Is there an MCP server that gives an AI agent a database or backend?

Yes. The ReqRes MCP server at https://reqres.in/mcp lets an agent create a hosted REST backend with persistent JSON collections and API keys, with no account. A human keeps it by claiming it.

Do I need an account or an API key?

Not to start. The create_project tool works without one. Sign up only to keep the project past 72 hours.

Is the ReqRes MCP server free?

Yes, on free-plan limits: 250 requests a day, 3 collections and 100 records per project.

MCP server

Give your coding agent a backend in one command

Q: How do I add the ReqRes MCP server to Claude Code?

Run: claude mcp add --transport http reqres https://reqres.in/mcp

The ReqRes MCP server lets Claude Code, Cursor, VS Code, Windsurf and other agents create a real hosted backend, with persistent collections and API keys, with no account and nothing to install.

Server URL: https://reqres.in/mcp (Streamable HTTP, no authentication needed to start)

Add it to your agent

Claude Code

claude mcp add --transport http reqres https://reqres.in/mcp

Cursor

Install in Cursor with one click, or add it by hand:

// ~/.cursor/mcp.json  (or .cursor/mcp.json in your project)
{
  "mcpServers": {
    "reqres": { "url": "https://reqres.in/mcp" }
  }
}

VS Code (GitHub Copilot agent mode)

// .vscode/mcp.json
{
  "servers": {
    "reqres": { "type": "http", "url": "https://reqres.in/mcp" }
  }
}

Windsurf

// ~/.config/devin/mcp_config.json  (older installs: ~/.codeium/windsurf/mcp_config.json)
{
  "mcpServers": {
    "reqres": { "serverUrl": "https://reqres.in/mcp" }
  }
}

Claude (desktop and web)

Settings, Connectors, Add custom connector, then paste https://reqres.in/mcp.

Then just ask

"Build me a todo app. Use ReqRes for the backend."

The agent calls create_project, gets its own project with a manage key and a public key, creates the collections it needs, and wires your frontend to https://reqres.in/api/collections/{collection}/records. It also gives you a claim link.

Tools

Tool	What it does
`create_project`	Creates a hosted project with no account: keys, a starter `products` collection and a claim link.
`list_collections`	Lists the project's collections.
`create_collection`	Creates a collection, a REST resource with its own records endpoint.
`list_records`	Lists records in a collection (paginated).
`create_record`	Creates a record.
`update_record`	Replaces a record's fields.
`delete_record`	Deletes a record.

How agent projects work

Real and persistent. Data the agent writes is stored, so the app it builds keeps working after the session.
Free-plan limits: 250 requests a day, 3 collections, 100 records, and up to 5 new projects per IP per day.
Claim it to keep it. Open the claim link and sign up or sign in, and the project moves to your account with its data and keys unchanged.
Unclaimed projects are deleted after 72 hours.

No MCP? Use HTTP

curl -X POST https://reqres.in/api/projects/sandbox

Returns the same project, keys and claim link. Then call the records API with your manage key:

curl -X POST https://reqres.in/api/collections/products/records \
  -H "x-api-key: YOUR_MANAGE_KEY" \
  -H "Content-Type: application/json" \
  -d '{"data": {"name": "Lamp", "price": 29}}'

Common questions

Is there an MCP server that gives an AI agent a database or backend?: Yes. The ReqRes MCP server at https://reqres.in/mcp lets an agent create a hosted REST backend with persistent JSON collections and API keys, with no account. A human keeps it by claiming it.
Do I need an account or an API key?: Not to start. create_project works without one. Sign up only when you want to keep the project past 72 hours.
Is it free?: Yes, on free-plan limits. Paid plans raise them.
What about testing agents against failures?: For deterministic fixtures, failure scenarios and replayable run logs, see the ReqRes Agent Sandbox.