---
title: Claude Code
description: Anthropic's CLI coding agent. The default agent in AO.
---

import { Callout } from "fumadocs-ui/components/callout";

<div style={{ display: "flex", alignItems: "center", gap: "0.75rem", margin: "0.5rem 0 1.25rem" }}>
  <Logo name="claude-code" size={28} />
  <span style={{ fontSize: "0.8125rem", color: "var(--color-fd-muted-foreground)" }}>Slot: <code>agent</code> · Name: <code>claude-code</code> · Binary: <code>claude</code></span>
</div>

[Claude Code](https://docs.anthropic.com/en/docs/claude-code) is Anthropic's CLI coding agent. It's AO's default because it has first-class session resume, rich JSONL event logs, and a native hook system AO can register against.

<PlatformSupport macos="full" linux="full" windows="full" />

## Install

```bash
npm install -g @anthropic-ai/claude-code
```

Then sign in once:

```bash
claude
```

## Use

```yaml title="agent-orchestrator.yaml"
agent: claude-code
```

That's it — there are no plugin-level config keys.

## How it works

- **Launch:** `claude` runs inside the worktree. AO sets `CLAUDECODE=""`, `AO_SESSION_ID`, and `AO_ISSUE_ID` in the environment.
- **Activity tracking:** AO registers a PostToolUse hook in `.claude/settings.json` on workspace setup. The hook writes an AO activity entry each time Claude calls a tool, so the dashboard's `active/ready/idle` states stay accurate.
- **Session resume:** `claude --resume <sessionId>` rehydrates the previous chat. AO maps its session ID to Claude's via the JSONL at `~/.claude/projects/<project>/...jsonl`.
- **Cost reporting:** AO reads Claude's per-message cost field from the JSONL — visible on the dashboard card.

## Environment variables

| Variable | Set by AO | Purpose |
|---|---|---|
| `AO_SESSION_ID` | ✓ | Unique AO session identifier |
| `AO_ISSUE_ID` | ✓ (when spawned from an issue) | Issue identifier |
| `CLAUDECODE` | ✓ | Signals to Claude that it's running under a harness |

Your Anthropic API key comes from wherever `claude` normally reads it — `~/.claude/`, env, etc. AO doesn't touch it.

## Troubleshooting

<Accordions>
  <Accordion title="`claude` not found">
    `npm install -g @anthropic-ai/claude-code`, then reopen your terminal so the PATH picks it up.
  </Accordion>
  <Accordion title="Dashboard shows no activity state">
    AO registers the PostToolUse hook in `.claude/settings.json` on spawn. If the hook got removed, run `ao spawn` again — AO re-installs it idempotently.
  </Accordion>
  <Accordion title="Session won't resume">
    Claude's session JSONL lives at `~/.claude/projects/<project-slug>/<sessionId>.jsonl`. If that file is gone (cleaned up, moved), resume won't work — spawn fresh.
  </Accordion>
</Accordions>
