> 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/resolvetwin.md).

# Resolve twin

> Look up a digital twin's latest or pinned version as JSON.

Looks a digital twin up and emits the version `version` names, or the latest when it is `latest`. `ForecastSim` is the one sim with a `model` in-port to wire it into, for running against a twin chosen at run time rather than pinned in settings.

## At a glance

|                          |                           |
| ------------------------ | ------------------------- |
| Module type              | `ResolveTwin`             |
| Category                 | Primitives · Twins and IO |
| 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

### `version`

`string` · required · defaults to `"latest"`

`latest`, or a pinned twin version id.

### `twinId`

`string` · required · defaults to `""`

The digital twin to resolve.

## 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. |

## Outputs

| Port   | Kind   | Connects to                | Description                |
| ------ | ------ | -------------------------- | -------------------------- |
| `twin` | `json` | `json`, `scalar`, `signal` | The resolved twin version. |

***

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