AI-Powered Faxing: The Complete Guide to Faxify MCP (2026)

When I first proposed adding an MCP server to Faxify, the initial reaction was understandable skepticism: who wants their AI assistant sending faxes? It sounded like solving a problem nobody had. The more we looked at it, the more we noticed that the workflows that still require fax are exactly the ones humans most want to automate away. Healthcare intake. Legal filings. Insurance pre-authorizations. Real-estate disclosures. These aren't going digital because the regulators they answer to haven't caught up. So instead of waiting for the world to abandon fax, we put it inside the AI tools developers and operators already use every day.

Worth being upfront about: Faxify MCP is early. We shipped it ahead of clear demand because Model Context Protocol, Anthropic's open standard for AI-tool integration, is going to reshape how AI agents touch external systems. Fax is a category where being early matters. The pieces of the AI ecosystem that need this aren't fully in place yet (ChatGPT Plus / Free still don't have native MCP, for one), but they're coming fast. The tool is live; production adoption is just starting. What follows is what we built and why we built it now.

This guide covers the full picture: what Faxify MCP is, how it works under the hood, what AI tools it connects to, the use cases we built it for (with honest compliance framing), how it stacks up against the alternatives, and how to get started in about ten minutes.

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What Is Model Context Protocol?

The Model Context Protocol (MCP) is an open standard, originally introduced by Anthropic in November 2024, for connecting AI assistants to external systems — databases, APIs, file systems, internal tools — through a uniform interface. Before MCP, every AI tool integration was bespoke: Cursor had its own extension system, Claude Desktop had a different one, ChatGPT had plugins (later replaced by GPTs, then by the developer-mode MCP support), and so on. Building an integration once didn't mean it worked anywhere else.

MCP changes that by defining a protocol. An MCP server exposes a typed set of "tools" (function-like operations the AI can call), "resources" (data the AI can read), and "prompts" (parameterized templates). The AI client speaks MCP, the server speaks MCP, and any tool you build once works everywhere MCP is supported. Think of it as the "REST API" of the AI-tool integration era, except designed for the conversational, agentic patterns LLMs actually use, with streaming, structured outputs, and stateful interactions baked in.

By 2026, MCP is supported natively or via developer mode in every major AI surface: ChatGPT, Claude, Cursor, Continue.dev, Aider, and any OAuth 2.1-capable assistant. That's the surface area we built Faxify MCP to cover.

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What Is Faxify MCP?

Faxify MCP is a hosted Model Context Protocol server that turns any MCP-compatible AI assistant into a fax client. It exposes 17 typed tools for sending, receiving, drafting, searching, and managing faxes, all through the same Faxify account you use in the iOS, Android, and web apps. No separate signup, no separate billing, no separate page allowance.

The hosted part matters. You don't run an MCP server yourself, and you don't deploy infrastructure. You point your AI assistant at https://mcp.faxify.com/api/v1/mcp, complete an authentication flow (more on that below), and the tools appear in your assistant's tool palette. From there, you can fax in natural language: "send the signed agreement at this path to 555-123-4567 with my cover page." The assistant calls send_fax, Faxify validates and dispatches, and the status flows back into the conversation.

Faxify MCP is built for three kinds of users. Individuals who'd rather not switch apps when they need to fax something mid-conversation in ChatGPT or Claude. Operators who want to automate recurring fax workflows: invoice acknowledgments, intake forms, signed releases. Developers building dedicated agents that combine Faxify with other MCP servers like filesystem, email, or CRM to create end-to-end document workflows. These are the workflows we built the tool for; production adoption is still in its early stages.

You can explore the server directly at mcp.faxify.com.

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How Faxify MCP Works Under the Hood

Faxify MCP is a single HTTP endpoint at https://mcp.faxify.com/api/v1/mcp that speaks the Model Context Protocol over JSON-RPC. Different AI clients reach it two different ways, depending on whether they speak OAuth natively.

