Fax.Plus MCP Server - Fax.Plus API

The Fax.Plus MCP Server lets AI assistants send and receive faxes, manage contacts, and track delivery through the Model Context Protocol (MCP) — an open standard for connecting AI tools to external services. Connect it once and your assistant can fax a signed contract, tell you what arrived in your inbox this morning, or confirm whether last night’s transmission went through — in plain language, without you opening the dashboard.

MCP server URL

https://mcp.fax.plus/mcp

What you can do

Capability	Description
Send faxes	Upload a document and send it to any fax number worldwide
Receive faxes	Check your inbox for incoming faxes, filter by date or sender
Track delivery	Monitor outbox status and get real-time delivery confirmations
Manage contacts	List, create, update, and organize fax contacts and groups
View numbers	See assigned fax numbers, status, and notification settings
File uploads	Upload documents for faxing (PDF, TIFF, DOC, and more)

The MCP Server covers day-to-day faxing. Account provisioning, team management, and webhook configuration are handled through the REST API — see MCP and the REST API.

Prerequisites

Before connecting, make sure you have:

An active paid Fax.Plus plan — Basic or higher. See Plan availability.
At least one fax number assigned to your account, if you want to receive faxes.

No token or credential setup is needed in advance — authentication happens through OAuth when you add the server to your client.

Authentication

The MCP Server supports two authentication methods. OAuth 2.0 is the primary flow and works on every supported plan. Personal Access Tokens are an alternative for Enterprise accounts that need a static credential.

OAuth 2.0 (recommended)

Most MCP clients connect in three steps. No token or credential setup needed.

Add the URL

In your MCP client, add https://mcp.fax.plus/mcp as a remote server.

A screen opens in your browser. Log in to your Fax.Plus account to approve access.

Connected

Your assistant is connected. You can start interacting with the MCP in the chat.

Access and permissions are bound to the account you log in with.

Redirect URI allowlist — During registration, the redirect_uri your client supplies must match an allow-listed pattern (for example https://claude.ai/api/mcp/auth_callback, https://chatgpt.com/connector/oauth/*, or http://localhost:* for local development clients). Registration attempts with a redirect URI outside this list are rejected. Contact support@alohi.com if your MCP client needs to be added to the allowlist.

Personal Access Tokens (Enterprise only)

A PAT is useful when your client has no OAuth support, or for headless and server-side integrations where an interactive login isn’t possible. PATs are available on the Enterprise plan; on other plans, use OAuth.

Open Integrations

Manage tokens

Under Fax.Plus API, find Personal Access Tokens and click Manage.

Create and configure

Create a new token and select the appropriate scopes for your use case.

Copy your token

Copy the token immediately — it won’t be shown again.

How to create a PAT →

Scopes used by the MCP Server

Scope	Access
`fax:all:read`	Read-only access to all fax operations
`fax:all:edit`	Full access to all fax operations
`fax:fax:read`	View and list faxes, outbox, files, reports
`fax:fax:edit`	Send faxes, manage outbox and files
`fax:user:read`	View the current user’s account details (PAT owner)
`fax:user:edit`	Update the current user’s account details (PAT owner)
`fax:member:read`	View corporate member details
`fax:numbers:read`	List and view assigned fax numbers
`fax:numbers:edit`	Manage and configure fax numbers

For most use cases, fax:all:read and fax:all:edit provide the access you need. Use granular scopes when you want to restrict what the integration can do.

Additional scopes exist for webhook, shop, and AI endpoints, which are available through the REST API only. See Authentication for the full list.

Connecting to an MCP client

The Fax.Plus MCP Server works with any client that supports the Model Context Protocol over remote HTTP. Find your client below.

