Autolith: a Common Lisp programming agent

Autolith: a programming agent with a live runtime Autolith runs in a terminal and works directly in your repository. It can read and edit files, search the workspace, run commands and tests, keep project context, and use Common Lisp without leaving the conversation. Repository work. Filesystem, shell, and search tools with visible results. Continuity. Portable conversations, memories, agendas, checkpoints, and recovery. Live Lisp. An SBCL runtime it can inspect, test, and extend. For developers who want an agent they can inspect, extend, and recover. Autolith · Resident agent Install Autolith Autolith targets Linux x86-64. The binary release carries its own SBCL, Lisp dependencies, and native helpers; it checks for newer tagged releases and asks before updating. Nix is the recommended route when you want the complete build pinned from the start. Yes, piping a URL into a shell is evil. Read the installer before running it. Nix is the better installation path. Autolith executes model-generated code with your user privileges. Its process boundaries protect reliability, not against hostile code. Use it as a development agent, not as a security sandbox. Start Autolith · Binary, Nix, or source After the binary installer $ autolith --auth $ autolith Recommended · Nix $ nix run github:luciusmagn/autolith -- --auth $ nix run github:luciusmagn/autolith Build from the repository $ git clone https://github.com/luciusmagn/autolith $ cd autolith $ ./script/bootstrap $ ./script/check $ ./bin/autolith --auth $ ./bin/autolith A session starts with a concrete request This is a captured read-only session from autolith --immutable. The prompt asks for one repository listing; the tool output is shortened only by Autolith's normal terminal limit. The transcript reveals itself in order: request, tool call, bounded result, then the assistant's answer. It is the terminal's actual formatting, not a simulated chat window. Captured session · immutable mode ❯ you Inspect this repository without changing files. Use one tool to list the top-level files, then summarize what you found in one sentence. ◇ reasoning summary │ Listing top-level files▸ fs.list /root/common-lisp/frobREAD ∙ running fs.list · 00:00 ✓ fs.list cpu 0.001s · real 0.002s │ /root/common-lisp/frob │ d .git/ │ d .github/ │ d .qlot/ │ d bin/ │ d dist/ │ d docs/ │ d native/ │ d nix/ │ d recovery/ │ d script/ │ d src/ │ … +13 more lines ● autolith The repository is a Common Lisp project with source, tests, recovery tooling, documentation, build configuration, native assets, and GitHub/Nix/Quicklisp support. The agent and its tools run in one process Autolith is a terminal programming agent, not a wrapper around another agent process. Its Common Lisp image contains the provider client, terminal interface, tool registry, conversation state, persistent memories, workspace agenda, and the code that decides what happens next. It talks directly to the ChatGPT Codex subscription service. The Codex CLI is neither launched nor bundled. Filesystem, shell, search, memory, and Lisp operations remain explicit tools with visible results. Fast search, optional immutable mode Workspace search runs in-process through fff, a fast Rust search library. Autolith keeps the index warm instead of starting a new search process for every query. If you want inspection without active-image changes, start it with --immutable. The mode retains read-only inspection and recovery information while withholding evaluation, mutation, persistence, checkpoint, and rollback tools. Update the running agent without restarting it Autolith can inspect and replace complete functions, methods, classes, macros, conditions, and global settings in its running image. An exploratory change takes effect immediately and is recorded in an append-only mutation journal. It can be exercised, discarded, or retained as a private image commit. A useful change can then become a private image commit. The commit contains a manifest and a complete executable Lisp replay script, retained in a separate private Git history. It changes the active agent without quietly patching the tracked source repository. A representative mutation transaction → self.source APPLICATION-TOOL-CALL-ENTRY ← complete tracked DEFMETHOD → self.redefine (defmethod application-tool-call-entry ...) ← compiled and installed in the active image → self.diff ← one reconstructible live mutation → self.commit "Improve tool-call presentation" ← private image commit commit-id complete reconstruct.lisp retained in private Git Different kinds of state stay separate Source, conversations, useful facts, live mutations, exact heaps, and disposable experiments have different lifetimes. Autolith keeps them separate instead of pretending that one database or one saved core is everything. Persistent surfaces · Reconstruction evidence Conversations Append-only portable S-expressions with exact resume commands and crash-tail repair. Memories Workspace or global facts, preferences, and decisions with bounded prompt recall. Agendas Short workspace tasks and notes, available in full on every request. Private image commits Complete replay scripts for durable user-specific definitions and settings, retained in private Git. Generations A saved active core, exact tracked source commit, reconstruction script, manifest, and journal position. Worker images Immutable experimental SBCL cores with parentage and durable notes, never selected as the active agent. Recovery A separately built pristine image that can inspect a crash and select a known-working generation without loading the damaged core. © 2026 Lambda Symbolics OÜ Autolith · Revised 18 July 2026