client.defineJob({
  id: "background-fetch-job",
  name: "Background fetch Job",
  version: "0.0.1",
  trigger: eventTrigger({
    name: "example.event",
  }),
  run: async (payload, io, ctx) => {
    const response = io.backgroundFetch<CreateChatCompetionResponseData>(
      "fetch-some-data",
      "https://example.com/api/endpoint",
      {
        method: "POST",
        headers: {
          "Content-Type": "application/json",
          Authorization: redactString`Bearer ${auth.apiKey}`,
        },
        body: JSON.stringify({ foo: "bar" }),
      },
      {
        "429": {
          strategy: "headers",
          limitHeader: "x-ratelimit-limit",
          remainingHeader: "x-ratelimit-remaining",
          resetHeader: "x-ratelimit-reset",
        },
        "5xx": {
          strategy: "backoff",
          limit: 5,
          minTimeoutInMs: 1000,
          maxTimeoutInMs: 30000,
          factor: 1.8,
          randomize: true,
        },
      }
    );

    return response;
  },
});

This is used inside the OpenAI Integration for Tasks like Chat Completions Background Create

​
Parameters

cacheKey
string
required

Should be a stable and unique cache key inside the run(). See resumability for more information.

url
string
required

The url to fetch.

options
object

Options for the request

method
string

The HTTP method to use for the request.

headers
object

Any headers to send with the request. Note that you can use redactString to prevent sensitive information from being stored (e.g. in the logs), like API keys and tokens.

body
string | ArrayBuffer

The body of the request.

retry options
object

An object where the key is a status code pattern and the value is a retrying strategy. Supported patterns are:

  • Specific status codes: 429
  • Ranges: 500-599
  • Wildcards: 2xx, 3xx, 4xx, 5xx
  {
      "500-599": {
        strategy: "backoff",
        limit: 5,
        minTimeoutInMs: 1000,
        maxTimeoutInMs: 30000,
        factor: 1.8,
        randomize: true,
      },
      "429": {
        strategy: "backoff",
        limit: 10,
        minTimeoutInMs: 1000,
        maxTimeoutInMs: 60000,
        factor: 2,
        randomize: true,
      },
    }

An individual retrying strategy can be one of two types:

  • backoff: Retries the request with an exponential backoff.
  • headers: Retries the request using info from the response headers.
timeout options
object

Allows you to set timeouts for the request, as well as specific retry strategies for timeouts.

durationInMs
number
required

The amount of time to wait before timing out the request. The minimum value is 1s and max is 2min

retry
RetryOptions

​
Returns

A Promise that resolves with the JSON response body of the background fetch request. You can specify the type of the response body as a generic parameter.

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waitForRequest()backgroundPoll()