diff --git a/src/apiv2.ts b/src/apiv2.ts
index c4fb07d9c39..c9b716f9609 100644
--- a/src/apiv2.ts
+++ b/src/apiv2.ts
@@ -19,15 +19,16 @@ import * as FormData from "form-data";
 const pkg = require("../package.json");
 const CLI_VERSION: string = pkg.version;
 
-const agent = detectAIAgent();
-const agentStr = agent === "unknown" ? "" : ` agent-name/${agent}`;
-const platform = isFirebaseMcp() ? "FirebaseMCP" : "FirebaseCLI";
-const clientVersion = `${platform}/${CLI_VERSION}${agentStr}`;
-
-export const STANDARD_HEADERS: Record<string, string> = {
-  Connection: "keep-alive",
-  "User-Agent": clientVersion,
-  "X-Client-Version": clientVersion,
+export const standardHeaders: () => Record<string, string> = () => {
+  const agent = detectAIAgent();
+  const agentStr = agent === "unknown" ? "" : ` agent-name/${agent}`;
+  const platform = isFirebaseMcp() ? "FirebaseMCP" : "FirebaseCLI";
+  const clientVersion = `${platform}/${CLI_VERSION}${agentStr}`;
+  return {
+    Connection: "keep-alive",
+    "User-Agent": clientVersion,
+    "X-Client-Version": clientVersion,
+  };
 };
 
 // Don't use this one.
@@ -309,7 +310,7 @@ export class Client {
     if (!reqOptions.headers) {
       reqOptions.headers = new Headers();
     }
-    for (const [h, v] of Object.entries(STANDARD_HEADERS)) {
+    for (const [h, v] of Object.entries(standardHeaders())) {
       if (!reqOptions.headers.has(h)) {
         reqOptions.headers.set(h, v);
       }
diff --git a/src/bin/mcp.ts b/src/bin/mcp.ts
index 6ad168b1a7f..ff48e8cea31 100644
--- a/src/bin/mcp.ts
+++ b/src/bin/mcp.ts
@@ -4,6 +4,7 @@ import { resolve } from "path";
 import { parseArgs } from "util";
 import { useFileLogger } from "../logger";
 import { FirebaseMcpServer } from "../mcp/index";
+import { setFirebaseMcp } from "../env";
 import { markdownDocsOfPrompts } from "../mcp/prompts/index.js";
 import { markdownDocsOfResources } from "../mcp/resources/index.js";
 import { markdownDocsOfTools } from "../mcp/tools/index.js";
@@ -82,7 +83,7 @@ export async function mcp(): Promise<void> {
   }
   if (earlyExit) return;
 
-  process.env.IS_FIREBASE_MCP = "true";
+  setFirebaseMcp(true);
   useFileLogger();
   const activeFeatures = (values.only || "")
     .split(",")
diff --git a/src/env.ts b/src/env.ts
index 70014af79a7..782d1652d05 100644
--- a/src/env.ts
+++ b/src/env.ts
@@ -8,8 +8,13 @@ export function isFirebaseStudio() {
   return googleIdxFolderExists;
 }
 
+let isFirebaseMcpFlag = false;
 export function isFirebaseMcp() {
-  return !!process.env.IS_FIREBASE_MCP;
+  return isFirebaseMcpFlag;
+}
+
+export function setFirebaseMcp(value: boolean) {
+  isFirebaseMcpFlag = value;
 }
 
 // Detect if the CLI was invoked by a coding agent, based on well-known env vars.
diff --git a/src/gcp/cloudsql/fbToolsAuthClient.ts b/src/gcp/cloudsql/fbToolsAuthClient.ts
index 53791303fca..be6ecc575a5 100644
--- a/src/gcp/cloudsql/fbToolsAuthClient.ts
+++ b/src/gcp/cloudsql/fbToolsAuthClient.ts
@@ -39,7 +39,7 @@ export class FBToolsAuthClient extends AuthClient {
   public async getRequestHeaders(): Promise<Record<string, string>> {
     const token = await this.getAccessToken();
     return {
-      ...apiv2.STANDARD_HEADERS,
+      ...apiv2.standardHeaders(),
       Authorization: `Bearer ${token.token}`,
     };
   }