# Zod v3 to v4 Migration analysis
- Pre-existing version: `zod@^3.20.2` (devDependency)
- Files using Zod: 19 files
- No problematic patterns detected (no `invalid_type_error`, `ZodError.errors`, `ctx.path`, etc.)
- Main patterns: `.optional()`, `.default()`, `.strict()`, `.merge()`, standard schemas
## Migration Steps
### 1: Upgrade to Zod v4 with v3 compatibility
- Install `zod@^4.0.0` in drizzle-kit (v4.1.12 installed)
- Run tests to ensure no immediate breakage (found type error due to @hono/zod-validator)
### Step 2: Update imports to use v3 subpath temporarily
- Update all Zod imports from `'zod'` to `'zod/v3'` (19 files updated)
- Run tests to verify everything still works
**Issue Found:** @hono/zod-validator v0.2.1 doesn't support Zod v4 yet (issue drizzle-team#1148 in honojs/middleware). The type definitions from 'zod/v3' are not compatible with @hono/zod-validator's expected types, even though they should be runtime-compatible.
**Solution Applied:**
- Added type assertion (`as any`) to schema in studio.ts:517 for @hono/zod-validator compatibility
- Added explicit type annotation for column parameter in studio.ts:648
- TypeScript compilation passes

#### Files migrated (19 total):
- src/snapshotsDiffer.ts
- src/serializer/studio.ts
- src/schemaValidator.ts
- src/cli/validations/sqlite.ts
- src/cli/commands/utils.ts
- src/serializer/sqliteSchema.ts
- src/serializer/singlestoreSchema.ts
- src/serializer/pgSchema.ts
- src/serializer/mysqlSchema.ts
- src/cli/validations/studio.ts (⚠️ intersection fix applied)
- src/cli/validations/singlestore.ts
- src/cli/validations/postgres.ts
- src/cli/validations/mysql.ts
- src/cli/validations/libsql.ts
- src/cli/validations/common.ts
- src/cli/validations/cli.ts
- src/cli/commands/singlestorePushUtils.ts
- src/cli/commands/mysqlPushUtils.ts
- src/cli/commands/migrate.ts
#### For each file:
1. Change import from `'zod/v3'` to `'zod'` (or `'zod/v4'`)
2. Ensure tests are passing

Skips modernization of `.strict()` since .strict() still works and there's no mention of performance impact, and we have 115 occurrences, I recommend we skip modernizing .strict() for now. Here's why:
 1. Still functional - .strict() works in v4
 2. Large scope - 115 occurrences would require significant refactoring
 3. Risk vs reward - No performance benefit mentioned
 4. Backward compatibility - Easier to maintain
 5. Rewrite of drizzle-kit in drizzle-team#4439 may mean this kind of modernization is thrown away in later releases

The following impacts have been addressed to support the migration to zod v4 for the packages: drizzle-zod and drizzle-kit
# Changes
**drizzle-zod** (v0.8.0)
 - peerDependencies: `"zod": ">=4.0.0"`
 - devDependencies: `"zod": "^4.1.1"`
 - Files: drizzle-zod/package.json:68,79
**drizzle-kit** (v0.32.0)
 - devDependencies: `"zod": "^4.1.12"`
 - Files: drizzle-kit/package.json:116
 - Heavy internal usage in validation and serialization modules
**drizzle-orm** (v0.40.0)
 - devDependencies: `"zod": "^4.0.0"`
 - Files: drizzle-orm/package.json:204
**integration-tests**
 - dependencies: `"zod": "^4.1.1"`
 - Files: integration-tests/package.json:79
**examples/libsql**
 - dependencies: `"zod": "^4.1.1"`
 - Files: examples/libsql/package.json:22
 - Updated Dependencies: `@hono/zod-validator: ^0.4.1`, `znv: ^0.5.0`
# Out of date package-lock.json regeneration
These examples had zod 3.x references in their package-lock.json files from transitive dependencies. All lock files have been regenerated.
Note: These examples don't directly depend on zod. The old zod 3.x references were from transitive dependencies through drizzle-kit. After regenerating lock files, they now pull the latest drizzle-kit which uses Zod 4.x.
**examples/pg-proxy**
 - package-lock.json
**examples/mysql-proxy**
 - package-lock.json
**examples/better-sqlite3**
 - package-lock.json
**examples/aws-lambda**
 - package-lock.json
# Indirect references
The following examples don't have explicit zod dependencies but use drizzle-kit:
- **examples/cloudflare-d1** - uses drizzle-kit ^0.17.0
- **examples/postgresjs** - uses drizzle-kit 0.17.1-609a4f0
- **examples/neon-cloudflare** - needs verification
- **examples/sqlite-proxy** - needs verification
# Known Breaking Changes (Zod 3.x → 4.x)
Reference: https://github.com/colinhacks/zod/releases/tag/v4.0.0
Key changes to watch for:
- Error formatting changes
- `.parse()` behavior refinements
- Type inference improvements

Updates change log files for what is included in this family of commits (for drizzle-team#4570)