Imported from bg-szy/TOP-SKILLS (skills/marketplace/prisma-next-migrations/SKILL.md). Install upstream with npx skills add bg-szy/TOP-SKILLS --skill prisma-next-migrations. Copyright stays with the author.

Prisma Next — Migration Authoring

Edit your data contract. Prisma Next plans the migration. You fill in any data transforms.

The three-step user model:

1. You edit your data contract. (prisma-next-contract)
2. Prisma Next plans the migration for you. ← this skill
3. If a data transform is needed, you edit migration.ts and self-emit. ← this skill

Once the contract changes, you choose how the change reaches the database. This skill covers the two paths (db update and migration plan + migrate), the migration-package contract, the migration.ts authoring API, and the failure modes you recover from without leaving the loop.

Targets. Migration authoring is first-class for Postgres and Mongo. The CLI reads the target from prisma-next.config.ts (set during prisma-next init --target …). Migration commands do not accept a --target flag — use a config scoped to the target you need. Examples below call out target-specific imports, markers, factories, and transaction behavior where they diverge.

When to Use

• User edited the contract and wants to apply the change to the DB.
• User wants to author a migration with a data transform.
• User wants to run pending migrations against a local DB.
• User hit MIGRATION.HASH_MISMATCH, PN-MIG-2001 (unfilled placeholder), or a partially-applied migration.
• User mentions: migrate, migration, db push, db update, prisma migrate dev, prisma migrate deploy, drift, hash mismatch, data backfill.

When Not to Use

• User wants to know what migrations will run on deploy / on merge, or to manage refs and invariants → prisma-next-migration-review.
• User wants to edit the contract → prisma-next-contract.
• User wants a deeper read of a single structured error envelope → prisma-next-debug.

