Gcloud DB Access

Goal

Retrieve data from Cloud SQL PostgreSQL using MCP only.

Inputs to collect (ask only if missing)

• project_id
• instance_id
• database_name
• db_user
• local_proxy_port (default 5432)

Execution workflow

1. Authenticate in gcloud: gcloud auth login
2. Start Cloud SQL Auth Proxy: gcloud beta sql connect <instance_id> --project=<project_id> --user=<db_user> --database=<database_name> or run Cloud SQL Auth Proxy bound to localhost (127.0.0.1:<local_proxy_port>).
3. Configure MCP server in ~/.codex/config.toml with: command = "npx" and args ["-y", "@modelcontextprotocol/server-postgres", "postgresql://<db_user>@127.0.0.1:<local_proxy_port>/<database_name>"]
4. Use MCP tools/resources for schema discovery and read-only SQL queries.

Guardrails

• Pass --project in every command.
• Use read-only SQL (SELECT, WITH, EXPLAIN) only.
• Start with schema discovery and constrained queries (LIMIT, date filters).
• If auth or permissions fail, fix environment before retrying.

References

• MCP setup and usage: references/mcp-cloudsql-postgres.md