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Operate As

Integration

Lettr

Transactional and marketing email from one API, with a drag-and-drop editor. Your client pastes their Lettr key once, and your agent or your code works with their access.

Email

About Lettr

Through Operate As, your agent, n8n workflow or code works in Lettr with your client's own access. Your client pastes their API key from Lettr once. We store it encrypted, so it never sits in an email or a shared doc. Your agent reaches any endpoint of Lettr's API through the request tool, with the client's access attached.

Common uses in Email

  • Triage the inbox and draft replies for review
  • Follow up on leads and unanswered threads
  • Send updates and confirmations as they happen

Lettr

Lettr · Email

API key

Transactional and marketing email from one API, with a drag-and-drop editor

The client pastes their API key from Lettr's settings. We store it encrypted.

Tested against Lettr's live API.

Building with Lettr? The docs have setup steps and code for every tool.

Open the Lettr docs

Tools

Your agent calls any endpoint of Lettr's API with the request tool, with the client's access attached.

Base URL for request

https://app.lettr.com/api

  • request

    HTTPS ANY /v1/clients/{clientId}/lettr/{path}

    Any endpoint of Lettr's own API, with the client's access attached.

    servicestringrequired
    This service: lettr
    methodstringrequired
    GET, POST, PUT, PATCH or DELETE
    pathstringrequired
    The path under https://app.lettr.com/api
    queryobjectoptional
    Query parameters
    bodyobjectoptional
    A JSON body

Over MCP every tool also takes client_id, from list_clients. Over HTTPS send it as clientId to https://api.operate.as/v1.

What the client approves

  • Use the Lettr key you paste, with only the access you gave that key

Related

More in Email

Browse every service

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