Tusk

Read-only PostgreSQL MCP server for AI agents. Exposes schema introspection and SELECT-only query execution over the Model Context Protocol.

Install

# npx (no install needed)
npx tusk-mcp --host db.example.com --database mydb

# or clone + run
bun install
bun run src/index.ts --host localhost --database mydb

Setup UI

Interactive browser-based setup that generates config for Claude Desktop, Claude Code, Cursor, Windsurf, and OpenAI Codex.

npx tusk-mcp setup

Build standalone binary

bun run build           # Windows
bun run build:linux     # Linux
bun run build:macos     # macOS ARM

Connection

Individual flags (recommended)

tusk-mcp --host db.example.com --port 5432 --user admin --password 'p@ss' --database mydb

Connection string

tusk-mcp --connection-string "postgres://admin:p%[email protected]:5432/mydb"

Unencoded special characters in passwords (@, #) are handled automatically.

Environment variables

PGHOST=db.example.com PGDATABASE=mydb tusk-mcp

Priority: flags > --connection-string > DATABASE_URL > PG* env vars

Password security

# From file (Docker/K8s secrets)
tusk-mcp --host db --database mydb --password-file /run/secrets/db_pass

# From command (any secrets manager)
tusk-mcp --host db --database mydb --password-cmd 'vault kv get -field=password secret/db'
tusk-mcp --host db --database mydb --password-cmd 'op read op://vault/db/password'

SSL

Providing any certificate file automatically enables SSL.

tusk-mcp --host db --database mydb --ssl-ca /path/to/ca.crt       # CA verification
tusk-mcp --host db --database mydb \                               # mutual TLS
  --ssl-ca ca.crt --ssl-cert client.crt --ssl-key client.key

SSH tunnel

tusk-mcp --host db-internal --database mydb \
  --ssh-host bastion.example.com --ssh-user deploy --ssh-key ~/.ssh/id_rsa

Structure-only mode

Disables execute-query tool. Agents can see schema but not run queries.

tusk-mcp --host db --database mydb --structure-only

Tools

Tool	Description
list-schemas	List non-system schemas
list-tables	Tables and views with estimated row counts (partitions filtered out)
describe-table	Columns, types, PKs, FKs, and enum values inline
execute-query	Read-only SQL with limit (disabled in structure-only mode)

Output format

Tool results use compact text in content for the AI model and JSON-safe preview data in structuredContent for clients that support structured MCP output. Query text uses a tab-delimited preview with null=\N; strings are JSON-quoted, so empty strings render as "" and the literal string "\\N" is distinct from SQL null.

MCP config

{
  "mcpServers": {
    "tusk": {
      "command": "npx",
      "args": ["-y", "tusk-mcp", "--host", "localhost", "--database", "mydb"]
    }
  }
}

Claude Code

claude mcp add --transport stdio tusk -- npx -y tusk-mcp --host localhost --database mydb

OpenAI Codex (~/.codex/config.toml)

[mcp_servers.tusk]
command = "npx"
args = ["-y", "tusk-mcp", "--host", "localhost", "--database", "mydb"]

All flags

Flag	Type	Default	Description
--host	string	localhost	PostgreSQL host
--port	number	5432	PostgreSQL port
--user	string	—	Database user
--password	string	—	Database password
--password-file	string	—	Read password from file
--password-cmd	string	—	Run command for password
--database	string	—	Database name
--connection-string	string	—	Full connection URL
--ssl-ca	string	—	CA certificate path (enables SSL)
--ssl-cert	string	—	Client certificate path (enables SSL)
--ssl-key	string	—	Client key path (enables SSL)
--ssh-host	string	—	SSH tunnel host
--ssh-port	number	22	SSH tunnel port
--ssh-user	string	—	SSH username
--ssh-key	string	—	SSH private key path
--ssh-password	string	—	SSH password
--structure-only	boolean	false	Disable execute-query