Prisma Next — Contract Authoring

Edit your data contract. Prisma handles the rest.

The data contract is the single source of truth for your data layer. You edit a contract source — contract.prisma (PSL, the canonical surface) or contract.ts (TypeScript builder) — and the framework derives types, migrations, and runtime configuration from it. The three-step user model:

1. You edit your data contract.
2. The system plans the migrations for you. (prisma-next-migrations)
3. If you need data migrations, you edit migration.ts and execute it. (prisma-next-migrations)

Behind step 1 the agent runs prisma-next contract emit after every contract edit (or installs the Vite plugin so the bundler runs it on save — see prisma-next-build). Emit reads the contract source through the provider the façade picks based on the file extension of contract: in prisma-next.config.ts, then writes two artefacts colocated with the source:

• contract.json — the canonical, content-hashed Contract IR. Read by the planner, the runtime, and db verify.
• contract.d.ts — the precise TypeScript types the runtime + lanes propagate when you import Contract from it.

Both files are emitted artefacts. Edit the source; never the JSON or .d.ts.

When to Use

• User wants to add, change, or remove a model / field / relation.
• User wants to add an index, unique constraint, enum, or value object (composite type).
• User wants to add a namespace block (Postgres schema) or a cross-contract foreign key.
• User wants to set @@control on a model or configure defaultControlPolicy.
• User wants to use a custom type from an extension (pgvector.Vector(length: 1536), cipherstash.EncryptedString({...})).
• User wants to install or configure an extension via extensions: [...] in prisma-next.config.ts, including @prisma-next/extension-supabase.
• User is migrating between authoring sources (PSL ↔ TypeScript builder).
• User received PN-CLI-4002, PN-CLI-4003, or PN-CLI-4011 from contract emit.
• User mentions: schema, fields, models, attributes, prisma schema, PSL, contract.prisma, contract.ts, contract.json, contract.d.ts, contract emit, façade imports, @prisma-next/postgres/config, @prisma-next/postgres/contract-builder, extensions, pgvector, cipherstash, postgis, paradedb, supabase, namespaces, cross-space FK, @@control, enums, value objects, validations, callbacks, soft delete, paranoid, scopes. (The last cluster routes to What Prisma Next doesn't do yet below.)

When Not to Use

• User wants to apply a contract change to the DB → prisma-next-migrations.
• User wants to write a query against the contract → prisma-next-queries.
• User wants to wire db.ts (runtime entry point, middleware, env config) → prisma-next-runtime.
• User wants the Vite / bundler integration → prisma-next-build.
• User wants to set up Prisma Next for the first time → prisma-next-quickstart.
• User wants a deeper read of a single structured error envelope → prisma-next-debug.
• User wants to file a missing-feature request → prisma-next-feedback.

Key Concepts

• The @prisma-next/<target> façade is the only surface user-authored code imports from. For a Postgres app: @prisma-next/postgres/config, @prisma-next/postgres/contract-builder, @prisma-next/postgres/control, @prisma-next/postgres/runtime. Mongo has the same layout (@prisma-next/mongo/config, @prisma-next/mongo/contract-builder, @prisma-next/mongo/runtime). Each extension publishes its own façade — @prisma-next/extension-pgvector/control, @prisma-next/extension-postgis/control, @prisma-next/extension-paradedb/control. Never reach into @prisma-next/cli/*, @prisma-next/family-*, @prisma-next/target-*, @prisma-next/adapter-*, @prisma-next/driver-*, or @prisma-next/sql-contract-* from user code. The façade bakes the family / target / adapter / driver wiring in. See Common Pitfalls #4.

