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Lettr MCP connector

Connect Lettr to Elaichi and Claude, ChatGPT, Cursor, Microsoft Copilot and the Elaichi Agent can look up audience contacts, build lists, manage topics and update contact properties, with every call running as the person who signed in.

  • Connects with an API key
  • Free 14-day trial
  • No credit card
Claude Elaichi connected

Add these emails to the newsletter list as new contacts

Working in Lettr with Elaichi

  • List all Lettr audience contacts
  • Get single Lettr audience contact by ID
  • List all Lettr audience lists
Ask anything…
Governance / Audit log Last 24 hours
Lettr List all Lettr audience lists Emily Carter · Claude · 9:41 AM Done
Lettr Get single Lettr audience contact by ID Emily Carter · Claude · 9:41 AM Done
Lettr List all Lettr audience contacts Emily Carter · Claude · 9:41 AM Done
Lettr Lettr audience contact lists bulk create Megan Brooks · ChatGPT · 9:38 AM Done
Lettr Create a Lettr audience contact list Ryan Hayes · Cursor · 9:35 AM Done

How to connect Lettr to Claude, ChatGPT, Cursor or Microsoft Copilot

Step by step, for each AI app

Lettr MCP connector for Claude

  1. 1

    Open Customize, then Connectors.

  2. 2

    Press Add.

  3. 3

    Name it, paste the MCP server URL, then Continue.

    https://api.elaichi.ai/mcp
  4. 4

    Sign in and approve.

On Team and Enterprise, an Owner adds it once. Everyone else turns it on for themselves.

Lettr MCP connector for Claude Code

  1. 1

    In a terminal, run claude mcp add with the endpoint.

    https://api.elaichi.ai/mcp
  2. 2

    Start Claude Code and run /mcp.

  3. 3

    Pick elaichi, then sign in and approve in the browser.

Terminal

$ claude mcp add --transport http elaichi --scope user https://api.elaichi.ai/mcp

Use --scope project instead to share it with the repository through .mcp.json.

Lettr MCP connector for ChatGPT

  1. 1

    Open Plugins, then press the + button.

  2. 2

    Name it and paste the endpoint into Server URL.

    https://api.elaichi.ai/mcp
  3. 3

    Leave Authentication on OAuth, then tick the risk acknowledgement.

  4. 4

    Press Create, then sign in and approve.

Works on the web. The plugin directory lives at chatgpt.com/plugins.

Lettr MCP connector for Cursor

  1. 1

    Open ~/.cursor/mcp.json.

  2. 2

    Add the endpoint under mcpServers.

    https://api.elaichi.ai/mcp
  3. 3

    Reload Cursor, then sign in and approve.

~/.cursor/mcp.json

{
  "mcpServers": {
    "elaichi": {
      "url": "https://api.elaichi.ai/mcp"
    }
  }
}

Set up per machine, so repeat it on each computer you work from.

Lettr MCP connector for Microsoft Copilot

  1. 1

    In Copilot Studio, open your agent, then Tools, Add a tool, New tool and Model Context Protocol.

  2. 2

    Paste the endpoint into Server URL, choose OAuth 2.0, then Dynamic discovery, and press Create.

    https://api.elaichi.ai/mcp
  3. 3

    Create a new connection, sign in and approve, then press Add to agent.

  4. 4

    Under Channels, open Teams and Microsoft Copilot and make the agent available in Microsoft Copilot.

Server URL
https://api.elaichi.ai/mcp
Authentication
OAuth 2.0
Type
Dynamic discovery

Microsoft Copilot was called Microsoft 365 Copilot. Keep the tool on end-user credentials, so each person signs in as themselves.

Connect Lettr to any MCP client

  1. 1

    Add the endpoint as a remote MCP server.

    https://api.elaichi.ai/mcp
  2. 2

    Sign in and approve.

{
  "mcpServers": {
    "elaichi": {
      "url": "https://api.elaichi.ai/mcp"
    }
  }
}

The Elaichi Agent already has these tools, with nothing to set up.

What teams do with Lettr through Elaichi

Ask in plain English. Each person’s AI can do only what they’re allowed to, and every action it takes in Lettr is logged.

  • Marketing

    Add new sign-ups to the right list

    After a webinar, paste the attendee emails and have them created as Lettr contacts and added to the follow-up list in one go.

