> ## Documentation Index
> Fetch the complete documentation index at: https://docs.eucaengine.com/llms.txt
> Use this file to discover all available pages before exploring further.

# CLI reference

> The euca CLI — command groups, the self-describing discover/explain/schema commands, and how to target a server. The command set covers most of the HTTP API.

The `euca` CLI (`tools/euca-cli`) is a terminal client for a running server. It covers most of the
[HTTP API](/api-reference/introduction) — about 40 command groups, most mapping to a route family —
plus a few offline commands. Because it's **self-describing**, the live `euca discover` output is the
authoritative command list; this page mirrors it. (For the conceptual overview, see
[The euca CLI](/concepts/the-cli).)

## Targeting a server

```bash theme={null}
euca --server http://localhost:3917 <command>   # default: http://localhost:3917
```

There is no `EUCA_URL` environment variable — use `--server` (short `-s`) to point at another host.

## Command groups

The groups mirror the API families documented in [Guides](/systems/simulation):

| Area                   | Groups                                                                                                                                 |
| ---------------------- | -------------------------------------------------------------------------------------------------------------------------------------- |
| **World & simulation** | `entity`, `sim` (play / pause / step / reset), `scene`, `scenario`                                                                     |
| **Build**              | `template`, `prefab`, `rule`                                                                                                           |
| **Play**               | `game`, `trigger`, `projectile`, `ai`, `ability`, `effect`, `item`                                                                     |
| **Render & I/O**       | `camera`, `material`, `postprocess`, `fog`, `ui`, `animation`, `vfx` (particles), `terrain`, `foliage`, `audio`, `input`, `screenshot` |
| **Experiment**         | `fork` (with `fork probe`)                                                                                                             |
| **Platform**           | `nav`, `script`, `net`, `asset`, `auth`                                                                                                |
| **Ops & offline**      | `status`, `diagnose`, `events`, `profile`, `schema`, `package`, `discover`, `explain`                                                  |

A few HTTP families — assertions, the feature manifest, snapshots, levels, and entity tags — are
reachable over the [HTTP API](/api-reference/introduction) but do not yet have a dedicated CLI command
group. Use HTTP for those (or `fork probe` to advance-and-check assertions).

## Self-describing commands

These let an agent learn the surface at runtime instead of hard-coding it:

* **`euca discover`** — prints the command tree (groups, subcommands, arguments); `--json` for a
  machine-readable manifest; `--scope core|gameplay|media|moba|tools|all` to filter. **This is the
  authoritative, current command list — prefer it over any static catalogue.**
* **`euca explain <topic>`** — worked, copy-pasteable examples (topics include `quickstart`, `entity`,
  `combat`, `rule`, `assert`, `fork`, `scenario`). Baked into the binary; works offline.
* **`euca schema`** — the component/endpoint schema summary (the engine's `GET /schema`; see
  [Components & schema](/reference/components-and-schema)).

## Offline commands

A few commands run with no server: **`discover`** / **`explain`**, **`asset`** (mesh `info` /
`optimize` / LOD generation), and **`package`** (build + bundle assets). GLB → `.emesh` cooking is
handled by the separate **`euca-cook`** tool, not the `euca` CLI. Everything else is a thin HTTP call
to a server.

<Card title="The full HTTP surface" icon="server" href="/api-reference/introduction" horizontal>
  Every command maps to one of the \~114 endpoints in the API reference.
</Card>