{"passport":{"unfragile":{"@version":"1.0","version":"2026-05","artifact":{"id":"npm_npm-mcp-runtime-guard","slug":"npm-mcp-runtime-guard","name":"mcp-runtime-guard","type":"mcp","url":"https://www.npmjs.com/package/mcp-runtime-guard","page_url":"https://unfragile.ai/npm-mcp-runtime-guard","categories":["mcp-servers"],"tags":["mcp","model-context-protocol","proxy","policy","security","ai"],"pricing":{"model":"open_source","free":true,"starting_price":null},"status":"active","verified":false},"capabilities":[{"id":"npm_npm-mcp-runtime-guard__cap_0","uri":"capability://tool.use.integration.policy.based.mcp.tool.call.interception.and.validation","name":"policy-based mcp tool call interception and validation","description":"Intercepts MCP tool invocations at runtime and validates them against declarative policy rules before execution. Implements a proxy pattern that sits between the MCP client and server, parsing tool call requests, matching them against policy conditions (tool name, arguments, caller identity), and either allowing, denying, or modifying the call based on policy evaluation. Uses a rule-matching engine to enforce fine-grained access control without modifying underlying tool implementations.","intents":["I need to prevent certain MCP tools from being called by specific AI models or users","I want to enforce argument validation rules on tool calls before they execute","I need to audit which tools are being called and by whom in my MCP setup","I want to restrict tool access based on context like user role or request source"],"best_for":["teams deploying MCP servers in multi-tenant or untrusted environments","developers building AI agents that need runtime safety guardrails","organizations requiring compliance-driven tool access control"],"limitations":["Policy evaluation adds latency to every tool call — no caching mechanism for repeated identical calls","Limited to MCP protocol semantics — cannot intercept or validate non-MCP tool invocations","No built-in support for dynamic policy updates without server restart","Policy rule syntax and expressiveness unknown from package metadata — may lack support for complex conditional logic"],"requires":["Node.js 16+ (typical for MCP implementations)","MCP client and server compatible with proxy middleware pattern","Policy configuration file or API (format unspecified in metadata)"],"input_types":["MCP tool call requests (JSON-RPC format)","Policy rule definitions (format unknown)","Tool metadata and argument schemas"],"output_types":["MCP tool call responses (pass-through or modified)","Policy decision logs (allow/deny/modify)","Audit trail of tool invocations"],"categories":["tool-use-integration","safety-moderation"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_1","uri":"capability://safety.moderation.tool.call.argument.validation.and.transformation","name":"tool call argument validation and transformation","description":"Validates MCP tool call arguments against schema constraints and optionally transforms or sanitizes arguments before tool execution. Likely uses JSON Schema or similar validation to check argument types, ranges, and formats, with support for custom validation rules defined in policy. May include argument filtering (removing sensitive fields) or normalization (converting formats) based on policy directives.","intents":["I want to reject tool calls with invalid or out-of-range arguments before they reach the tool","I need to sanitize user-provided arguments to remove sensitive data before tool execution","I want to enforce type safety and format validation on tool inputs at runtime","I need to normalize or transform arguments (e.g., convert file paths to absolute paths) before execution"],"best_for":["developers building AI agents that accept user input and pass it to tools","teams needing to prevent injection attacks or malformed data from reaching tools","systems requiring argument normalization across heterogeneous tool implementations"],"limitations":["Validation rules must be defined per-tool — no automatic schema inference from tool definitions","No support for cross-argument validation (e.g., 'if arg A is X, then arg B must be Y')","Transformation logic is policy-driven — complex transformations may require custom policy extensions","Unknown whether validation errors are logged or returned to caller in a standardized format"],"requires":["Tool argument schemas defined in policy configuration","MCP tool definitions with argument metadata","Policy engine supporting validation rule syntax"],"input_types":["MCP tool call arguments (JSON objects)","Validation rule definitions (schema format unknown)","Tool argument schemas"],"output_types":["Validated/transformed arguments (JSON objects)","Validation error messages","Audit logs of argument transformations"],"categories":["safety-moderation","data-processing-analysis"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_2","uri":"capability://safety.moderation.caller.identity.and.context.aware.tool.access.control","name":"caller identity and context-aware tool access control","description":"Evaluates tool call permissions based on caller identity (user, model, application) and request context (source IP, timestamp, session). Implements identity-aware policy evaluation where rules can reference caller attributes and context metadata to make access decisions. Likely uses a context object passed through the MCP request to identify the caller and evaluate policies conditionally based on identity attributes.","intents":["I want to restrict certain tools to specific users or AI models","I need to enforce different tool access policies for different user roles","I want to prevent tool access from untrusted sources or IP addresses","I need to track which user or model called which