Client	Where to add it	Auth
Claude.ai (web and mobile)	Settings → Connectors	OAuth
Claude Desktop	Settings → Connectors	OAuth
Claude Code	`claude mcp add` (see below)	OAuth
Cursor	`.cursor/mcp.json`	OAuth
ChatGPT	Settings → Plugins	OAuth
VS Code (GitHub Copilot)	`.vscode/mcp.json`	OAuth
Other MCP clients	Client’s remote MCP server settings	OAuth
Headless / server-side	Anthropic API, OpenAI Agents SDK, custom	PAT

Clients with native OAuth support need nothing but the server URL — a login screen opens, you sign in to Fax.Plus, and you’re connected. If your client isn’t listed, it will still work provided it supports remote HTTP MCP servers and its redirect URI is allow-listed; contact support@alohi.com to have one added.

Claude.ai, Claude Desktop, and ChatGPT

Open Settings → Connectors(Claude) / Plugins(ChatGPT)
Add a custom connector with URL https://mcp.fax.plus/mcp
Complete the Fax.Plus login and authorization flow

Claude Code

claude mcp add --transport http faxplus https://mcp.fax.plus/mcp

Then run /mcp inside Claude Code and choose Authenticate to complete the OAuth flow.

Cursor

{
  "mcpServers": {
    "faxplus": {
      "type": "url",
      "url": "https://mcp.fax.plus/mcp"
    }
  }
}

VS Code (GitHub Copilot)

{
  "servers": {
    "faxplus": {
      "type": "http",
      "url": "https://mcp.fax.plus/mcp"
    }
  }
}

Claude Desktop with a PAT (Enterprise only)

Claude Desktop’s claude_desktop_config.json only supports stdio MCP servers (command + args). It does not accept "type": "url" — entries without command are ignored and may be removed when Claude Desktop saves the file. Use mcp-remote as a bridge:

{
  "mcpServers": {
    "faxplus": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://mcp.fax.plus/mcp",
        "--header",
        "Authorization:${FAXPLUS_PAT}"
      ],
      "env": {
        "FAXPLUS_PAT": "Bearer YOUR_PERSONAL_ACCESS_TOKEN"
      }
    }
  }
}

mcp-remote runs locally as a stdio process Claude Desktop can talk to, and forwards requests over HTTP to https://mcp.fax.plus/mcp. Passing the token via env keeps it out of the args array.

For most Claude Desktop users, Settings → Connectors is the simpler path and needs no config file or PAT.

Cursor and Claude Code with a PAT (Enterprise only)

{
  "mcpServers": {
    "faxplus": {
      "type": "url",
      "url": "https://mcp.fax.plus/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_PERSONAL_ACCESS_TOKEN"
      }
    }
  }
}

Anthropic API (MCP Connector)

Requires an Enterprise plan, since this path authenticates with a PAT.

import anthropic

client = anthropic.Anthropic()

response = client.beta.messages.create(
    model="claude-sonnet-4-6",
    max_tokens=1024,
    betas=["mcp-client-2025-11-20"],
    mcp_servers=[
        {
            "type": "url",
            "url": "https://mcp.fax.plus/mcp",
            "name": "faxplus",
            "authorization_token": "YOUR_PERSONAL_ACCESS_TOKEN",
        }
    ],
    messages=[
        {"role": "user", "content": "Check my fax inbox for anything received today"}
    ],
)

OpenAI Agents SDK

Requires an Enterprise plan, since this path authenticates with a PAT.

from openai_agents import Agent, MCPServerSse

faxplus_server = MCPServerSse(
    url="https://mcp.fax.plus/mcp",
    headers={"Authorization": "Bearer YOUR_PERSONAL_ACCESS_TOKEN"},
)

agent = Agent(
    name="Fax Assistant",
    instructions="Help the user send and receive faxes.",
    mcp_servers=[faxplus_server],
)

Available tools

The Fax.Plus MCP Server exposes 38 tools to connected AI assistants. Which tools are usable depends on your plan and, for PAT connections, the scopes on your token.