  • Sales

    Keep a prospect's details current

    After a call, update the contact's company, role and custom properties in Lettr so the next send goes out with accurate details.

  • Support

    Check what someone is subscribed to

    Look up a contact in Lettr to see which lists and topics they are on before answering a question about unwanted email.

  • Operations

    Clean up stale lists and topics

    Find lists nobody sends to anymore and remove them, or bulk remove contacts from a list that has run its course.

  • Events

    Build a list for a single event

    Create a new Lettr list, add the registrants in bulk, and subscribe them to an event updates topic.

  • Product

    Add a property to segment on

    Create a custom audience property such as plan tier, then fill it in on existing Lettr contacts so campaigns can target the right people.

Try asking

  • “Add these emails to the newsletter list as new contacts”
  • “Which topics is [email protected] subscribed to?”
  • “Create a plan tier property and fill it for these contacts”

See all 71 Lettr tools →

What connecting Lettr gets you

6 screens from Elaichi, each doing one job for your Lettr account.

Elaichi Agent

Ask Elaichi to work across your apps.

Add these emails to the newsletter list as new contacts

Which topics is [email protected] subscribed to?

Create a plan tier property and fill it for these contacts

Also runs in Claude, ChatGPT, Cursor or Microsoft Copilot

The agent

Ask about your Lettr audience in plain words.

Look up contacts, lists and topics from live Lettr records, no dashboard digging.

ElaichiAI apps
Claude ChatGPT Cursor Microsoft Copilot

Copy the endpoint

https://api.elaichi.ai/mcp
Client Connected by Status Last used
Claude
E

Emily Carter

• Connected 4 minutes ago
Cursor
M

Megan Brooks

• Connected 2 hours ago
ChatGPT
R

Ryan Hayes

• Connected Yesterday

AI apps

One endpoint puts Lettr in every client.

Claude, ChatGPT and Cursor share one governed endpoint, no SDK and no shared API key.

ElaichiTools
Tool Action Description
Lettr audience contact lists bulk create Create Bulk attach contacts to lists (POST /api/audience/contacts/lists/bulk). Attach every combination of `contact_ids × list_ids` (up to 1000 contacts × 50 lists). Existing pairs are reported in `already_attached`. Requires the `audience:write` scope and is blocked for sandbox API keys. Required: contact_ids, list_ids.
Lettr audience contact lists bulk delete Delete Bulk detach contacts from lists (DELETE /api/audience/contacts/lists/bulk). Detach every combination of `contact_ids × list_ids` (up to 1000 contacts × 50 lists). Pairs that were not attached are reported in `not_present`. Requires the `audience:write` scope and is blocked for sandbox API keys. Required: contact_ids, list_ids.
Create a Lettr audience contact list Create Attach contact to list (POST /api/audience/contacts/{contactId}/lists/{listId}). Add a contact to a list. Returns `201` if the contact was newly attached, or `200` if the contact was already in the list. Requires the `audience:write` scope and is blocked for sandbox API keys. Required: contact_id, list_id.
Delete a Lettr audience contact list by ID Delete Detach contact from list (DELETE /api/audience/contacts/{contactId}/lists/{listId}). Remove a contact from a list. Idempotent — returns `204` whether the pair existed or not. Requires the `audience:write` scope and is blocked for sandbox API keys. Lettr answers 204 with no body. Required: id, contact_id.
Lettr audience contact topics bulk create Create Bulk subscribe contacts to topics (POST /api/audience/contacts/topics/bulk). Subscribe every combination of `contact_ids × topic_ids` (up to 1000 contacts × 50 topics). Pairs that already exist are reported in `already_subscribed`. Requires the `audience:write` scope and is blocked for sandbox API keys. Required: contact_ids, topic_ids.

Tool catalog

All 71 Lettr tools, no code to write.

Contacts, lists, topics and properties are covered out of the box, bulk actions included.

ElaichiToolboxes
Name Source template Tools Created

Marketing toolbox

Lettr · lists and topics

Lettr starter 18 Mar 4, 2026

Sales toolbox

Lettr · prospect contacts and properties

— 9 Mar 2, 2026

Support toolbox

Lettr · contact lookups

— 24 Feb 27, 2026

Operations toolbox

Lettr · list cleanup

Lettr starter 6 Feb 19, 2026

Events toolbox

Lettr · event lists and attendees

— 31 Jan 30, 2026

Product toolbox

Lettr · audience properties

— 12 Jan 22, 2026

Toolboxes

Every team gets its own Lettr toolbox.

