Prisma Queue

Features

Simple, reliable and efficient concurrent work queue for Prisma + PostgreSQL

• Leverages PostgreSQL SKIP LOCKED feature to reliably dequeue jobs
• Supports crontab syntax for complex scheduled jobs
• Pluggable retry strategies with exponential backoff by default
• Cooperative worker cancellation via AbortSignal
• Separate jobError / error events for clean observability
• Compatible with Prisma 7+ and any Prisma driver adapter (e.g. @prisma/adapter-pg)
• Written in TypeScript for static type checking with exported types along the library.
• Built by tsup to provide both CommonJS and ESM packages.

Install

npm install @mgcrea/prisma-queue --save
# or
pnpm add @mgcrea/prisma-queue

Peer dependencies

This library requires Prisma 7+ with a driver adapter:

pnpm add @prisma/client @prisma/adapter-pg

Quickstart

1. Append the QueueJob model to your schema.prisma file

2. Create your queue

import { createQueue } from "@mgcrea/prisma-queue";
import { prisma } from "./prisma"; // your PrismaClient instance

type JobPayload = { email: string };
type JobResult = { status: number };

export const emailQueue = createQueue<JobPayload, JobResult, typeof prisma>(
  { prisma, name: "email" },
  async (job, client) => {
    const { id, payload } = job;
    console.log(`Processing job#${id} with payload=${JSON.stringify(payload)})`);
    // await someAsyncMethod();
    await job.progress(50);
    const status = 200;
    if (Math.random() > 0.5) {
      throw new Error(`Failed for some unknown reason`);
    }
    console.log(`Finished job#${id} with status=${status}`);
    return { status };
  },
);

Note: The client parameter in the worker is a transaction-scoped client (in the default transactional mode) with full typed access to your Prisma models. TypeScript infers the client type from the prisma option you pass.

• Queue a job

import { emailQueue } from "./emailQueue";

const main = async () => {
  const job = await emailQueue.enqueue({ email: "[email protected]" });
};

main();

• Schedule a recurring job

import { emailQueue } from "./emailQueue";

const main = async () => {
  const nextJob = await queue.schedule(
    { key: "email-schedule", cron: "5 5 * * *" },
    { email: "[email protected]" },
  );
};

main();

• Start queue processing (usually in another process)

import { emailQueue } from "./emailQueue";

const main = async () => {
  await queue.start();
};

main();

Advanced usage

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | prisma | PrismaClient | (required) | Your Prisma client instance | | name | string | "default" | Queue name for partitioning jobs | | maxAttempts | number \| null | null | Max retry attempts (null = unlimited) | | maxConcurrency | number | 1 | Max concurrent jobs | | pollInterval | number | 10000 | Polling interval in ms | | jobInterval | number | 50 | Delay between job dispatches in ms | | tableName | string | "queue_jobs" | Database table name (must match @@map in your schema) | | deleteOn | "success" \| "failure" \| "always" \| "never" | "never" | When to delete completed jobs | | transactionTimeout | number | 1800000 | Transaction timeout in ms (30 min) | | retryStrategy | RetryStrategy | Exponential backoff | Custom retry logic | | transactional | boolean | true | Run worker inside the dequeue transaction |

Events

The queue emits typed events:

queue.on("enqueue", (job) => {
  console.log(`Job ${job.id} enqueued`);
});

queue.on("dequeue", (job) => {
  console.log(`Job ${job.id} picked up for processing`);
});

queue.on("success", (result, job) => {
  console.log(`Job ${job.id} succeeded with`, result);
});

// Job execution failures (worker threw)
queue.on("jobError", (error, job) => {
  console.error(`Job ${job.id} failed:`, error);
});

// System/infrastructure errors (poll failures, cron scheduling errors)
queue.on("error", (error) => {
  console.error("Queue system error:", error);
});

Custom Retry Strategy

By default, failed jobs are retried with exponential backoff (2^attempts seconds + jitter). You can provide a custom retryStrategy:

import { createQueue, type RetryContext } from "@mgcrea/prisma-queue";

const queue = createQueue<JobPayload, JobResult, typeof prisma>(
  {
    prisma,
    name: "email",
    maxAttempts: 5,
    retryStrategy: ({ attempts, maxAttempts, error }: RetryContext) => {
      // Return delay in ms, or null to stop retrying
      if (maxAttempts !== null && attempts >= maxAttempts) return null;
      // Linear backoff: 1s, 2s, 3s, ...
      return 1000 * attempts;
    },
  },
  async (job, client) => {
    // ...
  },
);

Cooperative Worker Cancellation

Dequeued jobs expose an AbortSignal that is triggered when queue.stop() is called. Use it to cooperatively cancel long-running work:

const queue = createQueue<JobPayload, JobResult, typeof prisma>(
  { prisma, name: "email" },
  async (job, client) => {
    for (const item of items) {
      if (job.signal.aborted) {
        throw new Error("Job cancelled");
      }
      await processItem(item);
    }
    return { status: "done" };
  },
);

Non-Transactional Mode

By default, the worker runs inside the dequeue transaction (exactly-once semantics). Set transactional: false to run the worker outside the transaction, giving it access to the full PrismaClient with $transaction support (at-least-once semantics):

import { createQueue, type JobWorkerWithClient } from "@mgcrea/prisma-queue";

const queue = createQueue<JobPayload, JobResult, typeof prisma>(
  { prisma, name: "email", transactional: false },
  async (job, client) => {
    // client is the full PrismaClient — $transaction is available
    await client.$transaction(async (tx) => {
      await tx.user.update({ where: { id: 1 }, data: { email: job.payload.email } });
      await tx.auditLog.create({ data: { action: "email_updated" } });
    });
    return { status: 200 };
  },
);

Trade-offs: In non-transactional mode, a process crash between claiming and completing a job can leave it "stuck" (processedAt set, finishedAt null). Use requeueStale() to recover:

// Requeue jobs claimed more than 5 minutes ago that never completed
const count = await queue.requeueStale({ olderThanMs: 5 * 60 * 1000 });

Note: isLocked() returns false during worker execution in non-transactional mode since the row lock is released after claiming.

