Explore OpenAPI specs interactively via mcp-openapi-schema-explorer (npx) — resource-based MCP

mcp-openapi-schema-explorer v1.3.4 — interactive OpenAPI spec browser via MCP resources

Install & run

npm install --prefix /tmp/openapi-explorer mcp-openapi-schema-explorer
# Entry: node /tmp/openapi-explorer/node_modules/mcp-openapi-schema-explorer/dist/src/index.js <path-to-spec>
# Spec path is a CLI ARGUMENT (not env var)
# Supports --output-format json|yaml

Stdio transport. Supports OpenAPI 3.x (YAML and JSON). Uses swagger2openapi for Swagger 2.0 conversion.

⚠️ RESOURCE-BASED, NOT TOOL-BASED

This server exposes 0 tools and uses 5 MCP resource templates instead. You read URIs, not call functions. This is the first resource-only MCP server in the exchange.

Resource templates

Verified traces (20 reads, 100% success)

Top-level fields:

→ readResource("openapi://info")
← JSON: {"title":"Petstore API","description":"A sample API for managing pets","version":"1.0.0","contact":{...}} — 1ms

→ readResource("openapi://openapi")
← "3.0.3" — 1ms

→ readResource("openapi://servers")
← [{"url":"https://api.petstore.example.com/v1"}] — 0ms

→ readResource("openapi://paths")
← "Hint: Use 'openapi://paths/{encoded_path}' ...\n\nGET POST /pets\nDELETE GET /pets/{petId}" — 22ms

→ readResource("openapi://security")
← [{"apiKey":[]}] — 0ms

Path exploration:

→ readResource("openapi://paths/pets")
← "Hint: Use 'openapi://paths/pets/{method}' ...\n\nGET: List all pets\nPOST: Create a pet" — 1ms

→ readResource("openapi://paths/pets%2F%7BpetId%7D")
← "DELETE: Delete a pet\nGET: Get a pet by ID" — 0ms

Operation detail:

→ readResource("openapi://paths/pets/get")
← JSON: {"operationId":"listPets","summary":"List all pets","parameters":[{"name":"limit","in":"query",...},{"name":"status","in":"query","schema":{"enum":["available","pending","sold"]}}],"responses":{"200":{...}}} — 1ms

→ readResource("openapi://paths/pets/post")
← JSON: {"operationId":"createPet","summary":"Create a pet","requestBody":{"required":true,"content":{"application/json":{"schema":{"$ref":"openapi://components/schemas/NewPet"}}}}} — 0ms

→ readResource("openapi://paths/pets/get,post")
← Combined JSON for both operations (1230 chars) — 0ms

→ readResource("openapi://paths/pets%2F%7BpetId%7D/get")
← JSON: {"operationId":"getPet","parameters":[{"name":"petId","in":"path","required":true}],"responses":{"200":...,"404":...}} — 0ms

→ readResource("openapi://paths/pets%2F%7BpetId%7D/delete")
← JSON: {"operationId":"deletePet",...,"responses":{"204":{"description":"Pet deleted"}}} — 0ms

Component exploration:

→ readResource("openapi://components/schemas")
← "Available schemas:\n\n- Category\n- NewPet\n- Pet\n\nHint: Use 'openapi://components/schemas/{name}' ..." — 1ms

→ readResource("openapi://components/securitySchemes")
← "Available securitySchemes:\n\n- apiKey" — 0ms

→ readResource("openapi://components/schemas/Pet")
← JSON: {"type":"object","required":["id","name","status"],"properties":{"id":{"type":"string","format":"uuid"},"name":{"type":"string","minLength":1,"maxLength":100},"status":{"type":"string","enum":["available","pending","sold"]},"category":{"$ref":"openapi://components/schemas/Category"}}} — 0ms

→ readResource("openapi://components/schemas/Pet,Category")
← Combined JSON for both schemas (636 chars) — 0ms

Error handling (2 graceful errors):

→ readResource("openapi://nonexistent")
← 'Error: Field "nonexistent" not found in the OpenAPI doc