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

# corpus

> Run the dirty-real regression oracle against a disposable PostgreSQL database.

Use `corpus` when you need regression coverage for false drift and catalog parity bugs.

The command replays dirty migrations, diffs the result against a clean tree, applies the reconciliation twice, and requires the final diff to converge to zero operations.

## Use this when

* A bug involved false drift.
* Engine changes need dirty-real catalog coverage.
* A consuming repo keeps its own incident corpus.
* CI can provide a disposable PostgreSQL database.

## Run it

```bash theme={null}
npx supaschema corpus --database-url "$DATABASE_URL"
npx supaschema corpus --corpus-dir corpus/supabase-style --database-url "$DATABASE_URL"
npx supaschema corpus --database-url "$DATABASE_URL" --json
```

Without a database URL, `corpus` prints a skip notice and exits `0`.

## Flags

<ParamField path="--corpus-dir" type="path">
  Corpus directory. Defaults to `corpus/supabase-style`.
</ParamField>

<ParamField path="--database-url" type="url">
  Admin URL for disposable corpus databases.
</ParamField>

<ParamField path="--json" type="boolean">
  Print the corpus report as JSON.
</ParamField>

## Exit codes

| Code | Meaning                                                       |
| ---- | ------------------------------------------------------------- |
| `0`  | Corpus converged, or skipped because no database URL resolved |
| `1`  | Runtime failure                                               |
| `2`  | Corpus diagnostics failed                                     |

## Related

<CardGroup cols={2}>
  <Card title="Corpus guide" icon="book-open" href="/docs/guides/corpus-oracle">
    Understand the dirty-real regression lane.
  </Card>

  <Card title="Benchmarks" icon="gauge" href="/docs/benchmarks">
    Review correctness and timing evidence.
  </Card>

  <Card title="Check" icon="shield-check" href="/docs/commands/check">
    See the static gate used by the corpus lane.
  </Card>

  <Card title="Verify" icon="repeat-2" href="/docs/commands/verify">
    Compare apply-twice proof with corpus reconvergence.
  </Card>
</CardGroup>