fen documentation #

fen is a small Fennel→Lua coding-agent CLI. It is built as a reloadable microkernel: a tiny core (agent loop, canonical types, provider dispatch, extension registry) with providers, the UI, session storage, and even the built-in tools all shipped as first-party extensions. It mirrors pi-mono's interface shapes in simplified form and targets Lua 5.4 on ARMv7/Raspberry-Pi-class hardware.

For a project overview, install instructions, and a quick start, see the repository README.

fen TUI demo: reading the README and describing itself

Guides #

Development workflow — dev workflow, hot reload, checks, Nix result symlinks.
Architecture notes — module map, canonical types, reloadable microkernel, design principles.
Extensions — extension discovery, manifests, API surface, reload, packaging, examples.
Providers — provider interface, auth/wire differences, models.json custom providers.
Tools — built-in tool contracts and deliberate omissions.
Sessions — JSONL session format and flags.
Scripts — portable Lua/Fennel script runner.
Skills — SKILL.md discovery and prompt behavior.
Distribution — Nix artifacts, single-file binary format, package.searchers precedence, dev overlays, releases.

Generated reference #

The generated site includes contracts, API, registries, and graphs pages scanned directly from source. Use the sitemap for a dense index of every page and the machine-readable artifacts. It is part of the published documentation site rather than the repository.