> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sendler.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Send LinkedIn Message

> Send a message from a workspace sender to a LinkedIn profile.

Requires `inbox:send`. Required fields are `senderId`, `recipientLinkedinUrl`, and `message` (1–8,000 characters). `campaignId` and `leadId` are optional associations; they do not replace the required recipient URL.

This REST request sends when accepted. For a campaign-lead target and supported name variables, use [Send to Lead](https://docs.sendler.ai/api-reference/endpoint/post-send-to-lead.md).

Use an [Idempotency-Key](https://docs.sendler.ai/api-reference/behavior.md#idempotent-writes). Sender limits apply independently of API rate limits. If delivery is uncertain, inspect the conversation before retrying; do not switch keys to force a second send.


## OpenAPI

````yaml POST /v1/inbox/send
openapi: 3.0.0
info:
  title: SendPilot External API
  description: >

    # SendPilot External API v1


    Public API for integrating with SendPilot programmatically.


    ## Authentication


    Requests authenticate with a workspace API key in the `X-API-Key` header:


    ```

    X-API-Key: sp_live_your_api_key_here

    ```


    `Authorization: Bearer sp_live_...` (or `sp_test_...`) is also accepted.
    Prefer one header; `X-API-Key` takes precedence. Clerk OAuth tokens for MCP
    connection URLs are not public REST API keys.


    A key only reaches what its scopes and creator's current workspace
    permissions allow. Each operation lists the scopes it needs in
    `x-sp-scopes`. Use `GET /v1/me` to inspect the effective permissions and
    subscription state.


    ## Rate Limits


    - **Per API Key**: 300 requests/minute

    - **Per Workspace**: 50,000 requests/day


    Responses that reach the rate limiter include these headers; early
    authentication failures may not:

    - `X-RateLimit-Limit`: Max requests per minute

    - `X-RateLimit-Remaining`: Remaining requests in current window

    - `X-RateLimit-Reset`: Epoch timestamp when limit resets


    ## LinkedIn Sender Limits


    When using messaging endpoints, these headers show account limits:

    - `X-LinkedIn-Messages-Remaining`: Messages left today

    - `X-LinkedIn-Connections-Remaining`: Connection requests left today

    - `X-LinkedIn-Quota-Reset-At`: When daily limits reset


    ## Retries


    Send an `Idempotency-Key` header on POST and PATCH requests. A retry with
    the same key within 24 hours returns the first result (with
    `Idempotent-Replayed: true`) instead of acting twice. The same key with a
    different request answers 422 `IDEMPOTENCY_KEY_REUSED`; a retry while the
    first request still runs answers 409 `IDEMPOTENCY_IN_PROGRESS`.


    Once execution is attempted, its response (including errors) is retained. If
    a process stops or result storage fails after the attempt, the durable
    record blocks another execution for the replay window and returns 409
    `IDEMPOTENCY_IN_PROGRESS` or `IDEMPOTENCY_REPLAY_UNAVAILABLE`. Check the
    operation's status before using a new key: an uncertain outcome may already
    have acted. Requests refused before execution is claimed, such as
    authentication or rate-limit refusals, can be retried with the same key.


    ## Webhooks


    Configure webhooks in the SendPilot app to receive real-time events:

    - `lead.tag.updated`

    - `lead.updated`

    - `message.sent`

    - `reply.received`

    - `connection_request.sent`

    - `connection_request.accepted`

    - `campaign.started`

    - `campaign.paused`

    - `campaign.resumed`

    - `campaign.finished`


    ## Error Codes


    Errors return a JSON body. Use the machine-readable `code` when supplied;
    validation messages can be arrays, and some legacy errors omit `code`. A
    typical error is:

    ```json

    {
      "statusCode": 400,
      "error": "Bad Request",
      "code": "SPECIFIC_ERROR_CODE",
      "message": "Human-readable description"
    }

    ```
  version: '1.0'
  contact:
    name: SendPilot Support
    url: https://sendpilot.ai
    email: support@sendpilot.ai
servers:
  - url: https://api.sendpilot.ai
security: []
tags: []
paths:
  /v1/inbox/send:
    post:
      tags:
        - External API - Inbox
      summary: Send LinkedIn message
      description: >-
        Sends a message via LinkedIn. The recipient must be a 1st degree
        connection of the sender.
      operationId: inbox.sendMessage
      parameters: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/SendMessageDto'
      responses:
        '200':
          description: Message sent or queued
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/SendMessageResponseDto'
        '400':
          description: Invalid request or sender not found
        '429':
          description: Daily message limit exceeded
      security:
        - api-key: []
components:
  schemas:
    SendMessageDto:
      type: object
      properties:
        senderId:
          type: string
          description: LinkedIn sender ID to use (must be connected to workspace)
          example: sender_123
        recipientLinkedinUrl:
          type: string
          description: LinkedIn URL of the recipient (must be a 1st degree connection)
          example: https://www.linkedin.com/in/johndoe/
        message:
          type: string
          description: Message content to send
          example: Hi John, I wanted to follow up on our conversation...
          minLength: 1
          maxLength: 8000
        campaignId:
          type: string
          description: Optional campaign ID to associate this message with
          example: campaign_123
        leadId:
          type: string
          description: Optional lead ID to associate this message with
          example: lead_123
      required:
        - senderId
        - recipientLinkedinUrl
        - message
    SendMessageResponseDto:
      type: object
      properties:
        success:
          type: boolean
          description: Success status
          example: true
        messageId:
          type: string
          description: Message ID
          example: msg_123
        recipientLinkedinUrl:
          type: string
          description: Recipient LinkedIn URL
        leadId:
          type: string
          description: Lead ID if message was sent to a lead
        conversationId:
          type: string
          description: >-
            LinkedIn conversation ID, when the provider returns one (use with
            GET /v1/inbox/conversations/:conversationId/messages)
        status:
          type: string
          description: Message status
          example: sent
          enum:
            - queued
            - sent
            - failed
        error:
          type: string
          description: Error message if failed
        timestamp:
          format: date-time
          type: string
          description: Timestamp when message was sent/queued
      required:
        - success
        - messageId
        - recipientLinkedinUrl
        - status
        - timestamp
  securitySchemes:
    api-key:
      type: apiKey
      in: header
      name: X-API-Key
      description: 'API key for authentication (prefix: sp_live_ or sp_test_)'

````

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