About MCP OAuth Connect
MCP OAuth Connect provides a CLI checker, plugin, and skill for developers diagnosing remote MCP OAuth discovery issues. It checks login challenges, registration endpoints, PKCE S256, and protected-resource metadata, but does not complete a handshake or call tools.
Key features
- 01Check OAuth login challenges
- 02Detect client registration endpoints
- 03Verify PKCE S256 configuration
- 04Inspect RFC 9728 resource metadata
- 05Output JSON diagnostic reports
Use cases
- 01Diagnose connector failures with MCP servers
- 02Check completeness of OAuth discovery metadata
- 03Run diagnostics in command-line workflows
MCP support
The project includes a ping-only reference MCP server. Its main diagnostic tool checks discovery metadata for remote servers but does not obtain tokens or call tools/list.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://mcp.gfbytes.com/mcpclaude mcp add --transport http com-gfbytes-mcp-oauth-connect https://mcp.gfbytes.com/mcp{"mcpServers":{"com-gfbytes-mcp-oauth-connect":{"type":"http","url":"https://mcp.gfbytes.com/mcp"}}}Open in Cursor{"servers":{"com-gfbytes-mcp-oauth-connect":{"type":"http","url":"https://mcp.gfbytes.com/mcp"}}}Open in VS Code{"mcpServers":{"com-gfbytes-mcp-oauth-connect":{"type":"http","url":"https://mcp.gfbytes.com/mcp"}}}{"mcpServers":{"com-gfbytes-mcp-oauth-connect":{"serverUrl":"https://mcp.gfbytes.com/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
Tools
Details
From the project READMEMCP OAuth Connect
Free checker for when an MCP remote answers curl but dies in Claude / Cursor / Desktop / Grok Connectors.
| Live checker | check.gfbytes.com |
| This repo | CLI diagnose.py + plugin / skill |
| Web UI | mcp-gfbytes |
| Demo MCP | https://mcp.gfbytes.com |
Part of GFB's lab surface. Founder / peer identity: gregfredabytes.com · essay · what I run
What this is not
- Not a hosted MCP product.
https://mcp.gfbytes.comis a ping-only reference server. - Not a completed handshake. The checker reads discovery metadata. It does not do DCR, mint a token, or call
tools/list. A fail is a scoping signal, not a dead end. - Not the paid attach lab. Four-client attempt + written path lives on the studio product page.
Paste only the URL in a Connectors UI — no API key.
Clone / run
Stdlib Python ≥3.10. No install for the checker:
git clone https://github.com/GFB2026/mcp-oauth-connect.git
cd mcp-oauth-connect
python skills/mcp-oauth-connect/scripts/diagnose.py https://mcp.gfbytes.com
Exit 0 if connector-critical checks pass; 1 otherwise. JSON report on stdout.
Looks for a proper login challenge (not a bare 200 from curl), a registration endpoint, PKCE S256, and RFC 9728 protected-resource metadata.
Tests:
python -m pip install "pytest>=8"
python -m pytest
For AI assistants / contributors
Edit lanes and hard stops: .github/copilot-instructions.md.
Verify with python -m pytest (install pytest>=8; this tree is flat — no pip install -e).
Plugin install (optional)
Claude Code:
/plugin marketplace add GFB2026/mcp-oauth-connect
/plugin install mcp-oauth-connect@mcp-oauth-connect
Grok Build:
grok plugin marketplace add GFB2026/mcp-oauth-connect
grok plugin install mcp-oauth-connect --trust
Then run the same diagnose.py path as above.
template/
Public ping-only example behind https://mcp.gfbytes.com (MIT). Reference server, not a service SKU.
License
MIT for the plugin, skill, diagnose script, tests, and template/. Studio attach-lab / fix-round services are separate offers on gfbytes.com.
Comments
New to MCP?
From what the protocol is to installing your first server, these answers cover most first questions.
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