Key Concepts

• db update (quick path). Reads the emitted contract, diffs against the live DB, applies the change. Optional --dry-run prints the plan without executing. Interactive destructive-op confirmation (or -y to auto-accept). Writes no migration directory. Operations needing data transforms are not handled by this path — db update excludes the data operation class entirely and short-circuits where a data transform would be required. Use only against a database that has no shared history with anyone else (your local dev DB).
• migration plan (formal path). Reads the emitted contract, diffs against the head of the on-disk migration graph, writes a new migration package under migrations/app/<YYYYMMDDTHHMM>_<snake_slug>/. If any operation needs a data transform, the package's migration.ts contains placeholder(...) calls you fill in.
• The app/ segment in migration paths is the consuming application's contract-space id. Every migration you author lives under migrations/app/. Extensions your contract depends on get their own sibling directories (migrations/<extension-space-id>/) — those are managed by the extension package and you don't write into them. The app/ segment lands automatically the first time you run migration plan / db init against an app-level config.
• Migration package files (inside each migrations/app/<dir>/):
  • migration.json — manifest (metadata + migrationHash).
  • ops.json — canonical operation list. Content-addressed; migrationHash is computed over this.
  • migration.ts — TypeScript authoring source, framework-rendered by migration plan (or migration new). You edit specific holes in it (see Fill a placeholder below) and re-emit ops.json / migration.json by running it.
• Contract snapshots. migration.ts imports its bookend contracts from the shared, content-addressed store at migrations/snapshots/<hex>/contract.json + contract.d.ts (<hex> is the contract's 64-hex storage hash) — not from files inside the migration package.
• Self-emit. Running node migrations/app/<dir>/migration.ts regenerates ops.json and migration.json from the (possibly edited) TS source. This is the only supported way to update an existing migration package after edits.
• migration.ts shape. Framework-rendered. A class extending Migration (from @prisma-next/family-mongo/migration on Mongo, or re-exported via @prisma-next/postgres/migration on Postgres — see the framing block below), with an operations getter that returns an array of factory-call values. The file ends with MigrationCLI.run(import.meta.url, M) so executing it self-emits.
• placeholder(slot). A sentinel the planner emits into the rendered migration.ts (from @prisma-next/errors/migration on Mongo, or the @prisma-next/postgres/migration import on Postgres) wherever a data transform is needed. Calling placeholder(...) at emit time throws PN-MIG-2001 Unfilled migration placeholder. The user replaces the () => placeholder(...) arrow with a real query-plan closure (Postgres) or fills dataTransform({ check, run }) sources (Mongo — see Fill a placeholder), then self-emits.
• this.dataTransform(endContract, name, { check, run }). The data-transform factory. check is a rowset query whose presence-of-any-row signals "work remains"; run is one or more mutation queries that perform the backfill. Both are lazy closures returning query-plans built against endContract. The runner wraps check as EXISTS(...) for precheck and NOT EXISTS(...) for postcheck, so the same closure asserts both "there is work" and "the work is done".
• pendingPlaceholders. A boolean field on the JSON result of migration plan. true means the package was written but contains unfilled placeholders — migrate will throw PN-MIG-2001 until you edit migration.ts and self-emit.
• migrationHash. Content-addressed identity of a migration package. MIGRATION.HASH_MISMATCH fires when the stored hash in migration.json disagrees with the hash recomputed from the on-disk files (almost always: someone edited migration.ts without self-emitting).
• Marker. Records "this database is at contract hash X for space Y". Postgres: a row in prisma_contract.marker. Mongo: a document in the _prisma_migrations collection (keyed by space). Each successful migration advances the marker once schema verification passes for that space. db sign writes the marker from the current contract hash, but only after a schema-verification pass succeeds (it will not sign a database whose live schema disagrees with the contract).
• Apply atomicity. Postgres: each migration runs inside BEGIN ... COMMIT; on failure, Postgres rolls back and the marker stays at the previous migration's to hash. Mongo: DDL ops (createCollection, createIndex, collMod, setValidation, …) are not wrapped in a multi-document transaction; the runner applies ops, verifies the live schema against the destination contract, and advances the marker only on verify-pass (resumable across spaces — see the MongoDB family doc). Ordinary DDL + dataTransform flows stay consistent; partial state from failed mid-migration runs is diagnosed with db verify / db schema, not assumed away.
• Operation classes. Every operation declares an operationClass: additive, widening, data, or destructive. The CLI surfaces these in the plan preview and in JSON output. There is no long-running class and the framework does not emit CREATE INDEX CONCURRENTLY — operations stay transactional.

migration.ts is framework-rendered, not hand-authored

Files under migrations/<space-id>/<timestamp>/migration.ts (for your own app, <space-id> is always app/) are rendered for you by the framework — prisma-next migration plan writes a populated package whenever the contract changes, and prisma-next migration new writes an empty scaffold when you want to author operations directly. You do not write these files from scratch. You edit specific holes the framework leaves behind — chiefly replacing placeholder("<slot>") sentinels (Postgres) or filling dataTransform({ check, run }) pipeline slots (Mongo) — then self-emit.

Postgres rendered imports point at @prisma-next/postgres/migration (or @prisma-next/sqlite/migration for SQLite projects).

Mongo rendered imports use @prisma-next/family-mongo/migration for the Migration base class and @prisma-next/target-mongo/migration for operation factories (createIndex, dataTransform, …). MigrationCLI comes from @prisma-next/cli/migration-cli.

Treat the rendered import lines as framework-managed on both targets:

• Leave them where they are. Don't rewrite them to a different @prisma-next/<…> path; the framework's renderer is the authoritative shape and any change you make by hand will be reverted (and may trip MIGRATION.HASH_MISMATCH) the next time the package is re-rendered or self-emitted.
• If you need an additional factory symbol, add it to the existing rendered import line (Postgres: @prisma-next/postgres/migration; Mongo: @prisma-next/target-mongo/migration) rather than introducing a second import from a different @prisma-next/... subpath.
• The "user code imports only from @prisma-next/<target>" convention applies to your own modules (queries, runtime setup, contract authoring). The framework-rendered migration.ts scaffold is the framework's surface, not yours; the rule is suspended for that one file.

