[BUG] Figma MCP never transitions from auth mode to operational mode

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description:
The built-in Figma MCP server gets stuck in authentication mode and never exposes actual Figma tools, even after successfully completing the OAuth flow.

What Should Happen?

Steps to reproduce:

Open Claude Code — Figma MCP appears with only authenticate and complete_authentication tools
Call authenticate → receive OAuth URL
Open URL in browser → log in to Figma → browser shows "Authentication Successful"
Back in Claude: the auth tools disconnect, but no Figma tools appear — the MCP server simply goes away
After a delay, the MCP server reconnects — but only with the auth tools again (step 1 repeats)
Expected behavior:
After OAuth completes, the Figma MCP should expose its full set of tools (get_file, get_comments, etc.)

Actual behavior:
The MCP server disconnects after auth and never transitions to an operational state. The OAuth token does not appear to be persisted anywhere (not in macOS Keychain, not in ~/.claude/, not in ~/Library/Application Support/Claude/). Every restart and every auth attempt results in the same loop.

Error Messages/Logs

Additional context:

~/.claude/mcp-needs-auth-cache.json always shows {"figma":{"timestamp":...}} even after successful auth
No Figma-related token found in macOS Keychain (security find-generic-password returns nothing)

Steps to Reproduce

Steps to reproduce:

Open Claude Code — Figma MCP appears with only two tools: mcp__figma__authenticate and mcp__figma__complete_authentication
Call mcp__figma__authenticate → receive an OAuth URL
Open that URL in a browser → log in to Figma → browser shows "Authentication Successful / You can close this window. Return to Claude Code."
Back in Claude Code: the auth tools disconnect (system reminder: "MCP server disconnected")
No Figma tools appear. The MCP server goes silent.
After a delay, the MCP server reconnects — but only the two auth tools reappear. Loop repeats from step 1.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.142

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_