> ## 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.

# Atlas migrate lint is now paid: free Postgres alternatives

> Atlas made `atlas migrate lint` an Atlas Pro feature in v0.38 (October 2025). Here are free, Postgres-native migration-safety alternatives, including supaschema's free diff/check and scan.

If you relied on `atlas migrate lint` for free migration-safety checks, that command moved behind Atlas Pro. This page lists free, Postgres-native alternatives and shows where `supaschema` fits.

## What changed in Atlas

Starting with Atlas v0.38, the `atlas migrate lint` command is available only to Atlas Pro users, and the custom schema-policy linting rules are Pro-only as well. Atlas's current pricing pages describe separate CLI seat, pipeline project, and target-database pricing. Confirm the current pricing page before quoting a number.

<Info>
  Last verified 2026-06-18 against the Atlas documentation. Pricing and feature
  gating are set by Atlas and can change; confirm the current terms on the Atlas
  site before quoting them.
</Info>

## Free alternatives at a glance

| Tool         | License                      | Migration-safety scope                                                                                                                                                        | Needs a database or Docker?                              |
| ------------ | ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------- |
| `supaschema` | Open source (MIT)            | Replay-safety + lock-hazard checks on generated migrations (`check`), a destructive-operation advisory in `diff`, and a `scan` score with RLS-audit and least-privilege packs | No, generation and checks run from declarative SQL files |
| Squawk       | Open source (MIT/Apache-2.0) | Lock-safety linter for Postgres migration SQL                                                                                                                                 | No                                                       |
| pgfence      | Source-available             | Migration-safety CLI: lock-mode analysis, risk scoring, and safe-rewrite recipes                                                                                              | No                                                       |

Each tool is Postgres-native. None requires an Atlas Pro seat to run its free checks.

## Where supaschema fits

`supaschema` generates migrations from declarative SQL and proves them before apply. The migration-safety checks that overlap with `atlas migrate lint` are in the free core:

* `supaschema check` flags replay-safety and lock hazards on a generated migration (missing `IF EXISTS`/`IF NOT EXISTS` guards, table-rewriting `ALTER`s, `CREATE INDEX CONCURRENTLY` inside a transaction, and more), each as a `SUPA_*` diagnostic you can decode with `supaschema explain <CODE>`.
* `supaschema diff` surfaces a lock-impact advisory on each destructive operation that will actually run.
* `supaschema scan` produces a composite safety score with free RLS-audit and least-privilege packs.

```bash theme={null}
supaschema diff      # render a replay-safe migration from declarative SQL
supaschema check     # replay-safety and lock-hazard diagnostics
supaschema scan      # composite safety score (RLS + lock-safety packs)
```

Destructive changes fail closed until you add the exact object key to `hints.destructive` after reviewing the rendered SQL, so a drop or a type change cannot land silently.

## Licensing

`supaschema` is free and open source under MIT. Migration-safety checks, grant and RLS safety, and the standalone `type-contract --enforce` gate all ship in the same package without an entitlement check.

## Choosing between them

* You want Postgres migration-safety linting without a paid seat: use `supaschema check`, Squawk, or pgfence.
* You generate migrations from declarative SQL and want the safety check in the same tool: use `supaschema diff` then `supaschema check`.
* You already run the broader Atlas schema-as-code platform and want its hosted reporting: Atlas Pro is the paid path for that.

<CardGroup cols={2}>
  <Card title="Supabase CLI comparison" icon="layer-group" href="/docs/comparisons/supaschema-vs-supabase-cli">
    How supaschema's declarative diff compares to the Supabase CLI db diff
    workflow.
  </Card>

  <Card title="The check command" icon="shield-check" href="/docs/commands/check">
    The replay-safety and lock-hazard diagnostics supaschema runs on every
    migration.
  </Card>
</CardGroup>

## Sources

* [Atlas, "Verifying Migration Safety"](https://atlasgo.io/versioned/lint) — `atlas migrate lint` is Atlas Pro only since v0.38.
* [Atlas v0.38 release notes (2025-10-28)](https://atlasgo.io/blog/2025/10/28/v038-analyzers-pii-and-migration-hooks)
* [Atlas pricing](https://atlasgo.io/pricing)
* [Squawk, Postgres migration linter](https://squawkhq.com)
* [pgfence](https://pgfence.com)