auth0-diagnostics-mcp

Auth0 developer tools for Claude Code and any MCP-compatible AI assistant.

Decode JWTs, diagnose OAuth errors, validate tokens, and look up the right Auth0 flow — all without leaving your chat.

Installation

Add this to ~/.claude/settings.json:

{
  "mcpServers": {
    "auth0-local": {
      "command": "uvx",
      "args": ["auth0-diagnostics-mcp"]
    }
  }
}

Requires uv. No other setup needed — uvx fetches and runs the server automatically.

Tools

decode_token

Decode and explain a JWT. Shows the header, all claims, expiry status, and what each standard claim means. Does not verify the signature.

"Decode this token: eyJhbGci..."

validate_token

Verify a JWT's signature against an Auth0 tenant's public JWKS endpoint.

"Validate this token against my-auth0-tenant.us.auth0.com"

diagnose_auth_error

Explain an Auth0 or OAuth error code — what it means, why it happens, and how to fix it.

"What does invalid_grant mean?"

explain_flow

Recommend the right Auth0 / OAuth 2.0 flow for your app type and use case.

"What flow should I use for a React SPA that calls an API?"

get_tenant_config

Fetch and summarize an Auth0 tenant's OIDC discovery document — issuer, JWKS URI, supported scopes, grant types, and more.

"Show me the config for my-auth0-tenant.us.auth0.com"

Usage

Just describe what you need in plain English — Claude picks the right tool automatically:

• "Decode this JWT: eyJhbGci..."
• "Why am I getting server_error on my callback URL?"
• "What Auth0 flow should I use for a mobile app?"
• "Validate this token against my-auth0-tenant.us.auth0.com with audience https://my-api"

Requirements

• Python 3.10+
• uv