Prisma 7 client fails on Cloudflare Workers: “Wasm code generation disallowed by embedder”

Bug description

On Cloudflare Workers (workerd via wrangler), any Prisma call with Prisma 7.0.0 crashes at startup with:

CompileError: WebAssembly.Module(): Wasm code generation disallowed by embedder Stack points to internal/class.ts -> getQueryCompilerWasmModule -> loadQueryCompiler -> ClientEngine.ts. Cloudflare blocks dynamic WASM compilation; Prisma 7 still compiles the query compiler WASM at runtime even when using the edge runtime and D1 adapter.

Even when forcing imports to @prisma/client/runtime/edge and stubbing fileURLToPath, the client still tries to compile WASM at runtime, which Cloudflare blocks. A Workers-compatible build that avoids dynamic WASM compilation is needed.

Severity

Critical: Data loss, app crash, security issue

Reproduction

• Prisma 7.0.0, generator client using provider = "prisma-client" and output to ../src/generated/prisma.
• Cloudflare Workers (wrangler dev), D1 with @prisma/adapter-d1.
• Start wrangler dev; POST to a route that triggers a Prisma query.
• Runtime error: CompileError: WebAssembly.Module(): Wasm code generation disallowed by embedder during client startup.

If you need a repo, I can share a minimal CF Worker + D1 + Prisma 7 setup; the failure is immediate on first request.

Expected vs. Actual Behavior

Expected: Prisma client loads and queries D1.

Actual: Worker crashes before query executes with WASM compile error.

Frequency

Consistently reproducible

Does this occur in development or production?

Both development and production

Is this a regression?

Yes. Prisma 6.19.0 worked on Workers; upgrading to 7.0.0 causes the crash.

Workaround

Only workaround: downgrade to Prisma 6.19.0 for Workers. No viable patch; stubbing fileURLToPath or importing the edge runtime does not stop the WASM compile path.

Prisma Schema & Queries

generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
  // (no special runtime flags)
}

datasource db {
  provider = "sqlite"
  url      = env("DATABASE_URL") // D1
}

import { PrismaClient } from "./src/generated/prisma/client";
import { PrismaD1 } from "@prisma/adapter-d1";
export const prisma = new PrismaClient({ adapter: new PrismaD1(env.DB) });
await prisma.user.findMany();

Prisma Config

import { defineConfig } from "@prisma/config";
export default defineConfig({
  datasources: {
    db: { url: process.env.DATABASE_URL ?? "file:./dev.db" },
  },
});

Logs & Debug Info

CompileError: WebAssembly.Module(): Wasm code generation disallowed by embedder
      at decodeBase64AsWasm (.../libs/common/src/generated/prisma/internal/class.ts:36:10)
      at async Object.getQueryCompilerWasmModule (.../internal/class.ts:44:12)
      at async loadQueryCompiler (.../ClientEngine.ts:239:34)
      ...
      clientVersion: '7.0.0'

Environment & Setup

• OS: macOS (dev)
• Database: Cloudflare D1 (SQLite)
• Node.js: v24.x (wrangler uses workerd)
• Runtime: Cloudflare Workers (workerd via wrangler dev)

Prisma Version

prisma                : 7.0.0
@prisma/client        : 7.0.0
@prisma/adapter-d1    : 7.0.0