{"passport":{"unfragile":{"@version":"1.0","version":"2026-05","artifact":{"id":"npm_npm-msfeldsteinmcp-test-servers","slug":"npm-msfeldsteinmcp-test-servers","name":"@msfeldstein/mcp-test-servers","type":"mcp","url":"https://www.npmjs.com/package/@msfeldstein/mcp-test-servers","page_url":"https://unfragile.ai/npm-msfeldsteinmcp-test-servers","categories":["mcp-servers","testing-quality"],"tags":["mcp","model-context-protocol"],"pricing":{"model":"open_source","free":true,"starting_price":null},"status":"active","verified":false},"capabilities":[{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_0","uri":"capability://tool.use.integration.mcp.server.lifecycle.testing.with.working.reference.implementations","name":"mcp server lifecycle testing with working reference implementations","description":"Provides a suite of minimal but fully functional MCP server implementations (ping, resource, combined, env-echo) that demonstrate correct protocol compliance and server initialization patterns. Each server implements the MCP specification's required message handlers and resource/tool registration flows, allowing developers to validate their MCP client implementations against known-good server behavior without external dependencies.","intents":["I need to test my MCP client implementation against servers that definitely work correctly","I want to understand how to structure a minimal MCP server that passes protocol validation","I need reference implementations to compare against when my MCP integration is failing"],"best_for":["MCP client library developers building SDKs or frameworks","Teams integrating MCP into existing AI applications","Protocol implementers validating spec compliance"],"limitations":["Servers are intentionally minimal — do not include production features like authentication, rate limiting, or error recovery","No persistence layer — all state is ephemeral and reset on server restart","Single-threaded execution model — not suitable for load testing or concurrent client scenarios"],"requires":["Node.js 16+","npm or yarn package manager","@msfeldstein/mcp-test-servers package installed"],"input_types":["MCP protocol messages (JSON-RPC 2.0 format)","Environment variables (for env-echo server)"],"output_types":["MCP protocol responses (JSON-RPC 2.0 format)","Resource listings and content","Tool definitions and execution results"],"categories":["tool-use-integration","testing-quality"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_1","uri":"capability://tool.use.integration.intentional.mcp.server.failure.case.simulation","name":"intentional mcp server failure case simulation","description":"Includes deliberately broken server implementations (broken-tool, crash-on-startup) that trigger specific failure modes and error conditions defined in the MCP specification. These servers allow developers to validate error handling paths in their MCP clients by reproducing edge cases like malformed tool definitions, unhandled exceptions during initialization, and protocol violations without needing to manually craft error scenarios.","intents":["I need to test how my MCP client handles servers that fail to initialize properly","I want to verify my error handling for malformed tool definitions and invalid responses","I need to ensure my client gracefully degrades when a server crashes mid-operation"],"best_for":["MCP client library developers implementing robust error handling","QA teams building comprehensive test suites for MCP integrations","Developers implementing fallback and recovery strategies for MCP failures"],"limitations":["Failure modes are static and predefined — cannot simulate dynamic or intermittent failures","No timing control — cannot reproduce race conditions or timeout-related issues","Limited to the specific failure scenarios included in the package"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed","MCP client implementation with error handling hooks"],"input_types":["MCP protocol initialization messages","Tool invocation requests"],"output_types":["MCP error responses (protocol-compliant error objects)","Server crashes and connection terminations","Malformed or invalid protocol messages"],"categories":["tool-use-integration","testing-quality"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_2","uri":"capability://tool.use.integration.resource.serving.and.content.delivery.via.mcp.protocol","name":"resource serving and content delivery via mcp protocol","description":"Implements the MCP resource capability, allowing test servers to expose named resources (files, data, or computed content) that clients can request and retrieve through the MCP protocol. The resource server maintains a registry of available resources with metadata and serves content on-demand, demonstrating the resource discovery and retrieval patterns defined in the MCP specification.","intents":["I need to test my MCP client's resource discovery and retrieval logic","I want to validate how my client handles resource metadata and content streaming","I need a reference implementation for building MCP servers that expose