Reply to a LinkedIn inbox message

Continue a LinkedIn conversation after a prospect replies to a direct message or InMail sent through your Woodpecker campaign. First, retrieve the received reply, then use its ID to send your response.

Your response is sent from the LinkedIn account that received the reply. Responses to direct messages are sent as direct messages; responses to InMails are sent as InMails.

Request

Endpoint

POST https://api.woodpecker.co/rest/v2/linkedin/inbox/messages/{id}/reply

Headers

x-api-key: {YOUR_API_KEY}
Content-Type: application/json

For details on how to authenticate your requests, please see the authentication guide.

Parameters

Parameter	Required	Type	Description
id	Yes	integer	Path parameter. ID of the received reply: content[].id from the LinkedIn inbox messages endpoint or [].replied.id from the LinkedIn reply webhook

Body

{
  "message": "Thanks for your reply. Here is a short overview of our project."
}

The request accepts the message text only. You cannot send attachments or select a different sending account or message type.

Body schema

Field	Type	Required	Description
message	string	Yes	Message text; cannot be empty or contain only whitespace. Maximum: 6,000 characters for direct messages, or 1,900 for InMails

Sending uses the account's action limits for the corresponding message type, shared between campaigns and API requests. Direct messages count toward a rolling 24-hour limit, while InMails count toward a rolling 31-day limit. The exact limits depend on the LinkedIn account's configuration. If a limit is reached, the API returns 429.

Request samples

Reply to a received direct message

The examples use reply ID 123123 from the inbox response example.

cURL

curl --request POST \
  --url "https://api.woodpecker.co/rest/v2/linkedin/inbox/messages/123123/reply" \
  --header "x-api-key: {YOUR_API_KEY}" \
  --header "Content-Type: application/json" \
  --data '{
    "message": "Thanks for your reply. Here is a short overview of our project."
  }'

Python

import requests

def reply_to_linkedin_message(reply_id):
  url = f"https://api.woodpecker.co/rest/v2/linkedin/inbox/messages/{reply_id}/reply"
  headers = {
    "x-api-key": "{YOUR_API_KEY}",
    "Content-Type": "application/json"
  }
  payload = {
    "message": "Thanks for your reply. Here is a short overview of our project."
  }

  response = requests.post(url, headers=headers, json=payload)
  if response.status_code == 204:
    return "LinkedIn reply sent."
  raise Exception(f"POST request failed: {response.status_code}, {response.text}")

if __name__ == "__main__":
  try:
    print(reply_to_linkedin_message(123123))
  except Exception as error:
    print("Error:", error)

Java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class WoodpeckerApiClient {
  public static void main(String[] args) {
    try {
      long replyId = 123123;
      String url = "https://api.woodpecker.co/rest/v2/linkedin/inbox/messages/" + replyId + "/reply";
      String jsonData = """
        {
          "message": "Thanks for your reply. Here is a short overview of our project."
        }
        """;

      HttpClient client = HttpClient.newHttpClient();
      HttpRequest request = HttpRequest.newBuilder()
        .uri(URI.create(url))
        .header("x-api-key", "{YOUR_API_KEY}")
        .header("Content-Type", "application/json")
        .POST(HttpRequest.BodyPublishers.ofString(jsonData))
        .build();

      HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
      if (response.statusCode() == 204) {
        System.out.println("LinkedIn reply sent.");
      } else {
        throw new Exception(
          "POST request failed: " + response.statusCode() + ", " + response.body()
        );
      }
    } catch (Exception e) {
      System.out.println("Error: " + e.getMessage());
    }
  }
}

Node.js

const axios = require('axios');

async function replyToLinkedinMessage(replyId) {
  const url = `https://api.woodpecker.co/rest/v2/linkedin/inbox/messages/${replyId}/reply`;
  const headers = {
    'x-api-key': '{YOUR_API_KEY}',
    'Content-Type': 'application/json'
  };
  const data = {
    message: 'Thanks for your reply. Here is a short overview of our project.'
  };

  try {
    await axios.post(url, data, { headers });
    console.log('LinkedIn reply sent.');
  } catch (error) {
    console.error(
      'POST request failed:',
      error.response ? error.response.status : error.message
    );
  }
}

replyToLinkedinMessage(123123);

