prisma-next-contract

# 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: [...]` or `extensionPacks: [...]` 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, extensionPacks, 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, with two different field names because the surfaces consume two different descriptor types: - **In the config façade:** `extensions: [pgvector]` — array of *control* descriptors imported from `@prisma-next/extension-<name>/control`. The façade's underlying field is `extensionPacks`; the façade renames it to `extensions`. - **In the TS builder's `defineContract` (only when authoring `contract.ts`):** `extensionPacks: { 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. | Code | Meaning | Next move | |---|---|---| | `PN-CLI-4002` *Contract configuration missing* | `contract` not set in `prisma-next.config.ts`. | Add `contract: './src/prisma/contract.prisma'` (app layout) or `'./src/contract.prisma'` (contract-space-package layout) — likewise for `.ts` sources — to `defineConfig({...})` from `@prisma-next/postgres/config`. | | `PN-CLI-4003` *Contract validation failed* | Source loaded but the Contract IR failed structural validation. | Read `meta.diagnostics` / `meta.issues` for the offending model/field, fix the source, re-emit. | | `PN-CLI-4011` *Missing extension packs in config* | The contract uses a namespaced constructor (e.g. `pgvector.Vector(...)`) but `extensions` in the config does not list a matching descriptor. `meta.missingExtensionPacks` names them. | Install the package, import its control descriptor (`import pgvector from '@prisma-next/extension-pgvector/control'`), add it to `extensions: [...]` in `prisma-next.config.ts`. | ## 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: [...]`. ```bash 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. ```prisma 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`. PSL alias surface for repeated types lives in a top-level `types {}` block: ```prisma 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)`). ```typescript 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.extensionPacks` (record form). Then reference the namespaced constructor from the contract. `prisma-next.config.ts`: ```typescript 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`: ```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.missingExtensionPacks: ['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.