- Knock Agent is an AI agent for managing customer messaging resources, capable of creating and updating workflows, templates, audiences, segmenting users, and answering performance questions.
- The agent was built using a virtual filesystem and bash, inspired by Vercel's approach, allowing it to explore and script on resources via a filesystem instead of exposing numerous API tools.
- A custom Elixir-based virtual bash interpreter called just-bash was developed to provide a lightweight, in-memory environment without the performance overhead of a full sandbox.
- The agent uses a durable workflow with Oban and Postgres, lazy-loading resources into the filesystem and providing tools like bash, read_file, edit_file, write_file, and upsert_resource for operations.