One endpoint. A complete store listing.

Authentication

Authenticate every request with a Bearer token. Live keys are prefixed asa_live_; test keys are prefixed asa_test_ and render watermarked output without consuming paid credits.

Authorization: Bearer asa_live_xxxxxxxxxxxx

Get a key from the signup page after creating an account.

Store keys in CI secrets (recommended env var: APPSCREENSHOTAPI_KEY). Never commit keys or print them in logs, agents included.

Idempotency and retries

Send an Idempotency-Key header (Stripe semantics) to make retries safe: replays of the same key within 24 hours return the original response instead of rendering and billing twice.

Idempotency-Key: release-42-en-us

Every response includes rate-limit headers: X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset. On 429, retry after the window in Retry-After.

Image input

Screenshots are URL-first: pass { "url": "https://…" } and the renderer fetches it server-side through an SSRF-safe pipeline (public hosts only, no internal addresses, redirects validated). Inline base64 via { "b64": "…" } works when assets are not hosted anywhere.

• PNG, JPEG, and WebP input; output is always PNG.
• Up to 10 MB per image, decoded.
• Up to 32 MB total per request.
• Captures are scaled and composited pixel-exact, never upscaled by AI, never redrawn.

The response

Successful renders return the render object: an id (prefix rnd_), status, images[] with url, width, and height per export, the lint report, credits_used, and expires_at.

• Images are CDN URLs, never base64, retained for 30 days.
• credits_used equals the number of final exported images (1 credit = 1 screenshot).
• With output.format: "fastlane_zip", the response also includes an archive.url arranged in the folder structure deliver expects.
• Re-render any time: the engine is deterministic, so the same request body reproduces the same pixels.

Fetch images and archives

Image URLs in the render object are the simplest way to grab output. You can also fetch a single image or the whole set directly from the render:

• GET /v1/renders/{id}/images/{filename} streams one rendered PNG.
• GET /v1/renders/{id}/archive returns the full set as a deliver-ready archive (render with output.format: "fastlane_zip").

# Re-fetch a single rendered image during the 30-day window
curl -L https://api.appscreenshotapi.com/v1/renders/rnd_8Fq2yK/images/01.png \
  -H "Authorization: Bearer $APPSCREENSHOTAPI_KEY" \
  -o 01.png

# Or download the whole set as a deliver-ready archive
# (requires output.format: "fastlane_zip" on the render)
curl -L https://api.appscreenshotapi.com/v1/renders/rnd_8Fq2yK/archive \
  -H "Authorization: Bearer $APPSCREENSHOTAPI_KEY" \
  -o screenshots.zip

Errors

Errors use Stripe-style bodies with a stable type, code, human-readable message, offending param, and a doc_url:

{
  "error": {
    "type": "invalid_request_error",
    "code": "screenshot_unreachable",
    "message": "Could not fetch slides[1].screenshot.url (HTTP 404).",
    "param": "slides[1].screenshot.url",
    "doc_url": "https://appscreenshotapi.com/docs/#images"
  }
}

• 400/422: invalid request; param points at the field.
• 401: missing or invalid API key.
• 402: out of credits. The error includes a Stripe Checkout billing_url; agents should show it to a human and wait for explicit approval.
• 429: rate limited; respect Retry-After.

Locales and stores

output.locales fans the set out across markets in the same request. Per-locale headline strings are keyed by BCP-47 tag, RTL locales mirror automatically, and text fitting keeps long translations inside the locked type scale. output.stores renders the same design for appstore and play canvases at once.

"output": {
  "locales": ["en-US", "de-DE", "ja-JP"],
  "stores": ["appstore", "play"]
}

Brief-to-set assist (optional)

POST /v1/briefs is the one optional AI surface: it turns a one-sentence brief into an editable /v1/renders request body: a full design spec with preset, theme tokens, and slide copy. Review or edit the spec, then render it deterministically. AI proposes the design; it never touches your pixels.

It is bring-your-own-key: pass an llm object with your provider (openai, anthropic, gemini, or openrouter), model, and key. You pay your own LLM provider for the call; appscreenshotapi never bills render credits for it. The key is used once for the upstream request and is never stored, cached, or logged. The drafted spec is validated against the exact /v1/renders schema before it is returned, so it always renders.

curl -X POST https://api.appscreenshotapi.com/v1/briefs \
  -H "Authorization: Bearer $APPSCREENSHOTAPI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "brief": "A calm, dark, premium look for a habit tracker aimed at indie builders",
    "screenshots": [
      { "url": "https://acme.app/shots/home.png" },
      { "url": "https://acme.app/shots/streaks.png" }
    ],
    "llm": {
      "provider": "openai",
      "model": "gpt-4o-mini",
      "key": "$YOUR_OWN_LLM_KEY"
    }
  }'

# Bring your own LLM key: you pay your provider, never render credits.
# Providers: openai, anthropic, gemini, openrouter (vendor/model strings).
# The key is used once for the upstream call and is never stored or logged.
# → returns an editable /v1/renders request body (a design spec),
#   which the deterministic engine renders. AI never touches pixels.

Credits and limits

One credit equals one final exported screenshot image, matching pricing: a 6-slide set rendered to 2 canvases in 2 locales uses 24 credits. Free accounts start with 3 watermarked screenshots; packs are $18 for 1,000 and $48 for 3,500.

When a key runs out, the API returns 402 with a Stripe Checkout billing URL. Payments and store uploads always remain explicit human approval steps.

Agents and MCP

The API is built to be operated by coding agents: one tool call renders a full set, the request schema is published at /openapi.json (every style enum included), and the lint report is machine-readable so an agent can adjust the request and re-render until checks pass. To discover every available value, scrape the flat options reference or browse the visual gallery.

The agent contract exposes render_set and draft_brief style operations over the same API. Point your agent at the REST endpoints above and use the discovery files: /llms.txt and /.well-known/api-catalog. Agents can also create accounts through the standard form at /register.

SDKs, CLI, and CI

The API is plain REST plus JSON, so every language works today with its built-in HTTP client: the curl examples above translate directly to fetch, requests, or any client. See the Node and Python guides for ready-to-run raw-HTTP snippets.

The SDK guides show direct HTTP integrations for renders and briefs in Node and Python. CI helpers, GitHub Actions, and Fastlane lanes can take a render.json request file and write the finished set into deliver-ready folders are also planned. See CI/CD for current pipeline examples.