diff --git a/src/HttpClient.cpp b/src/HttpClient.cpp
index 1c73464..973d172 100644
--- a/src/HttpClient.cpp
+++ b/src/HttpClient.cpp
@@ -63,6 +63,16 @@ void HttpClient::beginRequest()
   iState = eRequestStarted;
 }
 
+void HttpClient::sendApiKeyHeader(const char* apiKey) {
+  if (iState < eRequestSent) {
+    finishHeaders();
+  }
+
+  String header = "apikey: ";
+  header += apiKey;
+  sendHeader(header);
+}
+
 int HttpClient::startRequest(const char* aURLPath, const char* aHttpMethod, 
                                 const char* aContentType, int aContentLength, const byte aBody[])
 {
diff --git a/src/HttpClient.h b/src/HttpClient.h
index 6a7aa1d..3fbd18f 100644
--- a/src/HttpClient.h
+++ b/src/HttpClient.h
@@ -211,6 +211,8 @@ class HttpClient : public Client
     void sendBasicAuth(const String& aUser, const String& aPassword)
       { sendBasicAuth(aUser.c_str(), aPassword.c_str()); }
 
+    void sendApiKeyHeader(const char* apiKey);
+
     /** Get the HTTP status code contained in the response.
       For example, 200 for successful request, 404 for file not found, etc.
     */