Marketing manages lists, support looks up contacts, each team scoped to what it needs.

ElaichiConnections
Connection Scope Status Access
LE

Lettr (Marketing)

Connected by Emily Carter

Personal • Active 1 team · 6 members
LE

Lettr (Sales EMEA)

Connected by Jake Morgan

Organization • Active 3 teams · 24 members
LE

Lettr (Support)

Connected by Megan Brooks

Organization • Active 2 teams · 11 members
LE

Lettr (Events)

Connected by Tyler Reed

Personal • Needs re-auth 1 team · 3 members
LE

Lettr (Product)

Connected by Ryan Hayes

Personal • Active Not shared
LE

Lettr (Newsletter)

Connected by Ashley Parker

Personal • Active 2 teams · 9 members

Shared connections

Share a Lettr connection, never the key.

Teammates work through one connected Lettr account without ever seeing the API key.

ElaichiAudit log
When Who What happened Type

2 minutes ago

Mar 6, 2026, 3:10 PM

E

Emily Carter

[email protected]

Restriction Created Access

8 minutes ago

Mar 6, 2026, 3:04 PM

J

Jake Morgan

[email protected]

Restriction Updated Access

14 minutes ago

Mar 6, 2026, 2:58 PM

M

Megan Brooks

[email protected]

Role Assigned Access

20 minutes ago

Mar 6, 2026, 2:52 PM

T

Tyler Reed

[email protected]

Lettr Users Updated MCP

26 minutes ago

Mar 6, 2026, 2:46 PM

R

Ryan Hayes

[email protected]

Lettr Contacts Created MCP

32 minutes ago

Mar 6, 2026, 2:40 PM

A

Ashley Parker

[email protected]

Lettr Contacts List Toolbox

Audit log

Know who changed which Lettr contact.

Every create, update and delete is logged with who, when, and which record.

From answering questions to doing the work

A trigger starts the work, inside the same permissions and the same audit log as everything else. Workflows, collections and live dashboards come with the Black plan.

Lettr digest

Run 418 · started 2 minutes ago · on behalf of Emily Carter

  1. ✓

    Schedule

    Every weekday at 8:00 AM

    0.2s
  2. ✓

    Fetch contacts

    Lettr

    1.4s
  3. ✓

    Group by owner

    Transform

    0.1s
  4. ✓

    Draft the digest

    Agent step

    Ran with 4 tools, returned a structured summary

    6.2s
  5. Approve the digest

    Needs approval

    Assigned to Jake Morgan

    Approve
  6. Post the digest

    Lettr

    Queued

Workflows

A schedule starts Lettr work, people approve it.

New Lettr contacts are fetched, grouped, drafted into a digest, approved, then posted back.

Lettr health

Refreshed 4 minutes ago · every 15 minutes · from the contacts collection

Live

Contacts

1,284 ↓ 12%

Lists

96 ↓ 8%

Needs attention

3 ↑ 2

Updated this week

412 ↑ 9%

Contacts created

Last 14 days

By team

Share of activity

Marketing 34%

Sales EMEA 27%

Support 21%

Events 18%

Collections and dashboards

Lettr audience health, computed without a model.

Contacts created over 14 days, broken down by team, refreshed on a schedule.

For IT and engineering

Elaichi vs Zapier MCP vs Composio for Lettr

All three can connect Lettr to an AI assistant, and all three have admin controls. They differ in where access lives and how you pay.

Elaichi compared with Zapier MCP and Composio for Lettr, by what to check
What to check Elaichi Zapier MCP Composio
Where the AI connects One address for the whole organization. https://api.elaichi.ai/mcp A server per member, created at sign-in. An MCP endpoint per team, or an SDK.
Control over Lettr tools Allow or restrict single Lettr tools, per role or user. App and action restrictions on the account. Role permissions, down to the action.
Record of calls One audit entry per Lettr call. A History tab of tool calls. A log of every tool call.
Single sign-on SAML or OIDC, plus SCIM, on Gold. SAML on Enterprise. SAML and OIDC on Enterprise.
Price Free for one person; $15 per user per month on Gold. 2 tasks per successful call. Billed per tool call.

