{"id":"apify-mcp-client-capabilities","name":"mcp-client-capabilities","homepage":"https://www.npmjs.com/package/mcp-client-capabilities","repo_url":"https://github.com/apify/mcp-client-capabilities","category":"devtools","subcategories":[],"tags":["mcp","model-context-protocol","capabilities","client-registry","typescript","python","json","compatibility-matrix"],"what_it_does":"Provides a language-friendly distribution of a single curated JSON database (mcp-clients.json) listing MCP client names, metadata, and capability flags compatible with MCP client capability schemas. Intended for MCP servers to decide how to present resources/tools/prompts/instructions based on known client feature support.","use_cases":["MCP server capability-aware behavior (e.g., offer alternate tools or instructions based on client support)","Building UI/agents that need to understand which MCP client features are likely available","Offline validation/testing and code generation against a maintained client capability matrix","Cross-language consumption of client capability metadata (TS/Python) via packaged exports or raw JSON URL"],"not_for":["A live registry or query service (the data is static JSON, not a network API)","Security authorization/token management between client and server","Guaranteeing actual runtime capability support of a specific client version (it’s a best-effort index, servers should rely on initialize params.capabilities)"],"best_when":"When you’re implementing MCP server logic and want a maintained reference table to complement/triage the official initialize handshake capabilities.","avoid_when":"When you need real-time updates, authoritative per-instance capability negotiation beyond initialize, or an API with query/update endpoints.","alternatives":["Rely solely on the MCP initialize request capabilities (params.capabilities) without this external index","Fetch the community feature-support matrix directly from the MCP clients feature matrix webpage","Maintain your own curated client capability mapping in-repo","Use other community-maintained MCP client capability lists (if available)"],"af_score":65.8,"security_score":95.5,"reliability_score":42.5,"package_type":"mcp_server","discovery_source":["github"],"priority":"high","status":"evaluated","version_evaluated":null,"last_evaluated":"2026-03-30T13:51:44.919151+00:00","interface":{"has_rest_api":false,"has_graphql":false,"has_grpc":false,"has_mcp_server":false,"mcp_server_url":null,"has_sdk":true,"sdk_languages":["TypeScript","Python","JavaScript (via package export)"],"openapi_spec_url":null,"webhooks":false},"auth":{"methods":[],"oauth":false,"scopes":false,"notes":"No authentication—package is a published data/library artifact."},"pricing":{"model":null,"free_tier_exists":false,"free_tier_limits":null,"paid_tiers":[],"requires_credit_card":false,"estimated_workload_costs":null,"notes":"No pricing information indicated; appears to be free/open-source distribution."},"requirements":{"requires_signup":false,"requires_credit_card":false,"domain_verification":false,"data_residency":[],"compliance":[],"min_contract":null},"agent_readiness":{"af_score":65.8,"security_score":95.5,"reliability_score":42.5,"mcp_server_quality":0.0,"documentation_accuracy":88.0,"error_message_quality":0.0,"error_message_notes":null,"auth_complexity":100.0,"rate_limit_clarity":0.0,"tls_enforcement":100.0,"auth_strength":100.0,"scope_granularity":100.0,"dependency_hygiene":70.0,"secret_handling":100.0,"security_notes":"No authentication or data collection described; package serves static capability metadata. Main security considerations are supply-chain integrity (verify npm/pypi provenance) and treating the data as non-authoritative per runtime handshake. TLS is not directly applicable since no network API is described, but typical package download occurs over HTTPS.","uptime_documented":0.0,"version_stability":60.0,"breaking_changes_history":60.0,"error_recovery":50.0,"idempotency_support":"false","idempotency_notes":null,"pagination_style":"none","retry_guidance_documented":false,"known_agent_gotchas":["This is not a network service; integration is via static JSON/library exports.","Servers should not treat the indexed capabilities as authoritative—README stresses prioritizing initialize.params.capabilities and ignoring out-of-date protocolVersion mismatches.","Capability fields are optional; code should handle missing properties (e.g., resources/prompts/tools might be absent)."]}}