Borrowing it
Nothing to install: this file belongs to MagicTurtle-s/claude-code-mcp-bridge. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/MagicTurtle-s/claude-code-mcp-bridge/master/.claude/skills/mcp-auth-handler/SKILL.mdgit clone --depth 1 https://github.com/MagicTurtle-s/claude-code-mcp-bridgeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/magicturtle-s/claude-code-mcp-bridge/mcp-auth-handler)<a href="https://agentmods.dev/skills/magicturtle-s/claude-code-mcp-bridge/mcp-auth-handler"><img src="https://agentmods.dev/badge/skills/magicturtle-s/claude-code-mcp-bridge/mcp-auth-handler/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/magicturtle-s/claude-code-mcp-bridge/mcp-auth-handler"><img src="https://agentmods.dev/badge/skills/magicturtle-s/claude-code-mcp-bridge/mcp-auth-handler.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00050 | $0.02386 |
| Opus 5.5 | $0.00020 | $0.00954 |
| Sonnet 5.5 | $0.00010 | $0.00477 |
| Haiku 4.5 | $0.00005 | $0.00239 |
Grade C, and why
mcp-auth-handler scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Asks for rootmediumPrivilege escalation
A mod that escalates privileges can change anything on the machine, not only the project.
chmod 600 ~/.claude/.credentials.json Reads agent configuration directoriesmediumAgent snooping
.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.
cat ~/.claude/.credentials.json How it starts
The opening of the file, as written. The whole thing — 372 lines — stays where its author put it; the contents beside it link to each section on GitHub.
MCP Authentication Handler
What This Skill Does
This skill helps Claude detect and resolve MCP server authentication failures when using the Claude Code MCP Bridge. It provides step-by-step guidance for OAuth authentication and token management.
When to Use This Skill
Activate this skill when you encounter any of these scenarios:
Error Messages
- "authentication failed"
- "unauthorized" (401/403 HTTP errors)
- "token expired"
- "MCP not authenticated"
- "Authentication required for SSE server"
- "Token expired without refresh token"
- "No scopes available from URL or metadata"
User Requests
- "MCP isn't working"
- "Can't access Asana/HubSpot/SharePoint"
- "OAuth not working"
- "How do I authenticate with MCPs?"
Symptoms
- MCP tools return auth errors instead of data
- First-time setup of new MCP server
- Re-authentication needed after token expiry
How Authentication Works
Bridge MCP Architecture
Claude Desktop → Bridge MCP → Claude Code CLI → .credentials.json → MCP Servers
Key Points:
- Bridge MCP does NOT handle credentials
- Claude Code CLI manages all authentication
- Tokens stored in
~/.claude/.credentials.json - OAuth flow triggered via
/mcpcommand
Token Lifecycle
| Token Type | Lifespan | Auto-Refresh? |
|---|---|---|
| Access Token | ~1 hour | ✅ Yes (via refresh token) |
| Refresh Token | Days/weeks | ❌ No (manual /mcp) |
Step-by-Step Troubleshooting
Step 1: Identify the Problem
Check error message:
- Does it mention "auth", "unauthorized", or "token"?
- Which MCP server is affected? (Asana, HubSpot, SharePoint, Neo4j)
- Is this first-time setup or re-authentication?
Example Error:
Error: The Asana MCP server needs authentication.
Authentication required for SSE server.
Step 2: Run /mcp Command
Action:
# In Claude Code CLI terminal:
/mcp
What Happens:
- Command detects which MCPs need authentication
- Browser opens for OAuth authorization
- User grants permissions
- Tokens automatically saved to
.credentials.json - Confirmation message appears
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 372 lines · 50 tokens per session scan C 1db7136c9f01
mcp-auth-handler is a skill published in the GitHub repository MagicTurtle-s/claude-code-mcp-bridge (1 stars, last pushed 26d ago), licensed MIT. It adds 50 tokens to every session and 2,386 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it C with 2 findings (asks for root, reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
mcp-auth-handler compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| mcp-auth-handlerMagicTurtle-s/claude-code-mcp-bridge | Skill | 1 | 26d ago | MIT | C | 50 | Claude Code |
| systematic-debuggingopen-metadata/OpenMetadata | Skill | 16k | today | Apache-2.0 | A | 37 | Claude Code |
| log-error-digestzebbern/claude-code-guide | Skill | 4.7k | yesterday | MIT | A | 71 | Claude Code, Codex |
| cwv-optimizeradobe/skills | Skill | 321 | today | Apache-2.0 | A | 112 | Claude Code |
| ci-fixersipyourdrink-ltd/bernstein | Skill | 1.2k | today | Apache-2.0 | A | 15 | Claude Code, Codex |
| incident-response-incident-responsermyndharis/antigravity-skills | Skill | 2.0k | yesterday | MIT | A | 36 | Claude Code, Codex |
| diagnosing-missing-recordingsPostHog/posthog | Skill | 41k | today | none | A | 76 | Claude Code, Codex |