Why are MCP tools not appearing in Claude?

This is usually caused by a JSON syntax error in your config file. Validate your JSON using jsonlint.com.

Why is my Smartlead API key not working?

Most issues are due to trailing spaces when copying the API key. Paste it into a plain-text editor to verify before using.

Do I need coding knowledge to set this up?

No. The setup only requires pasting your API key into a JSON file. No coding required.

How to Connect Smartlead to Claude Using MCP (Setup Guide)

Once Smartlead is connected with Claude or similar, you can ask Claude to audit your sending accounts, summarize campaign performance, or check which leads replied but are still active in sequences all without opening the Smartlead dashboard.

You can pull live data, diagnose deliverability issues, and get structured answers about your campaigns just by typing a question.

This guide covers the setup from start to finish. It takes under 5 minutes.

TL;DR

What This Guide Covers

How to connect Smartlead to Claude using MCP (Model Context Protocol). Once connected, Claude gets live access to your campaigns, sending accounts, lead lists, and deliverability data—no dashboard or coding required. Setup takes under 5 minutes with just an API key.

Prerequisites

A paid Smartlead account, Claude Desktop (Mac or Windows), Node.js (LTS version), and your Smartlead API key.

The 5 Steps

Get your API key, install the Smartlead MCP server, configure your local JSON file, connect Claude, and test using prompts like account health checks, campaign summaries, and reply gap audits.

Key Facts

116+ tools across 6 categories. The MCP server is free with any paid Smartlead plan. Requires Node.js (LTS version) to run locally.

Most Common Failure

Tools not appearing after restart is usually a JSON syntax error. Validate using jsonlint.com. API key issues are often caused by trailing spaces—verify in a plain-text editor.

Day-One Prompts to Try

Check connected email accounts, identify top-performing campaigns, and analyze reply rates to quickly validate your setup.

What You'll Need Before You Start

Before you begin, make sure you have:

A Smartlead account on any paid plan.
Claude Desktop installed on your laptop/desktop
Node.js installed. Download the LTS version from nodejs.org. This is required for the npx command that runs the MCP server. If you skip this step, you'll hit a "npx command not found" error in Step 4.
Your Smartlead API key. You'll grab this in Step 1 (it lives under Settings > Integrations > API Keys)‍
Time take: < 5 minutes

That's it. No terminal expertise or special permissions required.

Step 1: Get Your Smartlead API Key

In your Smartlead dashboard, go to Settings → Integrations → API Keys. You'll see an API key listed there, click to copy it.

If you haven't generated one before, there may be a button to create a new key. Do that, then copy it.

One thing worth noting: treat this key like a password.

It gives whoever holds it full API access to your Smartlead account. Don't paste it into a shared doc or send it over Slack.

We'll talk about where it actually goes in a moment and it's a local file only you can access.

For the full API reference and what each endpoint does, the complete docs are here: API Doc

Step 2 - Install and Configure Claude Desktop

If you don't have Claude Desktop yet, download it from [claude.ai/download](https://claude.ai/download) and install it.

It runs on Mac and Windows. The setup is straightforward, just install it like any other app.

Once it's installed, you need to find (or create) the MCP configuration file. This is a JSON file that tells Claude Desktop which MCP servers to connect to. Here's where it lives depending on your OS:

- Mac:`~/Library/Application Support/Claude/claude_desktop_config.json`

- Windows: `%APPDATA%\Claude\claude_desktop_config.json`

On Mac, you can open Finder, press `Cmd + Shift + G`, and paste the path `~/Library/Application Support/Claude/` to navigate there directly.

On Windows, press `Win + R`, type `%APPDATA%\Claude\`, and hit Enter.

If the file doesn't exist yet, that's normal, especially if you haven't connected any MCP servers before.

Create the `Claude` folder first if it doesn't exist, then create the file. You can use any text editor (TextEdit on Mac in plain text mode, Notepad on Windows, or something like VS Code if you have it).

