Sqbyl MCP Server

The full sqbyl dev toolkit: introspect, profile, annotate, synth, eval, Coach, judges, console, optimizer, release builder.

Local serverstdioPython

What is the Sqbyl MCP server?

Sqbyl MCP server exists for a simple reason — assistants are far more useful when they can act on Sqbyl directly instead of describing what you should do. The full sqbyl dev toolkit: introspect, profile, annotate, synth, eval, Coach, judges, console, optimizer, release builder.

What you get

Bring your own database and one LLM provider key (Anthropic or OpenAI). sqbyl uses your chosen model to both answer natural-language questions against your data and coach you on how to make the agent answer them better — then ships the result as a single portable file you can drop into production.

  • No black box. — Every prompt, judge, and improvement proposal is readable, editable plain text/JSON
  • No second vendor. — A single provider key (Anthropic or OpenAI) powers the agent, the judges, and the Coach. Context selection is LLM/lexical, so there's no embeddings provider or vector store to run
  • No surprise bill. — The free, deterministic work (connect, profile, infer joins) runs first at $0. Paid work is estimated up front, metered live, and capped by --budget
  • Versioned like code. — Your whole "agent" is a directory of YAML you diff, review, and git revert
  • Defensible by design. — The headline accuracy is deterministic and measured on a held-out set the improvement loop can never touch — so "we hit 94%" is a claim that survives scrutiny, not a benchmark you overfit. (more below)

Setting it up

Installation goes through your MCP client rather than a global install: point it at sqbyl on PyPI and it is fetched when the client starts. The copy-paste blocks for Claude Desktop, Claude Code and Cursor are further down this page.

Configuration and credentials

You will need 3 environment variables: ANTHROPIC_API_KEY, DATABASE_URL, OPENAI_API_KEY. The server will not start without them, which is usually why the tools fail to appear on a first run. Keep credentials in your client's env block or a secrets manager rather than in a file you might commit.

  • Python (managed via uv) - An LLM provider API key — Anthropic (ANTHROPIC_API_KEY) or OpenAI (OPENAI_API_KEY) - A SQL database, reachable read-only (DATABASE_URL). DuckDB and Postgres are the first-class dialects; SQLite, MySQL, Snowflake, and BigQuery are supported behind a dialect seam. ---

Before you rely on it

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Missing credentials fail quietly in some clients — if no tools show up, check the environment block first.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the sqbyl mcp server does with a few real requests.

Choosing this one

Among the AI and media services options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. It is maintained by Jack Werner; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

How to install the Sqbyl MCP server

{
  "mcpServers": {
    "sqbyl": {
      "command": "uvx",
      "args": ["sqbyl"],
      "env": {
        "ANTHROPIC_API_KEY": "your-value",
        "DATABASE_URL": "your-value",
        "OPENAI_API_KEY": "your-value"
      }
    }
  }
}

Add to claude_desktop_config.json, then restart Claude Desktop.

Configuration

  • Python (managed via uv) - An LLM provider API key — Anthropic (ANTHROPIC_API_KEY) or OpenAI (OPENAI_API_KEY) - A SQL database, reachable read-only (DATABASE_URL). DuckDB and Postgres are the first-class dialects; SQLite, MySQL, Snowflake, and BigQuery are supported behind a dialect seam. ---
VariableDescriptionRequired
ANTHROPIC_API_KEYCredential the server authenticates with.Yes
DATABASE_URLEndpoint or connection string the server talks to.Yes
OPENAI_API_KEYCredential the server authenticates with.Yes

Frequently asked questions

It connects Sqbyl to MCP-compatible AI assistants such as Claude and Cursor. Instead of copying data back and forth by hand, the assistant works with Sqbyl directly.