fix: install the project-owned local Postgres runtime

README.md

@@ -15,6 +15,10 @@ bunx create-prisma@latest my-app
 
 The CLI initializes Prisma 8 with `prisma@latest`, installs dependencies, emits the contract, and generates a deployable Composer app. PostgreSQL projects use Composer's native Prisma Postgres provider, including migrations and a typed runtime client.
 
+PostgreSQL apps with Composer include `@prisma/dev` as a project devDependency for
+local Postgres. In a monorepo it belongs at the root, where Composer runs. Prisma 8
+does not include this runtime itself. MongoDB and Deno-only apps do not need it.
+
 For npm, use 11.6.0 or newer, which includes the [upstream resolver fix](https://github.com/npm/cli/pull/8448).
 Older npm releases can crash resolving the dependency tree (`Cannot read properties of null (reading 'edgesOut')`). Run
 `npm install --global npm@11` to update. create-prisma checks the selected npm

src/constants/dependencies.ts

@@ -5,6 +5,7 @@ export const dependencyVersionMap = {
   "@elysiajs/node": "^1.4.5",
   "@prisma/composer": "0.19.0",
   "@prisma/composer-prisma-cloud": "0.19.0",
+  "@prisma/dev": "0.25.2",
   "@prisma/orm-mongo": "8.0.0-rc.10",
   // Must match @prisma/composer-prisma-cloud's exact peerDependency.
   "@prisma/orm-postgres": "8.0.0-rc.10",

src/tasks/install.ts

@@ -164,8 +164,10 @@ export const writePrismaDependenciesEffect = Effect.fn("Dependencies.writePrisma
   options: { skillsSync?: boolean; template?: CreateTemplate } = {},
 ) {
   const databaseDependencies = [getDbPackages(provider)];
+  const devDependencies = ["@types/node", "prisma"];
   if (provider === "postgres" && packageManager !== "deno") {
     databaseDependencies.push("temporal-polyfill");
+    devDependencies.push("@prisma/dev");
   }
   if (provider === "mongo") databaseDependencies.push("arktype", "mongodb");
   const dependencies =
@@ -175,7 +177,7 @@ export const writePrismaDependenciesEffect = Effect.fn("Dependencies.writePrisma
   if (packageManager === "deno") dependencies.push("dotenv");
   yield* addPackageDependencyEffect({
     dependencies,
-    devDependencies: ["@types/node", "prisma"],
+    devDependencies,
     scripts: getPrismaScriptMap(packageManager, options.skillsSync ?? true),
     projectDir,
   });

tests/install.test.ts

@@ -69,6 +69,7 @@ describe("writePrismaDependencies", () => {
       expect(packageJson.dependencies?.dotenv).toBeUndefined();
       expect(packageJson.devDependencies).toMatchObject({
         prisma: dependencyVersionMap.prisma,
+        "@prisma/dev": dependencyVersionMap["@prisma/dev"],
       });
       expect(packageJson.scripts).toMatchObject({
         "contract:emit": "prisma contract emit",
@@ -99,6 +100,7 @@ describe("writePrismaDependencies", () => {
         mongodb: dependencyVersionMap.mongodb,
       });
       expect(packageJson.dependencies?.["@prisma/orm-postgres"]).toBeUndefined();
+      expect(packageJson.devDependencies?.["@prisma/dev"]).toBeUndefined();
       expect(packageJson.scripts?.["db:seed"]).toBeUndefined();
     });
   });
@@ -117,6 +119,7 @@ describe("writePrismaDependencies", () => {
         prisma: dependencyVersionMap.prisma,
       });
       expect(packageJson.devDependencies?.["@prisma/cli-engine"]).toBeUndefined();
+      expect(packageJson.devDependencies?.["@prisma/dev"]).toBeUndefined();
       expect(packageJson.scripts).toMatchObject({
         "contract:emit": `deno run -A npm:${PRISMA_DENO_CLI_PACKAGE} contract emit`,
         "db:init": `deno run -A --env-file=.env npm:${PRISMA_DENO_CLI_PACKAGE} db init`,
@@ -271,8 +274,17 @@ describe("generated templates", () => {
                 packageManager,
               });
               await writeCreateTemplateDependencies({ template, packageManager, projectDir });
+              await writePrismaDependencies(provider, packageManager, authoring, projectDir, {
+                template,
+              });
 
               const packageJson = await readPackageJson(projectDir);
+              expect(packageJson.devDependencies?.["@prisma/dev"]).toBe(
+                provider === "postgres" && packageManager !== "deno"
+                  ? dependencyVersionMap["@prisma/dev"]
+                  : undefined,
+              );
+              expect(packageJson.dependencies?.["@prisma/dev"]).toBeUndefined();
               if (packageManager === "bun") {
                 expect(packageJson.packageManager).toBe("bun@1.4.1");
               }
@@ -341,11 +353,10 @@ describe("generated templates", () => {
                 await pathExists(path.join(projectDir, prismaSourceRelative, "starter-data.ts")),
               ).toBe(false);
               if (template === "turborepo") {
-                await writePrismaDependencies(provider, packageManager, authoring, projectDir, {
-                  template,
-                });
                 const server = await readPackageJson(path.join(projectDir, "apps/server"));
                 const database = await readPackageJson(path.join(projectDir, "packages/database"));
+                expect(server.devDependencies?.["@prisma/dev"]).toBeUndefined();
+                expect(database.devDependencies?.["@prisma/dev"]).toBeUndefined();
                 const root = await readPackageJson(projectDir);
                 expect(packageJson.workspaces).toEqual(["apps/*", "packages/*"]);
                 expect(packageJson.devDependencies?.turbo).toBe(dependencyVersionMap.turbo);