Run custom server-side Puppeteer code with the Browserless /function REST API without hosting a runtime

Documented steps

1. POST https://production-sfo.browserless.io/function?token=YOUR_API_TOKEN - accepts Content-Type application/javascript (raw code body) or application/json ({"code":"...","context":{...}}).
2. Code is an ESM default export receiving a Puppeteer page and optional context: export default async ({ page, context }) => { ...; return { data, type }; }.
3. The return object's data can be a Buffer, JSON, or text, and type is the Content-Type the API responds with - e.g. return await page.pdf({printBackground:true}) for a binary PDF, or return { data:{...}, type:'application/json' } for structured JSON.
4. Import remote ESM packages at request time, e.g. import { faker } from "https://esm.sh/@faker-js/faker" - no install step needed.
5. Wrap page automation in try/catch to return structured error info (e.g. page.screenshot({encoding:'base64'}) on failure) instead of failing the request outright.
6. Auth and regional hosts match the other REST endpoints (?token=, production-sfo/lon/ams). Ref: https://docs.browserless.io/rest-apis/function