OpenAPI MCP servers that turn any REST API into tools
MCP servers and generators that turn OpenAPI or Swagger specs into tools, so an AI agent can call any documented REST API without custom code.
What to know about OpenAPI MCP servers
OpenAPI servers read a Swagger or OpenAPI document and expose each operation as an MCP tool, complete with parameter schemas taken from the spec. That makes it possible to connect an agent to an internal API or a niche SaaS product in minutes, without waiting for someone to write a dedicated server.
There are two flavours. Runtime bridges load a spec when they start and proxy calls to the API. Generators produce source code for a standalone server that you can edit, test, and publish. Bridges are fastest for experiments; generated servers are easier to harden, because you can trim operations and rewrite descriptions.
Large specs are the common problem. An API with hundreds of endpoints creates hundreds of tools, which crowds the model's context and makes tool choice worse. Look for servers that let you filter operations by tag or path, and write clear summaries in the spec, because those become the tool descriptions the model reads.
OpenAPI MCP servers
The 12 strongest of 271 matching servers. Servers that name the topic directly come first, then by trust score.
- 69Trust score 69 of 100, Good
gknowledge
by openapi · Python
Search, read and grow a Karpathy-style LLM wiki of linked Markdown pages, with cited answers.
RegistryLicenseQualityMaintenanceLicense: A. MIT is a permissive open source license.Quality: Not graded. No README or tool list has been captured yet.Maintenance: B. Last commit or release 22 days ago. Down one letter for 34 open issues against 19 stars. - 68Trust score 68 of 100, Good
mcp-graphql-enhanced
by letoribo · TypeScript
GraphQL gateway for LLMs. Handles huge GitHub GraphQL & @neo4j/graphql schemas without crashing
RegistryLicenseQualityMaintenanceLicense: A. MIT is a permissive open source license.Quality: Not graded. No README or tool list has been captured yet.Maintenance: A. Last commit or release 12 days ago. - 61Trust score 61 of 100, Good
Discover, preview, call, and inspect configured Swagger/OpenAPI APIs through 11 fixed tools.
RegistryLicenseQualityMaintenanceLicense: A. MIT License is a permissive open source license.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. 
58Trust score 58 of 100, FairPostman MCP Server
by postmanlabs · TypeScript
Give your AI agents trusted access to the full Postman platform.
RegistryRemoteLicenseQualityMaintenanceLicense: A. Apache-2.0 is a permissive open source license.Quality: Not graded. No README or tool list has been captured yet.Maintenance: A. Last commit or release 15 days ago.- 55Trust score 55 of 100, Fair
MCP server for Webull OpenAPI: trading and market data access for AI assistants
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 55Trust score 55 of 100, Fair
Local read-only OpenAPI and Swagger inspection with secret-safe schema summaries. Tools include...
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 55Trust score 55 of 100, Fair
Type-safe MCP server for OpenAPI Sync to inspect, validate, and synchronize OpenAPI specs.
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 55Trust score 55 of 100, Fair
HTTP request echo from Postman Echo. No key required.
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 52Trust score 52 of 100, Fair
Aggregates multiple OpenAPI specifications into a unified virtual routing mesh with service namespac
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 52Trust score 52 of 100, Fair
Send one HTTP request, or one per row of a dataset, CSV or Google Sheet, and get the response back
RegistryRemoteLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 52Trust score 52 of 100, Fair
Lint OpenAPI 3.x documents for missing security, responses, descriptions and versioning.
RegistryLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded. - 52Trust score 52 of 100, Fair
Revenue Agent — OpenAPI Audit & Change Detection
Unknown author
Paid OpenAPI audit and API change detection for agents. $0.10 USDC per analysis via x402 on Base.
RegistryRemoteLicenseQualityMaintenanceLicense: Not graded. No license is recorded for this server.Quality: Not graded. No README or tool list has been captured yet.Maintenance: Not graded. No commit or release date has been recorded.
How to install one
- Compare the shortlist. gknowledge leads this topic. Open two or three listings and compare their tools, transport, and required API keys.
- Copy the config for your client. Each listing has an install guide, for example Claude Desktop, Claude Code, Cursor, or VS Code. The client guides show where each config file lives.
- Scope credentials, then restart. Use the narrowest token or folder the server needs, restart the client, and check that the new tools appear.
OpenAPI MCP questions
How do OpenAPI MCP servers handle API authentication?
Most read the security schemes in the spec and accept an API key, bearer token, or OAuth credentials through environment variables. Check that the server never logs headers, since they carry your secrets.
Is there an equivalent for GraphQL APIs?
Yes. GraphQL servers introspect the schema and expose query and mutation tools. Because one GraphQL tool can reach the whole schema, restrict mutations if the agent only needs to read.
Should I generate a server or write one by hand?
Generate first to see which operations the agent actually uses, then trim to those. A hand-written server with a few well-described tools usually beats a generated one with hundreds. The guides cover building and publishing your own server.