• Contract source. A file the framework reads and lowers to the canonical Contract IR. Two flavours, both first-class:

  • contract.prisma (PSL) — schema-flavoured DSL. Canonical for typical apps and brownfield Prisma users. Wired by contract: './<path>/contract.prisma' — the defineConfig façade detects the .prisma extension and routes through the PSL provider.
  • contract.ts (TypeScript builder) — programmatic authoring with defineContract({...}, ({ field, model, rel, type }) => ({...})) from @prisma-next/postgres/contract-builder (or @prisma-next/mongo/contract-builder). Wired by contract: './<path>/contract.ts' — the façade detects the .ts extension and routes through the TS provider. Use when you need programmatic composition (per-tenant variants, generated fields) or constructs PSL doesn't yet express (e.g. registering a parameterised extension type — see pgvector's contract).

• prisma-next.config.ts. Wires the contract source, the database connection, the migrations directory, and any installed extensions. Use defineConfig({...}) from @prisma-next/postgres/config (or @prisma-next/mongo/config). The four fields the façade accepts: contract (path string — .prisma or .ts), db ({ connection?: string }), extensions (array of control descriptors), migrations ({ dir?: string }). The output path for contract.json is auto-derived from contract (e.g. ./src/prisma/contract.prisma → ./src/prisma/contract.json).

• Emit pipeline. prisma-next contract emit --config <path>? reads prisma-next.config.ts, calls the provider the façade picked, validates the resulting Contract, then atomically writes contract.json + contract.d.ts colocated with the source.

• Extension namespaces. Extensions contribute namespaced constructors (pgvector.Vector(length: 1536), cipherstash.EncryptedString({equality: true})) and helper presets. Install them by adding the descriptor to two places — both fields are named extensions, but the two surfaces consume two different descriptor types and shapes:

  • In the config (façade and core): extensions: [pgvector] — array of control descriptors imported from @prisma-next/extension-<name>/control.
  • In the TS builder's defineContract (only when authoring contract.ts): extensions: { pgvector } — record of pack descriptors imported from @prisma-next/extension-<name>/pack.

• Contract space. Every package that emits a contract owns its own contract space — a prisma-next.config.ts at package root, a contract source, the colocated emitted artefacts, and a migrations/ directory. There are two intentional on-disk layouts, picked by whether the contract space is the consuming application or a contract-space package (an extension, an internal aggregate-root package, etc.):

  • Application layout (what you use when building an app). prisma-next.config.ts at repo root; src/prisma/contract.{prisma,ts}; src/prisma/contract.{json,d.ts} colocated; src/prisma/db.ts colocated; migrations under migrations/app/<timestamp>_<slug>/. The app/ segment is the consuming application's space-id; extension space-ids land in sibling migrations/<extension-space-id>/ directories that the extension packages manage. This is what examples/prisma-next-demo uses. prisma-next init currently scaffolds something different (prisma/... at repo root) — that's a defect (TML-2532); the canonical layout is what every command actually expects to see.
  • Contract-space-package layout (what you use when publishing a contract-space package — extensions, internal monorepo packages). prisma-next.config.ts at package root; src/contract.{prisma,ts} directly (no prisma/ subdir); src/contract.{json,d.ts} colocated; migrations/<timestamp>_<slug>/ directly under migrations/ (no <space-id> segment — the package is a single space). Documented in .cursor/rules/contract-space-package-layout.mdc and ADR 212.

  Both layouts let defineConfig's contract: path point at the source; the framework derives everything else (emit output, migration root) from there. Pick the layout that matches what you're building and stick with it — don't mix.

Diagnostic codes you route on

prisma-next contract emit surfaces structured errors with stable codes; branch on code rather than message text.

Workflow — Read the contract source of truth

The concept: every contract change starts by locating the source file. The config is authoritative — read prisma-next.config.ts, find the contract: field (a path string under the façade), and open the file it points at. The same field tells you the installed extensions: [...].

cat prisma-next.config.ts

If contract: ends in .prisma, the source is PSL; if it ends in .ts, the source is the TS builder. If prisma-next.config.ts is missing, route to prisma-next-quickstart.

