> For the complete documentation index, see [llms.txt](https://docs.rootcause.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rootcause.ai/more-details/applications/application-modules/switch.md).

# Switch

> Route by a value: one out-port per case, then otherwise.

Routes `data` to the out-port of the first case whose `match` equals `value`, or to `otherwise`.

Each case owns a port minted with it, so adding a case adds a port. `dataKind` sets the kind of every routed port at once — a Switch carries frames or JSON, not a mixture. Exactly one port emits, and the rest emit nothing at all, which is what lets the branches that did not fire be skipped rather than run.

## At a glance

|                          |                        |
| ------------------------ | ---------------------- |
| Module type              | `Switch`               |
| Category                 | Primitives · Control   |
| Default tier             | `reactive`             |
| Runs on                  | `reactive`, `durable`  |
| Starts a flow            | no                     |
| Holds a body             | no                     |
| Keeps state between runs | no                     |
| Available in             | every application type |

## Parameters

### `dataKind`

`"json" | "dataframe"` · required · defaults to `"dataframe"`

The kind every routed port carries; a Switch routes frames or JSON, not a mixture.

### `cases`

`object[]` · required · defaults to `[{"match":"","portId":"<minted per module>"}]`

The cases, tried in order; each owns the out-port minted with it.

## Inputs

| Port    | Kind        | Required | Description                                                                                                                           |
| ------- | ----------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------- |
| `on`    | `event`     | no       | Implicit on every module that does not itself start a flow: wire an event here to make this module the start of what that event runs. |
| `value` | `scalar`    | yes      | The value the cases are matched against.                                                                                              |
| `data`  | `dataframe` | no       | What is routed; unconnected, the ports carry the value itself.                                                                        |

## Outputs

| Port            | Kind        | Connects to           | Description                                               |
| --------------- | ----------- | --------------------- | --------------------------------------------------------- |
| `case_<caseId>` | `dataframe` | `dataframe`, `signal` | The routed payload, on the port of the case that matched. |
| `otherwise`     | `dataframe` | `dataframe`, `signal` | The routed payload, when no case matched.                 |

***

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