| name | mcp-artifact |
| description | Validate, diagnose, and understand MCP server declarations and runtime behavior across Claude Code, Cursor, and Codex — transport types, declaration format, and vendor support. |
Use this skill when working with MCP server declarations — validating configuration, diagnosing startup or connection failures, or understanding what each vendor supports.
Declaration format (shared across vendors):
{
"mcpServers": {
"server-name": {
"command": "npx",
"args": ["-y", "@scope/server"],
"env": {"KEY": "value"}
}
}
}
Transport types:
stdio: local process, command + args. Most widely supported.HTTP/SSE: remote server via URL. Claude Code and Cursor support this; Codex does not.streamable HTTP: Cursor-specific extension with OAuth support.
Diagnostic approach for MCP failures:
- Check declaration file exists in the right location for the vendor (paths differ — see references/)
- Check the server process starts: run the command manually
- Check transport: stdio servers write to stderr for debug output
- Check vendor support: some transports and features are vendor-specific
- Use MCP Inspector for local stdio debugging (
make mcp in eyelock/mcp-toolkit)
Plugin vs project declaration: file location differs by vendor — see references/. In Claude Code, --plugin-dir does NOT auto-activate MCP; requires /plugin enable.
For MCP spec details (tools, resources, prompts, sampling, elicitation, pagination, cancellation), see references/mcp-spec.md. For implementation patterns, see references/mcp-toolkit.md.