Diagnostic codes you route on

Decision — which path do you take?

Dev → ship transition (the db ref pattern)

Example — iterate locally with db update, then publish the first real migration:

pnpm prisma-next db init --db $DATABASE_URL
pnpm prisma-next contract emit && pnpm prisma-next db update --db $DATABASE_URL
pnpm prisma-next contract emit && pnpm prisma-next migration plan --name add_feature
pnpm prisma-next migrate --db $DATABASE_URL
pnpm prisma-next db verify --db $DATABASE_URL

The db ref is a named pointer at migrations/app/refs/db.json — just { hash, invariants }. It records which contract hash the project's dev database has been brought up to — the offline planner's stand-in for "where is my local DB?" without opening a connection at plan time. The contract it names resolves through the shared content-addressed store at migrations/snapshots/<hex>/contract.json by that hash, the same store every migration graph node resolves through.

What db init / db update write. When run against the project's default --db URL (no explicit --db flag), both commands implicitly advance the db ref: they write-if-absent the post-command contract IR into the snapshot store, then write the ref's pointer. Override the ref name with --advance-ref <name>. When you pass --db <non-default-url>, ref advancement is suppressed unless --advance-ref is explicit — reconciling a different database is not the same as checkpointing this project's dev state.

The on-disk layout is just the pointer:

migrations/app/refs/
└── db.json                 # { "hash": "<hex>", "invariants": [] }

First migration plan after dev iteration. migration plan defaults --from to the db ref. When the on-disk migration graph is still empty and the db ref points at a non-null hash with a store entry (typical after one or more db update cycles), the planner emits two bundles instead of one:

1. Baseline: null → from-hash (introduces from-hash as a graph node)
2. Delta: from-hash → current_contract

Both land on disk in one invocation — expect two new directories in git status. migrate then finds a path through the baseline and applies the delta. This closes the dev → ship trap where a single-bundle plan referenced a hash that was not yet a graph node and produced an unapplyable migration (MIGRATION.PATH_UNREACHABLE at apply time).

The forgot-the-flag pitfall. After the graph is non-empty, the default db ref may point past the graph tip (the ref advanced on every db update while you iterated, but you never committed migrations). The next implicit-default migration plan refuses with MIGRATION.HASH_NOT_IN_GRAPH and names reachable refs that point at graph nodes.

Recovery when you see MIGRATION.HASH_NOT_IN_GRAPH on plan:

# Option A — plan from a graph node explicitly
pnpm prisma-next migration plan --from production --name my_change

# Option B — realign the db ref to a graph-node hash, then plan with the default
pnpm prisma-next ref set db <graph-node-hash>
pnpm prisma-next migration plan --name my_change

If the db ref's pointer is itself missing and the hash isn't a graph node either (MIGRATION.SNAPSHOT_MISSING), create it with ref set db <hash> or advance it with db update --advance-ref db.

After plain migrate. migrate does not implicitly advance the db ref (production-shaped commands stay explicit). The live marker advances while the ref may lag. Refresh with db update (no-op on DB when already current) or migrate --advance-ref db in the same invocation.

When to switch paths. Use db update while the schema is in flux on a solo dev database. Switch to migration plan + migrate when the change needs a reviewable, replayable migration — typically before opening a PR or touching any shared environment. The db ref bridges the two: it captures dev iteration state on disk so the first formal plan knows where you left off.

Graph-node rule (plan time). Any hash used as a from end — explicit --from, default db ref, or ref name — must already be a node in the on-disk migration graph once the graph is non-empty. The auto-baseline two-bundle emission is the one exception: it applies only on an empty graph with a non-null ref-resolved from and an available store entry. If the ref's pointer is missing and the hash isn't a graph node either, plan refuses with MIGRATION.SNAPSHOT_MISSING instead.