Workflow — Edit a model / field / relation (PSL)

The concept: PSL models lower to tables (or collections, on Mongo); fields lower to columns; @relation(...) declares the FK side. Add the relation only on the owning side — the framework derives the back-reference automatically.

model User {
  id    Int    @id @default(autoincrement())
  email String @unique
}

model Post {
  id       Int    @id @default(autoincrement())
  title    String
  authorId Int
  author   User   @relation(fields: [authorId], references: [id], onDelete: Cascade)

  @@unique([title, authorId])
  @@index([authorId])
}

Then run pnpm prisma-next contract emit (or rely on the Vite plugin — see prisma-next-build). Specify cascade behaviour explicitly with onDelete / onUpdate; the default is Restrict.

@@index also accepts expression: (instead of a fields list), where: (partial-index predicate), unique:, type:/options: (target-registered access method), and name: xor map::

@@index(expression: "lower(email)", name: "users_email_lower")
@@index([authorId], where: "(archived_at IS NULL)", name: "posts_author_active")

name: declares a managed index (physical name <name>_<8-hex hash>, renames plan as ALTER INDEX … RENAME); map: adopts an exact physical name verbatim (for infer-captured objects — combining it with a SQL body warns, because drift detection byte-compares the authored text against Postgres's reprint). An expression: requires name: or map:. The TS builder mirrors this via constraints.index([cols.x], {...}) / constraints.index({ expression, ... }) — see packages/2-sql/2-authoring/contract-ts/README.md.

PSL alias surface for repeated types lives in a top-level types {} block:

types {
  Email = String
}

model User {
  id    Int    @id @default(autoincrement())
  email Email  @unique
}

Note: scalar lists (e.g. String[]) and implicit Prisma-ORM many-to-many (list nav on both sides without a join model) are rejected by the SQL interpreter — use a join model. Composite/embeddable types (type Address { ... } with address Address on a model) are supported: the interpreter lowers them to valueObjects in the domain and stores them as jsonb columns. See Workflow — Value objects below.

Workflow — Edit a model / field / relation (TS builder)

The concept: same model, different authoring surface. The façade re-exports defineContract, field, model, rel, plus the family/target packs as default exports of @prisma-next/postgres/family and @prisma-next/postgres/target. Use the callback overload (defineContract({...}, ({ field, model, rel, type }) => ({...}))) to get the higher-level helpers (field.text(), field.id.uuidv7String(), field.temporal.createdAt(), type.sql.String(35)).

import sqlFamily from '@prisma-next/postgres/family';
import { defineContract } from '@prisma-next/postgres/contract-builder';
import postgresPack from '@prisma-next/postgres/target';

export const contract = defineContract(
  {
    family: sqlFamily,
    target: postgresPack,
  },
  ({ field, model }) => ({
    models: {
      User: model('User', {
        fields: {
          id: field.id.uuidv7String(),
          email: field.text().unique(),
          createdAt: field.temporal.createdAt(),
        },
      }).sql({ table: 'app_user' }),
    },
  }),
);

Then pnpm prisma-next contract emit. The field.<scalar>() helpers are only available inside the callback overload; outside the callback only field.column(...), field.generated(...), field.namedType(...) exist.

For Mongo, swap every @prisma-next/postgres/* import for @prisma-next/mongo/*. The Mongo builder also exposes index and valueObject.

Workflow — Add an extension-typed scalar (pgvector)

The concept: an extension contributes a namespace (pgvector.*) plus two descriptor flavours — a control descriptor for the config façade and a pack descriptor for the TS builder. Register the control descriptor in defineConfig.extensions (array form). If you're authoring with the TS builder, also register the pack descriptor in defineContract.extensions (record form). Then reference the namespaced constructor from the contract.

prisma-next.config.ts:

import pgvector from '@prisma-next/extension-pgvector/control';
import { defineConfig } from '@prisma-next/postgres/config';

export default defineConfig({
  contract: './src/prisma/contract.prisma',
  extensions: [pgvector],
});

src/prisma/contract.prisma:

model Document {
  id        Int                          @id @default(autoincrement())
  content   String
  embedding pgvector.Vector(length: 1536)
}

Emit. The named-type lowering puts vector(1536) on the column and the type map in contract.d.ts carries the right TS type.

