# Prisma ORM 7 to 8 (PostgreSQL)

This guide is for teams running a Prisma ORM 7 application on PostgreSQL who want to move to **Prisma ORM 8** without a rewrite. You will install Prisma ORM 8 next to Prisma ORM 7 in the same application, move routes over one at a time, hand migration ownership to Prisma ORM 8, and remove Prisma ORM 7 once nothing depends on it.

Both versions run against the same PostgreSQL database the whole time. The database, its data, and its connection string do not change; only application code and tooling do. Because each route stays on Prisma ORM 7 until you deliberately move it, the application remains shippable at every point in the migration.

The guide covers **PostgreSQL only**. Guidance for other databases will follow. If you are coming from v6 on MongoDB, see the [MongoDB guide](/guides/upgrade-prisma-orm-mongodb).

:::callout{intent="note"}
Step 2.1 installs the `latest` version of both Prisma ORM 8 packages: `prisma`, the Prisma ORM 8 CLI, and `@prisma/orm-postgres`. This guide was written with `prisma` at `8.0.0-rc.17` and `@prisma/orm-postgres` at `8.0.0-rc.13`: the CLI is released separately, so the two numbers differ. Prisma ORM 7 stays at `7.10.0`: the example app in step 1.1 starts on it, and step 1.2 installs `@prisma/prisma7@7.10.0`.
:::

## [How the incremental migration works](#how-the-incremental-migration-works)

The migration runs in five phases. The application works at the end of each one.

1. **Prepare Prisma ORM 7 for side-by-side operation.** Move Prisma ORM 7 onto its own package name, binary, and config file. No behavior changes.
2. **Add Prisma ORM 8.** Install the Prisma ORM 8 CLI and runtime with their own config, schema contract, and generated client. No application code uses them yet.
3. **Migrate one route.** One route runs on Prisma ORM 8 while the rest stay on Prisma ORM 7, all against the same database.
4. **Transfer migration ownership.** Prisma ORM 8 takes over planning and applying schema changes.
5. **Remove Prisma ORM 7** once nothing imports it.

The ownership timeline matters more than the code timeline. Prisma ORM 7 owns schema migrations through phases 1 to 3, and routes move to Prisma ORM 8 independently of that. Prisma ORM 8 takes over migrations only in phase 4, after a database signature and a `db` ref are in place; the first `migration plan` then writes the baseline migration itself. You can pause between phases for as long as you need.

The [prisma8-and-7-example](https://github.com/prisma/prisma8-and-7-example) repository shows the finished result of each phase (tags `step-0` through `step-3`).

## [Prerequisites](#prerequisites)

- **Node.js 22.18 or newer (on the 24 line, 24.11 or newer)**; Node.js 24 recommended
- A working **Prisma ORM 7** application on PostgreSQL: `prisma.config.ts`, the `prisma-client` generator, and a driver adapter
- **TypeScript 5.9 or newer** with `"strict": true`. [Step 2.6](#26-set-up-tsconfigjson-for-the-prisma-orm-8-client) tells you whether to change the `module` setting in `tsconfig.json`

## [1. Prepare Prisma ORM 7 for side-by-side operation](#1-prepare-prisma-orm-7-for-side-by-side-operation)

Prisma ORM 8 expects the `prisma` package name, the `prisma` binary, and the `prisma.config.ts` file name. In this phase you move Prisma ORM 7 off those three names so Prisma ORM 8 can take them without ambiguity. Nothing migrates yet.

### [1.1. Confirm the application works](#11-confirm-the-application-works)

The guide follows a small Hono API with two routes. Map the file names to your own project. The Prisma ORM 7 pieces that matter:

```title="package.json (excerpt)"
{

  "scripts": {

    "prisma:generate": "prisma generate",

    "db:migrate": "prisma migrate dev"

  },

  "dependencies": {

    "@prisma/adapter-pg": "^7.10.0",

    "@prisma/client": "^7.10.0"

  },

  "devDependencies": {

    "prisma": "^7.10.0"

  }

}
```

```title="prisma/schema.prisma"
generator client {

  provider = "prisma-client"

  output   = "../generated/prisma"

}

datasource db {

  provider = "postgresql"

}

model User {

  id    Int     @id @default(autoincrement())

  email String  @unique

  name  String?

  posts Post[]

}

model Post {

  id        Int     @id @default(autoincrement())

  title     String

  published Boolean @default(false)

  authorId  Int

  author    User    @relation(fields: [authorId], references: [id], onDelete: Cascade)

  @@index([authorId])

}
```

```title="prisma.config.ts"
import "dotenv/config";

import { defineConfig } from "prisma/config";

export default defineConfig({

  schema: "prisma/schema.prisma",

  migrations: {

    path: "prisma/migrations",

  },

  datasource: {

    url: process.env["DATABASE_URL"],

  },

});
```

```title="src/db.ts"
import "dotenv/config";

import { PrismaPg } from "@prisma/adapter-pg";

import { PrismaClient } from "../generated/prisma/client.js";

const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL! });

export const prisma = new PrismaClient({ adapter });
```

