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

# schemabrain check

> Detect drift between persisted definitions in the store and the live source schema. CI-friendly JSON mode for monitoring.

# `schemabrain check`

Probes the live source Postgres and compares its current schema to the snapshot in the local store. Surfaces three kinds of drift:

* Tables that were indexed but no longer exist.
* Columns that were indexed but no longer exist.
* Type / nullability changes on existing columns.

This is the **source-side** drift check. For drift between the store and an on-disk YAML project tree, use [`schemabrain diff`](/reference/cli/diff).

```bash theme={null}
schemabrain check --url-env DATABASE_URL --store-path ./schemabrain.db
```

***

## Flags

| Flag                | Default            | Purpose                                                                                               |
| ------------------- | ------------------ | ----------------------------------------------------------------------------------------------------- |
| `--source URL`      | (none)             | Source URL. Deprecated when the URL contains a password. One of `--source` / `--url-env` is required. |
| `--url-env VARNAME` | (none)             | Env var holding the source URL. Preferred.                                                            |
| `--store-path PATH` | `./schemabrain.db` | Path to the local SQLite store.                                                                       |
| `--json`            | (off)              | Emit JSON to stdout instead of the rich-rendered report to stderr. Pipe-friendly for CI / monitoring. |

***

## When to run it

* After any database migration.
* On a schedule, paired with an alert when the JSON output reports non-empty drift.
* Before running `schemabrain serve` in a long-lived environment.

After `check` reports drift, re-run `schemabrain index --url-env DATABASE_URL --store-path ./schemabrain.db` to refresh the snapshot. Indexing is idempotent and only re-enriches changed columns.

***

## Examples

### Default human report

```bash theme={null}
schemabrain check --url-env DATABASE_URL --store-path ./schemabrain.db
```

### CI-friendly JSON

```bash theme={null}
schemabrain check --url-env DATABASE_URL --store-path ./schemabrain.db --json > drift.json
```

### Refresh after detecting drift

```bash theme={null}
schemabrain check --url-env DATABASE_URL --store-path ./schemabrain.db || \
  schemabrain index --url-env DATABASE_URL --store-path ./schemabrain.db
```

***

## Related

<CardGroup cols={2}>
  <Card title="schemabrain index" icon="database" href="/reference/cli/index-command">
    Refresh the snapshot after `check` reports drift.
  </Card>

  <Card title="schemabrain diff" icon="code-compare" href="/reference/cli/diff">
    The orthogonal drift question — project tree vs store.
  </Card>

  <Card title="schemabrain doctor" icon="stethoscope" href="/reference/cli/doctor">
    Broader health check covering host config + store.
  </Card>

  <Card title="schemabrain inspect" icon="magnifying-glass" href="/reference/cli/inspect">
    Browse the indexed schema without re-probing the source.
  </Card>
</CardGroup>