If you reference pgvector.* without registering the pack in the config, emit fails with PN-CLI-4011 and meta.missingExtensions: ['pgvector']. The envelope's fix text says "Add the missing extension descriptors to extensions in prisma-next.config.ts" — that field name matches the façade.

For canonical worked examples covering single and multi-extension setups, read examples/multi-extension-monorepo/app/prisma-next.config.ts and examples/prisma-next-postgis-demo/prisma-next.config.ts.

Workflow — Polymorphism (@@discriminator / @@base)

The concept (SQL targets): one base model declares the discriminator field; each variant model declares its base + discriminator value. The variant chooses STI vs MTI by whether it sets @@map(...): no @@map means the variant inherits the base's table (single-table inheritance); @@map("variant_table") means the variant gets its own table joined 1:1 by primary key (multi-table inheritance).

model Task {
  id    Int    @id @default(autoincrement())
  title String
  type  String

  @@discriminator(type)
  @@map("tasks")
}

// STI variant — shares the `tasks` table.
model Bug {
  severity String

  @@base(Task, "bug")
}

// MTI variant — joins to `tasks` via PK; carries its own `features` table.
model Feature {
  priority Int

  @@base(Task, "feature")
  @@map("features")
}

Verify the polymorphism syntax against the interpreter tests if in doubt: packages/2-sql/2-authoring/contract-psl/test/interpreter.polymorphism.test.ts.

Mongo has no schema layer, so polymorphism on Mongo is modelled by an explicit discriminator field on the model in the TS builder (see @prisma-next/mongo/contract-builder); @@base / @@discriminator PSL attributes are SQL-only.

Querying the variants is a runtime concern — see prisma-next-queries.

Workflow — Value objects (composite types)

The concept: type Foo { ... } blocks declare value-object shapes. The interpreter lowers them to valueObjects in the contract domain and stores them as jsonb columns. Nested value-object references are supported.

type Address {
  street  String
  city    String
  zip     String?
  country String
}

model User {
  id      String   @id @default(uuid())
  email   String
  address Address?
}

Emitted contract.json carries domain.namespaces.<ns>.valueObjects.Address with its field descriptors, and the address column lands as codecId: "pg/jsonb@1" / nativeType: "jsonb" in storage.

Canonical worked example: examples/prisma-next-demo/src/prisma/contract.prisma.

Workflow — Enums

The concept: PSL enum blocks declare a domain enum: a named value-set stored through a declared codec (@@type("pg/text@1") → a text column) and enforced by a planner-generated CHECK constraint. Each member maps to its database value with Name = "value". Use the enum name as a field type on any model in the same contract.

enum user_type {
  @@type("pg/text@1")
  admin = "admin"
  user  = "user"
}

model User {
  id   String    @id @default(uuid())
  kind user_type
}

Canonical worked example: examples/prisma-next-demo/src/prisma/contract.prisma.

Workflow — Namespaces (Postgres schemas)

The concept: wrap models in a namespace <name> { ... } block to place them in a non-default Postgres schema. Models outside any block go into the implicit default namespace.

namespace public {
  model Profile {
    id       String @id @default(uuid())
    username String
    userId   String @unique
    @@map("profile")
  }
}

Canonical worked example: examples/supabase/src/contract.prisma.

