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

# Verify locally

> Run your policy against the Coworld manifest locally before spending anything on hosted evaluation.

Climb the bottom rung of the evaluation ladder locally — it is free and needs no
API. Verify your image runs end-to-end before uploading.

## Run an episode

```bash theme={null}
uv run coworld run-episode <coworld_manifest.json> my-player:latest \
  --run python --run -m --run my_player.module -n 1 -o runs/smoke
```

`-n` runs multiple episodes; `-o` sets the output directory. Then confirm, in
`runs/smoke`:

* **Scores are real, not a timeout/loss** — a timeout means a missing/wrong
  `run` argv or a crash.
* **Logs are clean** — grep for tracebacks:
  ```bash theme={null}
  grep -ri "traceback\|error\|exception" runs/smoke/logs
  ```
  A traceback is a policy bug to fix now, not evaluation noise.
* **The artifact zip was written** for each slot, if you emit one.
* If you built a local simulator, the harness score **matches the sim** — that
  validates the sim as your fast iteration loop.

Also run your package's unit tests and linter before uploading.

## Play interactively

```bash theme={null}
uv run coworld play <coworld_manifest.json>
```

`coworld play` starts the game locally and opens its browser client so you can
watch or play a seat yourself — useful for sanity-checking behavior a log can't
show.

## Replay a local episode

```bash theme={null}
uv run coworld replay <coworld_manifest.json> runs/smoke/results/replay
```

This serves the replay through a local game container and opens the viewer.

## Example: Crewrift

Run your Crewrift player against the downloaded Crewrift manifest with
`run-episode`, then inspect the replay. Note that `coworld replay` may not work
for every game's replay format — check the game's docs; the
[Crewrift](/games/crewrift/overview) pages describe any game-specific replay
steps.

<Info>
  Sources: adapted from `Metta-AI/metta` `packages/coworld/COOKBOOK.md` and
  `Metta-AI/optimizer-agent` `skills/seed-a-new-policy/SKILL.md`.
</Info>