MockMCP
Hosted MCP endpoint returning realistic fake data for prototyping agents. Paste one URL, zero setup.
Live at mockmcp.io — https://mockmcp.io/mcp
Built for devs who want to prototype agent workflows without wiring up a backend, writing fixtures, or standing up a local MCP server. 12 pre-built tools covering the scenarios in most agent tutorials.
Try it
# Initialize a session and get back a session id
curl -i -X POST https://mockmcp.io/mcp \
-H "Content-Type: application/json" \
-H "Accept: application/json, text/event-stream" \
-d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"curl","version":"0.1"}}}'
# Use the Mcp-Session-Id header in subsequent calls:
curl -X POST https://mockmcp.io/mcp \
-H "Content-Type: application/json" \
-H "Accept: application/json, text/event-stream" \
-H "Mcp-Session-Id: <paste-id-here>" \
-d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"list_users","arguments":{"limit":3}}}'
Connect your client
Claude Code
claude mcp add --transport http mockmcp https://mockmcp.io/mcp
Cursor — add to ~/.cursor/mcp.json:
{
"mcpServers": {
"mockmcp": {
"url": "https://mockmcp.io/mcp"
}
}
}
Claude Desktop — Settings → Connectors → Add custom connector → paste https://mockmcp.io/mcp as the URL.
No mcp-remote proxy required. All three clients speak Streamable HTTP natively.
Tools
| Tool | What it does |
|---|---|
list_users | Paginated list of mock users |
get_user | One mock user by id or seed |
create_user | Create a mock user (no persistence) |
list_products | Paginated list of mock products |
get_product | One mock product |
list_orders | Mock orders with optional status filter |
get_order | One mock order |
create_order | Create a mock order (no persistence) |
list_events | Mock analytics events |
create_event | Record a mock event |
send_email | Returns fake success, nothing delivered |
search_knowledge_base | Mock KB search with ranked results |
All data is seeded from your inputs — same input, same output.
Limits
Free tier, per hashed IP + User-Agent fingerprint:
- 30 requests per minute
- 500 requests per day
Hit the wall? Drop your email at mockmcp.io/waitlist for paid-tier access when it launches.
429 responses carry a structured JSON-RPC error with upgrade_url and retry_after_seconds. Every successful response carries X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, and X-RateLimit-Scope headers.
Run locally
npm install
npm run dev
Server listens on http://localhost:3000. MCP endpoint at /mcp. Without Upstash env vars, rate limiting falls back to an in-memory store (per-process, fine for dev).
Stack
@modelcontextprotocol/sdk— MCP server + Streamable HTTP transport- Raw Node
http— no framework overhead, clean shutdown @faker-js/faker— deterministic fake data via seeds@upstash/ratelimit+@upstash/redis— sliding-window rate limitingzod— tool input validation
Deploy (for forks)
Targets Node 20+. Build + start are pinned via nixpacks.toml; health checks + restart policy via railway.json.
- Fork this repo, push to GitHub.
- Railway → New Project → Deploy from GitHub → pick your fork.
- Add env vars in Railway → Variables:
| Var | Notes |
|---|---|
UPSTASH_REDIS_REST_URL | From upstash.com free tier |
UPSTASH_REDIS_REST_TOKEN | Paired with the URL above |
PORT | Railway sets this automatically |
- Railway service → Settings → Networking → Custom Domain → paste your domain → follow the DNS instructions.
Health check
GET /health returns {"ok":true}. Railway pings this during deploy.
Waitlist signups
POST /api/waitlist logs a structured JSON line per signup:
{"event":"waitlist_signup","email":"alice@example.com","at":"2026-04-24T19:33:06.396Z"}
Grep them with railway logs | grep waitlist_signup. Storage-free by design — swap in Resend, a Tally forward, or a DB when the paid tier is live.
License
MIT — see LICENSE.