> ## 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 apply

> Walk a project tree (entities/, metrics/, joins/) and apply every YAML to the store. Pairs with init --emit-yaml-dir and the per-resource export-all commands.

# `schemabrain apply`

Walks an on-disk project tree and applies each subdirectory's YAML files to the store. The tree shape mirrors what `schemabrain init --emit-yaml-dir` and `schemabrain {entities,metrics,joins} export-all` produce, so the full store ↔ YAML round-trip closes here.

```bash theme={null}
schemabrain apply ./schemabrain --url-env DATABASE_URL
```

Expected layout:

```text theme={null}
<project_dir>/
├── entities/
│   ├── users.yaml
│   └── orders.yaml
├── metrics/
│   └── daily_revenue.yaml
└── joins/
    └── user_orders.yaml
```

Missing subdirectories are skipped cleanly. The walker applies in a deliberate order — **entities first**, then **metrics** and **joins** which reference entities. The per-resource apply commands enforce FK invariants internally, so a broken reference fails the inner command and surfaces in the outer summary; the outer walker does not abort on a single bad file.

***

## Flags

| Argument / Flag            | Default            | Purpose                                                                      |
| -------------------------- | ------------------ | ---------------------------------------------------------------------------- |
| `project_dir` (positional) | `./schemabrain`    | Path to the project tree.                                                    |
| `--source URL`             | (none)             | Source URL the YAMLs attach to. Deprecated when the URL contains a password. |
| `--url-env VARNAME`        | (none)             | Env var holding the source URL. Preferred.                                   |
| `--store-path PATH`        | `./schemabrain.db` | Path to the local SQLite store.                                              |

***

## How it relates to per-resource `apply`

| You want to …              | Use                                 |
| -------------------------- | ----------------------------------- |
| Apply a whole project tree | `schemabrain apply <dir>`           |
| Apply one entity file      | `schemabrain entities apply <file>` |
| Apply one metric file      | `schemabrain metrics apply <file>`  |
| Apply one join file        | `schemabrain joins apply <file>`    |

The top-level `apply` is a convenience over the three per-resource `apply` commands; it never does anything the per-resource commands can't.

***

## Examples

### Round-trip: snapshot the store to disk, then re-apply

```bash theme={null}
# Snapshot
schemabrain entities export-all --dir ./schemabrain/entities
schemabrain metrics export-all  --dir ./schemabrain/metrics
schemabrain joins export-all    --dir ./schemabrain/joins

# Commit
git add ./schemabrain && git commit -m "snapshot semantic layer"

# Re-apply on another machine
schemabrain apply ./schemabrain --url-env DATABASE_URL
```

### Bootstrap from `init --emit-yaml-dir`

```bash theme={null}
schemabrain init --url-env DATABASE_URL --emit-yaml-dir ./schemabrain
# Edit the YAMLs to your heart's content
schemabrain apply ./schemabrain --url-env DATABASE_URL
```

### Drift-check before applying (recommended)

```bash theme={null}
schemabrain diff ./schemabrain --url-env DATABASE_URL && \
  schemabrain apply ./schemabrain --url-env DATABASE_URL
```

`diff` exits `0` only when there's no drift; chain with `&&` to apply only on clean state.

***

## Related

<CardGroup cols={2}>
  <Card title="schemabrain diff" icon="code-compare" href="/reference/cli/diff">
    Drift check between project tree and store before applying.
  </Card>

  <Card title="schemabrain init --emit-yaml-dir" icon="rocket" href="/reference/cli/init">
    Produces the project tree this command consumes.
  </Card>

  <Card title="schemabrain entities" icon="table" href="/reference/cli/entities">
    Per-resource apply / export commands.
  </Card>

  <Card title="schemabrain metrics" icon="chart-line" href="/reference/cli/metrics">
    Per-resource apply / export for metrics.
  </Card>
</CardGroup>