PostgreSQL MCP Server

tl;dr: Anthropic’s @modelcontextprotocol/server-postgres is archived (read-only since 2025-05-29). The original is a one-tool, read-only server over any postgresql:// URL. For new work, crystaldba/postgres-mcp (3.3k stars) is the strongest generic community option; for managed Postgres, supabase/mcp or AWS Labs’ RDS / Aurora DSQL MCPs fit better.

Status of the original

The Anthropic reference lives at modelcontextprotocol/servers-archived/src/postgres. It exposes one tool, query, which runs SQL inside a read-only transaction, and resource templates postgres://<host>/<table>/schema for schema discovery. The npm package still installs; the source is read-only.

Pick one

Install — crystaldba/postgres-mcp (default recommendation)

uvx postgres-mcp --access-schema=public --access-mode=unrestricted

Claude Desktop:

{
  "mcpServers": {
    "postgres": {
      "command": "uvx",
      "args": ["postgres-mcp", "--access-schema=public", "--access-mode=unrestricted"],
      "env": {
        "DATABASE_URI": "postgresql://user:pass@localhost:5432/mydb"
      }
    }
  }
}

Flags worth knowing: --access-schema (limit the agent to one schema) and --access-mode=restricted (block any DDL/DML). The server supports both stdio and SSE transports — pass --transport=sse (with --port) to share one server across multiple MCP clients. The README also has an OPT-30K-style prompt budget hint for limiting how much of the schema it introspects.

Install — the archived one (still works)

npx -y @modelcontextprotocol/server-postgres postgresql://user:pass@localhost:5432/mydb

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres", "postgresql://user:pass@localhost:5432/mydb"]
    }
  }
}

For Docker on the same host as the DB, use host.docker.internal instead of localhost. The original is locked to one tool: query running inside a read-only transaction.

Safety

Any of these servers will execute SQL the model generates. The original is read-only by design; crystaldba/postgres-mcp defaults to restricted mode and you can scope it to one schema. For production:

1. Use a dedicated, read-only DB user.
2. Restrict to one schema with --access-schema.
3. Lock the network path (security group, VPC, or SSH tunnel).
4. Enable statement logging in postgresql.conf and forward logs.

Gotchas

• The archived Anthropic package is no longer maintained. Issues stay open but no fixes land.
• host.docker.internal is macOS/Windows; on Linux, point at the host’s actual IP or run the MCP on the host instead of in a container.
• Connection-pool exhaustion: each MCP session is one PG connection. Long-lived clients with many parallel tools can hit max_connections.

Related

• Supabase MCP — managed Postgres
• AWS MCP — for RDS / Aurora DSQL
• SQLite MCP — local DB
• MCP Servers Explained