Two routes read and write through this client, `/users` and `/posts`:

```title="src/routes/users.ts"
import { Hono } from "hono";

import { prisma } from "../db.js";

export const users = new Hono();

users.get("/", async (c) => {

  const result = await prisma.user.findMany({

    include: { posts: true },

    orderBy: { id: "asc" },

  });

  return c.json(result);

});

users.post("/", async (c) => {

  const body = await c.req.json<{ email: string; name?: string }>();

  const user = await prisma.user.create({ data: body });

  return c.json(user, 201);

});
```

`src/routes/posts.ts` follows the same pattern for `Post`.

Start the app and run a read and a write:

::::tabs
:::tab{title="bun"}
```
bun run dev
```
:::

:::tab{title="pnpm"}
```bash
pnpm run dev
```
:::

:::tab{title="yarn"}
```bash
yarn dev
```
:::

:::tab{title="npm"}
```bash
npm run dev
```

```bash
curl -X POST localhost:3000/users -H 'content-type: application/json' \
  -d '{"email":"alice@prisma.io","name":"Alice"}'
curl localhost:3000/users
```

Do not continue until both requests succeed. That confirms the Prisma ORM 7 application works before you change its configuration.
:::
::::

```
curl -X POST localhost:3000/users -H 'content-type: application/json' \

  -d '{"email":"alice@prisma.io","name":"Alice"}'

curl localhost:3000/users
```

Do not continue until both requests succeed. That confirms the Prisma ORM 7 application works before you change its configuration.

### [1.2. Replace the `prisma` package with `@prisma/prisma7`](#12-replace-the-prisma-package-with-prismaprisma7)

::::tabs
:::tab{title="bun"}
```
bun remove prisma

bun add --dev @prisma/prisma7@7.10.0
```
:::

:::tab{title="pnpm"}
```bash
pnpm remove prisma
pnpm add --save-dev @prisma/prisma7@7.10.0
```
:::

:::tab{title="yarn"}
```bash
yarn remove prisma
yarn add --dev @prisma/prisma7@7.10.0
```
:::

:::tab{title="npm"}
```bash
npm uninstall prisma
npm install --save-dev @prisma/prisma7@7.10.0
```

`@prisma/prisma7` is the same Prisma ORM 7 CLI under a version-specific name. It exposes a `prisma7` binary and keeps `prisma` 7 as a transitive dependency. Your `@prisma/client` and `@prisma/adapter-pg` dependencies stay untouched.
:::
::::

`@prisma/prisma7` is the same Prisma ORM 7 CLI under a version-specific name. It exposes a `prisma7` binary and keeps `prisma` 7 as a transitive dependency. Your `@prisma/client` and `@prisma/adapter-pg` dependencies stay untouched.

### [1.3. Rename the Prisma ORM 7 config](#13-rename-the-prisma-orm-7-config)

```
mv prisma.config.ts prisma7.config.ts
```

```title="prisma7.config.ts"
import "dotenv/config";

import { defineConfig } from "prisma/config"; 

import { defineConfig } from "@prisma/prisma7/config"; 

export default defineConfig({

  schema: "prisma/schema.prisma",

  migrations: {

    path: "prisma/migrations",

  },

  datasource: {

    url: process.env["DATABASE_URL"],

  },

});
```

The `prisma7` CLI discovers `prisma7.config.ts` automatically, so no `--config` flag is needed. Renaming frees the `prisma.config.ts` name for Prisma ORM 8, which only accepts its own config format under that name.

### [1.4. Point scripts at the `prisma7` binary](#14-point-scripts-at-the-prisma7-binary)

```title="package.json (excerpt)"
{

  "scripts": {

    "prisma:generate": "prisma generate", 

    "db:migrate": "prisma migrate dev"

    "prisma7:generate": "prisma7 generate", 

    "prisma7:migrate": "prisma7 migrate dev"

  }

}
```

After Prisma ORM 8 is installed, the `prisma` binary runs the Prisma ORM 8 CLI. Update every script, CI job, and deployment command that must continue using Prisma ORM 7 to call `prisma7` instead.

