Fix: honor HTTPS_PROXY/HTTP_PROXY in proxy-only environments

package.json

@@ -48,6 +48,7 @@
     "@modelcontextprotocol/sdk": "^1.26.0",
     "dotenv": "^17.2.1",
     "rollbar": "^3.0.0-alpha.6",
+    "undici": "^7.25.0",
     "zod": "^3.25.76"
   },
   "devDependencies": {

src/config.ts

@@ -1,14 +1,10 @@
-import dotenv from "dotenv";
+import "./load-env.js";
 import { readFileSync, existsSync } from "node:fs";
 import path from "node:path";
 import { homedir } from "node:os";
 import packageJson from "../package.json" with { type: "json" };
 import { z } from "zod";
 
-// Load environment variables from .env file
-// `quiet: true` to prevent logging to stdio which disrupts some mcp clients
-dotenv.config({ quiet: true } as Parameters<typeof dotenv.config>[0]);
-
 const DEFAULT_ROLLBAR_API_BASE = "https://api.rollbar.com/api/1";
 
 const HttpUrlSchema = z

src/index.ts

@@ -1,5 +1,7 @@
 #!/usr/bin/env node
 
+import "./load-env.js";
+import "./utils/proxy.js";
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
 import { registerAllTools } from "./tools/index.js";

src/load-env.ts

@@ -0,0 +1,4 @@
+import dotenv from "dotenv";
+
+// Keep dotenv quiet so MCP stdio stays clean for clients.
+dotenv.config({ quiet: true } as Parameters<typeof dotenv.config>[0]);

src/utils/proxy.ts

@@ -0,0 +1,11 @@
+import { ProxyAgent, setGlobalDispatcher } from "undici";
+
+const proxyUrl =
+  process.env.HTTPS_PROXY ||
+  process.env.HTTP_PROXY ||
+  process.env.https_proxy ||
+  process.env.http_proxy;
+
+if (proxyUrl) {
+  setGlobalDispatcher(new ProxyAgent(proxyUrl));
+}

tests/unit/utils/proxy.test.ts

@@ -0,0 +1,111 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { mkdtempSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+
+const mockSetGlobalDispatcher = vi.fn();
+const mockProxyAgentConstructor = vi.fn();
+
+vi.mock("undici", () => ({
+  setGlobalDispatcher: mockSetGlobalDispatcher,
+  ProxyAgent: mockProxyAgentConstructor,
+}));
+
+describe("proxy setup", () => {
+  const originalEnv = process.env;
+  const originalCwd = process.cwd();
+
+  beforeEach(() => {
+    process.env = { ...originalEnv };
+    vi.clearAllMocks();
+    vi.resetModules();
+  });
+
+  afterEach(() => {
+    process.env = originalEnv;
+    process.chdir(originalCwd);
+  });
+
+  it("sets global dispatcher when HTTPS_PROXY is set", async () => {
+    process.env.HTTPS_PROXY = "http://proxy.example.com:8080";
+    await import("../../../src/utils/proxy.js");
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://proxy.example.com:8080",
+    );
+    expect(mockSetGlobalDispatcher).toHaveBeenCalledTimes(1);
+  });
+
+  it("sets global dispatcher when HTTP_PROXY is set", async () => {
+    process.env.HTTP_PROXY = "http://proxy.example.com:8080";
+    await import("../../../src/utils/proxy.js");
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://proxy.example.com:8080",
+    );
+    expect(mockSetGlobalDispatcher).toHaveBeenCalledTimes(1);
+  });
+
+  it("sets global dispatcher when lowercase https_proxy is set", async () => {
+    process.env.https_proxy = "http://proxy.example.com:8080";
+    await import("../../../src/utils/proxy.js");
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://proxy.example.com:8080",
+    );
+    expect(mockSetGlobalDispatcher).toHaveBeenCalledTimes(1);
+  });
+
+  it("sets global dispatcher when lowercase http_proxy is set", async () => {
+    process.env.http_proxy = "http://proxy.example.com:8080";
+    await import("../../../src/utils/proxy.js");
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://proxy.example.com:8080",
+    );
+    expect(mockSetGlobalDispatcher).toHaveBeenCalledTimes(1);
+  });
+
+  it("prefers HTTPS_PROXY over HTTP_PROXY", async () => {
+    process.env.HTTPS_PROXY = "http://https-proxy.example.com:8080";
+    process.env.HTTP_PROXY = "http://http-proxy.example.com:8080";
+    await import("../../../src/utils/proxy.js");
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://https-proxy.example.com:8080",
+    );
+  });
+
+  it("does not set global dispatcher when no proxy env vars are set", async () => {
+    delete process.env.HTTPS_PROXY;
+    delete process.env.HTTP_PROXY;
+    delete process.env.https_proxy;
+    delete process.env.http_proxy;
+    await import("../../../src/utils/proxy.js");
+    expect(mockSetGlobalDispatcher).not.toHaveBeenCalled();
+  });
+
+  it("honors proxy values loaded from .env before proxy setup runs", async () => {
+    const tempDir = mkdtempSync(path.join(tmpdir(), "rollbar-mcp-proxy-"));
+
+    writeFileSync(
+      path.join(tempDir, ".env"),
+      "ROLLBAR_ACCESS_TOKEN=test-token\nHTTPS_PROXY=http://proxy.example.com:8080\n",
+    );
+
+    process.chdir(tempDir);
+    process.env = {
+      ...originalEnv,
+      HOME: tempDir,
+    };
+    delete process.env.ROLLBAR_ACCESS_TOKEN;
+    delete process.env.ROLLBAR_CONFIG_FILE;
+    delete process.env.HTTPS_PROXY;
+    delete process.env.HTTP_PROXY;
+    delete process.env.https_proxy;
+    delete process.env.http_proxy;
+
+    await import("../../../src/load-env.js");
+    await import("../../../src/utils/proxy.js");
+
+    expect(mockProxyAgentConstructor).toHaveBeenCalledWith(
+      "http://proxy.example.com:8080",
+    );
+    expect(mockSetGlobalDispatcher).toHaveBeenCalledTimes(1);
+  });
+});