Step 3 - Add the Smartlead MCP Server Configuration

Open `claude_desktop_config.json` in your text editor. Paste in the following configuration:

Add the following block inside your JSON file, replacing your-api-key-here with your Smartlead API key:

{
  "mcpServers": {
    "smartlead": {
      "command": "npx",
      "args": ["-y", "@smartlead/mcp-server"],
      "env": {
        "SMARTLEAD_API_KEY": "your-api-key-here"
      }
    }
  }
}

Replace your-api-key-here with the API key you copied in Step 1. The key goes inside the quotes without spaces and extra characters.

If the file already has other MCP servers configured, don't replace everything. Just add the `"smartlead"` block inside the existing `"mcpServers"` object. It'll look something like this:

The key rule: one `mcpServers` object, with each server as a named block inside it. Don't create two separate `mcpServers` sections.

Save the file when you're done.

If you already have other MCP servers configured, add Smartlead inside your existing JSON like this:

{
  "mcpServers": {
    "some-other-server": {
      "command": "...",
      "args": [...]
    },
    "smartlead": {
      "command": "npx",
      "args": ["-y", "@smartlead/mcp-server"],
      "env": {
        "SMARTLEAD_API_KEY": "your-api-key-here"
      }
    }
  }
}

Step 4 - Restart Claude Desktop

This part confuses people: you need to fully quit Claude Desktop, not just close the window. On Mac, right-click the Claude icon in the menu bar and choose Quit.

On Windows, find it in the system tray, right-click, and exit.

Then reopen it.

Once Claude Desktop is back open, look for the tools indicator, it usually appears as a hammer icon or a small tools count in the interface.

If Smartlead MCP connected successfully, you should see Smartlead's tools listed there. The number of available tools should be in the hundreds.

If you don't see anything change, jump ahead to the Troubleshooting section, the most common cause is a JSON syntax error in the config file.

Step 5 - Test the Connection With Your First Prompt

Here are three prompts to try right away. These are designed to give you an immediate, useful result rather than just confirming the connection works.

Prompt 1 - Account health check:

Try this prompt in Claude to check your account health:

> "Check all my connected email accounts and tell me if any have disconnected or have warmup issues."

This pulls live account status across your entire workspace. Good for a quick sanity check before a campaign goes out.

Prompt 2 - Campaign summary:

Use this prompt to identify your top-performing campaigns:

> "Summarize my top 5 campaigns by reply rate from the last 30 days."

This gives you a ranked view of what's working. Claude will pull campaign stats directly from Smartlead and format them into a readable summary.

Prompt 3 - Reply detection gap:

Use this prompt to identify reply gaps and missed opportunities:

> "Show me leads who replied in the last 7 days but are still active in sequences."

This is the kind of thing that normally requires you to cross-reference multiple views in the dashboard. With MCP, Claude can just go get that data directly.

What to expect: Claude will call the relevant Smartlead tools in the background, retrieve live data from your account, and respond with a structured answer. The first run may take 10 to 20 seconds depending on how much data it's pulling which is normal. It's making real API calls, not pulling from a cache.

Troubleshooting Common Setup Issues

Most setup problems come down to one of four things: a JSON syntax error, a bad API key, a missing Node.js installation, or no config file to begin with. Work through the relevant section below and you should be back on track in under two minutes.

Tools not appearing after restart

Nine times out of ten this is a JSON syntax error. Even a single missing comma or misplaced bracket will cause Claude Desktop to silently ignore the config file.

Open the config file and paste its contents into jsonlint.com. It'll highlight the exact line with the error. Fix it, save, and restart Claude Desktop.

Also double-check the file path. On Mac, the path is case-sensitive. Claude with a capital C. Make sure the file is saved as plain text, not rich text format.

Authentication error / API key rejected

Go back to Smartlead Settings > Integrations > API Keys and regenerate the key. Then update the config file with the new key.

