Fully Hosted
No server to deploy, no Docker image to maintain. Just point your MCP client at https://mcp.verjson.dev/mcp.
Open Beta · Free while we build
Hosted MCP Server for Any OpenAPI – and Every VerJSON API
mcp.verjson.dev is a fully hosted Model Context Protocol server.
Point Claude, Cursor or any MCP-compatible agent at /mcp with a VerJSON API key and they can
discover operations, read schemas and call your APIs – no glue code, no extra hosting.
Streamable HTTP MCP · Bearer auth · Works with Claude, Cursor and MCP Inspector
What it is
One Endpoint. Any OpenAPI Spec. Every Agent.
mcp.verjson.dev runs a Streamable HTTP MCP server that wraps the universe of OpenAPI-described APIs in a consistent tool catalogue. It has first-class support for VerJSON published documents and works with any standards-compliant OpenAPI 3.x spec on the public web.
Bearer Auth
Authenticate every request with a scoped VerJSON API key. Invalid or expired keys are rejected with a clean 401.
VerJSON-Native
Use create_verjson_session(subdomain) and the server fetches the spec for you – every published VerJSON API is one call away.
Generic OpenAPI
Point create_session at any OpenAPI 3.x URL – internal or public – and the full tool surface works the same way.
Tool catalogue
Everything an Agent Needs to Understand & Call an API
The server exposes a focused, composable tool catalogue that covers session lifecycle, schema introspection, operation discovery, request scaffolding, execution and structured querying of responses.
Session
create_session, create_verjson_session, get_session_info, list_sessions, close_session – fast onboarding for any spec or VerJSON subdomain.
Schema
list_schemas, get_schema, find_property – navigate component schemas, follow $refs and pinpoint properties without downloading the whole spec.
API
list_operations, get_operation, execute_operation – discover endpoints, inspect parameters and execute requests with the agent's chosen credentials.
Payload
scaffold_request_body, scaffold_response_example – generate valid request bodies and realistic example responses from the schema.
Query
jmespath_search – run JMESPath expressions over any structured result so the agent can drill into the parts it actually needs.
Spec-compliant transport
Streamable HTTP MCP over POST, GET and DELETE /mcp with the required Accept: application/json, text/event-stream header semantics.
Streamable HTTP MCP
OpenAPI 3.0 / 3.1
VerjsonAPI
Bearer auth
JMESPath
Claude Desktop
Cursor
MCP Inspector
Connect in 30 seconds
Plug Any MCP Client Into mcp.verjson.dev
The endpoint speaks Streamable HTTP MCP. All you need is a VerJSON API key and a client that supports Bearer-token MCP servers.
Endpoint
POST/GET/DELETE https://mcp.verjson.dev/mcp
Required header: Authorization: Bearer <vj_api_key>
Claude Desktop
Add the server in your MCP config with a Bearer credential pointing at https://mcp.verjson.dev/mcp. Claude will load the tool catalogue on first use.
Cursor
Register it as a remote MCP server with the static Bearer token. .well-known OAuth probes intentionally return 404 so the Bearer fallback kicks in.
MCP Inspector
Run npx @modelcontextprotocol/inspector and target https://mcp.verjson.dev/mcp with the same Authorization header to explore the tools interactively.
Custom client
Use the official MCP SDK (TypeScript or Python). Make sure POST requests send Accept: application/json, text/event-stream – the spec requires it.
Health & spec
GET /health returns liveness info. GET /api-docs.json returns the OpenAPI description of the HTTP surface.
Pricing
Free While We're in Open Beta
The hosted MCP server is part of VerJSON's open beta. Use it freely with any valid VerJSON API key while we refine the product. Paid subscription tiers will be introduced later, with clear notice and a generous free tier preserved.
Open Beta · Free
Full access to the tool catalogue, every published VerJSON API, and any public OpenAPI spec your agent points at.
- Unlimited sessions
- Bearer auth via VerJSON API keys
- VerJSON-native and generic OpenAPI tools
Subscription Tiers · Coming Later
Future paid plans will cover higher rate limits, advanced telemetry and team-level controls. Beta users will get plenty of notice before anything changes.
- Permanent free tier
- Team and Business plans
- Transparent pricing announced ahead of launch
Frequently Asked Questions
What is mcp.verjson.dev?
It's VerJSON's hosted Model Context Protocol server. A Streamable HTTP MCP endpoint at /mcp that lets AI agents introspect and call any OpenAPI-described API, with first-class support for VerJSON published documents.
How does authentication work?
Every request to /mcp must include Authorization: Bearer <verjson_api_key>. Keys are validated against VerJSON; invalid or expired keys return 401. OAuth discovery endpoints return 404 on purpose so clients fall back to the static Bearer token.
Can I use it with APIs that aren't published on VerJSON?
Yes. create_session(specUrl) accepts any OpenAPI 3.x URL on the public web. All schema, operation, payload and JMESPath tools work identically regardless of where the spec is hosted.
What does it cost?
It's free during VerJSON's open beta. Paid subscription tiers will be introduced later, with a generous free tier preserved and clear notice ahead of any change.
How do I get an API key?
Sign in at verjson.dev, open Account → API keys and create a key with the scopes you need. Use that key as the Bearer credential for mcp.verjson.dev/mcp.
Give Your Agents a Hosted MCP Server Today
Grab a VerJSON API key, point your MCP client at mcp.verjson.dev/mcp and start calling APIs from any agent.