Quickstart

This guide takes you from a published template to a rendered PDF using nothing but curl.

1. Publish a template and issue an API key

1. Design a document in the studio and publish it — publishing freezes the current draft as an immutable version. The API always renders the published version, never your work-in-progress draft.
2. Issue an API key under Settings → API keys. Keys can be scoped to a single workspace and revoked independently, so issue one key per integration.

Store the key server-side. It is a bearer credential — anyone holding it can render and download documents in its scope.

2. Find your canvas

curl https://composepdf.com/v1/canvases \
  -H "x-api-key: $COMPOSEPDF_API_KEY"

The response lists the published canvases your key can reach, with their ids.

To see what data a template expects, fetch its data contract:

curl https://composepdf.com/v1/canvases/{canvasId}/schema \
  -H "x-api-key: $COMPOSEPDF_API_KEY"

3. Render a PDF

curl -X POST https://composepdf.com/v1/canvases/{canvasId}/pdf \
  -H "x-api-key: $COMPOSEPDF_API_KEY" \
  -H "content-type: application/json" \
  -d '{
    "data": {
      "customer": { "name": "Acme Inc." },
      "items": [
        { "name": "Design work", "price": 1200 },
        { "name": "Hosting",     "price": 90 }
      ]
    }
  }' \
  --output invoice.pdf

The response body is the PDF. If the payload does not match the template’s declared variables, you get a 400 listing the violating paths instead of a silently wrong document.

Where to go next

• TypeScript instead of curl — pnpm add composepdf, and generate the payload types from your own templates. See TypeScript.
• Many records, one file — pass dataList (an array of payloads) to collate one document per record into a single PDF. See Render API.
• Long-running renders — add Prefer: respond-async to get a 202 and a job id instead of holding the connection. See Render API.
• Live preview in your product — embed the template as an iframe and stream your form state to it. See Embedded live preview.