add http api server

README.md

@@ -18,3 +18,43 @@ View your app in AI Studio: https://ai.studio/apps/96002e3b-5eec-4566-85e8-71871
 2. Set the `GEMINI_API_KEY` in [.env.local](.env.local) to your Gemini API key
 3. Run the app:
    `npm run dev`
+
+## Run the API server
+
+The UI runs on port `3000`. The HTTP API runs separately on port `3002`.
+
+1. Set `GEMINI_API_KEY` in `.env.local` or your shell.
+2. Start the API:
+   `npm run api`
+3. Check the API:
+   `http://localhost:3002/api/health`
+
+### API examples
+
+Generate or edit with JSON/base64:
+
+```bash
+curl -X POST http://localhost:3002/api/generate \
+  -H "Content-Type: application/json" \
+  -d "{\"prompt\":\"Create a clean product poster for a white coffee mug\",\"imageSize\":\"1K\",\"aspectRatio\":\"1:1\"}"
+```
+
+Upload an image or document with a prompt:
+
+```bash
+curl -X POST http://localhost:3002/api/generate/upload \
+  -F "prompt=Change the background to a bright studio scene" \
+  -F "imageSize=1K" \
+  -F "aspectRatio=1:1" \
+  -F "files=@input.png"
+```
+
+Analyze a document:
+
+```bash
+curl -X POST http://localhost:3002/api/analyze-document \
+  -F "prompt=Summarize this document in Chinese" \
+  -F "files=@report.pdf"
+```
+
+Optional API auth: set `API_AUTH_TOKEN`, then send either `Authorization: Bearer <token>` or `x-api-key: <token>`.