faucet

Turn any SQL database into a secure REST API.
One binary. One command.

Faucet is an open-source, single-binary API server that auto-generates REST endpoints, OpenAPI specs, and MCP tools from your database schema at runtime. No code generation, no ORM, no boilerplate.

Docs · Getting Started · Docker · MCP Server · Issues

What is Faucet?

Faucet is a database-to-REST-API gateway — a lightweight, self-hosted server that connects to your SQL databases, introspects the schema, and generates a full CRUD REST API with authentication, role-based access control (RBAC), and OpenAPI documentation. It also exposes an MCP server so AI agents (Claude, GPT, etc.) can query your data directly.

Think of it as an open-source alternative to DreamFactory, PostgREST, or Hasura — but with multi-database support, a built-in admin UI, and native AI agent integration, all in a single ~22MB binary.

Use Cases

• Instant backend for apps — Skip writing CRUD APIs by hand. Point Faucet at your database and start building your frontend.
• AI agent data access — Give Claude, GPT, or any MCP-compatible agent governed, read/write access to your databases.
• Internal tools & dashboards — Generate APIs for internal databases without modifying existing infrastructure.
• Legacy database modernization — Put a REST API in front of SQL Server 2008, MySQL 5.7, or PostgreSQL 9.6 without code changes.
• Multi-database aggregation — Connect PostgreSQL, MySQL, SQL Server, Oracle, and more to a single Faucet instance and query them all through one API.
• Rapid prototyping — Go from empty database to working API in under 60 seconds.

How It Works

┌──────────────┐       ┌───────────────────────────────────────┐       ┌──────────────┐
│ PostgreSQL   │       │              F A U C E T              │       │   REST API   │
│ MySQL        │──────▶│                                       │──────▶│   /api/v1/*  │
│ MariaDB      │  SQL  │  ┌─────────┐ ┌──────┐ ┌───────────┐   │       ├──────────────┤
│ SQL Server   │◀──────│  │ Schema  │ │ RBAC │ │  OpenAPI  │   │──────▶│  OpenAPI 3.1 │
│ Oracle       │       │  │ Intro-  │ │ Auth │ │ Generator │   │       │ /openapi.json│
│ Snowflake    │       │  │ spection│ │      │ │           │   │       ├──────────────┤
│ SQLite       │       │  └─────────┘ └──────┘ └───────────┘   │──────▶│  MCP Server  │
└──────────────┘       │                                       │       │  (AI Agents) │
                       │  ┌──────────────────────────────────┐ │       ├──────────────┤
                       │  │   Embedded Admin UI (Preact)     │ │──────▶│   Admin UI   │
                       │  └──────────────────────────────────┘ │       │  :8080/admin │
                       └───────────────────────────────────────┘       └──────────────┘

Connect any SQL database → Faucet introspects the schema → Instantly generates REST endpoints, OpenAPI docs, MCP tools, and an Admin UI — all secured with API keys, JWT auth, and role-based permissions.

Screenshots

Manage multiple database connections — PostgreSQL, MySQL, SQL Server, and more

Schema Explorer — Browse tables, columns, types, and constraints across all connected databases

API Explorer — Test REST endpoints interactively with live response data

Key Features

API Generation

• Full CRUD REST API — GET, POST, PUT, PATCH, DELETE with filtering, ordering, and pagination
• Schema introspection — Discovers tables, columns, types, and constraints at runtime
• Schema DDL — Create, alter, and drop tables via API
• Stored procedure calls — Execute stored procedures with typed parameters
• Human-readable query filters — (age > 21) AND (status = 'active')
• OpenAPI 3.1 spec — Auto-generated from live database schema at /openapi.json

Security & Access Control

• API key authentication — SHA-256 hashed keys with per-key role assignment
• JWT authentication — HMAC-SHA256 signed tokens for admin sessions
• Role-based access control (RBAC) — Per-table verb permissions (GET, POST, PUT, DELETE)
• Row-level security filters — Restrict data access per role with SQL filter expressions
• Schema contract locking — Lock your API contract against silent breaking schema changes with three modes (none, auto, strict), drift detection, and CLI management

AI Agent Integration (MCP)

• Built-in MCP server — 8 tools + 2 resources for Model Context Protocol
• Claude Desktop ready — Drop-in config for Claude Desktop and Claude Code
• stdio + HTTP transport — Works locally or over the network
• Governed AI queries — AI agents respect the same RBAC rules as API clients

Developer Experience

• Single binary — Zero external dependencies, ~22MB, cross-platform (Linux, macOS, Windows)
• Embedded admin UI — Preact + Tailwind dashboard with setup wizard, schema explorer, API tester
• SQLite config store — All configuration stored locally, no external database required
• npm + Homebrew + Docker — Install in seconds on any platform (npx @faucetdb/faucet)
• Health endpoints — /healthz and /readyz for Kubernetes-style probes

Supported Databases

60-Second Quickstart

Install

npm (Node.js 18+):

npx @faucetdb/faucet serve

Homebrew (macOS / Linux):

brew install faucetdb/tap/faucet

Docker:

docker run -p 8080:8080 -v faucet-data:/data faucetdb/faucet

Go:

go install github.com/faucetdb/faucet/cmd/faucet@latest

Binary download: See GitHub Releases for pre-built binaries (Linux, macOS, Windows).

