---
id: flow--start-flow
title: "Start flow"
summary: "Starts another flow of the repository, in the same way as pressing Start for it, and then calls `Continue` either right after the flow has started or after it has stopped. No data is passed to the started flow and nothing is returned from it."
audience: user
keywords: "input, continue, flowid, waitforfinish"
---
# Start flow

Starts another flow of the repository, in the same way as pressing Start for it, and then calls `Continue` either right after the flow has started or after it has stopped. No data is passed to the started flow and nothing is returned from it.

## Pins

| Pin | Kind | Types | Description |
|---|---|---|---|
| Input | input | any | Each record starts the configured flow. |
| Continue | output | any | Called with the original input record and metadata, after start or after end (see `WaitForFinish`). |

## Configuration

| Field | Type | Default | Description |
|---|---|---|---|
| `FlowId` | flow (FlowExplorer) | | Required. The flow to start, picked in the flow explorer. The stored value is the flow id. |
| `WaitForFinish` | boolean | `false` | `false`: call `Continue` as soon as the flow has started. `true`: call `Continue` when the started flow has stopped. |

## Behaviour

- The flow is started as a normal flow (not in debug mode, as the system user): its start components (unconnected start / input pins, Timers, listeners) run as usual.
- If the target flow is already running, the start request is accepted without restarting it, and `Continue` is called as for a successful start.
- With `WaitForFinish` = `true`, `Continue` is called when the started flow is unloaded from the host. A flow that keeps running (Timer, listeners, keep-alive setting) never ends, so `Continue` is never called.
- `Continue` is called from a background thread after `Execute` has returned; the component that sent the record does not wait for it.
- A flow cannot start itself (error).

## Notes

- The started flow receives no input data. To send data to another flow and receive a result, build the other flow as a flow plugin (a "Plugin port" entry point with a "Plugin port response") and use it as a component; Start flow does not trigger "Plugin port" components.
- Start failures (unknown flow, build errors) are raised on a background thread: they are not passed back to the caller and are not caught by Try catch; `Continue` is simply not called.
- Each record adds new start / end handlers to the component and they are never removed. When the component processes several records, later starts / ends also call `Continue` again for earlier records (with their old data). Use it for a single trigger per flow run (e.g. from a Timer or at flow start) rather than per record.

## Example

```json
{ "FlowId": "3f1c2a7e-0b4d-4c55-9a7e-1d2f3a4b5c6d", "WaitForFinish": true }
```

Timer → **Start flow** → Log