Apply-time complement. migrate reads the live marker before DDL. If the marker hash is not a graph node, the command refuses with MIGRATION.MARKER_MISMATCH — catching drift the offline planner cannot see. This is separate from MIGRATION.MARKER_NOT_IN_HISTORY, which fires later during the runner's graph walk when the marker is off the path being traversed. See prisma-next-migration-review for the full diagnostic catalog.

db is a default ref name, not a reserved one. The framework overwrites it on the next dev cycle; you may ref set db <hash> explicitly and accept that a subsequent db update replaces it when run against the default URL.

Canonical detail: Migration System § Contract resolution through the snapshot store, § migration plan, § Recovery affordances, ADR 218 — Refs with paired contract snapshots and universal graph-node invariant (TML-2629, its paired-snapshot part superseded — see the ADR's Status note), and ADR 240 — Contract snapshots live in a content-addressed store.

Workflow — db update (quick path)

The concept: db update resolves the destination (emitted contract) against the live DB and applies the difference. Preview with --dry-run. Destructive ops prompt interactively unless you pass -y or --no-interactive. The path excludes operations of the data class entirely — if the diff requires a data transform, db update fails with a planning error and you switch to migration plan to author the transform.

Run after a contract edit:

pnpm prisma-next contract emit
# Postgres: --db postgresql://...
# Mongo:    --db mongodb://...  (dev scaffolds often need ?replicaSet=rs0)
pnpm prisma-next db update --db $DATABASE_URL --dry-run
pnpm prisma-next db update --db $DATABASE_URL

db update already verifies schema and advances the marker on success — a follow-up db verify is redundant on the happy path. Use db verify only when you need a standalone diagnostic (see Verify contract vs DB).

Inspect the JSON output to drive the next move:

pnpm prisma-next db update --db $DATABASE_URL --json

The JSON contains plan.operations[] with each operationClass, plus (in apply mode) execution.operationsExecuted and the post-apply marker.storageHash. If the command failed because of destructive operations, the error envelope's meta.destructiveOperations[] lists exactly what would have been dropped.

Workflow — migration plan + migrate (formal path)

The concept: migration plan writes a new migration package on disk. If the planner needed any data transforms, the package is pending — migration.ts holds placeholder(...) calls until you fill them in. migrate runs every pending package in graph order, transactionally.

Plan a change:

pnpm prisma-next contract emit
pnpm prisma-next migration plan --name <snake_slug>

Read the result. The JSON shape exposes the queryable signals:

• dir — the path of the new package (e.g. migrations/app/20260515T1200_add_user_email/).
• pendingPlaceholders — true if migration.ts still contains placeholder(...) calls.
• operations[].operationClass — for spotting destructive and data ops.
• preview.statements — family-agnostic textual preview.

Inspect the package:

pnpm prisma-next migration show
pnpm prisma-next migration show <dirName-or-migrationHash-prefix>

migration show displays a single migration package. To see the ordered list of migrations that would run — across all contract spaces — use migrate --show:

# Online: reads the live DB marker as the origin.
pnpm prisma-next migrate --show --db $DATABASE_URL

# Offline: hypothetical path from any ref or hash.
pnpm prisma-next migrate --show --from <hash-or-ref> --to <hash-or-ref>

migrate --show is read-only and never writes to the DB or the migration graph. Use it before applying to confirm the execution order.

Fill in any data transforms (see Fill a placeholder), self-emit if you edited migration.ts, then:

pnpm prisma-next migrate --db $DATABASE_URL

migrate runs without prompting — destructive-op confirmation lives on db update, not here. Review destructive ops in the plan output or in migration show before applying.

Workflow — Fill a placeholder

The concept: the planner can detect that a data transform is needed but not what it should do. It writes a typed scaffold and stops; you fill the transform, then self-emit.

Postgres

The planner can detect that a data transform is needed (e.g. backfilling a new NOT NULL column with no default) but not what it should do. You fill check and run closures with real query plans built against endContract.

