---
id: flow--pin-plugin
title: "Pin to metadata"
summary: "Stores the record passing through in a named property of the flow metadata and forwards it unchanged. Later components and scripts of the same request can read the value from the metadata without a direct connection, for example to combine the original request with a later response."
audience: user
keywords: "input, output, propertyname"
---
# Pin to metadata

Stores the record passing through in a named property of the flow metadata and forwards it unchanged. Later components and scripts of the same request can read the value from the metadata without a direct connection, for example to combine the original request with a later response.

## Pins

| Pin | Kind | Types | Description |
|---|---|---|---|
| Input | input | any | The record to store. Its type becomes the type of the metadata property. |
| Output | output | same as input | The unchanged record, with the metadata now containing the stored value. |

## Configuration

| Field | Type | Default | Description |
|---|---|---|---|
| `PropertyName` | string (identifier) | | Required. Name of the metadata property, a valid C# identifier unique within the flow metadata. Changing it regenerates the metadata property. |

## Behaviour

- Reconfigure (changing `PropertyName` or pressing its reconfigure button) adds a property `PropertyName` to the flow's metadata type `<flow namespace>.FlowMetaData`, typed as the input connection's type (`Viaducta.TypeSystem.Metadata.NoInputData` when the input is not connected). The property belongs to this component; renaming replaces it.
- For each record the value is stored in the metadata (wrapped values are unwrapped first), then the record is sent to `Output` with the same metadata.
- Downstream, read it in scripts as `metaData.<PropertyName>` after casting the metadata to the flow's `FlowMetaData` (as the Decision router template does), or select it wherever metadata properties are offered.
- On start the plugin checks that the property exists on `FlowMetaData` and that its type matches the input connection's type; otherwise the flow fails to start ("The input type does not match metadata ..., reconfigure the pin component").

## Notes

- After changing the type of the input connection, reconfigure the component so the metadata property gets the new type.
- The value is stored per request (in that request's metadata). Components that create new metadata (for example a Plugin port request, or Timer-started branches) do not see it.
- The stored object is the same instance as the forwarded record; changes made downstream to the record are visible through the metadata property as well.

## Example

```json
{ "PropertyName": "OriginalRequest" }
```

Http listener → **Pin to metadata** → Http client → Script (uses `metaData.OriginalRequest`) → Http response