SendThisFax

Send real faxes to EU institutions from your AI agent, via a pay-per-fax checkout link or a prepaid API key.

View on sendthisfax.com

Documentation

Send faxes from your AI agent

SendThisFax speaks MCP. Connect Claude Code, Codex or any MCP client and let your agent prepare the fax — you only click the payment link.

New to this? Read the step-by-step guide.

Connect

The MCP endpoint is https://www.sendthisfax.com/mcp (streamable HTTP, no authentication required).

Claude Code

claude mcp add --transport http sendthisfax https://www.sendthisfax.com/mcp

Codex (~/.codex/config.toml)

[mcp_servers.sendthisfax]
url = "https://www.sendthisfax.com/mcp"

How it works

  1. Your agent uploads the PDF over plain HTTP — curl, fetch, any client:
curl -F "[email protected]" https://www.sendthisfax.com/api/upload
  1. It calls the send_fax tool with the recipient fax number, and receives a one-time payment link.
  2. You open the link and pay — no account, no subscription.
  3. The agent polls get_fax_status until the fax is delivered. If delivery fails, you are refunded automatically.

Tools

  • get_price — price quote for a page count and billing country, VAT included.
  • send_fax — submits an uploaded PDF and returns the payment link.
  • get_fax_status — live status: pending, sending, delivered or failed.
  • check_balance — remaining prepaid credit (API-key mode only).

Autonomous mode with an API key

With prepaid credits there is no payment link at all: connect with your API key and send_fax debits your balance and sends immediately. Failed faxes are re-credited.

claude mcp add --transport http sendthisfax https://www.sendthisfax.com/mcp \
  --header "Authorization: Bearer stf_live_..."

Buy credits and get your key on the API credits page. A REST API is also available: POST https://www.sendthisfax.com/api/v1/faxes. Check your balance and fax history on the dashboard.

Good to know

  • PDFs up to 50 MB and 1000 pages; encrypted PDFs are rejected.
  • Pricing is €5.00 for up to 5 pages plus €0.50 per extra page, plus VAT by billing country — same as on the website.
  • A plain JSON status endpoint is also available: GET https://www.sendthisfax.com/api/fax/:fax_id
  • Use +19898989898 as recipient for integration tests.