> **convex-migrate** — skill 22 of 33 in [convex/agent-skills](https://skillsdocs.com/convex/agent-skills).
>
> Book (all skills, one file): https://skillsdocs.com/convex/agent-skills.md
> Machine manifest: https://skillsdocs.com/convex/agent-skills/.well-known/agent-skills/index.json
> Install the book: `npx skills add convex/agent-skills`
> Upstream: https://github.com/convex/agent-skills/blob/main/skills/convex-migrate/SKILL.md @ `main`
> Raw bytes, no header: https://raw.githubusercontent.com/convex/agent-skills/main/skills/convex-migrate/SKILL.md
> Base for relative paths: https://raw.githubusercontent.com/convex/agent-skills/main/skills/convex-migrate/
> Licence: Apache-2.0 — https://spdx.org/licenses/Apache-2.0.html
>
> Content © its authors, served unmodified. Takedown: https://github.com/DreambaseAI/skillsdocs/issues/new?labels=takedown&title=Takedown+request

<!-- Verbatim upstream SKILL.md follows, YAML frontmatter included. -->

---
name: convex-migrate
description: "Migrate schema + backfill data on a deployed Convex app using @convex-dev/migrations."
---

<!-- GENERATED from convex-agents content/capabilities/migrate.json — do not edit by hand. -->

# Migrate the schema / data on a live app

Change a deployed schema without breaking existing data: stage the schema change, install @convex-dev/migrations, write a backfill that makes old rows valid, run it, and verify before tightening the validator.

## Workflow

1. Make the new field optional first (so deploy doesn't reject existing rows).
2. Install @convex-dev/migrations; write a migration that backfills/transforms existing rows.
3. Run the migration; verify all rows are valid.
4. Tighten the validator (make the field required) once the backfill is complete.

## Rules

- Never tighten a validator before the backfill completes — it rejects existing rows and breaks the live app.
- Add new fields as optional first, migrate, then require.
- Verify row counts before and after.