One API call gives your users a complete drag-and-drop template builder — embedded in an iframe, branded as yours, with real-time events piped back to your app.
Built for builders
No OAuth dance. No SDK install. Just an API key and an iframe.
Use the Zignature dashboard or API to create the base document template. This is your starting point — your users will customize it in the embedded editor.
POST to get a signed, time-limited URL. Pass your theme, allowed field types, and an optional webhook URL. The response gives you editor_url — that's your iframe src.
Drop the URL into an iframe. Listen for postMessage events to know when your user saves, finishes, or makes field changes.
editor.ready
Fires when the iframe has fully loaded and the editor is interactive. Use this to hide your loading spinner.
editor.saved
User clicked Save. Template changes are persisted. Payload includes updated field list and template metadata.
editor.done
User clicked the finish button (your custom label). Redirect or close the iframe — the user is finished editing.
editor.field.added
/ .removed
Fires when a field is placed or removed. Payload includes field type, position, and the signer role it's assigned to.
editor.error
An error occurred inside the editor. Payload includes a human-readable message you can surface to the user.
Building a document template editor from scratch takes months. This one is ready in an afternoon.
Pass accent_color, logo_url, and button_label per session. Every embed looks like your product.
Restrict users to only the field types relevant to your use case. No rogue checkbox fields or payment fields where you don't want them.
Editor URLs are cryptographically signed and expire after your configured window. No leaked URLs give strangers access to your users' templates.
All /embed/ paths have X-Frame-Options permanently stripped at the Rack layer. Embed from any origin, no CORS wrestling.
Pass a webhook_url in the session to receive server-side callbacks when the template is saved — no polling required.
Attach arbitrary JSON metadata to the session — customer ID, org ID, deal reference. It echoes back in every event and webhook payload.
Any SaaS product that involves documents can offer its users a powerful template builder — in a weekend.
Let HR teams build their own offer letters, NDAs, and policy acknowledgments inside your platform — without exporting to Word or emailing PDF attachments.
Give sales reps a deal-room document builder. They set up proposals, SOWs, and contracts without leaving your CRM — and send for signing in the same workflow.
Let brokers build custom listing agreements, disclosure forms, and lease addendums in your platform. Every form built once, used hundreds of times.
/embed/ paths have X-Frame-Options and Content-Security-Policy frame headers permanently stripped by a dedicated Rack middleware layer. Load the iframe from any domain — no CORS configuration required on your end.editor.error postMessage event with a session_expired reason. Your app can intercept this, request a new editor session, and swap the iframe src — the user sees a seamless refresh.Your users need a document builder. Yours took an afternoon to add — and it looks like it took months.
Free plan available · No SDK install · CORS-safe from any domain