The Start Power Automate / Azure Function action allows you to trigger a Power Automate flow using the premium "When an HTTP request is received" trigger, or a configured Azure Function. You might want to use this action if you need to automate some tasks from a Lightning Tools Action or from a Lightning Forms button that require actions that aren't available within our Action Builder. This might include using Power Automate's Approvals feature (or anything that requires waiting for a response), or performing some actions related to any of the hundreds of connectors available in Power Automate.
Action Configuration
| Property | Required | Type | Description |
|---|---|---|---|
URL |
yes | String | Specify the URL generated by the Power Automate "When an HTTP request is received" trigger, or the URL to an Azure Function |
| JSON Schema | no | Object | Define the JSON schema if you wish to pass parameters from the action to the flow |
The output of this action is ResponseBody.
Sequence of steps
Example walkthrough
To demonstrate how to use this action, we'll use an example of triggering an Approval flow, to have a Manager approve a travel request. Before beginning, we recommend entering at least one test item in your list (if it's a new list), so you have values to test with later in the process.
Add “Start Power Automate” action in Action Builder
In the Lightning Forms or Lightning Tools Actions Action Builder, double-click or drag the Start Power Automate / Azure Function action on to the sequence canvas.
In this action, the URL field will contain the request URL from the Power Automate flow. You won't have this URL until you create the Power Automate trigger with its JSON schema.
The JSON Schema field is optional, but it will usually be used, because you most often will want to pass some parameters to the flow. This would usually be values from the form or selected list item, or it could be values from a previous action or an Action Builder variable, or even expressions. We first need to write sample JSON to represent the parameters we wish to pass to the flow. You could do this in Notepad or similar, but you can also write it here in this field, where you will eventually need it anyway.
Sample JSON might look something like the following. Note that it must begin and end with curly braces, and each line must follow this format: “Parameter name”: “some sample value” with a comma at the end of each line except the last. For text values, enclose the sample value in double quotes; for numeric values, do not use quotes. Power Automate will use this sample to generate a JSON schema so it can “understand” the values passed to it from the Action Builder. You do not need to pass every field in your list, only the ones that are needed by the flow for whatever it is doing.
{
"Title": "title",
"Requestor": "requestor",
"Manager": "manager",
"Amount": 1
}
Create a Power Automate flow
Here, we assume that you have some familiarity with Microsoft Power Automate. Also, please note that the “When an HTTP Request is received” trigger in Power Automate is a premium trigger, which means that you must have a license beyond what comes included with your M365 subscription. If you do not currently have a premium Power Automate license, you can still select this trigger, and a 90-day trial will be started for you, so you can test this out. (Whether or not you can start a trial may depend on policies set by your tenant or Power Platform administrator.)
In Power Automate, create a new Instant Cloud Flow, give it a name, and select the “When an HTTP Request is received” trigger:
On the Power Automate canvas, click on the trigger (which currently seems to be renamed to “manual”) to open its parameters panel.
In the “Who can trigger the flow?” field, currently you must choose Anyone, due to a recent Microsoft change. We are working on adding support for other options.
Generate JSON Schema
Next, we'll use the sample JSON to generate the schema (pattern) that Power Automate requires. Below the “Request Body JSON Schema” box, click Use sample payload to generate schema. Paste your sample JSON in the dialog that opens. Make sure there are no red squiggly underlines, which would indicate invalid JSON syntax.
Click Done, and your JSON sample will be converted into a schema. You should see that the schema shows the correct data type (e.g. string or integer) for each of your parameters.
Get the Flow's URL
Now you need the URL of this Flow, to paste into the Start Power Automate action back in the Lightning Tools Action Builder. As the message in the HTTP URL field states, this will be generated after saving the Flow. In order to save the Flow, at least one action must be added after the trigger, so this can be anything at this point. An easy action to add for testing is Compose. This also allows you to see that your fields will be available as dynamic content for subsequent actions after the flow is triggered.
You must fill in something in the Inputs parameter of a Compose action, so just click on any of the dynamic fields, such as Title.
Now click Save to save this Flow.
You may see a message that the Flow can't be used, if you don't yet have a premium Flow license. As mentioned above, you can start a free 90-day trial from the dialog below, or request a license from your admin.
In any case, the Flow will have been saved, so re-open the “manual” trigger's property pane, and you should now see the HTTP URL. Click the Copy icon to copy it to your clipboard.
Before leaving Power Automate, go Back to this Flow's information page, and turn it on.
Complete the Action Builder action
Switch back now to the Lightning Tools Action Builder, where you added the Start Power Automate action.
Paste in the Flow's HTTP URL. Make sure it includes the sig= code at the end, as that's the authentication.
Now we need to add placeholders to the sample JSON so that actual values are passed to the Flow. In this example, we're simply passing some of the item's fields. Open the Expression Builder (the { } icon), and replace the sample values with placeholders, removing quotes around the text values. Note that for People fields, you should use the .Email placeholder, as that's what Power Automate will be looking for. It should look something like the following:
Before leaving the Expression Builder, click the Test button at the bottom to make sure values from one of your list items come through as expected.
We also recommend enabling Debug in the Action Builder, so any issues should be easier to troubleshoot in the browser logs.
Be sure to save the Form or List Action!
Test your process
We recommend testing this action by itself first, to make it easier to troubleshoot just this one action. You should now be able to trigger the action in whatever way you have set up (e.g. a Form button or a List Action), and then see in Power Automate that the Flow has run (after a few minutes), that there were no errors, and that your test values were passed to the Flow as expected.
