Your AI assistant prepares the fax. You check it and pay. Connect the PayPerFax MCP server to your AI assistant once. Then your assistant can prepare a fax in your conversation and give you a link. You open the link to check the fax and pay. No account, no API key, no subscription. Nothing is sent and nothing is charged before you pay.
MCP (Model Context Protocol) is a way to connect an AI assistant to another service. The PayPerFax MCP server connects your assistant to the same pay-per-fax service as payperfax.com.
Check that your AI assistant can add a connector
You need an AI assistant that lets you add a custom MCP server. Apps call this a “custom connector”, a “custom app” or an “MCP server”. Assistants that support custom MCP servers include Claude, Claude Code, Codex and Cursor. ChatGPT and the Gemini app offer them on some plans or in some countries. The rules change often, so check your assistant’s help pages.
If your assistant cannot add a connector, it can still help. See if your AI assistant cannot add a connector below.
Add the fax MCP server to your AI assistant
The server address:
https://fax.payperfax.com/mcpThe exact steps depend on the app. In most apps they look like this:
- Open the connector settings. Look for a section named “Connectors”, “Connected Apps”, “Integrations” or “MCP servers”.
- Add a custom server. Choose “Add custom connector” or similar. Name it “PayPerFax” and enter the address
https://fax.payperfax.com/mcp. PayPerFax needs no sign-in: if asked about authentication, choose “No sign in” or “None”. If asked for a transport, choose Streamable HTTP. - Turn the connector on. In the chat where you want to prepare the fax, turn on the PayPerFax connector.
There is no password, no API key and nothing to sign up for. Once the connector is on, your assistant can prepare a fax, check the status of a fax, and check the supported file types and limits.
Prepare your fax
Give your assistant the recipient’s fax number, your email address and the letter you want to send. For example: “Write a short letter to my landlord about the broken heater, and prepare a fax to the number on my lease. My email is …”
Your assistant prepares the fax and gives you a link. Open the link, check the preview and the price, and pay. Then PayPerFax sends the fax. The preview link works for four hours.
Tell your assistant which country you are in, so the price shows in your currency and the dates use your format. You can also choose the language of the preview, the payment page and the emails: English, Spanish, German, French, Italian, Japanese or Korean.
Adding a document you already have
Your assistant cannot upload a file through this connector. With the PayPerFax MCP server, you add existing files in your browser.
- If your assistant writes the letter, it includes the text when it prepares your fax. PayPerFax prints it as a plain black-on-white document. Headings, lists and tables are kept.
- If you already have a file (a signed form, a scan or a PDF you received), your assistant prepares the fax without it. It gives you a link to the fax form, filled in, where you add your file. The form shows the note “Your AI assistant prepared this fax.” This link works for 24 hours.
Assistants that can run commands on your computer, such as Claude Code, Codex and Cursor, can also include a file from your computer through the PayPerFax API. Both use the same PayPerFax service.
Check the status
After you pay, ask your assistant to check the status of the fax. It can tell you if the fax is still sending, delivered or not delivered. The tracking page in your browser shows the same status.
What this is not
The fax MCP server is for one person who sends one fax with help from an AI assistant. It is not a service to build faxing into a product. There are no accounts, no webhooks and no inbox for incoming faxes. It is not an email-to-fax subscription.
For automated or high-volume faxing, such as a healthcare platform that sends many referral faxes a day, choose a service built for that use.
If your AI assistant cannot add a connector
Ask your AI assistant to draft the letter, then upload the document to PayPerFax. Ask for the letter as a PDF, DOCX or Markdown file. Then open fax.payperfax.com, upload the file, check the preview and pay.
For step-by-step help with each kind of AI assistant, see can ChatGPT or Claude send a fax for me?.
Price
The fax MCP server uses the same pay-per-fax pricing as the website. There is no MCP tier.
- $2 covers the first three pages. The optional cover page counts as one of them.
- $0.75 covers each page after that.
- A fax that fails to transmit is not charged.
The preview shows the final guaranteed price before you pay. Billing is in your local currency where supported: USD, EUR, GBP, JPY or KRW. The full destination list and the per-country rates are on the pricing page.
Documentation
The PayPerFax documentation site has the setup details and the technical reference:
- MCP server reference: setup instructions and technical reference.
- Guide for AI assistants: what an assistant needs to know before it prepares a fax.
- Send a fax: API examples.
- Check the status: how to check the delivery status.
The documentation is in English only. The pages you see (the preview, the filled-in form and the tracking page) are in seven languages: English, Spanish, German, French, Italian, Japanese and Korean.
Short FAQ
Which AI assistants can use the fax MCP server?
Any AI assistant that lets you add a custom MCP server. Today that includes Claude, Claude Code, Codex and Cursor. ChatGPT and the Gemini app offer custom MCP servers on some plans or in some countries. If your assistant cannot add one, ask it to draft the letter, then upload the document to PayPerFax.
Does my assistant pay for the fax?
No. Your assistant prepares the fax and gives you a link. You check the preview and pay in your browser.
Do I need an account to use this?
No. You do not need a PayPerFax account. The fax MCP server has no API key and no password.
Can my assistant upload a file through the connector?
No. Your assistant can include a letter it wrote. If you already have a file (a signed form, a scan, a PDF), the assistant gives you a link to the fax form, filled in, where you add your file.
Is it safe to let an assistant prepare a fax for me?
The assistant can only prepare the fax. It cannot pay, and nothing is sent until you pay. You open the preview link to check the document and the fax number before you pay. Uploads use an encrypted connection (TLS), and documents are deleted after 30 days. The full policy is on the security page.