tool for compliance auditing"],"best_for":["multi-tenant AI systems where different users have different tool access levels","organizations with role-based access control (RBAC) requirements","teams needing to audit tool usage by caller identity for compliance"],"limitations":["Caller identity must be provided by MCP client — no built-in authentication mechanism","No support for dynamic identity resolution (e.g., looking up user role from external directory)","Context attributes are static per request — no session-level state management","Unknown whether identity spoofing is prevented or if caller identity is trusted implicitly"],"requires":["MCP client implementation that provides caller identity in request context","Policy rules that reference caller identity attributes","Identity attribute definitions in policy configuration"],"input_types":["MCP tool call requests with caller identity metadata","Policy rules with identity-based conditions","Caller identity attributes (user ID, role, source IP, etc.)"],"output_types":["Access decision (allow/deny) based on caller identity","Audit logs with caller identity and tool call details","Identity-based access control decisions"],"categories":["safety-moderation","tool-use-integration"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_3","uri":"capability://automation.workflow.policy.rule.definition.and.management","name":"policy rule definition and management","description":"Provides a declarative policy language or configuration format for defining tool access rules, validation constraints, and transformation logic. Likely uses a structured format (YAML, JSON, or custom DSL) to express policies as rules with conditions and actions. Includes mechanisms for loading, parsing, and evaluating policies at runtime, with support for rule composition and precedence.","intents":["I want to define tool access policies in a human-readable, version-controllable format","I need to express complex access control rules with multiple conditions and actions","I want to manage policies separately from code and update them without redeploying","I need to compose policies from multiple rule files or sources"],"best_for":["teams using infrastructure-as-code practices for security policies","organizations needing to audit and version-control tool access policies","developers building policy-driven MCP deployments"],"limitations":["Policy language syntax and expressiveness unknown — may lack support for complex logic","No built-in policy versioning or rollback mechanism","Policy updates require server restart — no hot-reload capability","Unknown whether policies support dynamic evaluation (e.g., calling external services for decisions)"],"requires":["Policy configuration file in supported format (format unknown)","MCP runtime with policy engine","Understanding of policy rule syntax and semantics"],"input_types":["Policy rule definitions (format unknown — likely YAML or JSON)","Tool metadata and schemas","Caller identity and context attributes"],"output_types":["Parsed policy rules","Policy evaluation results","Policy validation errors"],"categories":["automation-workflow","safety-moderation"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_4","uri":"capability://safety.moderation.tool.call.audit.logging.and.monitoring","name":"tool call audit logging and monitoring","description":"Logs all tool invocations (allowed, denied, modified) with metadata including caller identity, tool name, arguments, decision reason, and timestamp. Implements structured logging that captures the full context of each tool call decision, enabling audit trails and monitoring. Likely writes logs to stdout, files, or external logging services in a structured format (JSON or similar).","intents":["I need to audit which tools were called, by whom, and when for compliance purposes","I want to detect suspicious tool usage patterns or unauthorized access attempts","I need to troubleshoot why a tool call was denied or modified","I want to monitor tool usage metrics and trends over time"],"best_for":["organizations with compliance requirements (SOC 2, HIPAA, etc.)","security teams monitoring AI agent behavior for anomalies","developers debugging policy enforcement issues"],"limitations":["Logging format and destination are likely fixed — no built-in support for custom log sinks","No built-in log retention or archival policies","Sensitive data (arguments, caller identity) may be logged in plaintext — no encryption or redaction","Unknown whether logging is synchronous (adds latency) or asynchronous"],"requires":["Logging destination (stdout, file, or external service)","Sufficient disk space or log storage capacity","Log parsing and analysis tools (external)"],"input_types":["MCP tool call requests","Policy evaluation results","Caller identity and context"],"output_types":["Structured audit logs (JSON or similar format)","Tool call decision records","Compliance audit trails"],"categories":["safety-moderation","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_5","uri":"capability://safety.moderation.tool.call.denial.and.error.handling","name":"tool call denial and error handling","description":"Rejects tool calls that violate policy rules and returns standardized error responses to the caller. Implements a denial mechanism that prevents tool execution and communicates the denial reason (policy violation, validation failure, access denied) back through the MCP protocol. Likely returns MCP error responses with structured error details and policy violation reasons.","intents":["I want to prevent unauthorized tool calls from executing","I need to communicate policy violations to the caller in a clear, actionable way","I want to fail safely when a tool call violates security policies","I need to distinguish