The most common cause is a trailing space when pasting. If you copied from a browser, sometimes whitespace gets included. Paste the key into a plain-text editor first (like Notepad), verify it looks clean, then paste it into the config file.

npx command not found

This means Node.js isn't installed on your machine.

Install it from nodejs.org and download the LTS version. After installation, restart Claude Desktop and try again.

Claude Desktop doesn't have a config file

Create it manually. Navigate to the folder path for your OS (from Step 2). Create the Claude folder if it doesn't exist, then create a new text file named claude_desktop_config.json. Paste in the configuration from Step 3 and save.

Make sure the filename extension is exactly .json and not .json.txt.

On Windows, file extensions can be hidden by default. In Notepad, save as "All Files" and type the full filename including the .json extension.

What You Can Do Now (The 116+ Tools at a Glance)

Once you're connected, Smartlead MCP gives Claude access to six categories of tools covering essentially everything in your Smartlead account:

1. Campaign management - create campaigns, modify settings, pause or resume, analyze performance data

2. Lead lifecycle - add leads to campaigns, update lead statuses, pull individual lead data, manage lists and segments

3. Email account management - check connection health across all sending accounts, monitor warmup status, review sending limits and usage

4. Deliverability diagnostics - analyze bounce patterns, check domain health signals, identify accounts showing spam indicators

5. Analytics - pull reply rates, open rates, and sequence performance at the campaign or account level, get multi-period comparisons

6. Webhook automation - configure triggers based on campaign events like replies, bounces, or unsubscribes

The full list of available tools, including what each one does and what parameters it accepts, is in the [Smartlead API documentation].

Wrapping Up!

You're set up.

From here, the most useful thing is to just start asking questions.

The more specific, the better. Claude works best with Smartlead MCP when you give it a concrete task: a specific time window, a specific campaign, a specific problem to diagnose. Vague prompts get vague answers; specific prompts get structured, actionable data.

If you want to explore the full list of available tools and what each one does, the Smartlead API documentation has everything laid out.

The full help center reference is here: Smartlead MCP full documentation.

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Rajashree

Rajashree specializes in strategizing and planning B2B SaaS product marketing content. As a writer turned researcher, she has a deep-rooted affinity for writing data-driven content. With over 8 years of experience in the industry, Rajashree has documented her insights in a series of blogs covering genres such as SEO, Content Marketing, Lead Generation, and Email Marketing. Rajashree’s strategic approach and comprehensive industry knowledge make her a trusted authority in creating content that enhances brand visibility and supports business growth.

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Frequently asked questions

General Questions

What is Smartlead's cold email outreach software?

Smartlead's cold email outreach tool helps businesses scale their outreach efforts seamlessly. With unlimited mailboxes, fully automated email warmup functionality, a multi-channel infrastructure, and a user-friendly unibox, it empowers users to manage their entire revenue cycle in one place. Whether you're looking to streamline cold email campaigns with automated email warmups, personalization fields, automated mailbox rotation, easy integrations, and spintax, improve productivity, or enhance scalability with subsequences based on lead’s intentions, automated replies, and full white-label experience, our cold email tool implifies it in a single solution.

What is Smartlead, and how can it enhance my cold email campaigns?

Smartlead is a robust cold emailing software designed to transform cold emails into reliable revenue streams. Trusted by over 31,000 businesses, Smartlead excels in email deliverability, lead generation, cold email automation, and sales outreach. A unified master inbox streamlines communication management, while built-in email verification reduces bounce rates.
Additionally, Smartlead offers essential tools such as CNAME, SPF Checker, DMARC Checker, Email Verifier, Blacklist Check Tool, and Email Bounce Rate Calculator for optimizing email performance.

How does Smartlead's unlimited mailboxes feature benefit me?

Our "unlimited mailboxes" feature allows you to expand your email communications without restrictions imposed by a mailbox limit. This means you won't be constrained by artificial caps on the number of mailboxes you can connect and use. This feature makes Smartlead the best cold email software and empowers you to reach a wider audience, engage with more potential customers, and manage diverse email campaigns effectively.

