Autolith is a terminal-based programming agent that runs directly within a code repository, allowing developers to read, edit, search, and execute commands while maintaining project context. The tool operates using a Common Lisp runtime based on SBCL, with its own binaries for Linux, macOS, and BSD systems, and can be installed via prebuilt binaries or through Nix for reproducible builds.

Users authenticate with supported AI providers—such as ChatGPT Codex, Grok, Fireworks AI, Anthropic, and OpenAI-compatible endpoints—by using a browser device flow or an API key. The default model is gpt-5.6-sol. Autolith runs with the user's privileges and isolates process boundaries for reliability, not security.

Key capabilities include a live Lisp environment that can inspect and modify functions, classes, and macros in real time, a searchable workspace index built on a Rust library, and an immutable mode for read‑only inspection. The agent stores conversations, memories, agendas, private image commits, and crash‑recovery generations separately, enabling persistent state without conflating data. Recorded sessions demonstrate tasks such as listing condition classes across a large codebase, redefining functions live to handle extended durations, and recovering from crashes by reverting to a clean image.

The project documents installation steps for binary, Nix, or source builds, outlines how to update the running agent without restarting, and describes how to create private image commits that retain full executable replay scripts.