Fax with AI

Send fax with
Claude, ChatGPT & Grok

Connect SendFaxFast to Claude, ChatGPT or Grok.
Ask your AI to send a fax — it handles the rest.

Claude
ChatGPT
Grok
Connect now View all tools

Connect in 2 minutes

Option A – sign in (recommended): add this address as a custom connector. Your AI app opens a SendFaxFast sign-in page where you paste your sfx_... key once. The key is not part of the URL, and you can disconnect at any time.

https://sendfaxfast.com/api/mcp-oauth.php

Option B – personal URL: buy credits at ai-credits.html — your email contains your personal connector URL with your sfx_... key already built in. Paste that URL into your AI app as a custom connector. It is the address below plus ?key=sfx_... at the end.

https://sendfaxfast.com/api/mcp-credits.php

How to connect (Credits)

1

Buy Credits

Go to sendfaxfast.com/ai-credits.html and buy a credit package ($11.99 / $19.99 / $34.99). Your sfx_... API key and your personal connector URL arrive by email within seconds.

2

Add it in Claude

Claude (web or desktop app) → Customize → Connectors → Add custom connector. Paste https://sendfaxfast.com/api/mcp-oauth.php, click Add, then Connect: on the SendFaxFast page paste your sfx_... key and click “Allow & connect”. Or paste your personal connector URL (…/mcp-credits.php?key=sfx_...); keep that URL private, because it contains your key.

3

Or in ChatGPT, Grok or Gemini CLI

ChatGPT (web): turn on Developer mode under Settings → Apps → Advanced settings, then create an app with the sign-in URL and authentication “OAuth” (or with your personal URL and “No authentication”). Some ChatGPT plans only allow read-only tools. Grok: grok.com/connectors → New Connector → Custom → paste the URL and complete the sign-in. Gemini CLI: gemini mcp add --transport http sendfaxfast https://sendfaxfast.com/api/mcp-oauth.php, then sign in when asked.

4

Fax with a sentence

Say: "Fax this document to +1 212 555 0100." In ChatGPT, attach the PDF, JPG or PNG right in the chat. In Claude, Grok and Gemini, your AI gives you a secure one-time upload link: open it, pick the file or take a photo with your phone, then tell the AI you are done. The AI deducts 1 credit, sends the fax via Telnyx, and you receive a delivery confirmation by email.

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Available tools

Your AI assistant can call these 6 functions automatically. Listed with all parameters.

get_fax_price
No key required
Calculate the price for sending a fax before committing to it. Returns price, currency and whether the destination is supported.
fax_numberrequired — Recipient fax number in E.164 format, e.g. +12125550100
pagesoptional — Number of pages (default: 1, max: 100)
"What does it cost to fax 3 pages to +1 212 555 0100?"
create_upload_link
Key optional
Creates a secure one-time upload page for a PDF, JPG or PNG (max. 10 MB, valid for 30 minutes). Your AI shows you the link; you pick the file or take a photo with your phone, and the AI then sends it with send_fax. This step sends nothing and costs nothing.
No parameters required.
"I want to fax a photo of my signed form to +1 212 555 0100"
send_fax
Key optional
Send a PDF, JPG or PNG to a fax number. Without API key: creates a Stripe payment link (Pay-per-Fax, $2.49–$4.99+); the fax is sent automatically after payment. With API key: sends immediately from your credits or subscription quota — no payment step. Needs one of file, upload_id or document_url.
fax_numberrequired — Recipient fax number in E.164 format
fileoptional — The PDF, JPG or PNG you attached in ChatGPT (passed automatically)
upload_idoptional — ID from create_upload_link, after you uploaded the file (Claude, Grok, Gemini)
document_urloptional — Direct, public HTTPS link to a PDF file
emailoptional — Email for payment receipt and delivery confirmation
scheduled_atoptional — ISO 8601 datetime to schedule, e.g. 2026-10-08T09:00:00-05:00
"Fax the contract I just attached to +1 310 555 0199"
get_fax_status
No key required
Check the delivery status of any fax. Returns current status: queued, sending, delivered, failed, scheduled, or cancelled. For Pay-per-Fax orders it also returns the link to the transmission report once the fax is delivered.
tokenoptional — Token from send_fax response (Pay-per-Fax orders)
fax_idoptional — fax_id from send_fax response (subscription orders, requires key)
"Has my fax been delivered?"
get_account_info
Key required
Show your subscription plan details — remaining fax quota, plan type (Mini / Flex / Starter / Business), and current billing period.
No parameters required.
"How many faxes do I have left this month?"
list_fax_history
Key required
List recent faxes from your subscription account with fax number, page count, delivery status, and timestamp.
limitoptional — Number of results (1–50, default: 10)
offsetoptional — Pagination offset (default: 0)
"Show me my last 5 faxes"
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Prepaid Credits

Pay once — no subscription, no account. Credits never expire.

Starter

5 Credits
$11.99

$2.40 per fax

  • 5 faxes, any length
  • API key instant by email
  • Credits never expire
Buy Credits
Best Value

10 Credits
$19.99

$2.00 per fax

  • 10 faxes, any length
  • API key instant by email
  • Credits never expire
Buy Credits
Pro

20 Credits
$34.99

$1.75 per fax

  • 20 faxes, any length
  • API key instant by email
  • Credits never expire
Buy Credits
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Your API key

After purchasing credits, your sfx_... API key is sent to your email address automatically — no account needed. The same email contains your personal connector URL with the key built in: paste that URL into your AI app and you are done. Keep it private, because anyone with the URL can use your credits. If your app lets you add request headers, you can instead use the plain URL with the header x-api-key set to your key.

Buy Credits & get your key
No fax machine needed
SSL encrypted · GDPR compliant
Full refund if delivery fails
Personal support by the founder