mcp server
PromptFax
Send a one-off fax from inside ChatGPT or Claude. Pay-per-use, $2-$4.50 per delivered fax.
Description as published by the maintainer. Source
- version 0.1.0
- active
active — Registry entry last updated 2026-05-30.
What this server can do
8 functions, named and described by the server itself. Parameter names are shown because they say more about what a function does than its name usually does.
attach_document(fileUrls, sessionId, documentId)- Fallback/non-widget tool for binding a PromptFax document or one or more HTTPS PDF URLs into the current MCP session before requesting a quote. In ChatGPT widget sessions, prefer the widget's file controls after start_session instead of calling this tool unless the widget is unavailable or the user explicitly asks for fallback behavior. Required: sessionId.
cancel(sessionId, sendIntentId)- Use this when you need to cancel the active PromptFax send.
checkout(sessionId, sendIntentId, autoSendAfterAuthorization)- Fallback/non-widget tool for starting external Stripe Checkout after the user accepts a pay-per-use quote. Payment authorization is required before PromptFax can send; PromptFax treats webhook-confirmed authorization, not browser redirect, as payment truth. In ChatGPT widget sessions, do not call this after start_session because the widget's Pay & send step opens Checkout.
get_quote(fileUrls, faxNumber, sessionId, documentId)- Fallback/non-widget tool for creating a user-reviewable pay-per-use fax quote when you have a fax number and either an MCP session, a PromptFax documentId, or one or more HTTPS PDF URLs. A quote is required before Stripe Checkout and before any real fax transmission. In ChatGPT widget sessions, do not call this after start_session because the widget auto-quotes once the document and destination are ready.
get_status(sessionId, sendIntentId)- Use this when you need the latest PromptFax workflow state, quote/payment state, or fax transmission status.
retry_failed_fax(sessionId, sendIntentId)- Use this after a retry-eligible failed fax to prepare a new authorization attempt.
send_fax(sessionId, sendIntentId)- Fallback/non-widget tool for sending after payment is authorized and the user explicitly wants to send now. In ChatGPT widget sessions, do not call this after start_session unless the widget is unavailable or the user explicitly asks for fallback behavior.
start_session(files, hostType, metadata, faxNumber, sessionId, hostCapabilities)- Use this first when a user wants to send or price a fax. PromptFax is built for irregular, pay-per-use outbound faxing: every real send requires a user-reviewed quote and Stripe payment authorization before transmission. MCP clients should set hostType to identify their host: chatgpt, claude, browser, or other. When calling this from ChatGPT, set hostType to chatgpt so PromptFax uses the ChatGPT widget and file flow. In ChatGPT, this opens the PromptFax widget; after the widget is shown, let the widget handle file selection, destination entry, automatic quote creation, Stripe Checkout, and status tracking. If no document is attached, tell the user to attach a document in the widget. The widget does not provide a document preview step. Do not tell ChatGPT users to get a quote; after the widget has a document and valid destination, tell them to verify the price and use Pay & send when ready. For Claude and other MCP hosts that cannot pass files directly, use the agent-friendly hosted PromptFax session page to guide upload/review, request a quote, launch Stripe Checkout, and poll delivery status. Do not call get_quote, checkout, or send_fax for a ChatGPT widget session unless the user explicitly asks for fallback behavior or the widget is unavailable. Use get_status only for a textual status refresh.
Last successful function declaration observed on . Source: https://promptfax.app/mcp. We list what the server declared; we do not call any of these functions.
Endpoint status observed on . Source: https://promptfax.app/mcp.
Signals
These are separate measurements of different things. They are deliberately not combined into one score, because a popularity number that mixes website traffic with saves and stars cannot be checked or acted on.
| Signal | Value | What it measures | Window | Observed | Source |
|---|---|---|---|---|---|
| Latest published version | 0.1.0 | Latest version string the maintainer published to the registry. | as of fetch | Model Context Protocol | |
| Registry record last updated | 2026-05-30 | When the registry record was last updated by its maintainer. | point in time | Model Context Protocol | |
| First listed in the MCP Registry | 2026-05-30 | Date this server was first published to the official MCP Registry. Not a usage or quality measure. | point in time | Model Context Protocol | |
| mcp tools declared | 8 tools | Number of functions the server itself declared when asked to list them. This is what the server offers an agent, not a measure of how well any of them work. | as of probe | promptfax.app | |
| mcp endpoint status | ok | The server listed 8 functions when asked. | as of probe | promptfax.app |
Where to get it
This record as data
Every field on this page, with its source and observation date, is in the catalog JSON. Fetch the whole kind at once instead of parsing this HTML.
GET /api/v1/entries/mcp_server.json