How to integrate Lemlist MCP with Codex

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Introduction

Codex is one of the most popular coding harnesses out there. And MCP makes the experience even better. With Lemlist MCP integration, you can draft, triage, summarise emails, and much more, all without leaving the terminal or the app, whichever you prefer.

Also integrate Lemlist with

Why use Composio?

Apart from a managed and hosted MCP server, you will get:

  • CodeAct: A dedicated workbench that allows GPT to write its code to handle complex tool chaining. Reduces to-and-fro with LLMs for frequent tool calling.
  • Large tool responses: Handle them to minimise context rot.
  • Dynamic just-in-time access to 20,000 tools across 870+ other Apps for cross-app workflows. It loads the tools you need, so GPTs aren't overwhelmed by tools you don't need.

How to install Lemlist MCP in Codex

Run the setup command

Run this command in your terminal to add the Composio MCP server to Codex.

Terminal

It will initiate the authentication in a browser window, authorize Codex to access your Composio account.

Composio authentication page

(Optional) Authenticate with OAuth

To authenticate manually, run the login command to open a browser window and authorize Codex to access your Composio account.

bash
codex mcp login composio

Verify the connection

Run codex mcp list to confirm Composio appears as a registered MCP server.

bash
codex mcp list

Codex App

Codex App follows the same approach as VS Code.

  1. Click ⚙️ on the bottom left → MCP Servers → + Add servers → Streamable HTTP:
  2. Fill the header and Key fields with { "x-consumer-api-key" = "ck_*******" }.
  3. The Key is the Composio API key, that you can find on connect.composio.dev
  4. Click on Authenticate and authorize Codex to your Composio account and you're all set.
Codex App MCP setup
  1. Restart and verify if it's there in .codex/config.toml
bash
[mcp_servers.composio]
url = "https://connect.composio.dev/mcp"
http_headers = { "x-consumer-api-key" = "ck_*******" }

What is the Lemlist MCP server, and what's possible with it?

The Lemlist MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Lemlist account. It provides structured and secure access to your outreach campaigns, so your agent can manage leads, automate campaign exports, monitor unsubscribe lists, and orchestrate multichannel engagement on your behalf.

  • Automated campaign management: Retrieve campaign details by ID, audit campaign sequences, and start or monitor campaign exports for streamlined reporting and analytics.
  • Lead and subscriber control: Unsubscribe leads from campaigns, delete unsubscribed emails, or export detailed lists of campaign leads to keep your outreach data fresh and compliant.
  • Outreach data exports: Initiate and track asynchronous exports of campaign statistics or download CSVs of unsubscribed contacts for deeper insights and record-keeping.
  • Webhook administration: Fetch all configured webhooks to sync Lemlist with your other tools or audit integration points for better workflow automation.
  • Schedule management: Permanently delete schedules you no longer need, ensuring your campaigns stay organized and up to date.

Supported Tools & Triggers

Tools
Delete ScheduleTool to delete a specific schedule by scheduleid.
Delete Unsubscribed EmailTool to delete an email from the unsubscribed list.
Unsubscribe Lead From CampaignTool to unsubscribe a lead from a campaign.
Get All WebhooksTool to retrieve the list of all webhooks configured for the team.
Get Campaign By IDTool to retrieve a specific campaign by campaignid.
Start Campaign ExportTool to start an asynchronous export of all campaign statistics (csv).
Get Campaign Export StatusTool to check the status of an asynchronous campaign export.
Get Campaign SequencesTool to retrieve a list of all sequences for a campaign with steps and conditions.
Export Campaign LeadsTool to export campaign leads with state filtering and choose between json or csv output.
Export UnsubscribesTool to download a csv file containing all unsubscribed email addresses.
Get Unsubscribed EmailTool to retrieve a single unsubscribed email record.
Retrieve ActivitiesTool to fetch recent campaign activities.
Retrieve Lead By EmailTool to retrieve a lead by their email address.
Retrieve UnsubscribesTool to retrieve the list of all people who are unsubscribed.
Get Team CreditsTool to retrieve credits left in the team.
Get Team InfoTool to retrieve information about your team.
Get User InfoTool to retrieve all information of the authenticated user.
Mark Lead as Not Interested in CampaignTool to mark a lead as not interested in a specific campaign.
Update CampaignTool to update settings of a campaign.
Update ScheduleTool to update an existing schedule with new parameters.
Add Unsubscribe Email/DomainTool to add an email or domain to the unsubscribed list.
Add Variables to LeadTool to add one or more variables to a lead.
Associate schedule with campaignTool to associate a schedule with a campaign.
Create CampaignTool to create a new campaign.
Create ScheduleTool to create a new schedule for the team.
Mark Lead As InterestedTool to mark a lead as interested in all campaigns.
Mark Lead As Interested In CampaignTool to mark a lead as interested in a specific campaign.
Mark Lead As Not InterestedTool to mark a lead as not interested in all campaigns.
Pause a running campaignTool to pause a running campaign.
Pause LeadTool to pause a lead in all campaigns or a specific campaign.

Conclusion

You've successfully integrated Lemlist with Codex using Composio's MCP server. Now you can interact with Lemlist directly from your terminal, VS Code, or the Codex App using natural language commands.

Key benefits of this setup:

  • Seamless integration across CLI, VS Code, and standalone app
  • Natural language commands for Lemlist operations
  • Managed authentication through Composio
  • Access to 20,000+ tools across 870+ apps for cross-app workflows
  • CodeAct workbench for complex tool chaining

Next steps:

  • Try asking Codex to perform various Lemlist operations
  • Explore cross-app workflows by connecting more toolkits
  • Build automation scripts that leverage Codex's AI capabilities

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Use Lemlist MCP with Claude Code

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OpenClaw

Use Lemlist MCP with OpenClaw

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CrewAI

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FAQ

What are the differences in Tool Router MCP and Lemlist MCP?

With a standalone Lemlist MCP server, the agents and LLMs can only access a fixed set of Lemlist tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Lemlist and many other apps based on the task at hand, all through a single MCP endpoint.

Can I use Tool Router MCP with Codex?

Yes, you can. Codex fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Lemlist tools.

Can I manage the permissions and scopes for Lemlist while using Tool Router?

Yes, absolutely. You can configure which Lemlist scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

How safe is my data with Composio Tool Router?

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Lemlist data and credentials are handled as safely as possible.

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