How does Smartlead, as a cold emailing tool, automate the cold email process?

Smartlead’s robust cold email API and automation infrastructure streamline outbound communication by transforming the campaign creation and management processes. It seamlessly integrates data across software systems using APIs and webhooks, adjusts settings, and leverages AI for personalised content.

The cold emailing tool categorises lead intent, offers comprehensive email management with automated notifications, and integrates smoothly with CRMs like Zapier, Make, N8N, HubSpot, Salesforce, and Pipedrive. Smartlead supports scalable outreach by rapidly adding mailboxes and drip-feeding leads into active campaigns Sign Up Now!

What do you mean by "unibox to handle your entire revenue cycle"?

The "unibox" is one of the unique features of Smartlead cold email outreach tool, and it's a game-changer when it comes to managing your revenue cycle. The master inbox or the unibox consolidates all your outreach channels, responses, sales follow-ups, and conversions into one centralized, user-friendly mailbox.

With the "unibox," you gain the ability to:
1. Focus on closing deals: You can now say goodbye to the hassle of logging into multiple mailboxes to search for replies. The "unibox" streamlines your sales communication, allowing you to focus on what matters most—closing deals.
‍
2. Centralized lead management: All your leads are managed from one central location, simplifying lead tracking and response management. This ensures you take advantage of every opportunity and efficiently engage with your prospects.
‍
3. Maintain context: The "unibox" provides a 360-degree view of all your customer messages, allowing you to maintain context and deliver more personalized and effective responses.

How does Smartlead ensure my emails don't land in the spam folder?

Smartlead, the best cold email marketing tool, ensures your emails reach the intended recipients' primary inbox rather than the spam folder.
‍
Here's how it works:
1. Our "unlimited warmups" feature is designed to build and maintain a healthy sending reputation for your cold email outreach. Instead of sending a large volume of emails all at once, which can trigger spam filters, we gradually ramp up your sending volume. This gradual approach, combined with positive email interactions, helps boost your email deliverability rates.
‍
2. We deploy high-deliverability IP servers specific to each campaign.
‍
3. The ‘Warmup’ feature replicates humanized email sending patterns, spintax, and smart replies.

4. By establishing a positive sender reputation and gradually increasing the number of sent emails, Smartlead minimizes the risk of your emails being flagged as spam. This way, you can be confident that your messages will consistently land in the primary inbox, increasing the likelihood of engagement and successful communication with your recipients.

Can Smartlead help improve my email deliverability rates?

Yes, our cold emailing software is designed to significantly improve your email deliverability rates. It enhances email deliverability through AI-powered email warmups across providers, unique IP rotating for each campaign, and dynamic ESP matching.
Real-time AI learning refines strategies based on performance, optimizing deliverability without manual adjustments. Smartlead's advanced features and strategies are designed to improve email deliverability rates, making it a robust choice for enhancing cold email campaign success.

What features does Smartlead offer for cold email personalisation?

Smartlead enhances cold email personalisation through advanced AI-driven capabilities and strategic integrations. Partnered with Clay, The cold remaining software facilitates efficient lead list building, enrichment from over 50 data providers, and real-time scraping for precise targeting. Hyper-personalised cold emails crafted in Clay seamlessly integrate with Smartlead campaigns.

Moreover, Smartlead employs humanised, natural email interactions and smart replies to boost engagement and response rates. Additionally, the SmartAI Bot creates persona-specific, high-converting sales copy. Also you can create persona-specific, high-converting sales copy using SmartAI Bot. You can train the AI bot to achieve 100% categorisation accuracy, optimising engagement and conversion rates.

Can I integrate Smartlead with other tools I'm using?

Certainly, Smartlead cold email tool is designed for seamless integration with a wide range of tools and platforms. Smartlead offers integration with HubSpot, Salesforce, Pipedrive, Clay, Listkit, and more. You can leverage webhooks and APIs to integrate the tools you use. Try Now!

Is Smartlead suitable for both small businesses and large enterprises?

