fix: scope env substitution to targeted servers

.github/workflows/release.yml

@@ -51,6 +51,9 @@ jobs:
 
       - name: Build Linux x64
         run: bun build --compile --minify --target=bun-linux-x64 src/index.ts --outfile dist/mcp-cli-linux-x64
+
+      - name: Build Linux ARM64
+        run: bun build --compile --minify --target=bun-linux-arm64 src/index.ts --outfile dist/mcp-cli-linux-arm64
 
       - name: Build macOS x64
         run: bun build --compile --minify --target=bun-darwin-x64 src/index.ts --outfile dist/mcp-cli-darwin-x64
@@ -95,6 +98,7 @@ jobs:
           generate_release_notes: true
           files: |
             dist/mcp-cli-linux-x64
+            dist/mcp-cli-linux-arm64
             dist/mcp-cli-darwin-x64
             dist/mcp-cli-darwin-arm64
             dist/checksums.txt

src/commands/call.ts

@@ -110,13 +110,6 @@ async function parseArgs(
 export async function callCommand(options: CallOptions): Promise<void> {
   let config: McpServersConfig;
 
-  try {
-    config = await loadConfig(options.configPath);
-  } catch (error) {
-    console.error((error as Error).message);
-    process.exit(ErrorCode.CLIENT_ERROR);
-  }
-
   let serverName: string;
   let toolName: string;
 
@@ -129,6 +122,21 @@ export async function callCommand(options: CallOptions): Promise<void> {
     process.exit(ErrorCode.CLIENT_ERROR);
   }
 
+  try {
+    config = await loadConfig({
+      explicitPath: options.configPath,
+      serverNames: [serverName],
+    });
+  } catch (error) {
+     console.error((error as Error).message);
+     process.exit(ErrorCode.CLIENT_ERROR);
+   }
+
+  try {
+    console.error((error as Error).message);
+    process.exit(ErrorCode.CLIENT_ERROR);
+  }
+
   let serverConfig: ServerConfig;
   try {
     serverConfig = getServerConfig(config, serverName);

src/commands/info.ts

@@ -40,15 +40,18 @@ function parseTarget(target: string): { server: string; tool?: string } {
 export async function infoCommand(options: InfoOptions): Promise<void> {
   let config: McpServersConfig;
 
+  const { server: serverName, tool: toolName } = parseTarget(options.target);
+
   try {
-    config = await loadConfig(options.configPath);
+    config = await loadConfig({
+      explicitPath: options.configPath,
+      serverNames: [serverName],
+    });
   } catch (error) {
     console.error((error as Error).message);
     process.exit(ErrorCode.CLIENT_ERROR);
   }
 
-  const { server: serverName, tool: toolName } = parseTarget(options.target);
-
   let serverConfig: ServerConfig;
   try {
     serverConfig = getServerConfig(config, serverName);

src/config.ts

@@ -56,6 +56,11 @@ export interface McpServersConfig {
   mcpServers: Record<string, ServerConfig>;
 }
 
+export interface LoadConfigOptions {
+  explicitPath?: string;
+  serverNames?: string[];
+}
+
 // ============================================================================
 // Tool Filtering
 // ============================================================================
@@ -397,13 +402,16 @@ function getDefaultConfigPaths(): string[] {
  * Load and parse MCP servers configuration
  */
 export async function loadConfig(
-  explicitPath?: string,
+  input?: string | LoadConfigOptions,
 ): Promise<McpServersConfig> {
+  const options: LoadConfigOptions =
+    typeof input === 'string' ? { explicitPath: input } : input ?? {};
+
   let configPath: string | undefined;
 
   // Check explicit path from argument or environment
-  if (explicitPath) {
-    configPath = resolve(explicitPath);
+  if (options.explicitPath) {
+    configPath = resolve(options.explicitPath);
   } else if (process.env.MCP_CONFIG_PATH) {
     configPath = resolve(process.env.MCP_CONFIG_PATH);
   }
@@ -496,8 +504,26 @@ export async function loadConfig(
     }
   }
 
-  // Substitute environment variables
-  config = substituteEnvVarsInObject(config);
+  // Substitute environment variables only for the relevant servers.
+  // This avoids warning about unrelated missing variables when a command
+  // targets a single server (for example: `mcp-cli info chrome-devtools`).
+  if (options.serverNames && options.serverNames.length > 0) {
+    const targetServers = new Set(options.serverNames);
+    const substitutedServers: Record<string, ServerConfig> = {};
+
+    for (const [serverName, serverConfig] of Object.entries(config.mcpServers)) {
+      substitutedServers[serverName] = targetServers.has(serverName)
+        ? substituteEnvVarsInObject(serverConfig)
+        : serverConfig;
+    }
+
+    config = {
+      ...config,
+      mcpServers: substitutedServers,
+    };
+  } else {
+    config = substituteEnvVarsInObject(config);
+  }
 
   return config;
 }

tests/config.test.ts

@@ -128,6 +128,35 @@ describe('config', () => {
       await expect(loadConfig(configPath)).rejects.toThrow('MISSING_ENV_VAR');
     });
 
+    test('only substitutes env vars for targeted servers', async () => {
+      delete process.env.MCP_STRICT_ENV;
+
+      const configPath = join(tempDir, 'targeted_env.json');
+      await writeFile(
+        configPath,
+        JSON.stringify({
+          mcpServers: {
+            chrome: {
+              command: 'echo',
+              args: ['ok'],
+            },
+            context7: {
+              command: 'echo',
+              env: { API_KEY: '${MISSING_CONTEXT7_API_KEY}' },
+            },
+          },
+        })
+      );
+
+      const config = await loadConfig({
+        explicitPath: configPath,
+        serverNames: ['chrome'],
+      });
+
+      expect((config.mcpServers.chrome as any).command).toBe('echo');
+      expect((config.mcpServers.context7 as any).env.API_KEY).toBe('${MISSING_CONTEXT7_API_KEY}');
+    });
+
     test('throws error on empty server config', async () => {
       const configPath = join(tempDir, 'empty_server.json');
       await writeFile(