Image generation

The Create tab generates an image from your prompt, style and aspect ratio. It uses the generate edge function.

Add a style preset to the Create tab in this project. Add it to stylePresets in supabase/functions/generate/config.json, then redeploy generate.

The Create tab showing a prompt field, style preset chips, aspect ratio chips, a Generate button, and the Pro-required upgrade state below

Change presets, ratios or the model

To change	Edit	Then
Style presets	`stylePresets` in `generate/config.json`	Redeploy `generate`
Aspect ratios	`aspectRatios` in `generate/config.json`	Redeploy `generate`
The model	`generateModel` in `generate/config.json`	Redeploy `generate`

All three are defined in one file, supabase/functions/generate/config.json, which the Create tab also reads for its chips. The client sends the user’s prompt and the selected style and aspect-ratio IDs. The function looks up the prompt suffixes for those IDs in the same file. An unknown ID contributes an empty suffix, so redeploy after adding a preset or ratio.

Adding a style preset

Add it to generate/config.json

supabase/functions/generate/config.json


{ "id": "noir", "label": "Noir", "promptSuffix": ", black and white film noir, hard shadows, high contrast" }

Redeploy


supabase functions deploy generate

Verify

Check that the new chip appears and test it with a prompt. If its suffix seems to have no effect, confirm that the ID matches and that generate was redeployed.

Changing the model

Change the image generation model in this project. Update generateModel in supabase/functions/generate/config.json, then redeploy generate.

Pick a slug from openrouter.ai/models whose output modalities include image, then redeploy:

supabase/functions/generate/config.json


"generateModel": "google/gemini-3.1-flash-image"

A model from a different company changes who receives the user’s content, so bump consentVersion as well; see AI consent.

Gotchas

Without REVENUECAT_SECRET_KEY, the server cannot confirm Pro status and refuses generation for every user. See Secrets.

Aspect ratios are approximate. The function adds the ratio to the prompt as text; it does not request exact pixel dimensions.

Generations require Pro and do not count toward the monthly chat and scan allowance. See Quota and paywall.

Saving an image to the device asks for permission to add to the photo library, not to read it. On Android, app.config.js configures expo-media-library with granularPermissions: [] and blocks READ_MEDIA_VISUAL_USER_SELECTED, so the manifest declares none of READ_MEDIA_IMAGES, READ_MEDIA_VIDEO and READ_MEDIA_AUDIO. Google Play accepts those only from apps whose core use needs them. If you add code that reads the library itself instead of using the system photo picker, list the types you need in granularPermissions (photo, video, audio), remove the blocked permission and file the declaration described in Play’s photo and video permissions policy .

Error codes

Code	HTTP	Meaning
`invalid_request`	400	The prompt is empty or the request body has the wrong shape.
`unauthorized`	401	The Supabase access token is missing or invalid.
`ai_consent_required`	403	The user has not allowed AI, or allowed an older consent version. The app shows the consent card.
`pro_required`	403	Not a Pro user, or `REVENUECAT_SECRET_KEY` is unset.
`no_image`	502	The model replied without an image.
`provider_not_configured`	500	`OPENROUTER_API_KEY` isn’t set.
`internal_error`	500	An unexpected server or provider error. Check the function logs.

Files

- - create.tsx - Create route
- - CreateScreen.tsx - Create screen
  - generateImage.ts - Request and response types
  - repository.ts - Generation queries
  - - StylePresetChips.tsx - Style selection
    - AspectRatioChips.tsx - Ratio selection
    - GenerationResultCard.tsx - Result display
  - - generations.ts - Gallery queries and the generate mutation
- index.ts - Generation handler

How it works

generateImage() accepts prompt, style and aspectRatio strings. It sends a non-streaming request and returns the saved image’s path, its row id, and the prompt, model, style, aspect ratio and creation time. The image bytes are uploaded to Storage rather than returned in the response.

The generations table is owner-scoped by row-level security. Images are stored as paths rather than signed URLs, because signed URLs expire, and get signed again on demand when the gallery renders.