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
Usesupaschema 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
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.
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.
Atlas lint is paid: free alternatives
The free Postgres migration-safety options after the v0.38 change.
The check command
The replay-safety and lock-hazard diagnostics supaschema runs for free.
Sources
- Atlas, “Verifying Migration Safety” —
atlas migrate lintis Atlas Pro only since v0.38. - Atlas v0.38 release notes (2025-10-28)
- Atlas pricing