Workflow — Cross-contract foreign keys

The concept: a relation field can reference a model in another contract space using the <space>:<namespace>.<Model> form. The contract also supports top-level named-type aliases in a types {} block, backed by the same bare type-position constructors used by fields. The @db.X(args) channel is removed: rewrite @db.X as X and @db.X(args) as X(args); remaining uses fail with an actionable diagnostic naming the replacement.

types {
  AuthUserId = Uuid
}

namespace public {
  model Profile {
    id       String     @id @default(uuid())
    username String
    userId   AuthUserId @unique
    user     supabase:auth.AuthUser @relation(fields: [userId], references: [id], onDelete: Cascade)
    @@map("profile")
  }
}

supabase:auth.AuthUser means: model AuthUser in namespace auth of contract space supabase. The target space is provided by a registered extension pack (here @prisma-next/extension-supabase/pack).

Canonical worked example: examples/supabase/src/contract.prisma.

Workflow — @@control (control policy)

The concept: @@control(<policy>) on a model sets whether Prisma manages that table's DDL in migrations. The argument is a positional lowercase literal — one of managed, tolerated, external, or observed.

model AuditLog {
  id        Int    @id
  message   String

  @@control(observed)
}

A contract-level default can be set via defaultControlPolicy on prismaContract(path, { defaultControlPolicy }). See prisma-next-migrations for how control policies affect DDL planning.

Workflow — @prisma-next/extension-supabase

The concept: the Supabase extension provides the supabase contract space (the auth / storage schemas as external tables, plus the platform roles) and its own role-first runtime factory. It does not expose a /control subpath so it cannot be registered via the user-facing defineConfig({ extensions: [...] }) façade — it is wired via extensions in the low-level config. See examples/supabase for the full working pattern.

prisma-next.config.ts (mirrors the example):

import supabasePack from '@prisma-next/extension-supabase/pack';
import { defineConfig } from '@prisma-next/cli/config-types';
// ... other low-level imports

export default defineConfig({
  // ...
  extensions: [supabasePack],
});

db.ts does not use the stock postgres() factory — a Supabase app builds its client with the supabase() factory from @prisma-next/extension-supabase/runtime (role-first: asUser(jwt) / asAnon() / asServiceRole(), JWT validation, RLS). That runtime — and RLS policy authoring (policy_select / @@rls) — is covered by prisma-next-supabase; load it for anything past the config wiring.

Export subpaths: @prisma-next/extension-supabase/pack, @prisma-next/extension-supabase/runtime, @prisma-next/extension-supabase/contract. Canonical worked example: examples/supabase.

Workflow — Brownfield introspection

The concept: pull a contract source out of an existing database and continue from there. prisma-next contract infer --db <url> reads the live schema and writes a contract.prisma file. It stops there — follow it with contract emit and (when the schema matches a pinned hash) db sign as separate steps.

pnpm prisma-next contract infer --db $DATABASE_URL --output ./src/prisma/contract.prisma
pnpm prisma-next contract emit

Common Pitfalls

1. Forgetting to re-emit after an edit. contract.json and contract.d.ts go stale; downstream typecheck and migration plan see the old shape. Re-emit, or install the Vite plugin (prisma-next-build).
2. Editing the emitted artefacts. contract.json and contract.d.ts are emitted; edits there round-trip away on the next emit. Edit the source.
3. Wrong factory/import path for the TS builder. defineContract, field, model, rel come from @prisma-next/postgres/contract-builder (or @prisma-next/mongo/contract-builder). Outside the callback overload, the available field constructors are field.column(...), field.generated(...), field.namedType(...).
4. Reaching into internal packages from user code. User-authored files (prisma-next.config.ts, contract.ts, db.ts, control clients) import only from @prisma-next/<target>/<subpath> and @prisma-next/extension-<name>/<subpath>. Imports from @prisma-next/cli/*, @prisma-next/family-*, @prisma-next/target-*, @prisma-next/adapter-*, @prisma-next/driver-*, or @prisma-next/sql-contract-* are framework-internal — the façade composes them for you. If a façade subpath you need is missing for your target, see What Prisma Next doesn't do yet and route to prisma-next-feedback. The canonical worked examples are examples/multi-extension-monorepo/app/prisma-next.config.ts and examples/prisma-next-postgis-demo/prisma-next.config.ts.
5. Confusing the config extensions with the TS builder's extensions. Same packs, two surfaces, one field name but two shapes: defineConfig({ extensions: [pgvector] }) (array of control descriptors from @prisma-next/extension-<name>/control) versus defineContract({ extensions: { pgvector } }) (record of pack descriptors from @prisma-next/extension-<name>/pack).
6. Renaming a field and expecting the planner to detect it. Prisma Next has no in-contract rename hint; the planner sees a destructive drop+add. Hand-edit migration.ts after migration plan (see prisma-next-migrations), or use the keep-then-drop two-migration pattern.