file or data resources"],"best_for":["Developers building MCP clients that consume resources from servers","Teams implementing resource-based MCP servers","Protocol validators testing resource capability compliance"],"limitations":["Resources are static and pre-defined — no dynamic resource generation or templating","No resource versioning or change tracking — clients cannot detect updates","No access control or permission system — all resources are publicly accessible"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed","MCP client with resource request capability"],"input_types":["Resource URI or identifier strings","MCP resource request messages"],"output_types":["Resource metadata (name, description, MIME type)","Resource content (text, binary, or structured data)","Resource listings (available resources on server)"],"categories":["tool-use-integration","memory-knowledge"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_3","uri":"capability://tool.use.integration.tool.definition.and.invocation.testing.via.mcp.protocol","name":"tool definition and invocation testing via mcp protocol","description":"Provides working tool implementations that register themselves with the MCP protocol, accept tool invocation requests from clients, and return results in the correct format. The combined server demonstrates multiple tools with different signatures and return types, allowing clients to validate tool discovery, parameter validation, and result handling against a known-good implementation.","intents":["I need to test my MCP client's tool discovery and invocation logic","I want to validate parameter passing and result serialization for tool calls","I need reference implementations for building MCP servers that expose tools"],"best_for":["MCP client developers implementing tool calling functionality","Teams building MCP-based AI agent frameworks","Protocol validators testing tool capability compliance"],"limitations":["Tools are stateless and have no side effects — cannot test persistent state or external integrations","No parameter validation beyond basic type checking — cannot test complex validation scenarios","Tool execution is synchronous — cannot test async or long-running operations"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed","MCP client with tool calling support"],"input_types":["Tool invocation requests with parameters","MCP tool call messages"],"output_types":["Tool definitions (name, description, parameters schema)","Tool execution results (success or error)","Tool listings (available tools on server)"],"categories":["tool-use-integration","planning-reasoning"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_4","uri":"capability://tool.use.integration.environment.variable.exposure.and.echo.via.mcp","name":"environment variable exposure and echo via mcp","description":"The env-echo server reads environment variables from the host process and exposes them through the MCP protocol, allowing clients to retrieve environment configuration without direct system access. This demonstrates how MCP servers can bridge between system state and protocol clients, useful for testing clients that need to access host configuration or validate environment-aware behavior.","intents":["I need to test my MCP client's ability to retrieve host environment configuration","I want to validate how my client handles dynamic or environment-dependent server behavior","I need a reference for building MCP servers that expose system state"],"best_for":["Developers testing MCP clients in containerized or multi-environment deployments","Teams building MCP servers that need to expose host configuration","Protocol validators testing dynamic server behavior"],"limitations":["Exposes all environment variables without filtering — security risk if sensitive credentials are in environment","No caching — each request re-reads environment variables, adding latency","No environment variable modification — read-only access only"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed","Environment variables set in the host process"],"input_types":["Environment variable names or patterns","MCP resource or tool requests for environment data"],"output_types":["Environment variable values (as strings)","Environment variable listings","Structured environment configuration"],"categories":["tool-use-integration","data-processing-analysis"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_5","uri":"capability://tool.use.integration.ping.heartbeat.server.for.connection.validation","name":"ping/heartbeat server for connection validation","description":"Implements a minimal MCP server that responds to ping requests with pong responses, providing the simplest possible working MCP server implementation. This server validates basic protocol compliance, connection establishment, and message round-trip functionality without any complex features, serving as a baseline for testing MCP client connectivity and protocol parsing.","intents":["I need to verify my MCP client can establish a connection and send/receive messages","I want the simplest possible