Run

# Start the server
faucet serve

# Create an admin account
faucet admin create --email admin@example.com --password changeme123

# Add a database
faucet db add mydb --driver postgres --dsn "postgres://user:pass@localhost/mydb?sslmode=disable"

# Create an API key
faucet key create --role default

# Query your data
curl -H "X-API-Key: faucet_YOUR_KEY_HERE" http://localhost:8080/api/v1/mydb/_table/users?limit=10

Open http://localhost:8080 for the admin dashboard.

MCP Server for AI Agents

Faucet includes a built-in Model Context Protocol (MCP) server, enabling AI agents like Claude, GPT, and Copilot to query and modify your databases through governed, tool-based access.

Claude Desktop / Claude Code

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "faucet": {
      "command": "faucet",
      "args": ["mcp"]
    }
  }
}

HTTP Mode (remote clients)

faucet mcp --transport http --port 3001

Available MCP Tools

CLI Reference

faucet serve                    # Start HTTP server (default :8080)
faucet db add NAME              # Add database connection
faucet db list                  # List configured databases
faucet db test NAME             # Test database connectivity
faucet db schema NAME           # Dump database schema
faucet db lock NAME             # Lock schema contract
faucet db unlock NAME           # Remove contract locks
faucet db diff NAME             # Show schema drift
faucet db promote NAME          # Promote contracts to match live schema
faucet key create               # Create API key
faucet key list                 # List API keys
faucet role create              # Create RBAC role
faucet admin create             # Create admin account
faucet mcp                      # Start MCP server (stdio)
faucet openapi                  # Generate OpenAPI spec
faucet config set KEY VALUE     # Set configuration value
faucet version                  # Show version info

API Routes

GET  /healthz                                    # Liveness probe
GET  /readyz                                     # Readiness probe
GET  /openapi.json                               # OpenAPI 3.1 spec

POST   /api/v1/system/admin/session              # Admin login
GET    /api/v1/system/service                    # List services
POST   /api/v1/system/service                    # Create service
GET    /api/v1/system/role                       # List roles
POST   /api/v1/system/role                       # Create role
POST   /api/v1/system/api-key                    # Create API key

GET    /api/v1/{service}/_table                  # List tables
GET    /api/v1/{service}/_table/{table}          # Query records
POST   /api/v1/{service}/_table/{table}          # Insert records
PUT    /api/v1/{service}/_table/{table}          # Replace records
PATCH  /api/v1/{service}/_table/{table}          # Update records
DELETE /api/v1/{service}/_table/{table}          # Delete records

GET    /api/v1/{service}/_schema                 # List table schemas
POST   /api/v1/{service}/_schema                 # Create table
GET    /api/v1/{service}/_proc                   # List stored procedures
POST   /api/v1/{service}/_proc/{proc}            # Call procedure

Query Parameters

FAQ

How is Faucet different from PostgREST? PostgREST only supports PostgreSQL. Faucet supports 7 databases (PostgreSQL, MySQL, MariaDB, SQL Server, Oracle, Snowflake, SQLite), includes a built-in admin UI, and provides native MCP support for AI agents — all in a single binary.

How is Faucet different from Hasura? Hasura requires Docker, a PostgreSQL metadata database, and is primarily GraphQL-focused. Faucet is a single binary with no dependencies, generates REST APIs (not GraphQL), and includes built-in MCP server support for AI agent integration.

How is Faucet different from DreamFactory? DreamFactory is a PHP/Laravel application requiring a full LAMP/LEMP stack. Faucet is a single Go binary (~22MB) with zero dependencies. Faucet is fully open-source under MIT license with all features included — no paid tiers required for core functionality.

Does Faucet support GraphQL? Not currently. Faucet generates REST APIs and OpenAPI 3.1 specs. GraphQL support may be added in the future.

Is Faucet production-ready? Faucet is under active development. It is suitable for internal tools, prototyping, and AI agent integration. Check the releases page for the latest version.

Can AI agents write data through Faucet? Yes. MCP tools include faucet_insert, faucet_update, and faucet_delete. All operations respect RBAC roles, so you can give AI agents read-only or read-write access per table.

Does Faucet require a separate database for configuration? No. Faucet uses an embedded SQLite database for all configuration, credentials, roles, and API keys. Everything is stored locally in a single file.

Building from Source

git clone https://github.com/faucetdb/faucet.git
cd faucet
make build      # Builds UI + Go binary
make test       # Runs all tests
make dev        # Dev mode with hot reload

Tech Stack

• Go 1.25+ — Chi router, sqlx, Cobra/Viper CLI
• Preact + Vite + Tailwind — Embedded admin UI
• SQLite (pure Go, no CGO) — Configuration store
• MCP (Model Context Protocol) — AI agent integration

Documentation

Full documentation is available at the Faucet Wiki.

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for guidelines, or open an issue to report bugs and request features.

License

MIT — free for commercial and personal use.