# 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 | string[]">
  An optional label to assign to the workflow run.
  This can be useful for identifying and filtering runs in the dashboard or logs.

  Pass an array to attach multiple labels to a single workflow run. The run will
  then match a [logs](/workflow/basics/client/logs) or DLQ filter for any of its
  labels (OR semantics).
</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
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"
  },
  label: ["team-a", "high-priority"], // optional label(s); single string or array
})
```

```ts Multiple Workflows
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>