> ## Documentation Index
> Fetch the complete documentation index at: https://upstash.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# client.trigger

The `trigger` method starts a new workflow run and returns its `workflowRunId`.

You can also trigger multiple workflow runs in a single call by passing an array of arguments instead of a single object.

## Arguments

<ParamField body="url" type="string" required>
  The public URL of the workflow endpoint.
</ParamField>

<ParamField body="workflowRunId" type="string" optional>
  A custom identifier for the workflow run.
  Each run must use a unique ID.

  The final ID will be prefixed with `wfr_`.
  For example: passing `my-workflow` results in `wfr_my-workflow`.

  If omitted, a run ID will be generated automatically.
</ParamField>

<ParamField body="body" type="string | object" optional>
  The request payload to pass into the workflow run.
  Accessible as `context.requestPayload` inside the workflow.
</ParamField>

<ParamField body="headers" type="object" optional>
  HTTP headers to pass into the workflow run.
  Accessible as `context.headers` inside the workflow.
</ParamField>

<ParamField body="retries" type="string">
  Number of retry attempts for workflow steps. Default is 3.
</ParamField>

<ParamField body="retryDelay" type="string">
  Delay between retries. Can use expressions like "1000 \* (1 + retried)".
</ParamField>

<ParamField body="flowControl" type="object" optional>
  An optional flow control configuration to limit concurrency and execution rate of the workflow runs.

  See [Flow Control](/workflow/features/flow-control) for details.

  <Expandable title="properties">
    <ParamField body="key" type="string">
      A logical grouping key that identifies which requests share the same flow control limits.
    </ParamField>

    <ParamField body="rate" type="number">
      The maximum number of allowed requests per second.
    </ParamField>

    <ParamField body="parallelism" type="number">
      The maximum number of concurrent requests allowed.
    </ParamField>

    <ParamField body="period" type="string|number">
      The time window used to enforce the defined rate limit. Default is `1s`.
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="delay" type="string">
  Delay for the workflow run. This is used to delay the execution of the workflow run. The delay is in seconds or can be passed as a string with a time unit (e.g. "1h", "30m", "15s").
</ParamField>

<ParamField body="notBefore" type="number">
  Optionally set the absolute delay of this message.
  This will override the delay option.
  The message will not delivered until the specified time.

  Unix timestamp in seconds.
</ParamField>

<ParamField body="label" type="string">
  An optional label to assign to the workflow run.
  This can be useful for identifying and filtering runs in the dashboard or logs.
</ParamField>

<ParamField body="disableTelemetry" type="boolean">
  If set to true, telemetry data collection for this workflow run will be disabled.
  By default, telemetry is enabled to help improve Upstash services.

  See the [`disableTelemetry` parameter in serve options](/workflow/basics/serve/advanced#param-disable-telemetry) for more details.
</ParamField>

## Usage

<CodeGroup>
  ```ts Single Workflow theme={"system"}
  import { Client } from "@upstash/workflow";

  const client = new Client({ token: "<QSTASH_TOKEN>" })

  const { workflowRunId } = await client.trigger({
    url: "https://<YOUR_WORKFLOW_ENDPOINT>/<YOUR-WORKFLOW-ROUTE>",
    body: "hello there!",         // optional body
    headers: { ... },             // optional headers
    workflowRunId: "my-workflow", // optional workflow run id
    retries: 3,                   // optional retries
    retryDelay: "1000 * (1 + retried)", // optional delay between retries
    delay: "10s"                  // optional delay value
    failureUrl: "https://<YOUR_FAILURE_URL>", // optional failure url
    flowControl: {                // optional flow control
      key: "USER_GIVEN_KEY",
      rate: 10,
      parallelism: 5,
      period: "10m"
    },
  })
  ```

  ```ts Multiple Workflows theme={"system"}
  import { Client } from "@upstash/workflow";

  const client = new Client({ token: "<QSTASH_TOKEN>" })
  const results = await client.trigger([
    {
      url: "<YOUR_WORKFLOW_ENDPOINT>",
      // other options...
    },
    {
      url: "<YOUR_WORKFLOW_ENDPOINT>",
      // other options...
    },
  ])

  console.log(results[0].workflowRunId)
  // prints wfr_my-workflow
  ```
</CodeGroup>