Threading

You can easily spin of your workers in separate threads using worker_threads (Node.js >= 12.17.0).

It enables you to fully leverage your CPU cores and isolate your main application queue from potential memory leaks or crashes.

import { JobPayload, JobResult, PrismaJob } from "@mgcrea/prisma-queue";
import { Worker } from "node:worker_threads";
import { ROOT_DIR } from "src/config/env";
import { log } from "src/config/log";

const WORKER_SCRIPT = `${ROOT_DIR}/dist/worker.js`;

export const processInWorker = async <P extends JobPayload, R extends JobResult>(
  job: PrismaJob<P, R>,
): Promise<R> =>
  new Promise((resolve, reject) => {
    const workerData = getJobWorkerData(job);

    log.debug(`Starting worker thread for job id=${job.id} in queue=${job.record.queue}`);
    try {
      const worker = new Worker(WORKER_SCRIPT, {
        workerData,
      });

      worker.on("message", resolve);
      worker.on("error", reject);
      worker.on("exit", (code) => {
        if (code !== 0) {
          reject(
            new Error(
              `Worker for job id=${job.id} in queue=${job.record.queue} stopped with exit code ${code}`,
            ),
          );
        }
      });
    } catch (error) {
      reject(error as Error);
    }
  });

// eslint-disable-next-line @typescript-eslint/no-explicit-any
export type JobWorkerData<P extends JobPayload = any> = {
  id: bigint;
  payload: P;
  queue: string;
};

const getJobWorkerData = <P extends JobPayload, R extends JobResult>(job: PrismaJob<P, R>): JobWorkerData => {
  // Prepare the job data for structured cloning in worker thread
  return {
    id: job.id,
    payload: job.payload,
    queue: job.record.queue,
  };
};

• worker.ts

import { parentPort, workerData } from "node:worker_threads";
import { log } from "src/config/log";
import { workers } from "src/queue";
import { type JobWorkerData } from "src/utils/queue";
import { logMemoryUsage } from "./utils/system";

log.info(`Worker thread started with data=${JSON.stringify(workerData)}`);

const typedWorkerData = workerData as JobWorkerData;
const { queue } = typedWorkerData;
const workerName = queue.replace(/Queue$/, "Worker") as keyof typeof workers;

log.debug(`Importing worker ${workerName} for queue=${queue}`);
const jobWorker = workers[workerName];
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
if (!jobWorker) {
  log.error(`No worker found for queue=${queue}`);
  process.exit(1);
}

log.info(`Running worker for queue=${queue}`);
const result = await jobWorker(typedWorkerData);
log.info(`Worker for queue=${queue} completed with result=${JSON.stringify(result)}`);
parentPort?.postMessage(result);
process.exit(0);

Migration Guide

Migrating from v1.x to v2.0

v2.0 drops @prisma/client imports entirely, making the library compatible with Prisma 7+ and its new prisma-client generator. This is a breaking release.

Breaking changes

1. prisma option is now required

The library no longer creates a default PrismaClient. You must pass your own instance:

// v1
const queue = createQueue({ name: "email" }, worker);

// v2
import { prisma } from "./prisma";
const queue = createQueue({ prisma, name: "email" }, worker);

2. Third type parameter C for client type

createQueue and PrismaQueue now accept a third generic C that represents your PrismaClient type. TypeScript infers C from the prisma option, but if you explicitly specify type parameters, you must include all three:

// v1
createQueue<MyPayload, MyResult>({ name: "email" }, worker);

// v2
createQueue<MyPayload, MyResult, typeof prisma>({ prisma, name: "email" }, worker);

3. Peer dependency: Prisma 7+

The peer dependency changed from @prisma/client >=3 <7 to @prisma/client >=7 plus @prisma/adapter-pg >=7. You need a Prisma driver adapter:

pnpm add @prisma/client @prisma/adapter-pg pg

And configure your PrismaClient with the adapter:

import { PrismaPg } from "@prisma/adapter-pg";
import { PrismaClient } from "./prisma/client/client.js";

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

4. tableName defaults to "queue_jobs"

DMMF-based table name auto-detection has been removed. The default is now "queue_jobs" (matching the @@map in the documented schema). If you use a custom table name, pass it explicitly:

createQueue({ prisma, name: "email", tableName: "my_custom_table" }, worker);

5. PrismaLightClient type removed

The PrismaLightClient type has been replaced by TransactionClient<C>, which is computed from your actual PrismaClient type. If you referenced PrismaLightClient in your code, replace it with TransactionClient<typeof prisma>.

6. void is now a valid JobResult

Workers that don't return a value no longer need to return null. void is accepted as a result type:

type ScanResult = void;
createQueue<ScanPayload, ScanResult, typeof prisma>({ prisma, name: "scan" }, async (job, client) => {
  // no return needed
});

No schema changes required

The database schema, table structure, and indexes are unchanged from v1.x. No migration is needed for your database.

Authors

• Olivier Louvignes <[email protected]>

Credits

Inspired by

• pg-queue by

License

The MIT License

Copyright (c) 2022 Olivier Louvignes <[email protected]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
documentation files (the "Software"), to deal in the Software without restriction, including without limitation the
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit
persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the
Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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