Libretto

Libretto is an open-source toolkit for building and maintaining robust web integrations and browser automations. It gives your coding agent a live browser and a token-efficient CLI to inspect live pages, capture network traffic, record user actions, and debug broken workflows interactively against real sites. Originally built by Saffron Health to maintain browser integrations with healthcare software, it is now open-sourced under the MIT License for any team to use.

• Live Browser Access — Install via npm install libretto and run npx libretto setup to give your coding agent a headed Chromium browser for real-site interaction.
• Token-Efficient Snapshots — Use npx libretto snapshot to capture PNG and HTML snapshots analyzed by an LLM, keeping heavy visual context out of your agent's context window.
• Network Traffic Capture — Libretto records all network requests during browser sessions, enabling reverse-engineering of site APIs and conversion of UI automations to direct API calls.
• Action Recording & Replay — Record user actions in the browser with npx libretto save and replay them as Playwright TypeScript automation scripts.
• Interactive Debugging — Reproduce broken workflows, pause at any step, inspect the live page, and fix selector errors autonomously using npx libretto exec.
• Multi-Provider AI Support — Configure snapshot analysis with OpenAI, Anthropic, Gemini, or Vertex via npx libretto ai configure <provider>, reading credentials from environment variables or .env.
• Session & Profile Management — Persist authenticated browser state (cookies, localStorage) across runs using profiles stored in .libretto/profiles/.
• CLI-First Workflow — All functionality is accessible via npx libretto commands, making it easy to integrate into agent pipelines or run manually from the terminal.