OwnPG

PostgreSQL DBA tools for AI clients over the Model Context Protocol, scoped to one database and one schema.

• What it does
• Status
• Prerequisites
• Install
• Quick start
• Connecting a client
• Commands
• Configuration
• Tool groups
• Security
• Support
• Contributing
• License

What it does

OwnPG serves one PostgreSQL database and one schema to an MCP client, in read-only, write-only, or read-write mode. Every statement is parsed and classified before it runs, and the access mode decides what is allowed. A destructive statement asks for confirmation before it executes, and an append-only, hash-chained audit log records every call. OwnPG runs over stdio for a local MCP client such as Claude Desktop, or over Streamable HTTP for a remote MCP client, with bearer-token or OAuth authentication.

Status

OwnPG is pre-release software at version 0.1.0. No version is tagged, and the crate is not published on crates.io. Releases, installation, and issue reporting for OwnPG happen in the public devops-infinity/ownpg-releases repository.

Prerequisites

• Rust 1.89 or newer to build from source. The workspace pins Rust 1.97.1 for its own build and test process.
• A reachable PostgreSQL server, version 14 through 18.
• For the host-program tools (pg_dump, pg_dumpall, pg_restore, pg_basebackup, pg_upgrade --check), the matching PostgreSQL client programs on the machine running OwnPG.

Install

Clone the repository and install the ownpg binary from a checkout:

cargo install --path crates/ownpg --locked

Or build the container image from the Dockerfile in the repository root:

docker build -t ownpg .

docker-compose.yml in the repository root shows a full example deployment: a PostgreSQL service, Docker secrets for the database password and bearer tokens, and a read-only OwnPG service.

Quick start

Serve one database over stdio, read-only, with the default schema public:

ownpg serve -d app

Check the connection and settings before serving:

ownpg doctor -p staging --format json

Save a connection profile, and store its password in the OS keychain only if the database needs one:

ownpg config init
ownpg config set-password local

Serve over Streamable HTTP with bearer-token authentication:

OWNPG_BEARER_TOKENS="a-long-random-token read-write client-a" \
ownpg serve --http --auth bearer --bind 127.0.0.1:8765 -d app

Connecting a client

The client starts and stops OwnPG for you; nothing runs until the client needs it, and nothing keeps running after the session ends. Register one entry per project database in the client's own MCP server list, with the connection given directly.

Claude Code reads a .mcp.json file in the project root, so each project names its own database:

{
  "mcpServers": {
    "ownpg": {
      "command": "ownpg",
      "args": ["serve", "--database", "myproject_db", "--no-input"],
      "env": {
        "OWNPG_HOST": "127.0.0.1",
        "OWNPG_USER": "myproject_role"
      }
    }
  }
}

Add "OWNPG_PASSWORD": "..." to env only if the database actually needs one. A local PostgreSQL server using trust or peer authentication, the default for a superuser or your own OS user on a Homebrew or system install, needs no password at all: OwnPG connects the same way psql would, nothing to type, nothing to store.

Claude Desktop reads one file covering every project, so name each entry after the project it connects to. The file lives at ~/Library/Application Support/Claude/claude_desktop_config.json on macOS, or %APPDATA%\Claude\claude_desktop_config.json on Windows. The same command/args/env block goes under a project-named key:

{
  "mcpServers": {
    "ownpg-myproject": {
      "command": "ownpg",
      "args": ["serve", "--database", "myproject_db", "--no-input"],
      "env": {
        "OWNPG_HOST": "127.0.0.1",
        "OWNPG_USER": "myproject_role"
      }
    }
  }
}

A second project gets a second entry, ownpg-otherproject, pointed at a different database; each one launches as its own process, scoped to its own database.

If a password does need to go somewhere more permanent than a client config file, run ownpg config init once, then ownpg config set-password <name> to store it in the OS keychain, and reference --profile <name> instead of the raw connection flags. That's a convenience for a password you'd rather not retype or paste, not a required step; the plain env block above works with nothing set up beforehand. This repository also carries mcpb/manifest.json, the manifest for Claude Desktop's packaged extension format.

Connecting over Streamable HTTP

A remote MCP client, or a client that cannot spawn a local process, connects to a running ownpg serve --http instance instead of launching its own. Point the client at http://<bind-address>/mcp (the path is always /mcp, whatever --bind address you chose), and set --auth to match how the client authenticates:

• --auth none: no credential, only usable when --bind stays on the loopback interface.
• --auth bearer: the client sends Authorization: Bearer <token> on every request, checked against the tokens set with OWNPG_BEARER_TOKENS or OWNPG_BEARER_TOKENS_FILE.
• --auth oauth: the client sends a JWT issued by an OAuth authorization server, verified against that server's published JSON Web Key Set.

A client that supports MCP's OAuth-protected-resource discovery reads /.well-known/oauth-protected-resource/mcp on the same host and port to find the authorization requirements automatically.

Commands

• ownpg serve: serve the MCP protocol. The default command when no subcommand is given.
• ownpg doctor: check the connection and report the result as text or JSON.
• ownpg config: manage connection profiles and local state (show, path, init, set-password, unset-password, set-ssh-passphrase, unset-ssh-passphrase, cache-clear).
• ownpg audit verify: check that every line of an audit log chains to the one before it.
• ownpg man: print a manual page, for the whole tool or one named subcommand.
• ownpg completions: print a shell completion script for bash, elvish, fish, powershell, or zsh.

Run ownpg man for the full reference to every command, flag, and environment variable.

Configuration

OwnPG resolves its settings in this order: command-line flags, environment variables, a connection profile file, libpq-standard environment variables and files (PGHOST, PGUSER, PGDATABASE, PGSERVICE, PGSERVICEFILE, PGPASSFILE), and built-in defaults.

The connection takes a host, a port (default 5432), a user, and a password, which can come from a flag, an environment variable, a .pgpass file, or the OS keychain. --database is required, --schema defaults to public, and --mode defaults to read-only. A database behind a bastion host is reachable with --ssh, using an in-process SSH client or the system ssh command.

A connection profile is a TOML file with one [profiles.<name>] table per named connection, covering the mode, database, schema, connection string, TLS settings, timeouts, row and byte caps, the strict-role check, the extra tool groups to load, the audit log settings, and the SSH settings for that profile. ownpg config init writes a starter profile file naming every key. ownpg config show prints the resolved settings for a profile with secrets masked.

Run ownpg config init --dry-run or ownpg man for the complete list of environment variables and profile keys.

Tool groups

objects, read, and health load by default. write and transactions load automatically once the access mode allows writes (write-only or read-write). --tools (or OWNPG_TOOLS) adds any of ddl, roles, maintenance, monitoring, host. A tool group not allowed under the active access mode is refused at startup.

Security

A destructive statement runs only after an explicit confirm: true argument or an elicitation round trip sealed to that one statement. See SECURITY.md for the vulnerability-reporting process and the data OwnPG handles.

Support

File an issue at devops-infinity/ownpg-releases.

Contributing

File an issue at devops-infinity/ownpg-releases to report a bug or request a change.

License

OwnPG is dual-licensed under the MIT license (LICENSE-MIT) and the Apache License 2.0 (LICENSE-APACHE). You may choose either.