between different types of denials (access denied vs. validation failure)"],"best_for":["security-critical deployments where tool access must be strictly controlled","systems needing to provide clear feedback to users about why tool calls failed","developers debugging policy enforcement and access control issues"],"limitations":["Error response format is likely fixed — no customization of denial messages","Unknown whether error responses leak information about policy rules or tool existence","No support for graceful degradation (e.g., retrying with reduced permissions)","Denied tool calls are not queued or retried — they fail immediately"],"requires":["MCP client that handles error responses correctly","Policy rules that define denial conditions","Error handling logic in client application"],"input_types":["MCP tool call requests that violate policies","Policy evaluation results indicating denial"],"output_types":["MCP error responses with denial reason","Structured error details (policy violation, access denied, etc.)","Audit logs of denied tool calls"],"categories":["safety-moderation","tool-use-integration"],"confidence":0.5,"matches":0,"success_rate":0},{"id":"npm_npm-mcp-runtime-guard__cap_6","uri":"capability://tool.use.integration.mcp.protocol.aware.proxy.routing.and.request.forwarding","name":"mcp protocol-aware proxy routing and request forwarding","description":"Routes MCP requests through the proxy, parsing JSON-RPC messages, extracting tool call information, and forwarding validated requests to the underlying MCP server. Implements a transparent proxy that intercepts MCP protocol messages, applies policy evaluation, and forwards requests while maintaining protocol semantics. Handles both request and response routing, ensuring that tool responses are returned to the caller correctly.","intents":["I want to insert policy enforcement into my MCP setup without modifying clients or servers","I need to proxy MCP requests through a policy layer transparently","I want to maintain full MCP protocol compatibility while adding security policies","I need to route MCP requests to different servers based on policy rules"],"best_for":["teams deploying MCP in existing architectures without modifying clients or servers","organizations needing transparent security layers for MCP","developers building MCP infrastructure with centralized policy enforcement"],"limitations":["Proxy adds latency to every request — no request batching or pipelining optimization","Unknown whether proxy supports streaming responses or only request-response patterns","No support for request/response caching — every request is forwarded to the server","Protocol version compatibility unknown — may not support all MCP versions"],"requires":["MCP client compatible with proxy endpoint","MCP server to forward requests to","Network connectivity between proxy and server","Node.js runtime for proxy process"],"input_types":["MCP JSON-RPC requests (tool calls, resource access, etc.)","MCP protocol messages"],"output_types":["MCP JSON-RPC responses (tool results, errors, etc.)","MCP protocol messages","Policy enforcement decisions"],"categories":["tool-use-integration","automation-workflow"],"confidence":0.5,"matches":0,"success_rate":0}],"trust":{"score":29,"verified":false,"data_access_risk":"high","permissions":["Node.js 16+ (typical for MCP implementations)","MCP client and server compatible with proxy middleware pattern","Policy configuration file or API (format unspecified in metadata)","Tool argument schemas defined in policy configuration","MCP tool definitions with argument metadata","Policy engine supporting validation rule syntax","MCP client implementation that provides caller identity in request context","Policy rules that reference caller identity attributes","Identity attribute definitions in policy configuration","Policy configuration file in supported format (format unknown)"],"failure_modes":["Policy evaluation adds latency to every tool call — no caching mechanism for repeated identical calls","Limited to MCP protocol semantics — cannot intercept or validate non-MCP tool invocations","No built-in support for dynamic policy updates without server restart","Policy rule syntax and expressiveness unknown from package metadata — may lack support for complex conditional logic","Validation rules must be defined per-tool — no automatic schema inference from tool definitions","No support for cross-argument validation (e.g., 'if arg A is X, then arg B must be Y')","Transformation logic is policy-driven — complex transformations may require custom policy extensions","Unknown whether validation errors are logged or returned to caller in a standardized format","Caller identity must be provided by MCP client — no built-in authentication mechanism","No support for dynamic identity resolution (e.g., looking up user role from external directory)","builder identity is not verified yet","no observed match outcomes yet"],"rank_breakdown":{"adoption":0.05,"quality":0.24,"ecosystem":0.48000000000000004,"match_graph":0.25,"freshness":0.75,"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":"2026-05-24T12:16:23.903Z","last_scraped_at":"2026-05-03T14:23:57.237Z","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-mcp-runtime-guard","compare_url":"https://unfragile.ai/compare?artifact=npm-mcp-runtime-guard"}},"signature":"YSojK7niXyTTyKxWGuOIXublWX+eJ8ZY3uMdHeGp7XRR/AczJ/J/LJdtqQ1JkgmWoxqL8DbwFDuqx5q5REvMAA==","signedAt":"2026-06-20T01:12:14.858Z","signedBy":"unfragile.ai","version":1},"_links":{"self":"https://unfragile.ai/api/v1/passport/npm-mcp-runtime-guard","artifact":"https://unfragile.ai/npm-mcp-runtime-guard","verify":"https://unfragile.ai/api/v1/verify?slug=npm-mcp-runtime-guard","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"}}