Submit an uploaded PDF for faxing.
Step 1 (before this tool): upload the PDF over plain HTTP multipart, using any HTTP client you have — shell, JavaScript fetch with FormData, Python, etc.:
curl -F "file=@document.pdf" https://www.sendthisfax.com/api/upload
fetch("https://www.sendthisfax.com/api/upload", {method: "POST", body: formDataWithFile})
The response contains fax_public_id and page_count. PDFs must be unencrypted, at most 50 MB and 1000 pages.
Step 2: call this tool with the fax_public_id and the recipient fax number.
Two modes:
- With an API key (Authorization: Bearer stf_live_... on this MCP connection): the fax price is debited from the prepaid credit balance and sending starts immediately — no checkout, no browser. sender_email and billing_country are optional (they default to the key's records). Buy credits at https://www.sendthisfax.com/en/credits.
- Without an API key: sender_email and billing_country are REQUIRED and the tool returns a checkout_url the USER must pay in a browser; the fax is sent automatically once paid.
In both modes, poll get_fax_status until status reaches "delivered" or "failed" (failures after payment are auto-refunded).
For integration testing, +19898989898 is the designated test recipient number.
Connector