Job Data

Every job can have its own custom data. The data is stored in the data attribute of the job:

TypeScript

import { Queue } from 'bullmq';

const myQueue = new Queue('paint');

const job = await myQueue.add('wall', { color: 'red' });

job.data; // { color: 'red' }

Python

from bullmq import Queue

queue = Queue('paint')

job = await queue.add('wall', {'color': 'red'})

job.data # { color: 'red' }

Rust

use bullmq::{Queue, QueueOptions};

let queue = Queue::new("paint", QueueOptions::default()).await?;

let job = queue.add("wall", serde_json::json!({"color": "red"}), None).await?;

let data = job.data(); // {"color": "red"}

Update data

If you want to change the data after inserting a job, just use the updateData method. For example:

TypeScript

const job = await Job.create(queue, 'wall', { color: 'red' });

await job.updateData({
  color: 'blue',
});

job.data; // { color: 'blue' }

Python

from bullmq import Queue

queue = Queue('paint')

job = await queue.add('wall', {'color': 'red'})

await job.updateData({'color': 'blue'})
job.data # { color: 'blue' }

Rust

use bullmq::{Queue, QueueOptions};

let queue = Queue::new("paint", QueueOptions::default()).await?;

let mut job = queue.add("wall", serde_json::json!({ "color": "red" }), None).await?;

job.update_data(serde_json::json!({ "color": "blue" })).await?;

job.data(); // { "color": "blue" }

Data is serialized as JSON

Job data is sent through Redis as a string, so before being stored it is serialized with JSON.stringify and on the worker side it is deserialized with JSON.parse. This has a few practical consequences worth being aware of:

• The payload must be JSON-serializable. Values like undefined, functions, BigInt, Map/Set, circular references and similar are not preserved.
• If you pass a class instance as data, the worker will receive a plain object with the same enumerable own properties — but the prototype, and therefore any methods, getters or setters, will be gone. Calling something like job.data.getTimestamp() inside your processor will throw TypeError: job.data.getTimestamp is not a function.
• The DataType type parameter on Queue<DataType, ...> and Job<DataType, ...> describes the shape of the JSON payload, not a runtime class. TypeScript will happily accept a class instance there even though its methods will not survive the round-trip.

If you need behavior on the worker side, store the data as a plain object and re-instantiate the class in your processor:

import { Queue, Worker } from 'bullmq';

const queueName = 'paint';
const myQueue = new Queue(queueName);

class Message {
  constructor(
    public token: string,
    public timestamp: number,
  ) {}
  getTimestamp() {
    return this.timestamp;
  }
}

// Producer: pass a plain object, not the class instance.
await myQueue.add('send', { token: 't', timestamp: Date.now() });

// Worker: rebuild the instance from job.data.
const worker = new Worker(queueName, async job => {
  const msg = new Message(job.data.token, job.data.timestamp);
  msg.getTimestamp(); // works
});

Alternatively, implement a toJSON() method on your class — JSON.stringify calls it automatically — to control exactly how the instance is serialized.

Read more:

• 💡 Update Data API Reference