Sources: Zapier MCP docs, security, usage; Composio docs, gateway, enterprise, pricing. Checked September 2026.

Longer take: Zapier MCP alternative and when you don't need an MCP gateway.

Lettr tools for your AI agents

71 tools are ready to call through Elaichi's MCP endpoint the moment you connect Lettr, governed by the same roles, restrictions, and audit log as everything else in Elaichi.

Questions, answered

How do I connect Lettr to Claude?

Connect Lettr in Elaichi by pasting a Lettr API key, which is the only sign-in step Lettr needs; there is no OAuth application to register and no client ID or secret to generate. Then in Claude open Customize, then Connectors, then Add, and paste https://api.elaichi.ai/mcp. Sign in with your Elaichi account and Lettr is ready to use in Claude.

Does Lettr work with ChatGPT and Cursor as well as Claude?

Yes. Once Lettr is connected in Elaichi, the same endpoint, https://api.elaichi.ai/mcp, works in Claude, ChatGPT, Cursor, Microsoft Copilot, any other MCP client, and the Elaichi Agent. You connect Lettr once and every client sees it.

What can an AI agent actually do with my Lettr audience?

It can look up any Lettr audience contact, create new contacts one at a time or in bulk, update their details and custom properties, and remove them. It can create and rename lists and topics, add contacts to lists in bulk, and subscribe contacts to topics. Short asks like "add these ten emails to the newsletter list" work better than long paragraphs.

Does connecting Lettr give the AI my whole audience?

No more than the person who signed in already has. Every call to Lettr runs with that person's own access, so an agent sees the contacts, lists, topics and properties they could already see in Lettr. Elaichi can narrow that further with restrictions, and it never widens it.

Can my team share one Lettr connection?

Yes. One person connects Lettr with an API key and shares the connection with a team in Elaichi, so nobody else ever handles the key. Each teammate still signs in to Elaichi as themselves, so the audit log names who created, updated or deleted each Lettr contact or list.

Can I stop an agent from deleting or changing things in Lettr?

Yes. Restrictions in Elaichi work per action, so you can allow looking up and updating Lettr contacts while restricting deleting contacts, lists or topics, for a role or for one person. A restricted action still shows up in Elaichi's tool search, flagged as restricted, but no client can run it, whatever the prompt says.

What happens to a Lettr connection when someone leaves?

Offboarding them in Elaichi ends their access to Lettr through every client at once. If they shared a Lettr connection, it keeps working for everyone else on the team. If you want Lettr gone entirely, disconnect it once in Elaichi and it disappears from Claude, ChatGPT, Cursor, Microsoft Copilot and every other client.

Does the Lettr MCP connector work with Gemini, Codex, Claude Code or other MCP clients?

Yes. Lettr is reached over the same MCP endpoint every client uses, so anything that speaks MCP can call it — Gemini, Codex, Claude Code, Windsurf, Cline, Zed and OpenCode among them — alongside Claude, ChatGPT, Cursor, Microsoft Copilot, and the Elaichi Agent. The tools on offer and the access behind them are identical whichever client asks. Only the setup screen differs.

Is Elaichi an alternative to Zapier MCP for Lettr?

Yes. Both let Claude, ChatGPT or Cursor use Lettr. Zapier MCP fits a team that already automates in Zapier, since each person signs in and acts as themselves in that account. Elaichi fits when IT wants one address for the whole company, per-tool rules by role, and a record of every Lettr call.

How is Elaichi different from Composio for Lettr?

Composio gives AI agents tools and sign-in handling across 1,000+ apps, for developers building agents or people using an assistant, billed per tool call. Elaichi gives a company's own people governed access to Lettr: one address, restrictions per role or user, and $15 per user per month. Both have role permissions and a log of every call.

Put Lettr in front of your team

14 days of Black, no credit card. Connect it once and pick what each team can call.

When the trial ends, nothing is deleted. You move to the free Personal plan, and connections, roles and the audit log stay where they are.

Add one link to your AI app

The same link for everyone on your team.

https://api.elaichi.ai/mcp
  • ChatGPT
  • Claude
  • Cursor
  • Microsoft Copilot