Smartlead accommodates both small businesses and large enterprises with flexible pricing and comprehensive features. The Basic Plan at $39/month suits small businesses and solopreneurs, offering 2000 active leads and 6000 monthly emails, alongside essential tools like unlimited email warm-up and detailed analytics.

Marketers and growing businesses benefit from the Pro Plan ($94/month), with 30000 active leads and 150000 monthly emails, plus a custom CRM and active support. Lead generation agencies and large enterprises can opt for the Custom Plan ($174/month), providing up to 12 million active lead credits and 60 million emails, with advanced CRM integration and customisation options.

What type of businesses sees the most success with Smartlead?

No, there are no limitations on the number of channels you can utilize with Smartlead. Our cold email tool offers a multi-channel infrastructure designed to be limitless, allowing you to reach potential customers through multiple avenues without constraints.
‍
This flexibility empowers you to diversify your cold email outreach efforts, connect with your audience through various communication channels, and increase your chances of conversion. Whether email, social media, SMS, or other communication methods, Smartlead's multi-channel capabilities ensure you can choose the channels that best align with your outreach strategy and business goals. This way, you can engage with your prospects effectively and maximize the impact of your email outreach.

How can Smartlead integrate with my existing CRM and other tools?

Smartlead is the cold emailing tool that facilitates seamless integration with existing CRM systems and other tools through robust webhook and API infrastructure. This setup ensures real-time data synchronisation and automated processes without manual intervention. Integration platforms like Zapier, Make, and N8N enable effortless data exchange between Smartlead and various applications, supporting tasks such as lead information syncing and campaign status updates. Additionally, it offers native integrations with major CRM platforms like HubSpot, Salesforce, and Pipedrive, enhancing overall lead management capabilities and workflow efficiency. Try Now!

Do you provide me with lead sources?

No. Smartlead distinguishes itself from other cold email outreach software by focusing on limitless scalability and seamless integration. While many similar tools restrict your outreach capabilities, Smartlead offers a different approach.

Here's what makes us uniquely the best cold email software:

1. Unlimited Mailboxes: In contrast to platforms that limit mailbox usage, Smartlead provides unlimited mailboxes. This means you can expand your outreach without any arbitrary constraints.

2. Unique IP Servers: Smartlead offers unique IP servers for every campaign it sends out.

3. Sender Reputation Protection: Smartlead protects your sender reputation by auto-moving emails from spam folders to the primary inbox. This tool uses unique identifiers to cloak all warmup emails from being recognized by automation parsers.

4. Automated Warmup: Smartlead’s warmup functionality enhances your sender reputation and improves email deliverability by maintaining humanised email sending patterns and ramping up the sending volume.

How secure is my data with Smartlead?

Ensuring the security of your data is Smartlead's utmost priority. We implement robust encryption methods and stringent security measures to guarantee the continuous protection of your information. Your data's safety is paramount to us, and we are always dedicated to upholding the highest standards of security.

How can I get started with Smartlead?

Getting started with Smartlead is straightforward! Just head over to our sign-up page and follow our easy step-by-step guide. If you ever have any questions or need assistance, our round-the-clock support team is ready to help, standing by to provide you with any assistance you may require. Sign Up Now!

How can I reach the Smartlead team?

We're here to assist you! You can easily get in touch with our dedicated support team on chat. We strive to provide a response within 24 hours to address any inquiries or concerns you may have. You can also reach out to us at support@smartlead.ai

What our customers say

Felix Frank

Founder, StackOptimise

Smartlead's combination of automation, unlimited inboxes, and easy campaign management has completely transformed how we run cold email campaigns.

Justin Chi

Founder, Cold Email Hackers

We have about 15 companies and we use Smartlead for all of them.

Sander Poolman

Founder, DutchSave Media

One of the things I love about using Smartlead is the deliverability feature. If they landed in the bounce or spam folders, we could resolve this quickly.

Brigitta Ruha

Co-Founder, Growth Today

I want to continue to use Smartlead to make operations more seamless - the plan is to bring more clients here and build more SOPs.