Accounts

Tool	Description
`get-token-info`	Get current token metadata/scopes
`get-user`	Get account information
`get-plan`	Get plan type and admin/owner flags
`list-members`	List corporate members
`get-member-details`	Get corporate member role and quota

Numbers

Tool	Description
`list-numbers`	List assigned/purchased fax numbers
`get-number`	Get details for one fax number
`update-number`	Update number assignment

Faxes

Tool	Description
`list-faxes`	List fax records
`get-fax`	Get a specific fax record
`update-fax`	Update fax metadata (`is_read` / `comment`)
`bulk-update-faxes`	Bulk update fax metadata
`delete-fax`	Delete a single fax record (destructive)

Files

Tool	Description
`request-file-from-user`	Ask the user to attach a document to send
`pipeline_start`	Begin a send pipeline and return a `pipeline_id`
`upload-file`	Upload a document for sending
`get-file`	Download fax file (`pdf`/`tiff`)
`get-file-page`	Download single fax page
`get-fax-report`	Get fax confirmation report
`get-fax-thumbnail`	Get fax thumbnail image

Sending a document from chat — When you ask an assistant to send a file, the flow is pipeline_start → request-file-from-user → send-fax-uploaded. The assistant prompts you to attach the document, and the file is uploaded directly to Fax.Plus rather than passing through the model. You don’t call these tools yourself; your client handles the sequence.

Outbox

Tool	Description
`list-outbox-faxes`	List outgoing/queued faxes
`get-outbox-fax`	Get one outgoing fax
`send-fax-uploaded`	Send fax using uploaded file paths
`resend-fax`	Resend using an existing fax as source
`update-outbox-fax`	Update queued outbox fax
`bulk-update-outbox-faxes`	Bulk update queued outbox faxes
`delete-outbox-fax`	Delete queued outbox fax (destructive)

Contacts

Tool	Description
`list-contacts`	List contacts
`create-contact`	Create contact
`update-contact`	Update contact
`delete-contact`	Delete contact (destructive)
`list-contact-groups`	List contact groups
`create-contact-group`	Create contact group
`update-contact-group`	Update contact group
`delete-contact-group`	Delete contact group (destructive)
`set-contact-groups`	Assign contacts to groups
`share-contacts`	Share contacts with corporate members
`share-contact-groups`	Share contact groups with corporate members

MCP and the REST API

The MCP Server and the REST API serve different jobs. Use MCP to work with Fax.Plus from an assistant: reading faxes, sending documents, organizing contacts, checking delivery. It’s interactive, authorized in a browser, and revocable at any time. Use the REST API to build Fax.Plus into your own product. It’s headless, authenticated with a PAT, and covers the full surface. The following are available through the REST API only, and are deliberately not exposed as MCP tools:

Capability	REST API
Buying fax numbers	Shop endpoints — browse countries, areas, and available numbers
Releasing fax numbers	Revoke a number from an account
Account balance	Retrieve credit balance
Team management	Invite members, change roles and quotas, resend invitations
Account settings	Update the account owner’s own profile and settings
Webhooks	`/v3/webhooks` — create, list, update, delete
Bulk deletion	Bulk-delete fax and outbox records

These operations spend money, change who has access to an account, or destroy records that often serve as proof of transmission. They belong in code you control, with your own review and approval steps, rather than in a conversational session.

Webhook endpoints are signed with HMAC-SHA256, and the signing secret is only available from Settings → Integrations in the dashboard — the REST API never returns it. Set webhooks up there or via /v3/webhooks, then verify signatures as described in the webhook guide.

Usage examples

Once connected, you can interact with Fax.Plus through natural language. Here are some common workflows.

Send a fax

You: Send the attached contract to +1-212-555-0199

Assistant: I’ve uploaded your contract and sent it to +1-212-555-0199. The fax was delivered successfully — 3 pages, transmitted in 12 seconds. The fax ID is abc123def.

Check your inbox

You: Did I receive any faxes today?

Assistant: You received 2 faxes today: 1. From +1-415-548-5563 at 9:38 AM — 23 pages, status: success 2. From +1-312-555-0142 at 2:15 PM — 1 page, status: success

Track delivery

You: Did my fax to the courthouse go through?