### [1.5. Check that Prisma ORM 7 still works](#15-check-that-prisma-orm-7-still-works)

::::tabs
:::tab{title="bun"}
```
bunx prisma7 generate

bunx prisma7 migrate status
```
:::

:::tab{title="pnpm"}
```bash
pnpm dlx prisma7 generate
pnpm dlx prisma7 migrate status
```
:::

:::tab{title="yarn"}
```bash
yarn dlx prisma7 generate
yarn dlx prisma7 migrate status
```
:::

:::tab{title="npm"}
```bash
npx prisma7 generate
npx prisma7 migrate status
```

**Expected result:** `generate` writes the client to `generated/prisma` as before, and `migrate status` reports that the database schema is up to date. Start the app and query each route; behavior should be identical to step 1.1.
:::
::::

**Expected result:** `generate` writes the client to `generated/prisma` as before, and `migrate status` reports that the database schema is up to date. Start the app and query each route; behavior should be identical to step 1.1.

## [2. Add Prisma ORM 8](#2-add-prisma-orm-8)

### [2.1. Install the Prisma ORM 8 packages](#21-install-the-prisma-orm-8-packages)

::::tabs
:::tab{title="bun"}
```
bun add --dev prisma@latest

bun add @prisma/orm-postgres
```
:::

:::tab{title="pnpm"}
```bash
pnpm add --save-dev prisma@latest
pnpm add @prisma/orm-postgres
```
:::

:::tab{title="yarn"}
```bash
yarn add --dev prisma@latest
yarn add @prisma/orm-postgres
```
:::

:::tab{title="npm"}
```bash
npm install --save-dev prisma@latest
npm install @prisma/orm-postgres
```

`prisma@latest` is the Prisma ORM 8 CLI, and its `prisma/config` subpath provides `definePrismaConfig` for the Prisma ORM 8 config file. Installing it locally (not only running it through `npx`) is what makes that import resolve. `@prisma/orm-postgres` is the PostgreSQL ORM runtime your application code will import.

After this install, `npx prisma <command>` runs the Prisma ORM 8 CLI and `npx prisma7 <command>` runs Prisma ORM 7:
:::
::::

`prisma@latest` is the Prisma ORM 8 CLI, and its `prisma/config` subpath provides `definePrismaConfig` for the Prisma ORM 8 config file. Installing it locally (not only running it through `npx`) is what makes that import resolve. `@prisma/orm-postgres` is the PostgreSQL ORM runtime your application code will import.

After this install, `npx prisma <command>` runs the Prisma ORM 8 CLI and `npx prisma7 <command>` runs Prisma ORM 7:

::::tabs
:::tab{title="bun"}
```
bunx prisma --version
```
:::

:::tab{title="pnpm"}
```bash
pnpm prisma --version
```
:::

:::tab{title="yarn"}
```bash
yarn prisma --version
```
:::

:::tab{title="npm"}
```bash
npx prisma --version
```

**Expected result:** the command prints `8.0.0-rc.17` or a newer version. That number does not match the version of `@prisma/orm-postgres`, because the CLI is released separately.
:::
::::

**Expected result:** the command prints `8.0.0-rc.17` or a newer version. That number does not match the version of `@prisma/orm-postgres`, because the CLI is released separately.

### [2.2. Create the Prisma ORM 8 config](#22-create-the-prisma-orm-8-config)

```title="prisma.config.ts"
import "dotenv/config";

import { definePrismaConfig } from "prisma/config";

import { defineConfig as definePostgresConfig } from "@prisma/orm-postgres/config";

export default definePrismaConfig({

  orm: definePostgresConfig({

    contract: "prisma8/contract.prisma",

    output: "generated/prisma8",

    db: {

      connection: process.env["DATABASE_URL"],

    },

  }),

});
```

Both configs point at the **same** `DATABASE_URL`. Everything else is separate:

|                  | Prisma ORM 7           | Prisma ORM 8              |
| ---------------- | ---------------------- | ------------------------- |
| CLI              | `prisma7`              | `prisma`                  |
| Config           | `prisma7.config.ts`    | `prisma.config.ts`        |
| Schema           | `prisma/schema.prisma` | `prisma8/contract.prisma` |
| Generated client | `generated/prisma`     | `generated/prisma8`       |

Because the config carries the connection, the Prisma ORM 8 CLI commands below don't need a `--db` flag.