The scaffold the planner emits looks like:

// migrations/app/20260515T1200_add_user_name/migration.ts
import endContract from '../../snapshots/93f07d1b…c9e1e5a2/contract.json' with { type: 'json' };
import { Migration, MigrationCLI, addColumn, placeholder } from '@prisma-next/postgres/migration';

export default class M extends Migration {
  override get operations() {
    return [
      addColumn('public', 'user', {
        name: 'name',
        typeSql: 'text',
        defaultSql: '',
        nullable: true,
      }),
      this.dataTransform(endContract, 'backfill user.name', {
        check: () => placeholder('backfill user.name:check'),
        run:   () => placeholder('backfill user.name:run'),
      }),
    ];
  }
}

MigrationCLI.run(import.meta.url, M);

Replace both placeholder(...) calls with query-plan closures built from endContract. The check closure must return a rowset query whose presence of any row signals "work remains" — conventionally <table>.select('id').where(<violation predicate>).limit(1). Scalar/aggregate shapes (count(*), bool_and(...)) silently break the contract: the runner wraps check twice (EXISTS(...) for precheck, NOT EXISTS(...) for postcheck), and a query that always returns one row makes EXISTS always true and NOT EXISTS always false.

Build the query builder against endContract so the storage hashes line up — using a different contract reference raises PN-MIG-2005. The filled-in shape (the rendered scaffold above with placeholder(...) calls replaced; if you need an extra factory like setNotNull, add it to the existing @prisma-next/postgres/migration import line rather than authoring a second import). See prisma-next-queries for the surrounding db setup:

import endContract from '../../snapshots/93f07d1b…c9e1e5a2/contract.json' with { type: 'json' };
import { Migration, MigrationCLI, addColumn, setNotNull } from '@prisma-next/postgres/migration';
import { db } from './db'; // sql({ context: createExecutionContext({ contract: endContract, ... }) })

export default class M extends Migration {
  override get operations() {
    return [
      addColumn('public', 'user', {
        name: 'name',
        typeSql: 'text',
        defaultSql: '',
        nullable: true,
      }),
      this.dataTransform(endContract, 'backfill user.name', {
        check: () => db.users.select('id').where((f, fns) => fns.eq(f.name, null)).limit(1),
        run:   () => db.users.update({ name: '' }).where((f, fns) => fns.eq(f.name, null)),
      }),
      setNotNull('public', 'user', 'name'),
    ];
  }
}

MigrationCLI.run(import.meta.url, M);

Self-emit:

node migrations/app/20260515T1200_add_user_name/migration.ts

Self-emit regenerates ops.json and recomputes migrationHash in migration.json. The next migrate will see a consistent package.

Mongo

Mongo dataTransform operations take { check, run } objects whose source / run return Mongo query-plan shapes (often RawAggregateCommand / RawUpdateManyCommand from @prisma-next/mongo-query-ast/execution). The planner may leave placeholder(...) inside those sources until you fill them. Every rendered migration.ts includes describe() bookends (from / to contract hashes) — the Postgres examples above omit them for brevity. Import factories from @prisma-next/target-mongo/migration:

import { MigrationCLI } from '@prisma-next/cli/migration-cli';
import { Migration } from '@prisma-next/family-mongo/migration';
import { createIndex, dataTransform } from '@prisma-next/target-mongo/migration';
import { RawAggregateCommand, RawUpdateManyCommand } from '@prisma-next/mongo-query-ast/execution';

class M extends Migration {
  override describe() {
    return { from: '<hex>', to: '<hex>', labels: ['normalize-names'] };
  }

  override get operations() {
    return [
      createIndex('users', [{ field: 'name', direction: 1 }]),
      dataTransform('lowercase-user-name', {
        check: {
          source: () => ({
            collection: 'users',
            command: new RawAggregateCommand('users', [
              { $match: { name: { $regex: '[A-Z]' } } },
              { $limit: 1 },
            ]),
            meta: { target: 'mongo', storageHash: '…', lane: 'mongo-pipeline', paramDescriptors: [] },
          }),
        },
        run: () => ({
          collection: 'users',
          command: new RawUpdateManyCommand(
            'users',
            { name: { $exists: true } },
            [{ $set: { name: { $toLower: '$name' } } }],
          ),
          meta: { target: 'mongo', storageHash: '…', lane: 'mongo-raw', paramDescriptors: [] },
        }),
      }),
    ];
  }
}

export default M;
MigrationCLI.run(import.meta.url, M);

Self-emit the same way: node migrations/app/<dir>/migration.ts.

