This guide covers the current Rust workspace under `rust/` and the `claw` CLI binary. If you are brand new, make the doctor health check your first run: start `claw`, then run `/doctor`.
## Quick-start health check
Run this before prompts, sessions, or automation:
```bash
cd rust
cargo build --workspace
./target/debug/claw
# first command inside the REPL
/doctor
```
`/doctor` is the built-in setup and preflight diagnostic. Once you have a saved session, you can rerun it with `./target/debug/claw --resume latest /doctor`.
`claw` can talk to local servers and provider gateways through either Anthropic-compatible or OpenAI-compatible endpoints. Use `ANTHROPIC_BASE_URL` with `ANTHROPIC_AUTH_TOKEN` for Anthropic-compatible services, or `OPENAI_BASE_URL` with `OPENAI_API_KEY` for OpenAI-compatible services. OAuth is Anthropic-only, so when `OPENAI_BASE_URL` is set you should use API-key style auth instead of `claw login`.
### Anthropic-compatible endpoint
```bash
export ANTHROPIC_BASE_URL="http://127.0.0.1:8080"
export ANTHROPIC_AUTH_TOKEN="local-dev-token"
cd rust
./target/debug/claw --model "claude-sonnet-4-6" prompt "reply with the word ready"
```
### OpenAI-compatible endpoint
```bash
export OPENAI_BASE_URL="http://127.0.0.1:8000/v1"
export OPENAI_API_KEY="local-dev-token"
cd rust
./target/debug/claw --model "qwen2.5-coder" prompt "reply with the word ready"
`claw` has three built-in provider backends. The provider is selected automatically based on the model name, falling back to whichever credential is present in the environment.
### Provider matrix
| Provider | Protocol | Auth env var(s) | Base URL env var | Default base URL |
|---|---|---|---|---|
| **Anthropic** (direct) | Anthropic Messages API | `ANTHROPIC_API_KEY` or `ANTHROPIC_AUTH_TOKEN` or OAuth (`claw login`) | `ANTHROPIC_BASE_URL` | `https://api.anthropic.com` |
The OpenAI-compatible backend also serves as the gateway for **OpenRouter**, **Ollama**, and any other service that speaks the OpenAI `/v1/chat/completions` wire format — just point `OPENAI_BASE_URL` at the service.
### Tested models and aliases
These are the models registered in the built-in alias table with known token limits:
| Alias | Resolved model name | Provider | Max output tokens | Context window |
Any model name that does not match an alias is passed through verbatim. This is how you use OpenRouter model slugs (`openai/gpt-4.1-mini`), Ollama tags (`llama3.2`), or full Anthropic model IDs (`claude-sonnet-4-20250514`).
### User-defined aliases
You can add custom aliases in any settings file (`~/.claw/settings.json`, `.claw/settings.json`, or `.claw/settings.local.json`):
```json
{
"aliases": {
"fast": "claude-haiku-4-5-20251213",
"smart": "claude-opus-4-6",
"cheap": "grok-3-mini"
}
}
```
Local project settings override user-level settings. Aliases resolve through the built-in table, so `"fast": "haiku"` also works.
### How provider detection works
1. If the resolved model name starts with `claude` → Anthropic.
2. If it starts with `grok` → xAI.
3. Otherwise, `claw` checks which credential is set: `ANTHROPIC_API_KEY`/`ANTHROPIC_AUTH_TOKEN` first, then `OPENAI_API_KEY`, then `XAI_API_KEY`.
4. If nothing matches, it defaults to Anthropic.
## FAQ
### What about Codex?
The name "codex" appears in the Claw Code ecosystem but it does **not** refer to OpenAI Codex (the code-generation model). Here is what it means in this project:
- **`oh-my-codex` (OmX)** is the workflow and plugin layer that sits on top of `claw`. It provides planning modes, parallel multi-agent execution, notification routing, and other automation features. See [PHILOSOPHY.md](./PHILOSOPHY.md) and the [oh-my-codex repo](https://github.com/Yeachan-Heo/oh-my-codex).
- **`.codex/` directories** (e.g. `.codex/skills`, `.codex/agents`, `.codex/commands`) are legacy lookup paths that `claw` still scans alongside the primary `.claw/` directories.
- **`CODEX_HOME`** is an optional environment variable that points to a custom root for user-level skill and command lookups.
`claw` does **not** support OpenAI Codex sessions, the Codex CLI, or Codex session import/export. If you need to use OpenAI models (like GPT-4.1), configure the OpenAI-compatible provider as shown above in the [OpenAI-compatible endpoint](#openai-compatible-endpoint) and [OpenRouter](#openrouter) sections.
`claw` honours the standard `HTTP_PROXY`, `HTTPS_PROXY`, and `NO_PROXY` environment variables (both upper- and lower-case spellings are accepted) when issuing outbound requests to Anthropic, OpenAI-, and xAI-compatible endpoints. Set them before launching the CLI and the underlying `reqwest` client will be configured automatically.
./target/debug/claw prompt "hello via the corporate proxy"
```
Notes:
- When both `HTTPS_PROXY` and `HTTP_PROXY` are set, the secure proxy applies to `https://` URLs and the plain proxy applies to `http://` URLs.
-`NO_PROXY` accepts a comma-separated list of host suffixes (for example `.corp.example`) and IP literals.
- Empty values are treated as unset, so leaving `HTTPS_PROXY=""` in your shell will not enable a proxy.
- If a proxy URL cannot be parsed, `claw` falls back to a direct (no-proxy) client so existing workflows keep working; double-check the URL if you expected the request to be tunnelled.