"Understanding and Using JSON" matching MCP servers:

Validates JSON syntax and optionally checks against a JSON Schema, with pay-per-call via x402 micropayments.

Validates JSON payloads against JSON Schema deterministically, providing precise validation results and error paths.

Enables agents to interact with the Logflare API by writing JavaScript functions that run in a Vercel Sandbox, using three tools: search, execute_read, and execute_write.

MCP server that validates dashboardbase setup files and widget endpoint responses against the dashboardbase JSON contract, reporting errors and warnings before deployment.

ozon-mcp is a knowledge-rich MCP server that turns the entire Ozon seller toolkit into 15 high-leverage tools. AI agents (Claude, Cursor, Cline, Continue, Goose, Zed, …) can search the API in Russian or English, drill into any of 466 methods with a fully-resolved JSON Schema, and execute calls with built-in safety guards. Subscription- aware, automatic pagination over all 4 cursor styles, retry/ba

Enables AI agents to create, run, and manage HTTP requests using the Invoker API client's .ivk format. It provides tools for scanning collections, executing requests, managing environments, and building documentation sites.

Autonomous synthetic health checks, JSON-RPC 2.0 handshake validation, breaking schema drift detection, and credential leak scanning for remote MCP servers.

Self-healing API proxy MCP that sends REST requests, diagnoses failures using Claude, patches requests, and retries. Successful fixes are remembered for instant reuse.

CLIRank - API discovery for AI agents. APIs scored on CLI relevance: auth method, JSON responses, headless operation, pricing transparency. Search by capability, compare alternatives, read agent-contributed docs. 6 MCP tools for discovery, comparison, and documentation. Agents contribute observations back - crowdsourced API docs by machines, for machines.

A TypeScript-based MCP server that enables AI assistants to execute HTTP requests with full control over methods, headers, and body content. It facilitates seamless interaction with web APIs and endpoints through a versatile tool that handles automatic JSON formatting and response truncation.

Generates schema-compliant mock data from OpenAPI JSON Schema definitions using AI, enabling seamless testing without manual fixtures.

An MCP server that enables LLMs to make arbitrary HTTP requests (GET, POST, PUT, DELETE, etc.) with custom headers, bodies, and cookies, supporting JSON and error handling.

Enables local analysis of OpenAPI 3 and Swagger 2 JSON/YAML spec files on disk, with no remote fetching of specs or credentials. It groups endpoints by tag, flags operations that appear to lack security, lists deprecated operations, and produces short markdown cheat sheets for agents.

Enables MCP-compatible AI clients to query, search, create, and update YApi API definitions and categories using natural language, with write operations excluding deletion for safety.

Replay-verified minimal JSON reproductions and deterministic TypeScript/OpenAPI drift checks. Local-first CLI and MCP server.

Enables AI assistants to search, browse, and generate example payloads from Sage Intacct REST API documentation using OpenAPI specs.

Integrates Bruno CLI for API testing, enabling users to run API requests and collections, manage environments, generate test reports (JSON/JUnit/HTML), and validate collection structures through natural language commands.

Validates AI-generated artifacts (JSON, API responses, SQL) against a contract and returns a verdict.

Generates comprehensive API test plans (positive, negative, and boundary/edge cases) from endpoint metadata using LLMs, and exports them as Excel files.

Conformance test harness for Model Context Protocol servers, validating JSON-RPC, transport, capability, schema, and more across multiple spec versions.