Workflow — Author a migration by hand

The concept: the same Migration class shape lets you author operations directly when the planner has nothing to plan (a custom data fix, an extension install, a baseline). Even here you don't write the file from scratch — migration new renders an empty package for you, and you edit the operations getter inside it, then self-emit.

pnpm prisma-next migration new --name <snake_slug>

Add factory names to the framework-rendered import line for your target (Postgres: @prisma-next/postgres/migration; Mongo: @prisma-next/target-mongo/migration). Browse with --help and the import list the renderer emitted.

Postgres factories (representative set):

• Tables: createTable, dropTable.
• Columns: addColumn, dropColumn, alterColumnType, setNotNull, dropNotNull, setDefault, dropDefault.
• Constraints: addPrimaryKey, addForeignKey, addUnique, dropConstraint.
• Indexes: createIndex, dropIndex.
• Enums: createEnumType, addEnumValues, renameType, dropEnumType.
• Dependencies: createSchema, createExtension, installExtension.
• Raw escape hatch: rawSql({ id, label, operationClass, target, precheck, execute, postcheck, ... }).
• Data transforms: this.dataTransform(endContract, name, { check, run }) (instance method, not a free factory).

Mongo factories (from @prisma-next/target-mongo/migration):

• Collections: createCollection, dropCollection, validatedCollection, setValidation.
• Indexes: createIndex, dropIndex.
• Collection options: collMod.
• Data transforms: dataTransform(name, { check, run }) (free factory; check/run use Mongo query-plan shapes).

Self-emit (node migrations/app/<dir>/migration.ts) after each edit.

Workflow — Inspect the live schema

The concept: db schema is read-only and never writes files. It prints the live schema as a tree by default or as JSON with --json. Use it during planning and as part of verification.

pnpm prisma-next db schema --db $DATABASE_URL
pnpm prisma-next db schema --db $DATABASE_URL --json > schema.json

There is no built-in filter flag — pipe the JSON through jq (or your favourite JSON tool) if you only want one table.

Workflow — Verify contract vs DB (diagnostic)

The concept: db verify is a standalone diagnostic — not a routine step after db update or migrate on the happy path (those commands already verify and advance the marker when they succeed). Reach for db verify when you suspect drift or need to prove the DB matches the contract:

• Following manual SQL or ad-hoc edits outside Prisma Next.
• When restoring a database from backup.
• If a migrate fails or partially applies (especially on Mongo, where DDL is resumable rather than transaction-wrapped).
• When PN-RUN-3002 / PN-RUN-3001 surfaces at runtime or from another command.

Modes:

• Default — full verification (schema + marker).
• --marker-only — skip schema verification, only check the marker.
• --schema-only — skip marker verification, only check schema satisfies contract.
• --strict adds: schema elements not present in the contract are an error (default is "DB may have extras").

pnpm prisma-next db verify --db $DATABASE_URL

On mismatch, the error envelope names the failure mode (PN-RUN-3002 hash mismatch, PN-RUN-3001 marker missing, target mismatch, schema issues with structured paths).

Workflow — Re-sign the marker

The concept: db sign rewrites the marker to the current contract hash. Use after a manual repair where the DB is the source of truth and the marker is stale. db sign performs a schema-verify first and refuses to sign a DB whose schema disagrees with the contract — so a successful sign always means the schema matches and the marker is now correct.

pnpm prisma-next db sign --db $DATABASE_URL

Workflow — Recover from drift

The concept: drift means db verify reports the live DB schema doesn't match what the marker says it should be. Two valid moves, picked by which side is correct:

• The contract is right; the DB is wrong → run a migration. Either db update (quick path, dev DB only) or migration plan + migrate (everywhere else).
• The DB is right; the contract or marker is wrong → edit the contract to match the DB (see prisma-next-contract), emit, then db sign to refresh the marker.

