feat(mcp): Adds "get_environment" tool

Author: mbleigh

src/mcp/index.ts

@@ -97,12 +97,11 @@ export class FirebaseMcpServer {
     return getProjectId(await this.resolveOptions());
   }
 
-  async getAuthenticated(): Promise<boolean> {
+  async getAuthenticated(): Promise<string | null> {
     try {
-      await requireAuth(await this.resolveOptions());
-      return true;
+      return (await requireAuth(await this.resolveOptions())) ?? null;
     } catch (e) {
-      return false;
+      return null;
     }
   }
 
@@ -115,7 +114,7 @@ export class FirebaseMcpServer {
       _meta: {
         projectRoot: this.projectRoot,
         projectDetected: hasActiveProject,
-        authenticated: await this.getAuthenticated(),
+        authenticatedUser: await this.getAuthenticated(),
         activeFeatures: this.activeFeatures,
         detectedFeatures: this.detectedFeatures,
       },
@@ -129,7 +128,8 @@ export class FirebaseMcpServer {
     if (!tool) throw new Error(`Tool '${toolName}' could not be found.`);
 
     const projectId = await this.getProjectId();
-    if (tool.mcp._meta?.requiresAuth && !(await this.getAuthenticated())) return mcpAuthError();
+    const accountEmail = await this.getAuthenticated();
+    if (tool.mcp._meta?.requiresAuth && !accountEmail) return mcpAuthError();
     if (tool.mcp._meta?.requiresProject && !projectId) return NO_PROJECT_ERROR;
 
     try {
@@ -141,6 +141,7 @@ export class FirebaseMcpServer {
         host: this,
         config,
         rc,
+        accountEmail,
       });
       await trackGA4("mcp_tool_call", { tool_name: toolName, error: res.isError ? 1 : 0 });
       return res;

src/mcp/tool.ts

@@ -7,6 +7,7 @@ import { RC } from "../rc";
 
 export interface ServerToolContext {
   projectId?: string;
+  accountEmail?: string | null;
   config: Config;
   host: FirebaseMcpServer;
   rc: RC;

src/mcp/tools/core/get_environment.ts

@@ -0,0 +1,48 @@
+import { z } from "zod";
+import { tool } from "../../tool.js";
+import { toContent } from "../../util.js";
+import { getAliases } from "../../../projectUtils.js";
+import { dump } from "js-yaml";
+import { getAllAccounts } from "../../../auth.js";
+
+export const get_environment = tool(
+  {
+    name: "get_environment",
+    description:
+      "Retrieves information about the current Firebase environment including current user, project directory, active project, and more.",
+    inputSchema: z.object({}),
+    annotations: {
+      title: "Get Firebase Environment Info",
+      readOnlyHint: true,
+    },
+    _meta: {
+      requiresAuth: false,
+      requiresProject: false,
+    },
+  },
+  async (_, { projectId, host, accountEmail, rc, config }) => {
+    const aliases = projectId ? getAliases({ rc }, projectId) : [];
+    return toContent(`# Environment Information
+
+Project Directory: ${host.projectRoot}${host.fixedRoot ? " (immutable - set via startup flag)" : ""}
+Project Config Path: ${config.path("firebase.json")}
+Active Project ID: ${
+      projectId ? `${projectId}${aliases.length ? ` (alias: ${aliases.join(",")})` : ""}` : "<NONE>"
+    }
+Authenticated User: ${accountEmail || "<NONE>"}
+
+# Available Project Aliases (format: '[alias]: [projectId]')
+
+${dump(rc.projects).trim()}
+
+# Available Accounts:
+
+${dump(getAllAccounts().map((account) => account.user.email)).trim()}
+
+# firebase.json contents:
+
+\`\`\`json
+${config.readProjectFile("firebase.json")}
+\`\`\``);
+  },
+);

src/mcp/tools/core/index.ts

@@ -5,11 +5,13 @@ import { get_project } from "./get_project.js";
 import { use_project } from "./use_project.js";
 import { get_sdk_config } from "./get_sdk_config.js";
 import { list_apps } from "./list_apps.js";
+import { get_environment } from "./get_environment.js";
 
 export const coreTools: ServerTool[] = [
   get_project,
   use_project,
   list_apps,
   get_sdk_config,
   consult_assistant,
+  // get_environment, // leaving commented out for the moment
 ];