Tutorials

Connect an AI agent (Cursor, VS Code / Copilot, Claude Desktop, or any stdio MCP client) to PostgreSQL using pREST: a REST API from PostgreSQL plus a read-only PostgreSQL MCP server on the same process.

This tutorial is local-first. You will:

1. Run pREST against Postgres

2. Prefer a read-only database role

3. Install the prest-mcp adapter

4. Wire an AI client to MCP tools

Requires pREST v2.1.0+.

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Architecture

AI client (Cursor / VS Code / Claude / …)
        ↓ stdio
   prest-mcp
        ↓ HTTP POST /_mcp
   prestd
        ↓
   PostgreSQL (read-only role recommended)

The adapter only bridges transports. Schema discovery and queries are implemented in pREST — see MCP Overview.

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1. Run PostgreSQL and pREST

Start Postgres locally (Docker, Homebrew, or your existing instance). Then install and run pREST — pick a channel from Distribution or Get pREST.

Example with Homebrew for the server:

brew install prestd

Configure connection settings (Configuring pREST) and start prestd. Confirm the REST API and MCP discovery:

curl -s http://localhost:3000/_mcp | head

You should see "name": "prest" and a tools array.

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2. Use a read-only role

Create a least-privilege role with CONNECT, USAGE, and SELECT only — full SQL: Read-only PostgreSQL for AI. Point pREST’s Postgres credentials at that role for AI-facing instances.

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3. Install the MCP adapter

On macOS:

brew install prest/tap/prest-mcp

Or:

go install github.com/prest/prest-mcp-adapter/cmd/prest-mcp@latest

Details: Install pREST MCP Adapter · Homebrew tutorial.

Quick check:

PREST_MCP_URL=http://localhost:3000/_mcp prest-mcp

(Leave it running only if you are testing manually; MCP clients spawn it themselves.)

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4. Connect your AI client

Cursor

Create .cursor/mcp.json:

{
  "mcpServers": {
    "prest": {
      "command": "prest-mcp",
      "env": {
        "PREST_MCP_URL": "http://localhost:3000/_mcp"
      }
    }
  }
}

Full guide: Use with Cursor. Optional rules/skills: pREST for Cursor plugin.

VS Code / GitHub Copilot

Create .vscode/mcp.json with a servers entry ("type": "stdio", command prest-mcp, env PREST_MCP_URL). Use Copilot Agent mode to verify. Guide: Use with VS Code and Copilot.

Claude Desktop

Edit claude_desktop_config.json with the same command / env pattern (prefer an absolute path on macOS). Guide: Use with Claude Desktop.

OpenClaw

openclaw plugins install clawhub:@prest/prest-openclaw

Configure MCP with prest-mcp and PREST_MCP_URL (see plugin examples/mcp-readonly/openclaw-mcp.example.json). Plugin guide: pREST for OpenClaw.

Other tools

Cline, Continue, Windsurf, and generic stdio clients: Other AI tools.

Registry package name: io.github.prest/prest.

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5. Try it

Ask the agent:

• “List databases available through pREST.”

• “Describe public.users.”

• “Select 5 rows from public.users.”

Expected tools include prest.list_databases, prest.describe_table, and prest.select.*. Limits and auth: MCP over HTTP.

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Troubleshooting

Symptom	Fix
No /_mcp response	Upgrade to pREST v2.1.0+; confirm host/port
Adapter exits on start	Set PREST_MCP_URL
Client cannot spawn binary	Absolute path to prest-mcp; brew install prest/tap/prest-mcp
Empty tools	Grants / permissions; restart pREST after schema changes
Auth errors	Set PREST_MCP_TOKEN when JWT auth is enabled

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Next steps

• AI and MCP landing

• MCP Overview

• Install adapter with Homebrew

• Distribution channels