Guide: Create a video from a template

This guide walks through calling Synthesia's API to generate a video from a template with variables. For how to build a template and add each type of variable (script, canvas text, media, or avatar), see Add variables for programmatic video creation.

Create a video from a template

To create a video from a template with Synthesia's API:

1. Build your template in Synthesia, adding variables for whatever should change between videos.
2. Publish the video as a template, then copy its template ID from your template library.
3. Call the Create a video from a template endpoint with:
   • templateId: The ID from step 2.
   • templateData: An object of key-value pairs, where each key is a variable name and each value is what to replace it with.
4. Optionally, personalize the video's title and description parameters too.
5. Once Synthesia receives your request, the video is processed and available shortly after.

Supplying values for media variables

For image and video variables, supply a value one of two ways:

• A URL—Synthesia fetches and uses the asset.
• An asset ID, after uploading the asset yourself.

Match the aspect ratio of the replacement image or video to what it's replacing, to avoid unexpected stretching or cropping—see Add variables for programmatic video creation for the specifics per variable type.

Supplying values for avatar variables

For an avatar variable, supply the target avatar's ID as the value.

To find an avatar's ID:

1. Go to the Avatars page.
2. Select the three-dot menu in the top-right corner of the avatar you want.
3. Select Copy ID.

Special characters in text variable values

By default, special characters in a text variable's value are HTML-escaped when you pass them in your request. For example, This & that becomes This & that.

To avoid this, pass the escaped entity yourself instead of the raw character. For example:

templateData: {my_text_variable: 'This & that'}

See this list of HTML entities for other special characters you might need to escape.