What screenshot inputs are required?

Clean simulator captures in PNG format are required. The studio composites each capture into the chosen device frame and applies your typography, layout and theme.

Can a project be saved and resumed later?

Yes. Authenticated users can save projects to the cloud, name them, and open them again from any device. Autosave runs every 30 seconds during an active session and uploads only the screenshot bytes that have actually changed. The Free tier supports one saved project; the Pro tier supports twenty.

Is the export compatible with fastlane?

Yes. The export bundle uses the exact directory layout expected by fastlane deliver and supply, including locale and device folders. iOS and Google Play screenshots may be mixed within a single bundle without further reorganisation.

Can multiple device sizes be rendered together?

Yes. Any combination of iOS 6.9, 6.7, 6.5 and Google Play may be selected. A single render produces every selected size and packages them in one bundle.

How customisable is the typography?

Each project supports an arbitrary number of named text fields. Within each field, individual character spans may be styled with their own font, size, weight, colour, italics, underline and alignment. More than 30 Google Fonts are available out of the box.

Where is data stored?

All data is hosted on infrastructure located in the European Union (Contabo, Düsseldorf). Render outputs are removed after 24 hours; screenshots associated with saved projects are retained for the lifetime of the project. No training is performed on customer data, and the studio interface uses no tracking cookies.

docs · api

Programmatic renders.

POST your screens, poll the job, download the zip. The API is HTTPS-only, authenticated with an X-API-Key header, and limited to Pro accounts. Free of vendor SDKs — anything that speaks HTTP works.

Quick start

1. Generate a key at /account/keys. Copy the ask_live_… string — you only see it once.

2. POST your PNGs as multipart/form-data:

curl https://api.appscreen.co/v1/render \
  -H "X-API-Key: $APPSCREEN_KEY" \
  -F 'theme=paper' \
  -F 'sizes=["ios-6.9"]' \
  -F 'langs=["en"]' \
  -F 'captions=[{"texts":{"Headline":{"type":"doc","content":[{"type":"paragraph","content":[{"type":"text","text":"Find people who share your taste."}]}]}}}]' \
  -F 'fields=[{"id":"Headline","label":"Headline"}]' \
  -F 'screens=@./shot1.png' \
  -F 'screens=@./shot2.png'

3. Poll the returned jobId until status === "done":

curl https://api.appscreen.co/v1/render/$JOB \
  -H "X-API-Key: $APPSCREEN_KEY"

4. GET the downloadUrl within 1 hour of the poll response — it's an HMAC-signed link served by AppScreen directly.

Authentication

Send your key as X-API-Key, or as Authorization: Bearer ask_live_… if your client only supports Bearer. Keys are per-account, never scoped to a single project.

Lost a key? Revoke it from /account/keys and create a new one. Revocation is immediate.

POST /v1/render

multipart/form-data with the following fields:

screens	file[]	PNG screenshots, max 200 files × 10 MB.
theme	string	flat \| paper \| frame \| card \| glass \| mesh \| image
sizes	json string	JSON array, e.g. '["ios-6.9","play"]'. Allowed: ios-6.9, ios-6.7, ios-6.5, play.
langs	json string	JSON array of locale codes, e.g. '["en","de","tr"]'. Up to 15.
captions	json string	Per-screen caption objects. See the captions schema below.
fields	json string	Optional caption field defs (id, label).
layout	string	default \| fastlane \| flutter \| react-native \| capacitor \| kmm
rounded	boolean	Marketing-asset mode (rounded canvas, alpha). Cannot combine with fastlane layouts.

Returns 202 Accepted with a job id:

{
  "jobId": "8c1c…-uuid",
  "status": "queued",
  "totalSteps": 4,
  "doneSteps": 0,
  "pollUrl": "/v1/render/8c1c…"
}

GET /v1/render/:jobId

Returns current job state. Poll every 2–5 s until status is done or failed. The signed downloadUrl is regenerated on every successful poll and expires in 1 hour.

{
  "jobId": "8c1c…",
  "status": "done",
  "doneSteps": 4,
  "totalSteps": 4,
  "downloadUrl": "https://api.appscreen.co/r/abc?exp=…&sig=…",
  "error": null
}

Idempotency

Pass a Idempotency-Key header (any string up to 200 chars). Retries with the same key within 24h return the original job — safe to retry network failures without re-paying render cost.

Limits & errors

screens / job	200
renders / month	500 (Pro)
request rate	30 / min per key
max upload	200 files × 10 MB
job timeout	20 min (server-side)

Common error shapes:

401	missing or revoked api key
402	free plan, monthly cap reached, or size/lang outside Pro tier
413	captions payload exceeds the per-screen size cap
429	per-key rate limit; retry after Retry-After seconds

TypeScript SDK

A minimal TS client lives in the sdk/ directory of the repo. It wraps the multipart upload and polling loop:

import { Appscreen } from "./sdk";

const client = new Appscreen({ apiKey: process.env.APPSCREEN_KEY! });

const job = await client.render({
  theme: "paper",
  sizes: ["ios-6.9"],
  langs: ["en"],
  fields: [{ id: "Headline", label: "Headline" }],
  captions: [
    { texts: { Headline: docFromText("Find people who share your taste.") } },
  ],
  screens: [
    { name: "shot1.png", data: await readFile("./shot1.png") },
  ],
});

const done = await client.waitForCompletion(job.jobId);
console.log(done.downloadUrl);