  Claude Web (OAuth)              Cursor / Claude Desktop
  ChatGPT Enterprise              Continue.dev / Aider
  (OAuth 2.1 native)              (stdio-based)
         │                                  │
         │ OAuth 2.1 DCR                    │ stdio
         │                                  ▼
         │                    ┌──────────────────────────┐
         │                    │  @faxify/mcp-client      │
         │                    │  (npm package)           │
         │                    └──────────────────────────┘
         │                                  │
         │                                  │ HTTPS + JWT
         ▼                                  ▼
  ┌────────────────────────────────────────────────────────┐
  │  Faxify MCP Server                                     │
  │  https://mcp.faxify.com/api/v1/mcp                     │
  └────────────────────────────────────────────────────────┘
                            │
                            │ JSON-RPC tools
                            ▼
  ┌────────────────────────────────────────────────────────┐
  │  Faxify Backend                                        │
  └────────────────────────────────────────────────────────┘
                            │
                            │ fax transmission
                            ▼
  ┌────────────────────────────────────────────────────────┐
  │  SignalWire carrier infrastructure (HIPAA-eligible)    │
  └────────────────────────────────────────────────────────┘
                            │
                            │ T.38 / G.711
                            ▼
                      Recipient fax

The two authentication flows

OAuth 2.1 with Dynamic Client Registration (RFC 7591), for HTTP-native clients. ChatGPT Developer Mode and OAuth-capable assistants discover Faxify's OAuth endpoints automatically via the well-known metadata at /.well-known/oauth-authorization-server (RFC 8414). The client self-registers without needing a whitelist, completes the standard authorization-code flow against your Faxify account (Google SSO, Apple SSO, Email/OTP), and receives a stateless JWT authorization code encrypted with AES-256-GCM. No client secret to leak, no redirect URI whitelist to maintain.

JWT tokens, for stdio-based clients (Cursor, Claude Desktop, Continue.dev, Aider). You sign in at mcp.faxify.com, copy a long-lived JWT from Settings → MCP Configuration, and paste it into your client's MCP config as the FAXIFY_JWT_TOKEN environment variable. The @faxify/mcp-client npm package handles the stdio-to-HTTP bridge so your local AI tool can talk to the hosted MCP server over a child-process pipe.

The 17 typed tools

Each tool is typed end-to-end. Input parameters, success responses, and error shapes are declared in the MCP schema, so your AI assistant gets autocomplete-quality argument suggestions and validates inputs before calling. The draft tools matter more than they look: an AI agent that drafts a fax, previews it, and waits for the user to confirm before calling send_fax_using_draft is the difference between "useful assistant" and "loose cannon."

What happens after send_fax

Faxify accepts the request, renders the document at the page-quality tier defined by your plan (Standard / Fine / Superfine), and dispatches the transmission through SignalWire's programmable fax infrastructure. SignalWire handles the T.38 (or G.711 fallback) negotiation with the recipient's fax endpoint, retries transient failures, and reports delivery status back to Faxify. The AI client polls get_fax_status or subscribes to webhook notifications until the fax reaches a terminal state (delivered, failed, busy, etc.).

This architecture is the actual differentiator. We didn't build a fax stack from scratch. We put a well-typed MCP layer on top of a carrier-grade fax provider that's been operating at scale for years. SignalWire's HIPAA-compliant infrastructure does what carrier providers do; Faxify MCP does what AI providers don't yet do.

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The Provider Chain

⚠️ Compliance note: Faxify is software that routes faxes through HIPAA-compliant infrastructure. Faxify itself is not a HIPAA-covered entity, and this section is not legal advice. If your workflow involves PHI, please consult your compliance officer and confirm Business Associate Agreements are in place with the parties handling that data.

If you're evaluating Faxify for a regulated workflow, the relevant question is the full chain. Here's an overview of who handles what:

The layers that handle fax documents and account data are HIPAA-eligible under their respective BAAs. Product analytics via Amplitude is scoped to non-PHI events — it sees usage signals, not document contents. To discuss BAA terms or specific compliance needs, reach out at faxify@constagility.com.

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Data Deletion

• Per-fax / per-draft deletion. When a user deletes a fax or draft — from the iOS app, Android app, web app, or via MCP using delete_fax / delete_draft — the fax document is cleared from our document storage (Google Cloud Storage) and from carrier records at SignalWire. Minimal metadata required for billing, legal, tax, and audit purposes is retained per the published Privacy Policy.
• Account deletion. Users can delete their entire account directly from the Faxify iOS app, Android app, or web app (app.faxify.com) — no email or support ticket required. Email-based deletion via hello@constagility.com is available as an alternative for users who can't access the apps.
• Automatic retention limits. For free and expired-paid accounts, fax documents and transmission metadata are automatically deleted 30 days after the last activity or subscription expiry. See the Privacy Policy and Terms for canonical details.

