3. Review the source evidence below and compare it with your environment.
  4. Apply one change at a time and rerun the smallest failing action.
  5. Keep the working fix documented for the team or deployment environment.

How to prevent it

  • Keep provider/tool configuration documented.
  • Record non-secret diagnostics such as tool version, provider name, model name, and command path.
  • Add a lightweight check before CI or production workflows depend on the tool.