Assistant: Yes — your fax to +1-218-413-7255 was delivered successfully at 12:14 PM today. 2 pages, 2 seconds transmission time.

Manage contacts

You: Show me all my fax contacts in the Office group

Assistant: You have 1 contact in the “Office_ch” group: Alohi Fax Machine near Scott, fax number +41 22 794 3479.

List fax numbers

You: What fax numbers do I have?

Assistant: You have one active fax number: +1-419-548-5563, acquired October 8, 2024, with email and push notifications enabled.

API reference

The MCP Server is built on the Fax.Plus REST API v3. For detailed endpoint documentation, schemas, and error codes:

API Documentation

Full endpoint reference with request/response examples

Quickstart Guide

Get up and running with the Fax.Plus API in minutes

Authentication

OAuth 2.0 and PAT setup guides

Help Center

FAQs, troubleshooting, and how-to articles

SDKs

Language	Package
Node.js	`@alohi/faxplus-api`
Python	`faxplus-api`

Plan availability

The MCP Server is available on all paid plans. View pricing

Plan	MCP Server	Notes
Free	✗	Upgrade to Basic or higher
Basic	✓	OAuth 2.0 only
Premium	✓	OAuth 2.0 only
Business	✓	OAuth 2.0 only
Enterprise	✓	OAuth 2.0 or Personal Access Token
Any plan with Advanced Security Controls	✗	Blocked, including HIPAA- and PHIPA-configured accounts

Personal Access Tokens are an Enterprise feature. On Basic, Premium, and Business plans, connect with an OAuth-capable MCP client.

Security and compliance

Fax.Plus is built with enterprise-grade security and meets strict regulatory requirements:

Encryption: AES-256 at rest, TLS 1.3+ in transit
Certifications: ISO 27001, SOC 2 Type 2, HIPAA (with BAA), PCI DSS
Compliance: GDPR, CCPA, eIDAS
Access control: SSO, 2FA, role-based permissions, fine-grained PAT scopes
Data residency: Flexible options across multiple regions
Audit trails: Complete logging of all fax activity

MCP and regulated workloads — The MCP Server is not available on accounts with Advanced Security Controls enabled, which covers HIPAA and PHIPA configurations. Advanced Security Controls restrict which external systems can access account data, and MCP clients are third-party applications operating outside that boundary. For compliant programmatic faxing, integrate against the REST API instead. See Fax.Plus HIPAA.

Limitations

Free plan not supported — The MCP Server requires a paid plan (Basic or higher).
Advanced Security Controls block MCP — Accounts configured for HIPAA or PHIPA compliance cannot connect.
PATs require Enterprise — On Basic, Premium, and Business plans, OAuth is the only authentication method, so clients without OAuth support cannot connect.
Provisioning, team management, and webhooks are API-only — See MCP and the REST API.
No account creation — New user accounts must be created through the Fax.Plus web dashboard.
No public sandbox — Contact support@alohi.com to request a test environment.
File size limits — Uploaded files are subject to size limits. Large documents should be split before uploading.
Rate limits — Requests are rate-limited. See the API documentation for current thresholds.
Fax delivery — Transmission success depends on the recipient’s fax machine availability and line quality. Automatic retries can be configured when sending.

Troubleshooting

Connection rejected on a HIPAA or PHIPA account

This is expected. Advanced Security Controls block third-party MCP clients from accessing the account. Use the REST API directly for programmatic access on these accounts, or contact support@alohi.com to discuss options.

Connection rejected on the Free plan

The MCP Server requires a paid plan. Upgrade to Basic or higher from your account and reconnect.

My assistant can’t buy a number, add a teammate, or set up a webhook

These operations aren’t exposed as MCP tools by design. Use the REST API, or the Fax.Plus dashboard for number purchases, team management, and webhook configuration. See MCP and the REST API.

”Invalid token” or 401 Unauthorized

If you connected via OAuth, your session may have expired or been revoked — remove the connector from your client and authorize again. If you connected with a PAT, the token may have expired or lack the required scopes. Generate a new token from Settings → Integrations → Personal Access Tokens in your Fax.Plus dashboard. Ensure it includes at least fax:all:read for read operations and fax:all:edit for sending faxes.

