> ## 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 comparison

> Compare supaschema with Atlas for Postgres migration generation and safety. Atlas migrate lint moved to the paid Atlas Pro tier in v0.38; supaschema keeps declarative diff and replay/lock-safety checks in the free core.

> *Last verified 2026-06-21.*

`supaschema` and Atlas both manage schema as code, but they aim at different scopes. `supaschema` is a PostgreSQL tool that generates a replay-safe migration from declarative SQL and proves it locally, against any Postgres provider (self-hosted, RDS/Aurora, Cloud SQL, AlloyDB, Neon, Azure, or Supabase). Atlas is a broader multi-database schema-as-code platform whose migration linting and custom policy rules moved to the paid Atlas Pro tier.

## Short answer

Use `supaschema` when you want free, Postgres-native migration generation plus replay-safety and lock-hazard checks from declarative SQL, with no Docker or shadow database. Use Atlas when you want its multi-database platform and hosted reporting and you are willing to pay for Atlas Pro to keep `atlas migrate lint`.

## Comparison

| Capability                    | supaschema                                                 | Atlas                                                           |
| ----------------------------- | ---------------------------------------------------------- | --------------------------------------------------------------- |
| Migration-safety linting cost | Free (`supaschema check`)                                  | `atlas migrate lint` is Atlas Pro only since v0.38 (2025-10-28) |
| Custom policy linting         | Free rule packs in `scan`                                  | Schema-policy rules are Atlas Pro only                          |
| Database focus                | Any PostgreSQL database (any provider)                     | Many database engines                                           |
| Parser                        | PostgreSQL's parser (libpg\_query) compiled to WebAssembly | Its own multi-engine schema engine                              |
| Docker or shadow database     | Not required                                               | Often used for diffing                                          |
| RLS policy body changes       | Compared structurally                                      | Postgres RLS coverage varies by feature                         |
| Generated types               | TypeScript and Zod from the schema files                   | Not the same generated-type workflow                            |
| Apply to production           | No, generation and proof only                              | Yes, Atlas applies migrations                                   |

## Why the workflow differs

`supaschema` parses declarative SQL into PostgreSQL parse trees and renders a guarded migration from the structural difference, then `supaschema check` flags replay-safety and lock hazards. Grant and RLS safety run through `scan` and deploy-safety gates, while `type-contract --enforce` fails on breaking TypeScript/Zod contract changes. The complete supaschema package is open source under MIT.

Atlas is a larger platform that spans multiple database engines and adds hosted reporting and CI integration. Starting with Atlas v0.38, `atlas migrate lint` and the custom schema-policy rule language require Atlas Pro. Atlas's current pricing pages describe separate CLI seat, pipeline project, and target-database pricing. If migration linting was the reason you used Atlas and you want a free Postgres-native option, `supaschema check` covers that lane.

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

<CardGroup cols={2}>
  <Card title="Atlas lint is paid: free alternatives" icon="scale-balanced" href="/docs/comparisons/atlas-migrate-lint-paid-alternatives">
    The free Postgres migration-safety options after the v0.38 change.
  </Card>

  <Card title="The check command" icon="shield-check" href="/docs/commands/check">
    The replay-safety and lock-hazard diagnostics supaschema runs for free.
  </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)