::::callout{intent="note"}
Read the Prisma ORM 7 schema instead

Instead of generating a contract file in steps 2.3 and 2.4, Prisma ORM 8 can read `prisma/schema.prisma` directly as its contract, so you keep one schema file while Prisma ORM 7 owns migrations. `schema.prisma` does not need the `// use prisma-8` first line that a contract file written for Prisma ORM 8 starts with (step 2.4 shows one). Skip steps 2.3 and 2.4, and change two lines in the `prisma.config.ts` you just wrote:

```title="prisma.config.ts"
import "dotenv/config";

import { definePrismaConfig } from "prisma/config";

import { defineConfig as definePostgresConfig } from "@prisma/orm-postgres/config"; 

import { defineConfig as definePostgresConfig, prisma7Schema } from "@prisma/orm-postgres/config"; 

export default definePrismaConfig({

  orm: definePostgresConfig({

    contract: "prisma8/contract.prisma", 

    contract: prisma7Schema("prisma/schema.prisma"), 

    output: "generated/prisma8",

    db: {

      connection: process.env["DATABASE_URL"],

    },

  }),

});
```

After step 2.5, run `npx prisma db sign`. [`db sign`](/guides/orm-db-sign) checks that the database matches the contract Prisma ORM 8 read from `schema.prisma` and records in the database that it does. Signing does not move your migrations to Prisma ORM 8. Prisma ORM 7 keeps planning and applying them, so after each Prisma ORM 7 migration, whether you ran `prisma7 migrate dev` or `prisma7 migrate deploy`, run `npx prisma contract emit` and then `npx prisma db sign` again. If you emit without signing, the Prisma ORM 8 client still runs queries, but `npx prisma db verify` reports that the contract no longer matches the one recorded in the database. [Use a Prisma ORM 7 schema](/guides/introduction-6-configuration#use-a-prisma-orm-7-schema) lists the parts of a Prisma ORM 7 schema that Prisma ORM 8 cannot read.

If you have not started phase 1 yet, one command does phase 1 and this setup for you:

:::code-group
```bash title="bun"
bunx prisma@latest orm init --from-prisma7-schema prisma/schema.prisma
```

```bash title="pnpm"
pnpm prisma contract infer --output prisma8/contract.prisma
```

```bash title="yarn"
yarn prisma contract infer --output prisma8/contract.prisma
```

```bash title="npm"
npx prisma contract infer --output prisma8/contract.prisma
```
:::

Write `prisma@latest`, because in a Prisma ORM 7 project `npx prisma` runs version 7. The command moves Prisma ORM 7 to the `prisma7` command and `prisma7.config.ts`, installs the Prisma ORM 8 packages, writes `prisma.config.ts` and a Prisma ORM 8 client in `src/prisma/db.ts`, and emits the contract. [`orm init` on a Prisma ORM 7 project](/guides/orm-orm-init#on-a-prisma-orm-7-project) lists what it changes. Then run `npx prisma db sign` and continue with phase 3, using the `db` client from `src/prisma/db.ts` instead of adding one to `src/db.ts` in step 3.1.

Prisma ORM 7 keeps owning migrations on this path until you are ready for [phase 4](#4-transfer-migration-ownership), where Prisma ORM 8 takes them over. Phase 4 needs a contract file written for Prisma ORM 8, so switch to one first. Either run `npx prisma contract print --output prisma8/contract.prisma`, which writes the contract Prisma ORM 8 read from `schema.prisma` as a Prisma ORM 8 contract file, or run steps 2.3 to 2.5. Then set `contract` in `prisma.config.ts` to `"prisma8/contract.prisma"`, the file you created. Then follow phase 4 as written. Its first step, `db sign`, checks the new contract against the database before Prisma ORM 8 takes over.
::::

### [2.3. Infer the contract from the live database](#23-infer-the-contract-from-the-live-database)

Prisma ORM 8 describes your schema as a [contract](/guides/contract-authoring-the-data-contract). Generate it from the database Prisma ORM 7 built:

::::tabs
:::tab{title="bun"}
```bash
bunx prisma contract infer --output prisma8/contract.prisma
```
:::

:::tab{title="pnpm"}
```bash
pnpm prisma contract emit
```
:::

:::tab{title="yarn"}
```bash
yarn prisma contract emit
```
:::

:::tab{title="npm"}
```bash
npx prisma contract emit
```

`contract emit` writes `contract.json` and `contract.d.ts` to `generated/prisma8`, the runtime and type inputs for the Prisma ORM 8 client. Re-run it after every contract change.
:::
::::

### [2.4. Edit the inferred contract](#24-edit-the-inferred-contract)

`contract infer` reads every table in the database, so it also writes a `PrismaMigrations` model for `_prisma_migrations`, the table where Prisma ORM 7 records which migrations it has applied. Delete that model from the contract, because Prisma ORM 8 must not manage the table. The table itself stays in the database, and an extra table that the contract does not describe is fine.