For workflows that need shorter deletion windows or stronger retention controls than the standard 30-day cycle, reach out at faxify@constagility.com.

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Supported AI Tools

Faxify MCP works with two categories of AI client. Both reach the same server at https://mcp.faxify.com/api/v1/mcp; only the transport and the authentication mechanism differ.

Native OAuth 2.1 clients

Use this path when your AI client supports native MCP-over-OAuth (no wrapper needed):

• Claude (Desktop with web auth, claude.ai web) — OAuth-native MCP. Add the server URL, complete the OAuth flow, done.
• ChatGPT Enterprise / Business (Developer Mode) — OAuth-native MCP works on the Enterprise and Business tiers, where Developer Mode is available. Add https://mcp.faxify.com/api/v1/mcp as a custom MCP server and authorize. Free, Plus, and Team tiers don't currently have this surface — see the stdio path below for those users.

Stdio-based clients (via @faxify/mcp-client + JWT)

This is the universal fallback. It works on every AI client that supports MCP-over-stdio. You generate a JWT in your Faxify account settings, drop it into the client's config file, and the @faxify/mcp-client npm package handles the stdio-to-HTTP bridge.

• Cursor — ~/.cursor/mcp.json.
• Claude Desktop — ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%/Claude/claude_desktop_config.json (Windows).
• Continue.dev, Aider, Cline, and any other stdio-based MCP client — same pattern.

Example configuration for stdio clients:

{
  "mcpServers": {
    "Faxify": {
      "command": "npx",
      "args": ["-y", "@faxify/mcp-client"],
      "env": {
        "FAXIFY_MCP_URL": "https://mcp.faxify.com/api/v1/mcp",
        "FAXIFY_JWT_TOKEN": "YOUR_JWT_TOKEN_HERE"
      }
    }
  }
}

The wrapper is open source — the Faxify/mcp-client repository on GitHub has the full implementation, and the npm package @faxify/mcp-client is currently at version 0.2.0.

What about ChatGPT Plus / Free?

Honest answer: there's no first-class MCP path on those tiers today. Two workable alternatives:

1. Wait for a ChatGPT Apps directory listing — getting Faxify into the ChatGPT Apps directory is on our roadmap. Once it ships, Plus and Free users would get a one-click connect without needing to deal with config files. No firm timeline yet.
2. Build a Custom GPT with JWT-authenticated Actions — define a Custom GPT with an OpenAPI Action that calls our HTTP endpoints directly using your Faxify JWT as a bearer token. This works on any ChatGPT tier and is the same pattern Claude users on the desktop client use with JWT. It's not full MCP (no tool autocompletion in the conversation UI), but it covers the core send/receive/list workflows.

We'll publish a dedicated walkthrough for the Custom GPT path as a follow-up spoke.

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Five Use Cases We Built For

Five categories where fax still matters and where AI agents have a real role. We don't have a corpus of customer case studies yet — Faxify MCP is new enough that production adoption is just beginning. What follows is the workflows we built the tool to support and where we expect the strongest fit.

1. Healthcare practice operations

⚠️ Compliance disclaimer: This use case discusses fax workflows in healthcare settings. Faxify is a software service that routes faxes through SignalWire's HIPAA-compliant carrier infrastructure. Faxify is not itself a HIPAA-covered entity, and this post is not legal advice. If you transmit PHI, consult your compliance officer and ensure appropriate Business Associate Agreements are in place with all parties handling that data.

A clinic's intake coordinator pastes an insurance pre-authorization request into Claude, asks it to extract the relevant fields and draft a formatted fax to the insurer's pre-auth line, then confirms and sends — all without leaving the conversation. The draft → preview → send pattern (using create_draft, get_draft_preview, then send_fax_using_draft) is the right shape for any PHI workflow: the AI never auto-sends; a human always reviews the preview first.

For the compliance layer: Faxify routes faxes through SignalWire's HIPAA-compliant carrier infrastructure, and SignalWire signs BAAs covering voice, messaging, fax, video, and AI workflows. If your practice handles PHI, you'll need a BAA covering your use of Faxify and should confirm the BAA chain with both Faxify and SignalWire before sending PHI in production.