PHP

<?php
require 'vendor/autoload.php';

use GuzzleHttp\Client;
use GuzzleHttp\Exception\RequestException;

$client = new Client([
  'base_uri' => 'https://api.woodpecker.co/rest/v2/',
  'headers' => [
    'x-api-key' => getenv('WOODPECKER_API_KEY'),
    'Content-Type' => 'application/json',
  ],
]);

try {
  $replyId = 123123;
  $response = $client->post("linkedin/inbox/messages/{$replyId}/reply", [
    'json' => [
      'message' => 'Thanks for your reply. Here is a short overview of our project.',
    ],
  ]);

  echo $response->getStatusCode(), "\n";
} catch (RequestException $e) {
  echo "Error: ", $e->getMessage(), "\n";
  if ($e->hasResponse()) {
    echo $e->getResponse()->getBody(), "\n";
  }
}

Response

Response examples

204

The LinkedIn reply was sent successfully.

Status: 204
Body: none

400

The path parameter id is not a valid integer.

{
  "type": "validation_error",
  "code": "invalid_request",
  "message": "Invalid request.",
  "request_id": "12345678-1234-1234-1234-123456789012"
}

Body schema

Field	Type	Description
type	string	Error type: validation_error
code	string	Error code: invalid_request
message	string	Human-readable error summary
request_id	string/null	Request identifier, or null when unavailable

401

The API key is missing or invalid. Review the authentication guide.

{
  "title": "Unauthorized",
  "status": 401,
  "detail": "Invalid api key",
  "timestamp": "2026-08-18 11:08:09"
}

Body schema

Field	Type	Description
title	string	A short title describing the error
status	integer	HTTP status code
detail	string	Details about the authorization error
timestamp	string	Time the error occurred in YYYY-MM-DD HH:MM:SS UTC format

404

The reply with given id is unavailable in your Woodpecker account.

{
  "type": "validation_error",
  "code": "reply_not_found",
  "message": "Reply not found.",
  "request_id": "12345678-1234-1234-1234-123456789012"
}

Body schema

Field	Type	Description
type	string	Error type: validation_error
code	string	Error code: reply_not_found
message	string	Human-readable error summary
request_id	string/null	Request identifier, or null when unavailable

422

The message is invalid, the LinkedIn account is not connected, or the message could not be sent.

The code identifies the error: invalid_fields, account_not_connected, or send_failed. For invalid_fields, details are provided in fields, as in this example:

{
  "type": "validation_error",
  "code": "invalid_fields",
  "message": "Invalid field(s)",
  "request_id": "12345678-1234-1234-1234-123456789012",
  "fields": [
    {
      "field": "message",
      "issue": "too_long",
      "value": "Max allowed 6000"
    }
  ]
}

Body schema

Field	Type	Description
type	string	Error type: validation_error
code	string	Error code: invalid_fields, account_not_connected, or send_failed
message	string	Human-readable error summary
request_id	string/null	Request identifier, or null when unavailable
fields	array[object]	Validation details; present for invalid_fields and omitted for the other error codes
└─ [].field	string	Name of the invalid field: message
└─ [].issue	string	Validation issue: required or too_long
└─ [].value	string/null	null for required; the character limit for too_long, such as Max allowed 6000

429

The LinkedIn account's action quota for the message type has been reached, or throttled. Campaign sends and API replies share the same quota. Direct messages use a rolling 24-hour window; InMails use a rolling 31-day window.

{
  "type": "validation_error",
  "code": "action_limit_exceeded",
  "message": "Daily action limit or action request rate limit exceeded.",
  "request_id": "12345678-1234-1234-1234-123456789012"
}

Body schema

Field	Type	Description
type	string	Error type: validation_error
code	string	Error code: action_limit_exceeded
message	string	Human-readable error summary
request_id	string/null	Request identifier, or null when unavailable

500

An unexpected server error occurred.

{
  "type": "internal_error",
  "code": "internal_server_error",
  "message": "An unexpected error occurred on the server.",
  "request_id": "12345678-1234-1234-1234-123456789012"
}