Start flow

The Start flow action starts a color flow on a Yeelight light, using a list of transitions that you define.

This is useful for creating dynamic lighting effects, such as a slow fade through colors or a flickering candle effect.

Using this action from the user interface

If you prefer building automations and scripts visually, Home Assistant walks you through this action step by step. You pick what to target, tweak a few options, and save. No YAML knowledge required.

To start a flow from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Select what you want to control. Under By target (see Targets), select the Yeelight light you want to control.
6. From the actions shown for that target, select Start flow.
7. Enter the Transitions, and optionally a Count and an Action.
8. Select Save.

Options in the UI

Using this action in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, refer to this action as yeelight.start_flow. A basic example looks like this:

action: yeelight.start_flow
target:
  entity_id: light.living_room
data:
  transitions:
    - TemperatureTransition: [1900, 1000, 80]
    - TemperatureTransition: [1900, 2000, 60]
    - SleepTransition: [1000]

Options in YAML

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label, and Home Assistant will run the action on every matching light entity behind that target.

• Entity: one specific light entity, such as light.living_room.
• Device: every light entity that belongs to a device.
• Area: every light entity in a room or area.
• Floor: every light entity on a floor.
• Label: every light entity that shares a label.

You can also select different target types in one action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Good to know

• The Set color flow scene (yeelight.set_color_flow_scene) action accepts the same transitions but uses a different Yeelight API call. If the light is off, it turns on. There may be firmware differences in how complex flows are handled.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] without writing a line of YAML.

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the action you’re calling and what you expected to happen, or share on our subreddit /r/homeassistant.

Related actions

These actions work well alongside this one:

• Set color flow scene: Starts a color flow on a Yeelight light using the scene API call.

• Set mode: Sets the operation mode of a Yeelight light.

• Set music mode: Enables or disables music mode on a Yeelight light.