convex-migrations

# Convex Migrations Evolve your Convex database schema safely with patterns for adding fields, backfilling data, removing deprecated fields, and maintaining zero-downtime deployments. ## Documentation Sources Before implementing, do not assume; fetch the latest documentation: - Primary: https://docs.convex.dev/database/schemas - Schema Overview: https://docs.convex.dev/database - Migration Patterns: https://stack.convex.dev/migrate-data-postgres-to-convex - For broader context: https://docs.convex.dev/llms.txt ## Instructions ### Migration Philosophy Convex handles schema evolution differently than traditional databases: - No explicit migration files or commands - Schema changes deploy instantly with `npx convex dev` - Existing data is not automatically transformed - Use optional fields and backfill mutations for safe migrations ### Adding New Fields Start with optional fields, then backfill: ```typescript // Step 1: Add optional field to schema // convex/schema.ts import { defineSchema, defineTable } from "convex/server"; import { v } from "convex/values"; export default defineSchema({ users: defineTable({ name: v.string(), email: v.string(), // New field - start as optional avatarUrl: v.optional(v.string()), }), }); ``` ```typescript // Step 2: Update code to handle both cases // convex/users.ts import { query } from "./_generated/server"; import { v } from "convex/values"; export const getUser = query({ args: { userId: v.id("users") }, ...