API Reference
REST API for PDF template management, field mapping, and document generation.
API Reference
SimplyFill's REST API lets you upload fillable PDFs, alias their fields into your own vocabulary, and generate filled PDFs from JSON data. Every endpoint is documented in the subsections below; this page is the high-level map.
Base URL
https://api.simplyfill.app/v1All paths under the API reference are appended to the base URL above. Endpoint signatures below use the shortened form (e.g. POST /templates/upload resolves to POST https://api.simplyfill.app/v1/templates/upload).
Authentication
Every request requires a Bearer token in the Authorization header:
curl -H "Authorization: Bearer $SIMPLYFILL_API_KEY" \
https://api.simplyfill.app/v1/templatesSee Authentication for key management, rotation, and environment scoping.
Endpoint groups
| Group | Surface |
|---|---|
| Templates | Upload, list, fetch, and delete fillable PDFs |
| Mappings | Alias raw PDF field names to your domain vocabulary |
| Generate | Sync and async PDF generation, status, download, bulk envelopes |
| Webhooks | Register and manage webhook configurations |
| Billing | Read subscription state, usage, and invoices |
| Errors | Status codes and machine-readable error bodies |
Rate limits
Hourly request limits per API key:
| Tier | Requests / hour |
|---|---|
| FREE | 100 |
| PRO | 1,000 |
| BUSINESS | 10,000 |
| ENTERPRISE | 100,000 |
Every response carries X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset headers. See Quotas for the full table including monthly PDF caps.
Response shape
Successful responses are JSON. The exact body depends on the endpoint, but every response carries:
200 OK/201 Created/204 No Contentfor success4xxfor client errors with a JSON body describing the problem5xxfor server errors (these are rare and trigger an internal alert)
See Errors for the full error schema.