You do not need to add `@@map` to the other models: a model without `@@map` uses its name, exactly as written, as its table name, so `User` reads and writes the `"User"` table that Prisma ORM 7 created.

After that edit, the contract looks like this:

```title="prisma8/contract.prisma"
// use prisma-8

model User {

  id    Int     @id(map: "User_pkey") @default(autoincrement())

  email String

  name  String?

  posts Post[]

  @@index([email], map: "User_email_key", unique: true)

}

model Post {

  id        Int     @id(map: "Post_pkey") @default(autoincrement())

  title     String

  published Boolean @default(false)

  authorId  Int

  author    User    @relation(fields: [authorId], references: [id], onDelete: Cascade, onUpdate: Cascade, map: "Post_authorId_fkey")

  @@index([authorId], map: "Post_authorId_idx")

}
```

Keep `// use prisma-8` as the first line of `prisma8/contract.prisma`. `contract emit` reads only `.prisma` files that start with this line, and this is the only file in your contract, so without it `contract emit` fails with `CONTRACT.SOURCE_LOAD_FAILED`. A `schema.prisma` that Prisma ORM 8 reads through `prisma7Schema(...)`, as in the tip at the end of step 2.2, does not need the line.

### [2.5. Emit the contract artifacts](#25-emit-the-contract-artifacts)

::::tabs
:::tab{title="bun"}
```
bunx prisma contract emit
```
:::

:::tab{title="pnpm"}
```bash
pnpm prisma db sign
pnpm prisma migration status
```
:::

:::tab{title="yarn"}
```bash
yarn prisma db sign
yarn prisma migration status
```
:::

:::tab{title="npm"}
```bash
npx prisma db sign
npx prisma migration status
```

`db sign` verifies that the live schema matches the emitted contract, writes Prisma ORM 8's marker at that contract version, stores the contract snapshot under `migrations/snapshots/`, and points a [ref](/guides/migrations-the-migration-graph#name-important-states-with-refs) named `db` at it. `migration plan` starts from that ref, so plans chain from the schema Prisma ORM 7 built and contain only your own changes.

**Expected result:** `Database signed`, and `migration status` shows the current and target contract hashes match with nothing pending.
:::
::::

`contract emit` writes `contract.json` and `contract.d.ts` to `generated/prisma8`, the runtime and type inputs for the Prisma ORM 8 client. Re-run it after every contract change.

### [2.6. Set up tsconfig.json for the Prisma ORM 8 client](#26-set-up-tsconfigjson-for-the-prisma-orm-8-client)

Your `tsconfig.json` must allow the JSON import you will write in step 3.1: `import contractJson from "../generated/prisma8/contract.json" with { type: "json" }`. TypeScript accepts the `with { type: "json" }` part only when `module` is `esnext`, `node18`, `node20`, `nodenext`, or `preserve`, and only in a file it treats as an ES module. Any other value, such as `commonjs`, `es2022`, or `node16`, rejects it, and leaving `module` unset fails too. Take the first case below that matches how your app runs:

- **`module` is already one of the five values and your build works with it, and either `package.json` has `"type": "module"` or `module` is `esnext` or `preserve`.** Keep it. Set `moduleResolution` to `bundler` if `module` is `esnext` or `preserve`, to `nodenext` if `module` is `nodenext`, and remove it if `module` is `node18` or `node20`. A `moduleResolution` of `node` or `node10` cannot resolve the `@prisma/orm-*` packages, so do not leave that in place.

- **You compile with `tsc`, run the output with `node`, and `package.json` has no `"type": "module"` (or has `"type": "commonjs"`).** Your app runs as CommonJS, and it can stay that way. Set `"module": "nodenext"` and `"moduleResolution": "nodenext"`, and do not add `"type": "module"`. Prisma ORM 8 works from CommonJS code, and your relative imports stay as they are, without extensions. TypeScript treats `db.ts` as CommonJS here, so in step 3.1 write the JSON import without the `with` part and copy the other import lines as shown.

  ```title="src/db.ts (CommonJS excerpt)"
  import contractJson from "../generated/prisma8/contract.json";
  ```

- **The app runs through `tsx`, or a bundler such as `vite`, `next`, or `esbuild` builds it, and you never run `tsc` output with plain `node`.** Set `"module": "preserve"` and `"moduleResolution": "bundler"`. You do not need file extensions on relative imports, and the import lines in step 3.1 work as shown. If you run the `.ts` files directly with `node` instead, its type stripping needs the `.ts` extension on every relative import, so add `"allowImportingTsExtensions": true` as well.

