API Documentation

Complete reference for the SemPDF REST API. All endpoints require authentication via Bearer token.

Base URL

https://sempdf.com/api/v1

Authentication

All requests require an API key passed in the Authorization header:

Authorization: Bearer spdf_your_api_key_here

Get your API key at sempdf.com/developers

Rate Limits & Credits

Each API call consumes credits based on the endpoint. Credits reset monthly. Response headers include:

X-Credits-Used

Credits consumed by this request

X-Credits-Remaining

Credits remaining in your plan

Endpoints

Convert a PDF file to an editable Word document (DOCX).

Request

Content-Type: multipart/form-data

Parameter	Type	Required	Description
file	File	Yes	PDF file to convert

Response

Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document

DOCX file binary

Content-Disposition: attachment; filename="output.docx"X-Credits-Used: 5X-Credits-Remaining: 1995

curl -X POST https://sempdf.com/api/v1/pdf-to-word \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -F "file=@document.pdf" \
  -o output.docx

Error Codes

Code	Description
400	Bad Request — missing or invalid parameters
401	Unauthorized — invalid or missing API key
403	Forbidden — no active API plan
429	Too Many Requests — insufficient credits or rate limit exceeded
500	Internal Server Error — something went wrong on our end
502	Bad Gateway — conversion service temporarily unavailable

Error Response Format

{
  "error": "Description of the error",
  "credits_remaining": 0,        // only on 429
  "credits_required": 5,         // only on 429
  "upgrade_url": "https://..."   // only on 429
}