2. Legal case filings and service of process

Solo practitioners and small firms still file motions, serve subpoenas, and exchange discovery materials over fax, especially in jurisdictions where the court accepts fax filings and email isn't recognized for service. With Faxify MCP, an attorney can ask their AI assistant to format a motion, generate the cover sheet with case caption and certificate of service, and dispatch to the clerk's fax line — without copying files into a separate fax app. The same get_fax_status tool that lets the AI confirm delivery also gives the firm a defensible record of when the transmission completed.

3. Real-estate disclosures and signature workflows

A closing coordinator drafts seller disclosures and FHA addenda in their CRM, asks an AI agent to package them as a fax to the cooperating broker's office, and uses the inbox tools (list_faxes, get_fax) to track incoming signed copies. For many older brokerages and title agencies, fax remains the preferred channel because of how the audit trail works — and an AI that can both send outgoing disclosures and ingest incoming signed pages turns what was a multi-day phone-tag exercise into a same-day workflow.

4. Accounting and finance: invoice and statement automation

Accounts-payable teams at clients who insist on faxed invoices (more common than you'd think in industrial supply, healthcare billing, and government contracting) can now have their accounting system pipe invoice PDFs into an AI agent that sends, polls for delivery, and writes the confirmation back into the ERP. The send_fax, get_fax_status, and list_faxes tools cover the full lifecycle.

5. Recruitment and HR: regulated-industry hiring

Background-check authorizations, drug-screen consents, and offer letters in regulated industries (defense contracting, healthcare, financial services) sometimes still require fax-based delivery to upstream verification providers. An AI agent that drafts the document, attaches the appropriate authorization form, and faxes to the verification service — then files the confirmation back to the candidate record — replaces the fax-machine-in-the-corner-of-HR workflow that nobody has time for anymore.

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Faxify MCP vs the Alternatives

If you're evaluating Faxify MCP, you're probably comparing it against either rolling your own integration on top of a carrier API, or using a programmable fax API directly without the MCP layer.

Be honest about when Faxify MCP isn't the right answer: if you're building a fax product that competes with us, Telnyx or SignalWire directly is the better starting point. If you're embedding fax into your own SaaS at high volume with custom routing logic, the same applies. Faxify MCP is for users and operators who want to use fax inside their AI tools, not for teams who want to rebuild fax from the carrier API up.

For the much larger group of users who fall into the first category — anyone whose primary job isn't fax infrastructure — building your own MCP server on top of a carrier like Telnyx is a roughly two-month engineering project to deliver something that does less than @faxify/mcp-client does today.

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Pricing and Page Limits

Faxify MCP is included in every Faxify plan, including the free tier. There is no separate MCP subscription and no surcharge for AI-initiated faxes versus app-initiated ones. MCP usage decrements the same monthly page allowance you'd use from the iOS, Android, or web apps.

• Free: 25 pages/month, no credit card required (includes ads in the apps; MCP usage has no ads).
• Basic: $4.99/month or $39.99/year — 100 pages/month, dedicated fax number on annual plans, Standard page quality.
• Standard: $7.99/month or $69.99/year — 250 pages/month, dedicated number on annual, Standard quality.
• Professional: $9.99/month or $89.99/year — 750 pages/month, Fine quality.
• Elite: $14.99/month or $129.99/year — 2,000 pages/month, Superfine quality.

The free tier is genuinely useful for evaluating Faxify MCP — 25 pages is enough to wire up your AI assistant, run a half-dozen real test sends, and decide whether the integration earns its keep before you put a card down. Current pricing on the pricing page is canonical.

For higher monthly page volumes than the published plans (more than 2,000 pages/month), unlimited usage tiers, enterprise BAA terms, or any other special requirements, contact us at faxify@constagility.com or +1 (945) 398-0695.

Faxify operates in the US and Canada.

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Getting Started in 10 Minutes

The fastest path depends on your AI client.

For Claude Desktop — Open ~/Library/Application Support/Claude/claude_desktop_config.json (or the Windows equivalent), add the JSON snippet shown earlier with your JWT token (copied from Settings → MCP Configuration at mcp.faxify.com), and restart Claude Desktop. Verify the connection by asking Claude "list the Faxify tools available" — you should see all 17.

For Cursor, Continue.dev, Aider, or Cline — Same shape, in each client's MCP config file (~/.cursor/mcp.json for Cursor, the equivalent for the others). Same JWT environment variable.

