# context.progress()

Update native upload progress for the active handler.

## Signature

```ts
context.progress(fraction: number): void
```

## Availability

Only on the context object passed to an active upload handler.

## Parameters

| Parameter | Required | Description |
| --- | --- | --- |
| `fraction` | Yes | Finite fraction of completed work. 0 means starting; 1 means complete. Supply a fraction, not a 0–100 percentage. |

## Return value

Returns `undefined`.

## Behavior and errors

Finite values are clamped to 0–1. Non-finite values and inactive upload IDs are ignored. Reporting 1 does not finish the handler: Mango still requires a valid returned URL. Mango reports initial 0 and final 1 itself. No cancellation or backpressure signal is returned.

## Example

```js
// Inside an upload handler:
context.progress(0.5) // halfway, not 50
```

See [grove.uploads.register()](grove-uploads-register.md).