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lemlist Inbox API

The unified reply inbox - conversations, messages, drafts, labels and sending on email, LinkedIn and WhatsApp.

lemlist Inbox API is one of 22 APIs that lemlist publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include Inbox and Multichannel Messaging. The published artifact set on APIs.io includes an OpenAPI specification.

This API exposes 15 operations across 10 paths, and defines 3 schemas. It is described by OpenAPI 3.2.0, at version 1.0.0.

Requests are made against a single base URL, https://api.lemlist.com/api.

15 operations 10 paths 3 schemas 2 DELETE6 GET1 PATCH6 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.2.0
API Version
1.0.0
Base URL
https://api.lemlist.com/api
Authentication
HTTP Basic
Resource Areas
1

Authentication & Security 1

lemlist Inbox API declares 1 security scheme for authenticating requests. It accepts HTTP basic authentication (basicAuth).

Paths & Operations 15

Across 10 paths, the API surfaces 15 operations — 2 DELETE, 6 GET, 1 PATCH, 6 POST. Each is listed below with its method, path, parameters, and response codes.

Inbox 15
GET
/inbox
Retrieve inbox list
3 params body → 200
GET
/inbox/{contactId}
Contact messages
6 params → 200
POST
/inbox/email
Send email
1 param body → 200
POST
/inbox/linkedin
Send LinkedIn message
1 param body → 200
POST
/inbox/whatsapp
Send WhatsApp message
1 param body → 200
GET
/inbox/labels
Get Many Labels
→ 200400401
POST
/inbox/labels
Create Label
body → 200400401409405
GET
/inbox/labels/{labelId}
Get Label
1 param → 200400401404405
POST
/inbox/conversations/labels/{contactId}
Attach Labels to Conversations
1 param body → 200400401404405
DELETE
/inbox/conversations/labels/{contactId}
Remove Labels from Conversation
1 param body → 200400401404405
GET
/inbox/{contactId}/drafts
List Drafts
2 params → 200400401405
POST
/inbox/{contactId}/drafts
Create Draft
2 params body → 201400401405
GET
/inbox/{contactId}/drafts/{draftId}
Get Draft
3 params → 200400401404405
PATCH
/inbox/{contactId}/drafts/{draftId}
Update Draft
3 params body → 200400401404405
DELETE
/inbox/{contactId}/drafts/{draftId}
Delete Draft
3 params → 200400401404405

Schemas 3

The contract defines 3 schemas that model the data the API accepts and returns. The most detailed are InboxMessage (6 properties), Label (5 properties), InboxConversation (4 properties). Each schema is shown below with its type and property counts.

InboxMessage
object
A single message within an inbox conversation.
6 properties
InboxConversation
object
A message thread between a user and a contact in the inbox.
4 properties
Label
object
A label used to categorize and organize inbox conversations.
5 properties

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

lemlist-inbox-api-openapi.yml Raw ↑

Other APIs lemlist publishes across the network.

lemlist MCP Server
lemlist Campaigns API
lemlist Sequences API
lemlist Leads API
lemlist People Database API
lemlist Enrich API
lemlist Contacts API
lemlist Companies API
lemlist Signal Agents API
lemlist Webhooks API
lemlist Unsubscribes API
lemlist Schedules API
Where this information came from

This is an independent, third-party profile of lemlist Inbox API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.

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