For ChatGPT Enterprise / Business — Enable Developer Mode, open the MCP servers panel, add https://mcp.faxify.com/api/v1/mcp as a new server, and complete the OAuth flow. The 17 Faxify tools appear in your tool palette once authorization is granted.

For ChatGPT Plus / Free / Team users — Native MCP isn't available on these tiers yet. Either wait for the ChatGPT Apps directory listing (in progress), or build a Custom GPT with JWT-authenticated Actions against the Faxify HTTP endpoints. A walkthrough for the Custom GPT path is shipping as a follow-up.

Once connected, try this as your first prompt: "Show me my Faxify subscription, the last 5 faxes I sent, and how many pages I have left this month." This single conversation will exercise get_subscription, list_faxes, and get_profile, and verifies your auth is working end-to-end before you send anything.

For deeper technical detail — full auth flow walkthroughs, error response formats, and per-client configuration — the documentation lives at mcp.faxify.com/en/docs.

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FAQ

What is the Faxify MCP server URL? The Faxify MCP server endpoint is https://mcp.faxify.com/api/v1/mcp. Stdio clients (Cursor, Claude Desktop) reach it through the @faxify/mcp-client npm wrapper with a JWT token. Direct HTTP clients (ChatGPT Developer Mode, custom MCP integrations) connect to the same URL using OAuth 2.1.

Does Faxify MCP cost extra, or is it included in my Faxify plan? Faxify MCP is included in every Faxify plan, including the free tier. MCP usage decrements the same monthly page allowance as the regular Faxify apps — 25 pages/month on free, 100 to 2,000 pages/month on paid plans. There is no separate MCP subscription.

Which AI assistants work with Faxify MCP? Faxify MCP works with any OAuth 2.1 compliant AI assistant — including ChatGPT (Web and Desktop), Claude (Desktop, claude.ai), Microsoft Copilot, Gemini, and Grok — plus stdio-based clients like Cursor, Continue.dev, and Aider via the @faxify/mcp-client wrapper.

Is Faxify MCP HIPAA-compliant? Faxify itself is not a HIPAA-covered entity, but Faxify routes fax transmissions through SignalWire's HIPAA-compliant carrier infrastructure. SignalWire signs BAAs and operates under HIPAA, SOC 2, and GDPR. If your workflow involves PHI, you remain responsible for your own HIPAA posture, including any required BAAs with Faxify and downstream parties — consult your compliance officer before sending PHI.

How does Faxify MCP authenticate? Two flows. Stdio clients (Cursor, Claude Desktop) use a long-lived JWT token from your Faxify account settings. HTTP clients use OAuth 2.1 with Dynamic Client Registration (RFC 7591) — the client self-registers and discovers endpoints via the well-known OAuth metadata at /.well-known/oauth-authorization-server. Authorization codes are stateless JWTs encrypted with AES-256-GCM.

Can I build a custom AI fax agent on top of Faxify MCP? Yes. Faxify MCP exposes 17 typed tools covering drafts (create, get, update, delete, list, preview), sending (send, send-using-draft, resend), inbox and status (list, get, get_status, delete), and account/plans (profile, subscription, plans, offerings). The @faxify/mcp-client npm package handles the stdio-to-HTTP bridge for non-OAuth clients.

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What's Next

Faxify MCP is the foundation we're building on for the next year of AI-fax work. The model that's emerging — a focused MCP server that connects a regulated, slow-moving communication channel into the fast-moving AI tools developers and operators already use — is more interesting than "fax for ChatGPT users." Once you have a typed interface to fax operations, you can build agents that do things the iOS app and the web app aren't designed for: high-volume document workflows, cross-system orchestration (fax + CRM + email in one agent), and likely patterns we haven't anticipated. We're betting that giving good tools to AI agents in a regulated channel produces workflows we couldn't have designed for in advance. We'll find out as the adoption builds.

The 25 free pages per month make it cheap to try. Setup is about ten minutes. And the 17 typed tools are enough to do real work, not just demos.

🌐 Explore Faxify MCP 📦 @faxify/mcp-client on npm · GitHub 📱 Download Faxify for iOS 📱 Get Faxify for Android 💻 Use Faxify on the Web 💰 See Faxify pricing

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Written by Jangul Aslam, founder of Const Agility, LLC — creators of Faxify.