working MCP server to validate my protocol implementation","I need a baseline server to test connection handling and error recovery"],"best_for":["MCP client developers validating basic protocol compliance","Teams debugging connection issues in MCP integrations","Protocol implementers testing message serialization and deserialization"],"limitations":["No features beyond ping/pong — cannot test tool calling, resources, or other capabilities","Minimal error handling — may not gracefully handle malformed requests","No state management — each request is independent"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed"],"input_types":["MCP ping messages"],"output_types":["MCP pong responses"],"categories":["tool-use-integration","testing-quality"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-msfeldsteinmcp-test-servers__cap_6","uri":"capability://tool.use.integration.combined.multi.capability.mcp.server.for.integration.testing","name":"combined multi-capability mcp server for integration testing","description":"Bundles multiple MCP capabilities (tools, resources, and other features) into a single server instance, allowing clients to test interactions between different capability types and validate that the client correctly handles servers with mixed feature sets. This server demonstrates how real-world MCP servers typically expose multiple capabilities simultaneously.","intents":["I need to test my MCP client against a server with multiple capabilities enabled","I want to validate how my client prioritizes and uses different server capabilities","I need a reference for building MCP servers that expose multiple features"],"best_for":["MCP client developers building production-ready implementations","Teams testing complex MCP integration scenarios","Protocol validators testing multi-capability server behavior"],"limitations":["Capabilities are independent — no cross-capability interactions or dependencies","No capability negotiation or feature detection — all capabilities are always enabled","Limited to the specific combination of capabilities included in the package"],"requires":["Node.js 16+","@msfeldstein/mcp-test-servers package installed"],"input_types":["MCP messages for any supported capability (tools, resources, etc.)"],"output_types":["MCP responses for any supported capability"],"categories":["tool-use-integration","testing-quality"],"confidence":0.5,"matches":0,"success_rate":0}],"trust":{"score":30,"verified":false,"data_access_risk":"high","permissions":["Node.js 16+","npm or yarn package manager","@msfeldstein/mcp-test-servers package installed","MCP client implementation with error handling hooks","MCP client with resource request capability","MCP client with tool calling support","Environment variables set in the host process"],"failure_modes":["Servers are intentionally minimal — do not include production features like authentication, rate limiting, or error recovery","No persistence layer — all state is ephemeral and reset on server restart","Single-threaded execution model — not suitable for load testing or concurrent client scenarios","Failure modes are static and predefined — cannot simulate dynamic or intermittent failures","No timing control — cannot reproduce race conditions or timeout-related issues","Limited to the specific failure scenarios included in the package","Resources are static and pre-defined — no dynamic resource generation or templating","No resource versioning or change tracking — clients cannot detect updates","No access control or permission system — all resources are publicly accessible","Tools are stateless and have no side effects — cannot test persistent state or external integrations","builder identity is not verified yet","no observed match outcomes yet"],"rank_breakdown":{"adoption":0.05,"quality":0.39,"ecosystem":0.46,"match_graph":0.25,"freshness":0.52,"weights":{"adoption":0.25,"quality":0.25,"ecosystem":0.15,"match_graph":0.23,"freshness":0.12}},"observed_outcomes":{"matches":0,"success_rate":0,"avg_confidence":0,"top_intents":[],"last_matched_at":null},"maintenance":{"status":"active","updated_at":"2026-05-24T12:16:23.904Z","last_scraped_at":"2026-05-03T14:23:52.621Z","last_commit":null},"community":{"stars":null,"forks":null,"weekly_downloads":null,"model_downloads":null,"model_likes":null}},"distribution":{"claim_url":"https://unfragile.ai/submit?claim=npm-msfeldsteinmcp-test-servers","compare_url":"https://unfragile.ai/compare?artifact=npm-msfeldsteinmcp-test-servers"}},"signature":"tyoD1V7lEltHqwkKAG2i3I89rFENycKfOONyUj6mjrXKjzC++ICUK9oH4KSLShmGp/ypHWrfP/JiQpxf5cqoBQ==","signedAt":"2026-06-20T11:45:18.140Z","signedBy":"unfragile.ai","version":1},"_links":{"self":"https://unfragile.ai/api/v1/passport/npm-msfeldsteinmcp-test-servers","artifact":"https://unfragile.ai/npm-msfeldsteinmcp-test-servers","verify":"https://unfragile.ai/api/v1/verify?slug=npm-msfeldsteinmcp-test-servers","publicKey":"https://unfragile.ai/api/v1/trust-passport-public-key","spec":"https://unfragile.ai/trust","schema":"https://unfragile.ai/schema.json","docs":"https://unfragile.ai/docs"}}