FastAPI

FastapiFastAPI

Generate a unique OG image for every page, or any on-demand graphic, from a single Imejis template. The pattern below uses a FastAPI endpoint as a thin proxy: your API key stays on the server, and the browser (and social crawlers) only ever see your own URL.

Set two environment variables first: IMEJIS_API_KEY (from your dashboard) and IMEJIS_DESIGN_ID (any design's ID).

.env

IMEJIS_API_KEY=your_api_key
IMEJIS_DESIGN_ID=your_design_id

1 an endpoint that renders the image1. An endpoint that renders the image

This endpoint takes a title query param, POSTs it to Imejis as a component.property override, and returns the finished image bytes. It uses httpx for a non-blocking request, and because the key is sent server-side it never reaches the client.

main.py

import os
 
import httpx
from fastapi import FastAPI, Response
 
app = FastAPI()
 
 
@app.get("/og")
async def og_image(title: str = "Untitled"):
    async with httpx.AsyncClient() as client:
        response = await client.post(
            f"https://render.imejis.io/v1/{os.environ['IMEJIS_DESIGN_ID']}",
            headers={
                "dma-api-key": os.environ["IMEJIS_API_KEY"],
                "Content-Type": "application/json",
            },
            json={"headline.text": title},
        )
    response.raise_for_status()
 
    return Response(
        content=response.content,
        media_type="image/jpeg",
        # Renders are deterministic, so cache aggressively at the edge/CDN.
        headers={"Cache-Control": "public, immutable, no-transform, max-age=31536000"},
    )

2 point your metadata at it2. Point your metadata at it

Reference the endpoint from your page's <head>, passing each page's real data. Social platforms fetch /og?title=… from your own domain, no key exposed.

template.html

<meta
  property="og:image"
  content="https://your-site.com/og?title=Hello%20from%20FastAPI"
/>

Override any field. Each dynamic component exposes keys like headline.text, title.color, or image.image. Send only the ones you want to change. A design's overridable fields are listed in its Share / API panel.