tabulus 0.0.1

Postgres MCP server — agent-first database workbench

Vigil

A Postgres MCP server built for AI agents.

Vigil is the database workbench for the AI-augmented developer. Connect Claude Code, Cursor, or any MCP-compatible client to your Postgres database and let the agent introspect the schema, sample data, and write safe queries — without copy-pasting schemas into chat windows.

Why

Every modern dev workflow now includes an AI agent. Every DB GUI was designed before that was true. Vigil flips the model: the agent is a first-class user, not a sidebar feature.

What that means in practice:

• Schema introspection optimized for LLM context windows (compact JSON, foreign keys flattened, sample rows inline).
• Read-only by default — INSERT/UPDATE/DELETE/DDL are rejected at the gateway. Agent can't drop your tables.
• EXPLAIN exposed as a tool so the agent can reason about query plans before proposing optimizations.
• Statement timeout + row cap enforced server-side. No agent can DOS your database by accident.

Status

v0.0.1 — alpha. Postgres only. Stdio MCP transport only. No GUI yet.

Install

pip install tabulus

Run

export DATABASE_URL=postgres://user:pass@host:5432/dbname
vigil

Then point your MCP client at the vigil command.

Claude Code (project-level)

Create .mcp.json in your project root:

{
  "mcpServers": {
    "vigil": {
      "command": "vigil",
      "args": [],
      "env": {
        "DATABASE_URL": "postgres://user:pass@host:5432/dbname"
      }
    }
  }
}

Restart Claude Code in that directory and approve the trust prompt.

Claude Code (user-level via CLI)

claude mcp add vigil "$(which vigil)" --env DATABASE_URL=postgres://user:pass@host:5432/dbname

Cursor

Add to ~/.cursor/mcp_servers.json:

{
  "mcpServers": {
    "vigil": {
      "command": "vigil",
      "env": { "DATABASE_URL": "postgres://user:pass@host:5432/dbname" }
    }
  }
}

Tools

Tool	Description
list_tables	All tables with row count estimates + sizes
describe_schema	Columns, PK, FKs, indexes, sample rows for a table
sample_rows	Random sample from a table
safe_select	Run a read-only SELECT (write keywords rejected)
explain	Get query plan (EXPLAIN FORMAT JSON)

Configuration

Variable	Default	Purpose
DATABASE_URL	— (required)	Postgres connection URL
VIGIL_MAX_ROWS	100	Hard cap on rows returned by any tool
VIGIL_SAMPLE_SIZE	3	Sample rows included in describe_schema
VIGIL_STATEMENT_TIMEOUT_MS	5000	Server-side query timeout
VIGIL_REDACT	off	Set on to scrub PII (emails, API keys, JWTs, credit cards, phones, IPs) from sample_rows, safe_select, and describe_schema output before the agent sees it. Recommended for production.
VIGIL_ALLOW_WRITES	false	Set true to disable the write block (NOT recommended)

Roadmap

• v0.1 — Postgres parity, polished install
• v0.2 — SQLite adapter
• v0.3 — MySQL / MariaDB adapter
• v0.x — Tauri desktop GUI shell on top of the same core
• v1.0 — Stable, cross-platform, multi-DB

License

MIT. See LICENSE.