The diagnostic that reveals which side is right:

pnpm prisma-next db schema --db $DATABASE_URL --json
pnpm prisma-next db verify --db $DATABASE_URL --json

Use db verify to confirm which side is wrong, then re-run it after either branch until it returns ok with no diagnostics.

Workflow — Recover from a partially-applied migration

The concept: on Postgres, each migration applies inside a transaction — a mid-migration failure rolls back and the marker stays at the previous migration's to hash. On Mongo, DDL is resumable with verify-gated marker advancement; diagnose with db verify / db schema, fix the failed package's migration.ts, self-emit, and re-run migrate.

Failures that can leak partial state include: Postgres rawSql(...) steps outside the transaction wrapper, Mongo DDL that partially applied before verify failed, or external side-effects (calls out to other systems from a run closure).

Diagnose:

pnpm prisma-next db verify --db $DATABASE_URL --json
pnpm prisma-next db schema --db $DATABASE_URL --json

Fix and re-run migrate:

node migrations/app/<dir>/migration.ts
pnpm prisma-next migrate --db $DATABASE_URL

If the failure was an out-of-band side-effect that left external systems half-changed, repair those by hand before re-applying.

Workflow — Recover from MIGRATION.HASH_MISMATCH

The concept: migrationHash is content-addressed. A mismatch means migration.json's stored hash disagrees with the hash recomputed from ops.json (and metadata). The cause is almost always: someone edited migration.ts and forgot to self-emit. The remediation is to self-emit the offending package.

node migrations/app/<dir>/migration.ts
pnpm prisma-next migrate --db $DATABASE_URL

If self-emit itself fails (e.g. the contract has moved on and the operations no longer make sense against the migration's end contract), the package is stale. Either restore it from version control or delete it and re-plan with migration plan.

Workflow — Resolve a destructive-operation prompt (db update only)

The concept: when db update would drop columns or tables, it stops and asks before applying. The prompt is db update-specific — migrate does not prompt and runs whatever the migration package contains, so review the plan or call migration show before migrate.

When db update reports destructive operations interactively, the warning lists them. The prompt is:

Apply destructive changes? This cannot be undone.

Routing:

• Answer yes if the data is no longer needed.
• Answer no, then either:
  • Re-shape the migration via migration plan and hand-edit migration.ts to preserve the data (e.g. copy-to-new-column, then drop), or
  • Skip the destructive operation by reverting the contract change.

In non-interactive contexts (CI, --no-interactive, --json), the destructive-op response is returned as a structured error — meta.destructiveOperations[] lists what would have been dropped. Re-run with -y to auto-accept, or address each operation individually.

Common Pitfalls

1. Using db update against shared or production databases. Never. The change leaves no migration history. Use migration plan + migrate.
2. Skipping a data transform. Leaving placeholder(...) in migration.ts makes the next migrate throw PN-MIG-2001. Fill every placeholder slot and self-emit.
3. Editing ops.json directly. It's the canonical artifact, not the authoring source. Edit migration.ts, then self-emit.
4. Forgetting to self-emit after editing migration.ts. The next migrate either uses the stale ops.json (if you only added comments) or fails with MIGRATION.HASH_MISMATCH (if you changed operations). Always self-emit.
5. Routine db verify after a successful db update or migrate. Redundant on the happy path — reserve db verify for drift diagnosis (manual edits, restore, failed migrate).
6. Aggregate check closure in Postgres this.dataTransform. Returning count(*) or bool_and(...) breaks the precheck/postcheck contract — both sides resolve to constants. Use a rowset shape: select('id').where(<violation>).limit(1).
7. Two contract references in one migration. Building a query plan against a different contract than the one passed to this.dataTransform(endContract, ...) raises PN-MIG-2005. Always import endContract once at module scope and use the same reference.
8. Renaming and expecting the planner to detect it (Postgres). Prisma Next has no in-contract rename hint today; the planner emits a destructive drop+add. Hand-edit migration.ts to rewrite the destructive op as a rawSql({ ... }) that issues ALTER TABLE ... RENAME COLUMN ... (or use the two-migration keep / backfill / drop pattern), then self-emit. See prisma-next-contract § Edit a field — rename.
9. Hand-authoring migration.ts from a blank file, or rewriting the rendered import line. Migration files are framework-rendered — let prisma-next migration plan (or migration new) render the package, then edit only the holes the framework leaves for you. On Postgres leave the rendered @prisma-next/postgres/migration (or @prisma-next/sqlite/migration) import path alone; on Mongo use @prisma-next/family-mongo/migration + @prisma-next/target-mongo/migration as rendered. Add symbols to the existing factory import line rather than introducing new import paths.

