mastro-connect

mastro-connect, made by Giulio Colleluori, is an MIT-licensed CLI and framework that converts the browser session you already hold into command-line access to a web app's own API. Each connector is an OpenAPI 3.1 document plus a capture manifest, and every endpoint becomes a mastro <app> <command> with flags, help and JSON output. The project describes itself as early (0.2).

What It Is

mastro is a connector framework and CLI for personal automation. Instead of an agent driving a browser click by click, it replays the requests a web app's frontend already makes, using your existing login, from your own machine. Output is structured JSON suitable for pipes, scripts and agents that run shell commands.

How the Capture and Replay Flow Works

A small generic Chrome extension reads only the credentials a connector's manifest names (such as a cookie or header) during a login you start, and hands them to a local loopback receiver. The credential is stored in ~/.mastro with mode 0600 and bound to the sites you logged in to. Commands are then sent from your machine, or run inside your own logged-in tab for apps that only answer a real browser session. Anything that changes state can be previewed with --dry-run, which prints the planned requests with auth headers redacted.

Connectors as Data

A connector is a folder with openapi.yaml, auth.manifest.json, a README and optional agent skills. Custom x-mastro-* extensions cover authentication, replay transport, dynamic enums, HTML extraction, multi-step workflows and CLI projection. mastro validate checks schema, references and credential hosts. The mastro-author skill lets an agent build a connector after watching you do a task once in the browser. A community catalog currently lists hackernews, reservecalifornia and depop connectors, fetched on first use.

Agent Skills and Setup

Connectors ship SKILL.md playbooks that teach agents preconditions, JSON shapes, rate limits and safety rules. They install with mastro skills add. Setup needs Node 18+ and runs via npx mastro-connect setup; it works with agents such as Claude Code, Codex, Gemini CLI and Cursor that run on your machine.

Status and Scope

The project says it is developed and tested on macOS with Chrome; Linux should work, while Windows and other Chromium browsers are untested. Catalog connectors are unofficial and may break when apps change. It is intended for personal automation, not bulk scraping or defeating bot defenses.