Hey Johnny! Great question about image handling in the API.
Currently, there's no way to programmatically pass images during generation. You can't upload them via multipart form data, base64 encoding, or hosted URLs. This is actually a product-wide limitation, not just API specific. Even in the Gamma web app, images have to be added after the initial generation completes.
The API can only handle text inputs and theme selection right now. So your generations will use Gamma's AI-selected images initially, and users would need to manually swap them out in the Gamma editor afterward.
This is a really common feature request we hear from developers building automation workflows.
Makes total sense for use cases where you want branded hero images, company logos, or specific product photos in the generated content.
No workarounds available at the moment unfortunately. The images have to be added post-generation through the Gamma web interface.
I can't speak to specific roadmap timing, but your use case adds to the chorus of developers who need this. The product team is definitely aware of how much this would unlock for API users.
What's your specific use case? Are you looking to insert product images, branding elements, or something else? Understanding the details helps when we compile feature requests for the team.
Also FYI we have a API Discussion channel specific to API related discussion.