# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## What This Is

agent0 is an agentic coding TUI built with Babashka (Clojure). It runs local LLMs via Ollama with tool-use capabilities (file editing, shell commands, code search, web research) in a terminal interface.

## Running

```bash
agent                          # Interactive
agent "prompt"                 # With initial prompt
agent --continue               # Resume latest session
agent --session <uuid>         # Resume specific session
```

**Requirements:** Babashka, Ollama running locally. Model defaults to `qwen3-coder-next` (override with `$AGENT_MODEL`). Ollama host defaults to `http://localhost:11434` (override with `$OLLAMA_HOST`).

## Architecture

**Runtime:** Babashka scripts (`bb.edn`), depends on local `../clojure-tui` for the TUI framework.

**Source files (`src/agent/`):**

- **app.clj** — TUI layer. Elm-architecture: `view` renders state, `update-fn` handles events. The agent loop runs async in a background thread; UI polls an event queue every 100ms. Manages session persistence, skill expansion, scrolling, and input.
- **core.clj** — Agent brain. `run-agent-loop!` iterates: call LLM → execute tool calls → append results → repeat (max 50 iterations). Tools return strings or `{:message str :diff str}` maps. Includes stuck-loop detection (exact repeats and research loops). `build-system-prompt` composes the base prompt with project context.
- **context.clj** — Loads project context from `.agent0/context.md`, `CLAUDE.md`, `.cursorrules`, or `.github/copilot-instructions.md`. Parses skill definitions from `~/.config/agent0/skills.md` (global) and `.agent0/skills.md` (project). Skills are `/name <arg>` templates with `{param}` substitution.
- **markdown.clj** — Converts markdown to ANSI-styled terminal text. Handles inline formatting, code blocks, headers, lists, links, and ANSI-aware word wrapping.
- **web_search.clj** — Subagent config for web research. Uses DuckDuckGo HTML search + URL fetching. Delegated to via the `delegate` tool.

**Data flow:** User input → skill expansion (if `/command`) → conversation history → `run-agent-loop!` (background future) → LLM call → tool execution → events pushed to atom queue → UI polls and renders.

**Event types:** `:text` (assistant response), `:tool` (tool label), `:diff` (file change preview), `:error`, `:done`.

**Persistence:** Sessions in `~/.local/share/agent0/sessions/`, logs in `~/.local/share/agent0/logs/`.

## Key Patterns

- Tools that modify files (`edit-file`, `create-file`) return `{:message ... :diff ...}` maps. `execute-tool` extracts the diff and passes it as a separate UI event. The LLM only sees the `:message` string.
- The TUI uses clojure-tui's hiccup-like syntax: `[:row {:widths [22 :flex]} left right]`, `[:col {:heights [:flex 3]} content input]`, `[:box {:border :rounded}]`, `[:text {:fg :red :bold true} "text"]`.
- `run-agent-loop!` returns `{:future f :cancel! atom}`. Setting `cancel!` to true + `future-cancel` interrupts the loop.
- Subagents (`web_search`) are synchronous mini-loops with their own tools and system prompt, invoked via the `delegate` tool.

## No Tests

There is no test suite. Verify changes by loading namespaces in the nREPL (`bb nrepl-server`) and testing functions interactively.