What Prisma Next doesn't do yet

• Runtime-apply migrations. Prisma Next doesn't apply pending migrations from your app's startup code (the "Drizzle pattern" for serverless / edge). Workaround: run prisma-next migrate from your deploy pipeline before the app starts. If you need runtime-apply built-in, file a feature request via the prisma-next-feedback skill.
• Seeds-as-first-class. Prisma Next doesn't ship a prisma db seed equivalent. Workaround: write a TypeScript script that imports your db instance and runs your setup queries; invoke it from package.json's scripts. If you need first-class seeding, file a feature request via the prisma-next-feedback skill.
• Migration squashing. Prisma Next doesn't squash older migrations into a baseline. They accumulate; for very large histories, manual baseline-and-truncate is the path. If you need built-in squashing, file a feature request via the prisma-next-feedback skill.
• In-contract rename hints. The planner cannot detect that a field rename is a rename rather than a drop+add. Workaround: hand-edit migration.ts to issue a RENAME COLUMN via rawSql(...), or use a keep / backfill / drop pattern across two migrations. If you need a contract-level rename hint, file a feature request via the prisma-next-feedback skill.

Graph and history commands

After planning or applying, you can inspect the migration graph offline:

• pnpm prisma-next migration list — enumerate all on-disk migrations, rendered as a graph tree. Supports --legend (print the glyph key), --ascii (pipe-safe glyphs), and --json.
• pnpm prisma-next migration log --db $DATABASE_URL — flat chronological table of applied migrations, read from the live DB. Supports --ascii and --json.

For the full graph topology: pnpm prisma-next migration graph (also supports --legend, --ascii, --dot, --json).

@@control and DDL scope

Objects whose @@control policy excludes them from Prisma Next's managed surface are omitted from planned DDL. The four policies are: managed (Prisma plans and applies DDL), tolerated (object may exist, no DDL emitted), external (object is expected to exist, no DDL), observed (Prisma reads but never writes). Declare @@control(managed|tolerated|external|observed) in your schema; see prisma-next-contract and packages/2-sql/2-authoring/contract-psl/README.md for authoring syntax.

Telemetry

The CLI collects anonymous usage data by default. To opt out, set PRISMA_NEXT_DISABLE_TELEMETRY=1 or DO_NOT_TRACK=1 in your environment. See docs/Telemetry.md for the full opt-out reference.

Checklist

• Contract emitted (contract.json + contract.d.ts current).
• Chose the right path: db update (local dev) vs migration plan + migrate (anything shared).
• For migration plan: ran migration show to review before migrate.
• Filled every placeholder(...) in migration.ts (if any), built against endContract.
• check closures are rowset queries, not scalar aggregates.
• Self-emitted (node migrations/app/<dir>/migration.ts) after editing the TS.
• Ran migrate (or db update) and saw it complete.
• Used db verify only when diagnosing drift — not as a routine post-apply step.
• Did NOT use db update against a shared or production database.
• Did NOT edit ops.json directly.
• Did NOT skip a destructive-op prompt without inspecting meta.destructiveOperations[].