From e2fd8c3345065bbb48517265fad1c608e499baf3 Mon Sep 17 00:00:00 2001
From: Narek Hovhannisyan <narhovhannisian@gmail.com>
Date: Tue, 2 Sep 2025 15:08:29 +0400
Subject: [PATCH 1/3] config: add MCP_USER_AGENT to configuration for Mailtrap
 MCP

---
 src/config/index.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/config/index.ts b/src/config/index.ts
index f1b5ad2..0859ce3 100644
--- a/src/config/index.ts
+++ b/src/config/index.ts
@@ -18,6 +18,7 @@ export default {
     GENERAL_ENDPOINT: "https://mailtrap.io",
     USER_AGENT:
       "mailtrap-nodejs (https://github.com/railsware/mailtrap-nodejs)",
+    MCP_USER_AGENT: "mailtrap-mcp (https://github.com/railsware/mailtrap-mcp)",
     MAX_REDIRECTS: 0,
     TIMEOUT: 10000,
   },

From 3bd652ada1f5ac642e04cd72477937b3bf2daf08 Mon Sep 17 00:00:00 2001
From: Narek Hovhannisyan <narhovhannisian@gmail.com>
Date: Tue, 2 Sep 2025 15:08:43 +0400
Subject: [PATCH 2/3] lib: replace static USER_AGENT with dynamic user agent
 function in MailtrapClient

---
 src/lib/MailtrapClient.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/lib/MailtrapClient.ts b/src/lib/MailtrapClient.ts
index a41060e..9fa46d5 100644
--- a/src/lib/MailtrapClient.ts
+++ b/src/lib/MailtrapClient.ts
@@ -6,12 +6,14 @@ import axios, { AxiosInstance } from "axios";
 import encodeMailBuffers from "./mail-buffer-encoder";
 import handleSendingError from "./axios-logger";
 import MailtrapError from "./MailtrapError";
+import getDynamicUserAgent from "./get-agent";
 
 import GeneralAPI from "./api/General";
 import TestingAPI from "./api/Testing";
 import ContactsBaseAPI from "./api/Contacts";
 import ContactListsBaseAPI from "./api/ContactLists";
 import TemplatesBaseAPI from "./api/Templates";
+import SuppressionsBaseAPI from "./api/Suppressions";
 
 import CONFIG from "../config";
 
@@ -22,13 +24,11 @@ import {
   BatchSendResponse,
   BatchSendRequest,
 } from "../types/mailtrap";
-import SuppressionsBaseAPI from "./api/Suppressions";
 
 const { CLIENT_SETTINGS, ERRORS } = CONFIG;
 const {
   SENDING_ENDPOINT,
   MAX_REDIRECTS,
-  USER_AGENT,
   TIMEOUT,
   TESTING_ENDPOINT,
   BULK_ENDPOINT,
@@ -66,7 +66,7 @@ export default class MailtrapClient {
       headers: {
         Authorization: `Bearer ${token}`,
         Connection: "keep-alive",
-        "User-Agent": USER_AGENT,
+        "User-Agent": getDynamicUserAgent(),
       },
       maxRedirects: MAX_REDIRECTS,
       timeout: TIMEOUT,

From 9da5776fad1f706e61b9f1be3b928ddf9b7eaedf Mon Sep 17 00:00:00 2001
From: Narek Hovhannisyan <narhovhannisian@gmail.com>
Date: Tue, 2 Sep 2025 15:09:06 +0400
Subject: [PATCH 3/3] lib: implement dynamic User-Agent detection for Mailtrap
 MCP context

---
 src/lib/get-agent.ts | 63 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/lib/get-agent.ts

diff --git a/src/lib/get-agent.ts b/src/lib/get-agent.ts
new file mode 100644
index 0000000..6a6943c
--- /dev/null
+++ b/src/lib/get-agent.ts
@@ -0,0 +1,63 @@
+import CONFIG from "../config";
+
+const { USER_AGENT, MCP_USER_AGENT } = CONFIG.CLIENT_SETTINGS;
+
+/**
+ * Checks if the main module filename indicates MCP context.
+ * @returns true if main module contains "mailtrap-mcp" and is not in node_modules
+ */
+function isMainModuleMCP(): boolean {
+  const mainFile = require?.main?.filename;
+
+  return !!(
+    mainFile &&
+    mainFile.includes("mailtrap-mcp") &&
+    !mainFile.includes("node_modules")
+  );
+}
+
+/**
+ * Checks if the current working directory indicates MCP context.
+ * @returns true if cwd contains "mailtrap-mcp" and is not in node_modules
+ */
+function isWorkingDirectoryMCP(): boolean {
+  try {
+    const cwd = process.cwd();
+    return cwd.includes("mailtrap-mcp") && !cwd.includes("node_modules");
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Checks if the call stack indicates MCP context.
+ * @returns true if stack contains "mailtrap-mcp" and is not from node_modules/mailtrap
+ */
+function isCallStackMCP(): boolean {
+  const { stack } = new Error();
+
+  return !!(
+    stack &&
+    stack.includes("mailtrap-mcp") &&
+    !stack.includes("node_modules/mailtrap")
+  );
+}
+
+/**
+ * Determines if the code is running in a Mailtrap MCP context.
+ * Uses multiple detection methods to ensure accurate context identification.
+ * @returns true if running in MCP context, false otherwise
+ */
+function isMailtrapMCPContext(): boolean {
+  return isMainModuleMCP() || isWorkingDirectoryMCP() || isCallStackMCP();
+}
+
+/**
+ * Gets the appropriate User-Agent string based on the current context.
+ * @returns The User-Agent string for the current context
+ */
+function getDynamicUserAgent(): string {
+  return isMailtrapMCPContext() ? MCP_USER_AGENT : USER_AGENT;
+}
+
+export default getDynamicUserAgent;