API Development MCP Servers for ChatGPT

httpbin MCP.

Free map of HubSpot legacy v1-v4 API operations to their date-based-versioning replacements.

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Cloudflare Workers MCP server: interactive-api-playground

Deterministic HTTP/WebSocket testing and policy-gated API execution for AI agents.

Manage Kong Konnect AI and API gateways, routes, plugins, and analytics from your agent.

Generate secured CRUD APIs over your database, run SQL, manage files, tasks and a headless browser

ThumbGate — Pre-action gates that block AI coding agents from repeating known mistakes. SQLite+FTS5 lesson DB with corrective-action

Mock REST APIs, fake OAuth2/OIDC provider, uptime monitors + heartbeats, live badge/QR images.

Multi-protocol API mock server: HTTP, GraphQL, gRPC, WebSocket, MQTT, SSE, SOAP.

Stateful WebSocket session registry with per-connection Shannon entropy delta tracking for schema di

Swagger Petstore API (v1.0.27) as MCP for testing and prototyping powered by the HAPI MCP server

JSONPlaceholder MCP — wraps JSONPlaceholder fake REST API (free, no auth)

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Refresh seconds;url shape, value discarded

Paid OpenAPI audit and API change detection for agents. $0.10 USDC per analysis via x402 on Base.

MCP server for secureFlows (secure-flows.com). Alias of io.github.michal-lefler/secureflows-mcp.

Receive, inspect, replay and deliver webhooks — with signature verification and agent triggers.

Fire-and-forget webhooks for agents with guaranteed, retried delivery and status polling. x402

Keyless webhook endpoints: capture, wait, replay, forward, and generate types from real traffic.

Anonymous webhook capture, inspection, waiting, and response configuration for AI agents.