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.
- Oversized context. Recursive inference over corpora larger than the model window.
- Continuity. Portable conversations, memories, agendas, checkpoints, and recovery.
- Live Lisp. An SBCL runtime it can inspect, test, and extend.
Read the source See the sessions Install Autolith
For developers who want an agent they can inspect, extend, and recover.
Autolith · Resident agent
curl -fsSL https://sh.lambda-symbolics.com/autolith | sh
click to copy, or, better yet, install via Nix
Install Autolith
Autolith v0.35.0 runs on Linux x86-64, Linux aarch64, macOS arm64, FreeBSD x86-64, NetBSD x86-64, and OpenBSD x86-64. The binary release carries its own SBCL 2.6.6, Lisp dependencies, and native helpers; Linux is served in glibc and musl builds. Installed releases check for newer tags and ask before updating. Nix is the recommended route when you want the complete build pinned from the start.
Providers sign in with a browser device flow or an API key: ChatGPT Codex subscription, Grok subscription, Fireworks AI, Anthropic API (pay-per-token), and OpenCode (zen/go). Any other OpenAI-compatible endpoint can be registered from the REPL. The default model is gpt-5.6-sol.
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
Three captured sessions
Real recordings against v0.35.0, driven by gpt-5.6-terra on the ChatGPT Codex subscription. Each window lists the exact prompt, wall time, token usage, the resulting artifact, and how to reproduce the session. Nothing is simulated and nothing is edited; long waits are only capped at two seconds during playback.
Captured session · a corpus larger than the context window
:::. ::: AUTOLITH v0.35.0
;;`;; ;;; ─────────────────────────────────────────
,[[ '[[, [[[ model gpt-5.6-terra (effort high)
c$$$cc$$$c $$' workspace /root/common-lisp/frob/
888 888,o88oo,.__\
YMM ""` """"YUMMM\
\
Autolith executes model-generated code with your user privileges.\
Sandboxing is no substitute for human oversight\
\
Tip: (resume) returns to a saved conversation from this workspace or another one.\
\
❯ you 2026-08-22 10:52
Use rlm.complete over autolith-source.txt in the workspace root. It is the concatenation of
```\
Load the recording · 4 min 36 sPromptUse rlm.complete over autolith-source.txt in the workspace root.
It is the concatenation of this repository's 121 src/*.lisp files
with ';;;; FILE:' headers, about 3.1 MB, larger than your
context window. Task: list every condition class defined in the
source, grouped by subsystem, with the defining file for each.
Use a budget of 32 calls, 400000 tokens, depth 2. Do not read or
search the file directly; if the budget exhausts, stop and report.ProviderChatGPT Codex subscription · gpt-5.6-terra (effort high)Wall time3 min 15 s for the answer; 4 min 36 s for the whole sessionTokens59.6K in the root conversation (58.7K input + 915 output); the corpus itself never enters a promptArtifactAll 83 condition classes, grouped by 14 subsystems, each with its defining fileTrace`inference:s2Wb1o2`, the complete frame conversation, readable in-session with resource.readReproduce`find src -name '*.lisp' | sort | while read f; do printf ';;;; FILE: %s\n' "$f"; cat "$f"; done > autolith-source.txt && autolith`, then the prompt above
Captured session · break the running agent, watch it recover
:::. ::: AUTOLITH v0.35.0
;;;; ;;; ───────────────────────────────────────── ,[[ '[[, [[[ model gpt-5.6-terra (effort high) c$$$cc$$$c $$' workspace /root/common-lisp/frob/ 888 888,o88oo,.__\ YMM "" """"YUMMM\
Autolith executes model-generated code with your user privileges. Sandboxing is no substitute for human oversight
Tip: (vault-discard) deletes only this conversation's recovery vault and blocked pending state.