Daniel Greaves

Founder, FueltoFly

Smartlead listens to the agencies and customers and builds according to what people want, that has really made things easier for us.

Harris Kenny

Founder, OutboundSync

We build an infrastructure product, and OutboundSync communicates with Smartlead itself. I love the webhook and API. They're really well done and keep getting better.

Sergio Ocampo

Founder, Axoleads

With SmartDelivery, you can put all of that in the hands of the tool. It ensures your emails land in inboxes, and by running a simple test, you can see if you're hitting the mark.

Bharatt Arorah

Founder, Claygen

Deliverability is the cornerstone of cold email outreach. You could have the best email copy in the world, but if no one is seeing it, it's useless. I really love the feature where you can actually give client accesses to your clients.

Wesley Hoang

Co-Founder, Cymate

I do not want to switch to another software. Pick a solution you trust, stick with it, and keep refining your copy.

Bruno Erckmam

CMO, Avalanche Capital

Managing large volumes of emails through multiple inboxes used to be a logistical nightmare. With Smartlead, the process is seamless. We book thousands of discovery calls through cold emails. These campaigns are generating leads at a scale we never thought possible.

Eric Nowoslawski

Founder, Growth Engine X

We came for the unlimited inboxes, and we stayed for the API. 1.5M cold emails/month, 7,767+ inboxes managed.

Ari Sohn

Head of Community & Ecosystem, TxtCart

You cannot replace having 10,000 touches with potential clients. When you have that much distribution and reach, you really start to see incredible results. The simplicity of Smartlead made all the difference. It doesn't require you to be a technical wizard.

Atishay Jain

Founder, Hyperke

Smartlead has been a game-changer for us. It increased our appointment volume, improved ease of use, and offered valuable features. 80% increase in appointments/month, peak of 276 appointments in a single month.

Matteo Fois

Founder, Kinetyca

Smartlead has been our cold email backbone from day one. The platform evolves constantly, keeping pace with how deliverability and personalization need to work today. 21% overall reply rate, $175K in 4 months for multiple B2B clients.

Gabriel Martinez

Founder, Reachflow

Smartlead is centered around deliverability and constantly evolving. Their API is not like any other platform. Smartlead covers all our needs. The focus on core features like deliverability and API integration is unmatched.

Maximilian Jendrall

CEO, Halfwarm

Our approach to crafting conversational emails led to reply rates that many of my peers thought were unattainable.

Maximilien Moriceau

Co-Founder, letstrike

We've grown on zero capital, zero marketing, purely cold emailing - and that's the story we love to tell. The best approach is no approach if you can't handle domain meltdown. The second best is something like Smartlead that's built from the ground up for deliverability at scale.

Omar Abdalla

Founder, Fenixtal

Smartlead's white-labeling and automation let us punch above our weight. The 12M euros sales potential? That's what happens when you combine human creativity with Smartlead's precision.

Preeti Malik

Co-Founder, Digital Creativs

Nine out of 10. Ninety percent of our clients are on Smartlead unless they come in with an existing setup. That's the default.

Ethan Chamish

Co-Founder, BuildingReach

At the end of the day, you have to take a bet on one tool or another. It was a no-brainer taking that bet on Smartlead. We had to even turn down the volume of our marketing campaigns - Smartlead was capable of driving more volume than our sales team was able to fulfill.

David Sinclair Black

Founder & MD, Prospectiv

Since starting the business in January of this year, we've already generated $200K in sales exclusively from cold email. Smartlead has been central to our operations and has exceeded our expectations.

Philipp Käming

Founder, Growthlynk

There's so much stuff built on top of it. I would be dead if I had to rebuild it with another tool. I can manage hundreds of senders easily. I can send hundreds of thousands of emails.

Aamir Bajwa

Founder, Corebits

The platform's HubSpot integration, real-time Slack updates, and advanced campaign customization have been game changers for our business and our clients'.