Personal Access Tokens option is missing from Settings

PATs are available on the Enterprise plan only. On Basic, Premium, and Business, connect via OAuth using an OAuth-capable MCP client.

Fax stuck in outbox or delivery failed

Check that the recipient’s fax number is in E.164 format (e.g., +12125550199). Verify the number is a working fax line. You can configure automatic retries with the retry parameter when sending.

403 Forbidden on member endpoints

Only corporate admin accounts can read member details. Verify your account has the corporate_admin role.

”invalid_redirect_uri” during OAuth setup

Dynamic Client Registration rejects any redirect_uri that isn’t on the server’s allowlist. This is expected for MCP clients that haven’t been vetted yet — contact support@alohi.com to request that your client be added.

Claude Desktop ignores my MCP server or removes it from the config

You likely used "type": "url" in claude_desktop_config.json. Claude Desktop only supports stdio servers there. Add the server via Settings → Connectors instead, or use the mcp-remote configuration if you’re on Enterprise with a PAT.

Getting help

Help Center: help.alohi.com
API Support: support@alohi.com
Enterprise Sales: alohi.com/contact-sales

​MCP server URL

​What you can do

​Prerequisites

​Authentication

​OAuth 2.0 (recommended)

​Personal Access Tokens (Enterprise only)

​Scopes used by the MCP Server

​Connecting to an MCP client

​Claude.ai, Claude Desktop, and ChatGPT

​Claude Code

​Cursor

​VS Code (GitHub Copilot)

​Claude Desktop with a PAT (Enterprise only)

​Cursor and Claude Code with a PAT (Enterprise only)

​Anthropic API (MCP Connector)

​OpenAI Agents SDK

​Available tools

​Accounts

​Numbers

​Faxes

​Files

​Outbox

​Contacts

​MCP and the REST API

​Usage examples

​Send a fax

​Check your inbox

​Track delivery

​Manage contacts

​List fax numbers

​API reference

API Documentation

Quickstart Guide

Authentication

Help Center

​SDKs

​Plan availability

​Security and compliance

​Limitations

​Troubleshooting

​Connection rejected on a HIPAA or PHIPA account

​Connection rejected on the Free plan

​My assistant can’t buy a number, add a teammate, or set up a webhook

​”Invalid token” or 401 Unauthorized

​Personal Access Tokens option is missing from Settings

​Fax stuck in outbox or delivery failed

​403 Forbidden on member endpoints

​”invalid_redirect_uri” during OAuth setup

​Claude Desktop ignores my MCP server or removes it from the config

​Getting help

MCP server URL

What you can do

Prerequisites

Authentication

OAuth 2.0 (recommended)

Personal Access Tokens (Enterprise only)

Scopes used by the MCP Server

Connecting to an MCP client

Claude.ai, Claude Desktop, and ChatGPT

Claude Code

Cursor

VS Code (GitHub Copilot)

Claude Desktop with a PAT (Enterprise only)

Cursor and Claude Code with a PAT (Enterprise only)

Anthropic API (MCP Connector)

OpenAI Agents SDK

Available tools

Accounts

Numbers

Faxes

Files

Outbox

Contacts

MCP and the REST API

Usage examples

Send a fax

Check your inbox

Track delivery

Manage contacts

List fax numbers

API reference

SDKs

Plan availability

Security and compliance

Limitations

Troubleshooting

Connection rejected on a HIPAA or PHIPA account

Connection rejected on the Free plan

My assistant can’t buy a number, add a teammate, or set up a webhook

”Invalid token” or 401 Unauthorized

Personal Access Tokens option is missing from Settings

Fax stuck in outbox or delivery failed

403 Forbidden on member endpoints

”invalid_redirect_uri” during OAuth setup

Claude Desktop ignores my MCP server or removes it from the config

Getting help