- **You compile with `tsc`, run the output with `node`, and `package.json` has `"type": "module"`, even if you use `tsx` in development.** Set `"module": "nodenext"` and `"moduleResolution": "nodenext"`. Node requires a file extension on every relative import when it runs ES modules, so every import that starts with `./` or `../` and points at a `.ts` or `.d.ts` file must end in `.js`, the extension of the compiled output: `import { postsRoutes } from "./routes/posts.js"`, and a directory import such as `./routes` becomes `./routes/index.js`. The `contract.json` import in step 3.1 keeps its `.json` extension and its `with { type: "json" }` part. Until every relative import has its extension, `npx tsc --noEmit` fails and names each one that still needs it. The [example project](https://github.com/prisma/prisma8-and-7-example) is set up this way; [the TypeScript module reference](https://www.typescriptlang.org/docs/handbook/modules/reference.html#node16-node18-nodenext) has the details.

Whichever case applies, add `"resolveJsonModule": true` so TypeScript can type the JSON import, and add `generated/prisma8/**/*.d.ts` to `include` so it sees the emitted `contract.d.ts`. If your `tsconfig.json` has no `include`, TypeScript already picks up every file under the project, so skip that part:

```title="tsconfig.json (excerpt)"
{

  "compilerOptions": {

    "resolveJsonModule": true

  },

  "include": [

    "src/**/*.ts",

    "generated/prisma/**/*.ts",

    "generated/prisma8/**/*.d.ts"

  ]

}
```

**Check:** `npx tsc --noEmit` passes. If you followed the last case, it fails until every relative import of a `.ts` or `.d.ts` file has its `.js` extension. Prisma ORM 8 is now installed and configured, but no application code uses it yet. This check does not test your `module` choice, because nothing imports `contract.json` until step 3.1. If TypeScript reports error TS2823 there, the `module` value rejects the `with` part; come back to this step and pick again. If it reports TS2856, TypeScript compiles `db.ts` as CommonJS, so remove the `with` part as the CommonJS case shows.

## [3. Migrate one route](#3-migrate-one-route)

Pick one small route and move only that code. The rest of the application stays on Prisma ORM 7.

### [3.1. Instantiate both clients](#31-instantiate-both-clients)

```title="src/db.ts"
import "dotenv/config";

import { PrismaPg } from "@prisma/adapter-pg";

import postgres from "@prisma/orm-postgres/runtime"; 

import type { Contract } from "../generated/prisma8/contract.js"; 

import contractJson from "../generated/prisma8/contract.json" with { type: "json" }; 

import { PrismaClient } from "../generated/prisma/client.js";

const connectionString = process.env.DATABASE_URL!;

const adapter = new PrismaPg({ connectionString });

export const prisma = new PrismaClient({ adapter });

export const db = postgres<Contract>({ url: connectionString, contractJson }); 
```

`prisma` is the Prisma ORM 7 client and `db` is the Prisma ORM 8 client, both connected to the same database.

### [3.2. Rewrite the route](#32-rewrite-the-route)

Move the users route to the Prisma ORM 8 [ORM client](/guides/reference-2-reference-orm-client). Queries start from `db.orm.<schema>.<Model>` (`public` here) and chain instead of taking one options object:

:::code-group
```title="After"
import { Hono } from "hono";

import { db } from "../db.js";

export const users = new Hono();

users.get("/", async (c) => {

  const result = await db.orm.public.User.include("posts", (posts) =>

    posts.orderBy((post) => post.id.asc()),

  )

    .orderBy((user) => user.id.asc())

    .all();

  return c.json(result);

});

users.post("/", async (c) => {

  const body = await c.req.json<{ email: string; name?: string }>();

  const user = await db.orm.public.User.create(body);

  return c.json(user, 201);

});
```

```typescript title="Before"
import { Hono } from "hono";
import { prisma } from "../db.js";

export const users = new Hono();

users.get("/", async (c) => {
  const result = await prisma.user.findMany({
    include: { posts: true },
    orderBy: { id: "asc" },
  });
  return c.json(result);
});

users.post("/", async (c) => {
  const body = await c.req.json<{ email: string; name?: string }>();
  const user = await prisma.user.create({ data: body });
  return c.json(user, 201);
});
```
:::

`src/routes/posts.ts` stays unchanged, on Prisma ORM 7.

