{"id":"giantswarm-mcp-debug","name":"mcp-debug","homepage":null,"repo_url":"https://github.com/giantswarm/mcp-debug","category":"devtools","subcategories":[],"tags":["model-context-protocol","mcp","debugging","cli","oauth","json-rpc","repl"],"what_it_does":"mcp-debug is a Go command-line tool for debugging Model Context Protocol (MCP) servers. It can connect to MCP servers (including via streamable-http), provide an interactive REPL to inspect tools/resources/prompts, log JSON-RPC traffic verbosely, and run in an MCP server mode itself. It also supports OAuth 2.1 authentication flow options (including PKCE, discovery, resource indicators, and optional CIMD/DRC) to access protected MCP endpoints.","use_cases":["Inspect an MCP server’s advertised capabilities (tools/resources/prompts)","Debug JSON-RPC tool calls and MCP notifications","Validate integration with AI assistants by running an MCP-facing debug server","Test and troubleshoot OAuth-protected MCP endpoints","Explore/verify server transports and authorization behaviors during development"],"not_for":["Production-grade MCP gateway/security proxy (it’s a debugging CLI)","Automating large-scale workloads without human-in-the-loop interaction","Handling highly sensitive tokens where you need guaranteed no logging of secrets"],"best_when":"You’re developing against MCP servers and need to introspect capabilities, test tool calls/notifications, and verify OAuth/OIDC authorization behaviors quickly.","avoid_when":"You need a stable, long-lived API surface for other services to call; or you must run in environments with strict constraints on interactive browser-based auth and verbose logging of protocol messages.","alternatives":["mcp-inspector or other MCP debugging/visualization tools (if available)","Generic MCP client libraries and custom scripts","OAuth-capable reverse proxies / gateways tailored to your IdP and MCP integration"],"af_score":46.2,"security_score":57.5,"reliability_score":36.2,"package_type":"mcp_server","discovery_source":["github"],"priority":"high","status":"evaluated","version_evaluated":null,"last_evaluated":"2026-03-30T15:26:57.411441+00:00","interface":{"has_rest_api":false,"has_graphql":false,"has_grpc":false,"has_mcp_server":true,"mcp_server_url":null,"has_sdk":false,"sdk_languages":[],"openapi_spec_url":null,"webhooks":false},"auth":{"methods":["OAuth 2.1 (with PKCE) via interactive browser flow"],"oauth":true,"scopes":false,"notes":"README indicates an OAuth 2.1 flow with authorization discovery (RFC 9728/RFC 8414), Resource Indicators (RFC 8707), PKCE validation, and optional client metadata (CIMD) with fallback to dynamic client registration. Specific scope strings/handling semantics are not detailed in the provided README."},"pricing":{"model":null,"free_tier_exists":false,"free_tier_limits":null,"paid_tiers":[],"requires_credit_card":false,"estimated_workload_costs":null,"notes":"Open-source tool (Apache-2.0). Cost is primarily your own infrastructure/IdP usage during OAuth authorization."},"requirements":{"requires_signup":false,"requires_credit_card":false,"domain_verification":false,"data_residency":[],"compliance":[],"min_contract":null},"agent_readiness":{"af_score":46.2,"security_score":57.5,"reliability_score":36.2,"mcp_server_quality":55.0,"documentation_accuracy":70.0,"error_message_quality":0.0,"error_message_notes":null,"auth_complexity":45.0,"rate_limit_clarity":10.0,"tls_enforcement":70.0,"auth_strength":80.0,"scope_granularity":40.0,"dependency_hygiene":50.0,"secret_handling":40.0,"security_notes":"OAuth 2.1 support with PKCE and resource indicators suggests security-forward design, but this evaluation is based only on the README content (no confirmation of safe logging behavior). Verbose JSON-RPC logging may risk leaking tokens/PII if the tool logs sensitive fields; TLS enforcement level is inferred from typical usage but not explicitly guaranteed in the provided README.","uptime_documented":0.0,"version_stability":60.0,"breaking_changes_history":50.0,"error_recovery":35.0,"idempotency_support":"false","idempotency_notes":null,"pagination_style":"none","retry_guidance_documented":false,"known_agent_gotchas":["This is primarily a CLI/debugger; agent automation may require driving interactive REPL/browser-based OAuth.","Verbose JSON-RPC logging could expose sensitive information in logs if misconfigured.","No evidence (from README alone) of structured machine-readable error formats for agents; failures may be CLI-output driven."]}}