What Prisma Next doesn't do yet

• In-contract rename hint. No @@rename(old: ..., new: ...) or similar. Use the workarounds in Common Pitfalls #6. To request first-class rename, file via prisma-next-feedback.
• Model validations. No declarative @validates(...) surface. Validate in application code (arktype). To request declarative validations in the contract, file via prisma-next-feedback.
• Lifecycle callbacks (beforeSave, afterCreate, etc.). Not supported. Use middleware (prisma-next-runtime) or app code. To request lifecycle callbacks, file via prisma-next-feedback.
• Soft delete / paranoid: true. No built-in soft-delete column. Add a nullable deletedAt DateTime? and filter explicitly in queries (or in middleware). To request built-in soft delete, file via prisma-next-feedback.
• Scopes / default filters. No ActiveRecord-style scopes. Compose query helpers yourself. To request scopes, file via prisma-next-feedback.
• Implicit Prisma-ORM many-to-many. List navigation on both sides without an explicit join model is rejected. Author the join model explicitly. To request implicit M2M, file via prisma-next-feedback.

Reference

• Run pnpm prisma-next contract --help for the live command surface.
• PSL feature surface and what the interpreter accepts: packages/2-sql/2-authoring/contract-psl/README.md.
• TS builder surface and the callback-helper vocabulary: packages/2-sql/2-authoring/contract-ts/README.md.
• Layouts (where contract.prisma, contract.json, contract.d.ts, and migrations/ live):
  • App layout (src/prisma/... + migrations/app/...) — what examples/prisma-next-demo demonstrates; the canonical shape consuming applications use.
  • Contract-space-package layout (src/contract.{prisma,ts} directly, migrations/<timestamp>_<slug>/ without a space-id segment) — for extensions and aggregate-root packages, documented in .cursor/rules/contract-space-package-layout.mdc and ADR 212.

Checklist

• Read prisma-next.config.ts and identified the contract source (path string ending in .prisma or .ts) and the installed extensions: [...].
• All user-authored imports resolve to @prisma-next/<target>/<subpath> (e.g. @prisma-next/postgres/config) or @prisma-next/extension-<name>/<subpath>. No imports from @prisma-next/cli/*, @prisma-next/family-*, @prisma-next/target-*, @prisma-next/adapter-*, @prisma-next/driver-*, or @prisma-next/sql-contract-* in user files.
• Edited the contract source (contract.prisma or contract.ts), not an emitted artefact.
• For new extension namespaces: added the package, imported its control descriptor (@prisma-next/extension-<name>/control), added it to extensions: [...] in defineConfig({...}) (and the matching pack descriptor to defineContract({extensions: {...}}) if using the TS builder).
• For renames: hand-edited migration.ts after migration plan (or used the keep-then-drop two-migration pattern) — Prisma Next has no rename hint today.
• Ran pnpm prisma-next contract emit after the edit (or let the Vite plugin re-emit on save).
• Confirmed contract.json and contract.d.ts updated next to the source.
• Did not hand-edit contract.json / contract.d.ts.
• Did not confabulate a missing feature (validations, callbacks, soft delete, scopes, in-contract rename hint) — referred the user to What Prisma Next doesn't do yet + prisma-next-feedback.