### [3.3. Exercise both code paths](#33-exercise-both-code-paths)

Start the app and hit both routes:

```
curl localhost:3000/users

curl -X POST localhost:3000/posts -H 'content-type: application/json' \

  -d '{"title":"Written by Prisma 7","authorId":1}'

curl localhost:3000/users
```

**Expected result:** the first request runs through Prisma ORM 8. The second writes through Prisma ORM 7. The third, through Prisma ORM 8 again, includes the post Prisma ORM 7 just wrote.

Remaining routes can move over the same way, one at a time, on any schedule. Prisma ORM 7 still owns schema migrations in this phase. If the schema changes, run `prisma7 migrate dev`, then re-run `contract infer` and `contract emit` so the Prisma ORM 8 contract stays current.

## [4. Transfer migration ownership](#4-transfer-migration-ownership)

So far every schema change has gone through `prisma7 migrate dev`. In this phase Prisma ORM 8 takes over planning and applying schema changes, and `prisma/schema.prisma` is frozen.

Treat the switch as a decision, not a routine step. After it, your team and your pipelines must stop using the Prisma ORM 7 migration workflow, even though routes still on the Prisma ORM 7 client keep working. See [how migrations work](/guides/migrations-how-migrations-work) for the full picture.

Prisma ORM 8 tracks schema state with four pieces, and the handoff creates each one exactly once:

- A **contract hash** identifies one version of the emitted contract.
- A **migration** is an on-disk package recording how to get from one contract hash to another. `migrate` only replays recorded migrations; it never invents one.
- The **marker** is Prisma ORM 8's record, stored in the database, of which contract hash the database currently satisfies.
- A **ref** is a named pointer at a contract hash. `migration plan` uses the `db` ref as its starting point.

Step 4.1 creates the marker and the ref with one command. The baseline migration is written by the first `migration plan` in step 4.3.

### [4.1. Sign the existing database](#41-sign-the-existing-database)

Your database already has every table the contract describes, so adopt it rather than replay anything:

::::tabs
:::tab{title="bun"}
```
bunx prisma db sign

bunx prisma migration status
```
:::

:::tab{title="pnpm"}
```bash
pnpm prisma contract emit
pnpm prisma migration plan --name add_user_bio
pnpm prisma db migrate --advance-ref db
pnpm prisma db verify
```
:::

:::tab{title="yarn"}
```bash
yarn prisma contract emit
yarn prisma migration plan --name add_user_bio
yarn prisma db migrate --advance-ref db
yarn prisma db verify
```
:::

:::tab{title="npm"}
```bash
npx prisma contract emit
npx prisma migration plan --name add_user_bio
npx prisma db migrate --advance-ref db
npx prisma db verify
```

**Expected result:** `migration plan` reports `Planned baseline + 1 operation(s)` and writes two packages under `migrations/app/`: a baseline that records the schema you adopted in step 4.1, and `add_user_bio` with the single operation `Add column "bio" to "User"`. `db migrate` skips the baseline, because the marker already records that state, and applies `add_user_bio`. `--advance-ref db` moves the ref so the next plan chains correctly, and `db verify` reports that marker and schema match the contract.

Restart the app: the Prisma ORM 8 route returns users with `bio`, and the Prisma ORM 7 route keeps working untouched, because its client doesn't know about the new column. Additive changes like nullable columns are safe next to legacy Prisma ORM 7 code. Be careful with renames or drops of columns that Prisma ORM 7 routes still read.
:::
::::

`db sign` verifies that the live schema matches the emitted contract, writes Prisma ORM 8's marker at that contract version, stores the contract snapshot under `migrations/snapshots/`, and points a [ref](/guides/migrations-the-migration-graph#name-important-states-with-refs) named `db` at it. `migration plan` starts from that ref, so plans chain from the schema Prisma ORM 7 built and contain only your own changes.

**Expected result:** `Database signed`, and `migration status` shows the current and target contract hashes match with nothing pending.

### [4.2. Retire the Prisma ORM 7 migration scripts](#42-retire-the-prisma-orm-7-migration-scripts)

Remove `prisma7 migrate` from your scripts so nobody runs it by accident. Keep `prisma7 generate`, because the legacy routes still need their client:

```title="package.json (excerpt)"
{

  "scripts": {

    "prisma7:generate": "prisma7 generate",

    "prisma7:migrate": "prisma7 migrate dev", 

    "prisma8:migrate": "prisma db migrate --advance-ref db"

  }

}
```

### [4.3. Verify the handoff with a schema change](#43-verify-the-handoff-with-a-schema-change)

Verify the migration handoff with a small additive schema change. Add a field to the contract:

```title="prisma8/contract.prisma (excerpt)"
model User {

  id    Int     @id(map: "User_pkey") @default(autoincrement())

  email String

  name  String?

  bio   String?

  ...

}
```

