Truelist

io.truelistPublished by truelist.ioOfficial publisherv0.1.1Updated Oct 24, 2026

Validate email addresses for deliverability and manage email validation batches with Truelist.

VerifiedStreamable HTTPWeb executableCommunication & Collaboration Business & Commerce

Server details

Identifier: io.truelist/mcp
Transport: Streamable HTTP
Runtime: Web executable
Trust: Verified
Published: Oct 15, 2026

Security note

MCP servers receive tool arguments from a conversation and may perform external actions. Review what a server can do before you enable it, and give it only the access it needs.

The registry verified that this server's namespace belongs to truelist.io, which also runs its endpoint. That identifies the publisher; it does not make the server's tools safe.

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Overview

AI-generated overview

Truelist MCP server that lets an assistant validate email addresses for deliverability, run batches, and check the Truelist account.

What you can do: Validate a single email address and get deliverability state, sub-state, domain, MX record and name suggestions. Validate up to 50 addresses in one batch. Check the connected Truelist account's name, email, plan and admin status.
When to use it: Useful when cleaning contact or signup lists, screening addresses before sending mail, or having an assistant judge whether an email is deliverable, disposable, role-based or a spam trap.
Requirements: A Truelist account and API key, supplied as the TRUELIST_API_KEY environment variable. Runs as a local process via npx or npm (Node.js), or as a remote endpoint at api.truelist.io with OAuth. Network access to the Truelist API.

Before you install

Requires the TRUELIST_API_KEY secret; keep it out of shared configs. Email addresses are sent to Truelist's third-party API for validation. Validation consumes plan credits, and the API enforces rate limits, so large batches may be throttled.

Installation

In SourceWeft

Open Truelist in the dashboard and add it to a workspace.
Connect the required credentials. They are stored privately and never shown on public pages.
Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.truelist%2Fmcp/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config. The client completes OAuth sign-in on first connect.

{
  "mcpServers": {
    "truelist": {
      "type": "http",
      "url": "https://api.truelist.io/mcp"
    }
  }
}

README

truelist-mcp

[Free tier] MCP (Model Context Protocol) server for Truelist email validation. Lets AI assistants like Claude, Cursor, and VS Code Copilot validate email addresses for deliverability.

What is this?

This package exposes Truelist's email validation API as MCP tools. Once configured, your AI assistant can:

Check if an email address is valid and deliverable
Validate batches of emails at once
Check your Truelist account info and plan

Start free — 100 validations + 10 enhanced credits, no credit card required. Get your API key → Works with the free plan.

Installation

Or run directly with npx:

Configuration

You need a Truelist API key. Get one at truelist.io.

Claude Desktop

Add to your claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

json

{  "mcpServers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

{  "mcpServers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

Claude Code

Add to your .claude/settings.json or run:

Then set the environment variable:

Cursor

Add to your Cursor MCP settings (.cursor/mcp.json in your project or global settings):

json

{  "mcpServers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

{  "mcpServers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

VS Code (GitHub Copilot)

Add to your VS Code settings (.vscode/mcp.json in your project):

json

{  "servers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

{  "servers": {    "truelist": {      "command": "npx",      "args": ["truelist-mcp"],      "env": {        "TRUELIST_API_KEY": "your-api-key"      }    }  }}

Tools

validate_email

Validate a single email address for deliverability.

Input:

Output:

json

{  "email": "[email protected]",  "state": "ok",  "sub_state": "email_ok",  "suggestion": null,  "domain": "example.com",  "canonical": "[email protected]",  "mx_record": "mx.example.com",  "first_name": "Jane",  "last_name": "Doe",  "verified_at": "2026-02-21T12:00:00Z",  "is_valid": true,  "is_deliverable": true}

{  "email": "[email protected]",  "state": "ok",  "sub_state": "email_ok",  "suggestion": null,  "domain": "example.com",  "canonical": "[email protected]",  "mx_record": "mx.example.com",  "first_name": "Jane",  "last_name": "Doe",  "verified_at": "2026-02-21T12:00:00Z",  "is_valid": true,  "is_deliverable": true}

States:

State	Meaning
`ok`	Email is deliverable
`email_invalid`	Email is not deliverable
`risky`	Email may be deliverable but has risk factors
`accept_all`	Domain accepts all addresses; deliverability uncertain
`unknown`	Could not determine deliverability

Sub-states:

Sub-state	Meaning
`email_ok`	No issues found
`accept_all`	Domain accepts all addresses
`is_disposable`	Temporary/disposable email
`is_role`	Role-based address (info@, support@, etc.)
`failed_mx_check`	Domain has no mail server
`failed_smtp_check`	SMTP verification failed
`failed_spam_trap`	Known spam trap address
`failed_no_mailbox`	Mailbox does not exist
`failed_greylisted`	Server temporarily rejected
`failed_syntax_check`	Invalid email syntax
`unknown`	Could not determine sub-state

validate_emails

Validate multiple email addresses in a single batch (max 50).

Input:

Output:

json

[  {    "email": "[email protected]",    "state": "ok",    "sub_state": "email_ok",    "is_valid": true  },  {    "email": "[email protected]",    "state": "email_invalid",    "sub_state": "failed_mx_check",    "is_valid": false  },  {    "email": "[email protected]",    "state": "ok",    "sub_state": "email_ok",    "is_valid": true  }]

[  {    "email": "[email protected]",    "state": "ok",    "sub_state": "email_ok",    "is_valid": true  },  {    "email": "[email protected]",    "state": "email_invalid",    "sub_state": "failed_mx_check",    "is_valid": false  },  {    "email": "[email protected]",    "state": "ok",    "sub_state": "email_ok",    "is_valid": true  }]

check_account

Check your Truelist account info including name, email, plan, and admin status.

Input: none

Output:

json

{  "email": "[email protected]",  "name": "Your Name",  "uuid": "a3828d19-...",  "timeZone": "America/New_York",  "isAdminRole": true,  "paymentPlan": "pro"}

{  "email": "[email protected]",  "name": "Your Name",  "uuid": "a3828d19-...",  "timeZone": "America/New_York",  "isAdminRole": true,  "paymentPlan": "pro"}

Environment Variables

Troubleshooting

"TRUELIST_API_KEY environment variable is required"

The server requires a TRUELIST_API_KEY environment variable. Make sure it's set in your MCP configuration's env block or exported in your shell.

Tool not showing up in Claude/Cursor

Restart your AI assistant after changing the MCP configuration
Check that npx truelist-mcp runs without errors when TRUELIST_API_KEY is set
Verify the config file path is correct for your platform

Authentication errors

Verify your API key is correct and active at truelist.io.

Rate limiting

Truelist enforces rate limits on the API. If you hit rate limits, the SDK will automatically retry with exponential backoff. For batch validation, emails are validated concurrently so large batches may trigger rate limits.

Getting Started

Sign up for a free Truelist account to get your API key. The free plan includes 100 validations and 10 enhanced credits — no credit card required.

License

MIT

Source: README.md at commit f536e2e

Tools

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Version history

v0.1.1LatestOct 15, 2026

Score

85% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

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