❯ you 2026-08-22 10:58 Show the source of terminal-ui--duration-text in your running image, then redefine it live so
Load the recording · 6 min 19 sPromptShow the source of terminal-ui--duration-text in your running
image, then redefine it live so durations of 24 hours and more
render as Dd H:MM:SS, for example 1d 2:00:00. Exercise the change
with assertions for 59 seconds, 61 minutes, and 26 hours, then
commit the mutation with a short message. Then deliberately break
the function with a redefinition that signals an error,
demonstrate the failure with self.eval, and recover by discarding
the broken mutation. Verify with self.eval that the committed
version is active again.ProviderChatGPT Codex subscription · gpt-5.6-terra (effort high)Wall timeAbout 6 minutes, including the crash and the recovery bootTokens289.0K total (286.1K input + 3.0K output), most of it the bounded crash context of the diagnosis turnArtifactPrivate image commit "Format long activity durations". The broken
formatter is used by the live status row, so the deliberate break
killed the active process outright: Autolith wrote crash capsule
`efa6aa16`, booted the pristine recovery image, restarted
from clean committed source with the private commit selected,
restored the conversation, and opened a read-only diagnosis turn
that asked before repairing anything. The committed mutation
survived its own author.TraceAppend-only mutation journal, the crash capsule, and the private commit's replay scriptReproduce`autolith` in any workspace, then the prompt above
Captured session · persist the environment, quit, resume, continue
root@lho-thinkpad: ~/common-lisp/frob # ./bin/autolith WARNING: redefining AUTOLITH::TERMINAL-UI--DURATION-TEXT in DEFUN
:::. ::: AUTOLITH v0.35.0
;;;; ;;; ───────────────────────────────────────── ,[[ '[[, [[[ model gpt-5.6-terra (effort high) c$$$cc$$$c $$' workspace /root/common-lisp/frob/ 888 888,o88oo,.__\ YMM "" """"YUMMM\
Autolith executes model-generated code with your user privileges. Sandboxing is no substitute for human oversight
Tip: (papercuts) shows problems Autolith recorded when something was not working.
Load the recording · 10 min 11 sPromptDefine autolith-demo-parse-fraction in the autolith package:
parse a string like "3/4" into a rational. Exercise it, then
persist it as a private image commit. Then add an agenda entry:
handle zero denominators in autolith-demo-parse-fraction.
After (quit) and autolith resume: Where were we? Check the
agenda, confirm autolith-demo-parse-fraction is still defined in
this fresh image by evaluating (autolith-demo-parse-fraction
"3/4"), then finish the agenda item: signal a clear error for a
zero denominator, exercise both paths, and mark the agenda entry
done.ProviderChatGPT Codex subscription · gpt-5.6-terra (effort high)Wall time10 min 11 s across two processes; each persist runs the full validation suite before anything is retainedTokens601.1K total for the resumed conversation (598.5K input + 2.6K output)ArtifactPrivate image commits 4048480f and 9eee3ae4. The function
defined before (quit) answers (autolith-demo-parse-fraction
"3/4") = 3/4 in the next process without any reloading; the
agenda entry written in the first session is found, finished,
and marked done in the second.TraceAppend-only conversation store, the two commits' replay scripts, and the workspace agendaReproduce`autolith`, the first prompt, `(quit)`, then `autolith resume` and the second prompt
## 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.
Context larger than the window is an environment, not a prompt.
**`rlm.complete`** interns the corpus as a
content-addressed object; the model receives only its label, size,
and digest, and drives a heap-isolated Lisp environment through
bounded slices, searches, and sub-inferences under an explicit
call and token budget. Every run leaves a readable inference
trace.
## Fast search, optional immutable mode
Workspace search runs in-process through
**[fff](https://github.com/dmtrKovalenko/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
→ lisp.source TERMINAL-UI--DURATION-TEXT target self ← complete tracked DEFUN
→ self.redefine (defun terminal-ui--duration-text ...) ← compiled and installed in the active image
→ self.exercise (assert (string= "1d 2:00:00" ...)) ← journaled assertion passed
→ self.diff ← one reconstructible live mutation
→ self.commit "Show days in long durations" ← 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. |
