feat: Externalize MCP server (#19699)

nzakas · mdjermanovic · web-flow · commit ba456e000e10 · 2025-05-15T11:31:14.000+02:00
* feat: Move MCP server to @eslint/mcp fixes #19682 * Remove unused dependencies * Update docs * Update docs/src/use/mcp.md Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com> * Install @eslint/mcp --------- Co-authored-by: Milos Djermanovic <milos.djermanovic@gmail.com>
diff --git a/bin/eslint.js b/bin/eslint.js
@@ -157,19 +157,15 @@ ${getErrorMessage(error)}`;
 
 	// start the MCP server if `--mcp` is present
 	if (process.argv.includes("--mcp")) {
-		const { mcpServer } = require("../lib/mcp/mcp-server");
-		const {
-			StdioServerTransport,
-		} = require("@modelcontextprotocol/sdk/server/stdio.js");
-
-		await mcpServer.connect(new StdioServerTransport());
+		console.warn(
+			"You can also run this command directly using 'npx @eslint/mcp@latest'.",
+		);
 
-		// Note: do not use console.log() because stdout is part of the server transport
-		console.error(`ESLint MCP server is running. cwd: ${process.cwd()}`);
+		const spawn = require("cross-spawn");
 
-		process.on("SIGINT", () => {
-			mcpServer.close();
-			process.exitCode = 0;
+		spawn.sync("npx", ["@eslint/mcp@latest"], {
+			encoding: "utf8",
+			stdio: "inherit",
 		});
 		return;
 	}
diff --git a/docs/src/use/mcp.md b/docs/src/use/mcp.md
@@ -23,7 +23,7 @@ Create a `.vscode/mcp.json` file in your project with the following configuratio
 		"ESLint": {
 			"type": "stdio",
 			"command": "npx",
-			"args": ["eslint", "--mcp"]
+			"args": ["@eslint/mcp@latest"]
 		}
 	}
 }
@@ -34,7 +34,7 @@ Alternatively, you can use the Command Palette:
 1. Press `Ctrl+Shift+P` (Windows/Linux) or `Cmd+Shift+P` (macOS)
 2. Type and select `MCP: Add Server`
 3. Select `Command (stdio)` from the dropdown
-4. Enter `npx eslint --mcp` as the command
+4. Enter `npx @eslint/mcp@latest` as the command
 5. Type `ESLint` as the server ID
 6. Choose `Workspace Settings` to create the configuration in `.vscode/mcp.json`
 
@@ -76,7 +76,7 @@ Create a `.cursor/mcp.json` file in your project directory with the following co
 	"mcpServers": {
 		"eslint": {
 			"command": "npx",
-			"args": ["eslint", "--mcp"],
+			"args": ["@eslint/mcp@latest"],
 			"env": {}
 		}
 	}
@@ -112,7 +112,7 @@ Add the following configuration to your `~/.codeium/windsurf/mcp_config.json` fi
 	"mcpServers": {
 		"eslint": {
 			"command": "npx",
-			"args": ["eslint", "--mcp"],
+			"args": ["@eslint/mcp@latest"],
 			"env": {}
 		}
 	}
diff --git a/lib/mcp/mcp-server.js b/lib/mcp/mcp-server.js
diff --git a/package.json b/package.json
@@ -115,7 +115,6 @@
     "@humanfs/node": "^0.16.6",
     "@humanwhocodes/module-importer": "^1.0.1",
     "@humanwhocodes/retry": "^0.4.2",
-    "@modelcontextprotocol/sdk": "^1.8.0",
     "@types/estree": "^1.0.6",
     "@types/json-schema": "^7.0.15",
     "ajv": "^6.12.4",
@@ -139,8 +138,7 @@
     "lodash.merge": "^4.6.2",
     "minimatch": "^3.1.2",
     "natural-compare": "^1.4.0",
-    "optionator": "^0.9.3",
-    "zod": "^3.24.2"
+    "optionator": "^0.9.3"
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "^0.17.0",
diff --git a/tests/bin/eslint.js b/tests/bin/eslint.js
@@ -1241,7 +1241,7 @@ describe("bin/eslint.js", () => {
 			});
 
 			child.stderr.on("data", data => {
-				assert.match(data.toString(), /ESLint MCP server is running/u);
+				assert.match(data.toString(), /@eslint\/mcp/u);
 				done();
 			});
 		});
diff --git a/tests/lib/mcp/mcp-server.js b/tests/lib/mcp/mcp-server.js

Original file line number	Diff line number	Diff line change
@@ -23,7 +23,7 @@ Create a `.vscode/mcp.json` file in your project with the following configuratio
`23`	`23`	`"ESLint": {`
`24`	`24`	`"type": "stdio",`
`25`	`25`	`"command": "npx",`
`26`		`- "args": ["eslint", "--mcp"]`
	`26`	`+ "args": ["@eslint/mcp@latest"]`
`27`	`27`	`}`
`28`	`28`	`}`
`29`	`29`	`}`
`@@ -34,7 +34,7 @@ Alternatively, you can use the Command Palette:`
`34`	`34`	1. Press `Ctrl+Shift+P` (Windows/Linux) or `Cmd+Shift+P` (macOS)
`35`	`35`	2. Type and select `MCP: Add Server`
`36`	`36`	3. Select `Command (stdio)` from the dropdown
`37`		-4. Enter `npx eslint --mcp` as the command
	`37`	+4. Enter `npx @eslint/mcp@latest` as the command
`38`	`38`	5. Type `ESLint` as the server ID
`39`	`39`	6. Choose `Workspace Settings` to create the configuration in `.vscode/mcp.json`
`40`	`40`
@@ -76,7 +76,7 @@ Create a `.cursor/mcp.json` file in your project directory with the following co
`76`	`76`	`"mcpServers": {`
`77`	`77`	`"eslint": {`
`78`	`78`	`"command": "npx",`
`79`		`- "args": ["eslint", "--mcp"],`
	`79`	`+ "args": ["@eslint/mcp@latest"],`
`80`	`80`	`"env": {}`
`81`	`81`	`}`
`82`	`82`	`}`
@@ -112,7 +112,7 @@ Add the following configuration to your `~/.codeium/windsurf/mcp_config.json` fi
`112`	`112`	`"mcpServers": {`
`113`	`113`	`"eslint": {`
`114`	`114`	`"command": "npx",`
`115`		`- "args": ["eslint", "--mcp"],`
	`115`	`+ "args": ["@eslint/mcp@latest"],`
`116`	`116`	`"env": {}`
`117`	`117`	`}`
`118`	`118`	`}`