feat: add mcp server

3 files changed, 180 insertions, 0 deletions

diff --git a/mcp/server/README.md b/mcp/server/README.md
new file mode 100644
index 0000000..f2bda68
--- /dev/null
+++ b/mcp/server/README.md
@@ -0,0 +1,36 @@
+# MCP-Server
+
+Let LLM-functions tools/agents be used through the Model Context Protocol.
+
+## Serve tools
+
+```json
+{
+  "mcpServers": {
+    "tools": {
+      "command": "node",
+      "args": [
+        "<path-to-llm-functions>/mcp/server/index.js",
+        "<path-to-llm-functions>"
+      ]
+    }
+  }
+}
+```
+
+## Serve the agent
+
+```json
+{
+  "mcpServers": {
+    "<agent-name>": {
+      "command": "node",
+      "args": [
+        "<path-to-llm-functions>/mcp/server/index.js",
+        "<path-to-llm-functions>",
+        "<agent-name>",
+      ]
+    }
+  }
+}
+```
diff --git a/mcp/server/index.js b/mcp/server/index.js
new file mode 100755
index 0000000..d725568
--- /dev/null
+++ b/mcp/server/index.js
@@ -0,0 +1,120 @@
+#!/usr/bin/env node
+
+import * as path from "node:path";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import { v4 as uuid } from "uuid";
+import { spawn } from "node:child_process";
+import { Server } from "@modelcontextprotocol/sdk/server/index.js";
+import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
+import {
+  CallToolRequestSchema,
+  ErrorCode,
+  ListToolsRequestSchema,
+  McpError,
+} from "@modelcontextprotocol/sdk/types.js";
+
+let [rootDir, agentName] = process.argv.slice(2);
+if (!rootDir) {
+  console.error("Usage: mcp-llm-functions <llm-functions-dir> [<agent-name>]");
+  process.exit(1);
+}
+rootDir = path.resolve(rootDir);
+
+let functionsJsonPath = path.join(rootDir, "functions.json");
+if (agentName) {
+  functionsJsonPath = path.join(rootDir, "agents", agentName, "functions.json");
+}
+let functions = [];
+try {
+  const data = await fs.promises.readFile(functionsJsonPath, "utf8");
+  functions = JSON.parse(data);
+} catch {
+  console.error(`Failed to read functions at '${functionsJsonPath}'`);
+  process.exit(1);
+}
+const env = Object.assign({}, process.env, {
+  PATH: `${path.join(rootDir, "bin")}:${process.env.PATH}`
+});
+
+const server = new Server(
+  {
+    name: `llm-functions/${agentName || "common-tools"}`,
+    version: "0.1.0",
+  },
+  {
+    capabilities: {
+      tools: {},
+    },
+  },
+);
+
+server.setRequestHandler(ListToolsRequestSchema, async () => {
+  return {
+    tools: functions.map((f) => ({
+      name: f.name,
+      description: f.description,
+      inputSchema: f.parameters,
+    })),
+  };
+});
+
+server.setRequestHandler(CallToolRequestSchema, async (request) => {
+  const functionObj = functions.find((f) => f.name === request.params.name);
+  if (!functionObj) {
+    throw new McpError(ErrorCode.InvalidRequest, `Unexpected tool '${request.params.name}'`);
+  }
+  let command = request.params.name;
+  let args = [JSON.stringify(request.params.arguments || {})];
+  if (agentName && functionObj.agent) {
+    args.unshift(command);
+    command = agentName;
+  }
+  const tmpFile = path.join(os.tmpdir(), `mcp-llm-functions-${process.pid}-eval-${uuid()}`);
+  const { exitCode, stderr } = await runCommand(command, args, { ...env, LLM_OUTPUT: tmpFile });
+  if (exitCode === 0) {
+    let output = '';
+    try {
+      output = await fs.promises.readFile(tmpFile, "utf8");
+    } catch { };
+    return {
+      content: [{ type: "text", value: output }],
+    }
+  } else {
+    return {
+      isError: true,
+      error: stderr,
+    };
+  }
+});
+
+function runCommand(command, args, env) {
+  return new Promise((resolve, reject) => {
+    const child = spawn(command, args, {
+      stdio: ['ignore', 'ignore', 'pipe'],
+      env,
+    });
+
+    let stderr = '';
+
+    child.stderr.on('data', (data) => {
+      stderr += data.toString();
+    });
+
+    child.on('close', (exitCode) => {
+      resolve({ exitCode, stderr });
+    });
+
+    child.on('error', (err) => {
+      reject(err);
+    });
+  });
+}
+
+async function runServer() {
+  const transport = new StdioServerTransport();
+  await server.connect(transport);
+  console.error("LLM-Functions MCP Server running on stdio");
+}
+
+runServer().catch(console.error);
\ No newline at end of file
diff --git a/mcp/server/package.json b/mcp/server/package.json
new file mode 100644
index 0000000..69bbcc2
--- /dev/null
+++ b/mcp/server/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "mcp-llm-functions",
+  "version": "1.0.0",
+  "description": "Let LLM-functions tools/agents be used through the Model Context Protocol",
+  "license": "MIT",
+  "author": "sigoden <sigoden@gmail.com>",
+  "homepage": "https://github.com/sigoden/llm-functions/tree/main/mcp/server",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/sigoden/llm-functions.git",
+    "directory": "mcp/server"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "type": "module",
+  "bin": {
+    "mcp-llm-functions": "index.js"
+  },
+  "dependencies": {
+    "@modelcontextprotocol/sdk": "^1.0.3",
+    "uuid": "^11.0.3"
+  }
+}