Emit, plan, and apply:

::::tabs
:::tab{title="bun"}
```
bunx prisma contract emit

bunx prisma migration plan --name add_user_bio

bunx prisma db migrate --advance-ref db

bunx prisma db verify
```
:::

:::tab{title="pnpm"}
```bash
pnpm remove @prisma/prisma7 @prisma/client @prisma/adapter-pg
```
:::

:::tab{title="yarn"}
```bash
yarn remove @prisma/prisma7 @prisma/client @prisma/adapter-pg
```
:::

:::tab{title="npm"}
```bash
npm uninstall @prisma/prisma7 @prisma/client @prisma/adapter-pg
```

```bash
rm prisma7.config.ts
rm -r prisma generated/prisma
```

Then delete the `prisma7:*` scripts from `package.json` and drop `generated/prisma/**/*.ts` from the `include` array in `tsconfig.json`.

Verify the end state:
:::
::::

**Expected result:** `migration plan` reports `Planned baseline + 1 operation(s)` and writes two packages under `migrations/app/`: a baseline that records the schema you adopted in step 4.1, and `add_user_bio` with the single operation `Add column "bio" to "User"`. `db migrate` skips the baseline, because the marker already records that state, and applies `add_user_bio`. `--advance-ref db` moves the ref so the next plan chains correctly, and `db verify` reports that marker and schema match the contract.

Restart the app: the Prisma ORM 8 route returns users with `bio`, and the Prisma ORM 7 route keeps working untouched, because its client doesn't know about the new column. Additive changes like nullable columns are safe next to legacy Prisma ORM 7 code. Be careful with renames or drops of columns that Prisma ORM 7 routes still read.

## [5. Remove Prisma ORM 7](#5-remove-prisma-orm-7)

Migrate the remaining routes as in phase 3. For `posts` here, that means swapping `prisma.post.findMany(...)` for `db.orm.public.Post.include("author").all()` and `prisma.post.create({ data })` for `db.orm.public.Post.create(data)`.

When nothing imports `generated/prisma` anymore, remove Prisma ORM 7:

::::tabs
:::tab{title="bun"}
```
bun remove @prisma/prisma7 @prisma/client @prisma/adapter-pg
```
:::

:::tab{title="pnpm"}
```bash
pnpm tsc --noEmit
pnpm prisma db verify
```
:::

:::tab{title="yarn"}
```bash
yarn tsc --noEmit
yarn prisma db verify
```
:::

:::tab{title="npm"}
```bash
npx tsc --noEmit
npx prisma db verify
```

Start the app and run a query against every route. The application now runs entirely on Prisma ORM 8, with schema changes managed by `prisma migration plan` and `prisma db migrate`.

> \[!NOTE]
> Prisma ORM 7's `_prisma_migrations` table remains in the database. It is inert (Prisma ORM 8 ignores it) and you can drop it whenever you like.
:::
::::

```
rm prisma7.config.ts

rm -r prisma generated/prisma
```

Then delete the `prisma7:*` scripts from `package.json` and drop `generated/prisma/**/*.ts` from the `include` array in `tsconfig.json`.

Verify the end state:

::::tabs
:::tab{title="bun"}
```
bunx tsc --noEmit

bunx prisma db verify
```
:::

:::tab{title="pnpm"}
:::

:::tab{title="yarn"}
:::

:::tab{title="npm"}
:::
::::

Start the app and run a query against every route. The application now runs entirely on Prisma ORM 8, with schema changes managed by `prisma migration plan` and `prisma db migrate`.

:::callout{intent="note"}
Prisma ORM 7's `_prisma_migrations` table remains in the database. It is inert (Prisma ORM 8 ignores it) and you can drop it whenever you like.
:::

## [Next steps](#next-steps)

- [How migrations work in Prisma ORM](/guides/migrations-how-migrations-work): the day-to-day `contract emit` → `migration plan` → `migrate` loop for schema changes
- [Contract authoring](/guides/contract-authoring-psl-syntax): the full PSL syntax for evolving `contract.prisma`
- [Prisma ORM CLI reference](/guides/reference-3-cli): every command used in this guide

## Related pages

- [Authentication & Tools](./authentication-tools-index.md)
- [Build](./build-index.md)
- [Changelog](../changelog.md)
- [Concepts](./concepts-index.md)
- [Console commands](./console-commands-index.md)
- [Contract Authoring](./contract-authoring-index.md)
- [Core Concepts](./core-concepts-index.md)
- [Data Modeling](./data-modeling-index.md)
- [Database](./database-index.md)
- [DB commands](./db-commands-index.md)

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