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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.

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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.
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.

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Free alternatives at a glance

ToolLicenseMigration-safety scopeNeeds a database or Docker?
supaschemaFree core (open)Replay-safety + lock-hazard checks on generated migrations (check), a destructive-operation advisory in diff, and a free scan score with RLS-audit and least-privilege packsNo, generation and checks run from declarative SQL files
SquawkOpen source (MIT/Apache-2.0)Lock-safety linter for Postgres migration SQLNo
pgfenceSource-availableMigration-safety CLI: lock-mode analysis, risk scoring, and safe-rewrite recipesNo
Each tool is Postgres-native. None requires an Atlas Pro seat to run its free checks.

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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 ALTERs, 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.
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.

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What is not free

supaschema is open-core. The migration-safety checks above are free. Grant and RLS safety also run through the free scan and deploy-safety gates. The current licensed standalone CLI gate is type-contract --enforce, which turns TypeScript/Zod breaking-change diagnostics into a failing command when a valid entitlement is present.

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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.

Supabase CLI comparison

How supaschema’s declarative diff compares to the Supabase CLI db diff workflow.

The check command

The replay-safety and lock-hazard diagnostics supaschema runs on every migration.

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Sources

Last modified on June 18, 2026