You can deep link to a composer action at this URL:
https://warpcast.com/~/composer-action?url=<url encoded composer action URL>
For example, to load Flappycaster, click the link below:
https://warpcast.com/~/composer-action?url=https%3A%2F%2Fflappycaster.com%2Fapi%2Fcomposer
Composer actions load as a full screen on mobile and a modal on web.
To load your action in the bottom sheet at 75% height rather than as a full screen, add a view=prompt parameter to the deep link:
https://warpcast.com/~/composer-action?url=https%3A%2F%2Fflappycaster.com%2Fapi%2Fcomposer&view=prompt
You can deep link into a composer action from a frame, using the link button type. If your frame displays a single deep link button, it will show a special purple CTA:
If your frame displays more than one button, deep links will render as standard frame buttons:
To pass data through to your action handler, you can add URL parameters to your initial action handler URL and include them in the URL-encoded deep link url query parameter. For example:
Action URL:
https://flappycaster.com/api/composer
Action URL with extra params:
https://flappycaster.com/api/composer?huh=wut&lmao=rofl
URL-encoded: https%3A%2F%2Fflappycaster.com%2Fapi%2Fcomposer%3Fhuh%3Dwut%26lmao%3Drofl
Full deep link:
https://warpcast.com/~/composer-action?url=https%3A%2F%2Fflappycaster.com%2Fapi%2Fcomposer%3Fhuh%3Dwut%26lmao%3Drofl
Just like a cast action, Warpcast will POST an initial Frame message to your action URL, including the query params.
Deep links are only enabled for published composer actions. For now, even mini-apps must be implemented as “composer actions,” but we can optionally hide them from discovery pages. If you need your action published, please follow the instructions here and reach out to horsefacts.