# Property Keyframes

Property Keyframes let you animate any numeric clip or layer property over time — opacity, volume, position, brightness, effect parameters — directly on the timeline, without needing a separate keyframe editor.

![Property keyframes on timeline](/files/3TQXO39ze1r9aDA1V6mR)

## What Can Be Keyframed?

Almost any numeric property shown in the Inspector can be keyframed:

| Category        | Properties                                                                       |
| --------------- | -------------------------------------------------------------------------------- |
| **Layer**       | Opacity, X/Y position, Width, Height                                             |
| **Audio**       | Volume (dB), Pan                                                                 |
| **Effects**     | Color Key tolerance, Luminance brightness/contrast/gamma, custom shader uniforms |
| **Data Tracks** | Any data track value                                                             |

## Adding Keyframes

### From the Inspector

1. Select a clip or layer in the Timeline.
2. In the Inspector, navigate to the property you want to keyframe.
3. Click the **◆ diamond icon** next to the property name. This creates a keyframe at the current playhead position with the current value.
4. Move the playhead to a new time.
5. Change the property value — a new keyframe is created automatically.

### From the Timeline (Keyframe Lane)

1. Right-click a clip in the Timeline and choose **Show Keyframes → \[Property Name]**.
2. A keyframe lane appears beneath the clip showing the property's value curve.
3. Click on the lane to add a keyframe at that time.
4. Drag a keyframe diamond to change its time or value.

![Keyframe lane on a clip](/files/qLC8Ra8d3rHYO0D1IFGu)

## Editing Keyframes

| Action                 | How                                                   |
| ---------------------- | ----------------------------------------------------- |
| **Select**             | Click a keyframe diamond                              |
| **Move (time)**        | Drag horizontally                                     |
| **Change value**       | Drag vertically, or edit numerically in the Inspector |
| **Delete**             | Select and press `Delete`                             |
| **Select all on lane** | `Ctrl+A` while the lane is focused                    |

## Interpolation

Right-click any keyframe to set its interpolation type:

| Type            | Behaviour                                                |
| --------------- | -------------------------------------------------------- |
| **Linear**      | Constant rate of change between keyframes                |
| **Ease In**     | Starts slowly, accelerates towards the next keyframe     |
| **Ease Out**    | Decelerates as it arrives at the keyframe                |
| **Ease In/Out** | Smooth S-curve — slow start, fast middle, slow end       |
| **Step**        | Value jumps instantly at the keyframe (no interpolation) |

## Slider Sync

When a keyframe lane is visible, adjusting the property slider in the Inspector **creates or updates** the keyframe at the current playhead position in real time. This "slider sync" workflow is the fastest way to set up animation:

1. Show the keyframe lane for the property.
2. Position the playhead.
3. Drag the slider — a keyframe is created/updated automatically at the playhead.
4. Advance the playhead, drag the slider to the new value, repeat.

## Example: Opacity Fade-In

1. Place a clip on the timeline.
2. Move the playhead to the clip start.
3. In the Inspector, set **Opacity** to `0` and click **◆** to add a keyframe.
4. Move the playhead forward 2 seconds.
5. Set **Opacity** to `100` and click **◆** again.

The clip now fades from fully transparent to fully opaque over 2 seconds. The keyframe curve is visible in the timeline lane as a rising line.

## API Access

Property keyframes are also manageable via the Effects Server REST API, which is useful for programmatic control from show-control systems:

| Endpoint                       | Method   | Purpose                          |
| ------------------------------ | -------- | -------------------------------- |
| `/property-keyframes`          | `GET`    | List all keyframes               |
| `/property-keyframes`          | `POST`   | Add or update keyframes          |
| `/property-keyframes/:trackId` | `DELETE` | Remove all keyframes for a track |

See [Effects Server API](/v3/developer-reference/effects-server-api.md#property-keyframes) for the full schema.


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