✨ feat: application

add pglite application

package.json

@@ -9,6 +9,7 @@
     "lint": "next lint"
   },
   "dependencies": {
+    "@electric-sql/pglite": "^0.2.14",
     "@hookform/resolvers": "^3.3.4",
     "@mlc-ai/web-llm": "^0.2.46",
     "@modelcontextprotocol/sdk": "^1.0.1",

src/components/applications/index.tsx

@@ -2,10 +2,12 @@
 
 import React from "react";
 import exampleRegister from "@/lib/applications/example";
+import pgliteRegister from "@/lib/applications/pglite";
 
 export default function ApplicationsRegister() {
     React.useEffect(() => {
         exampleRegister();
+        pgliteRegister();
     }, []);
     return null;
 }

src/lib/applications/pglite/client.ts

@@ -0,0 +1,18 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+
+export const starter = async (transport: Transport) => {
+  const client = new Client(
+    {
+      name: "pglite-client",
+      version: "1.0.0",
+    },
+    {
+      capabilities: {},
+    }
+  );
+
+  await client.connect(transport);
+
+  return client;
+};

src/lib/applications/pglite/index.ts

@@ -0,0 +1,10 @@
+import { registerClient, registerServer } from "../base/host";
+import { starter as clientStarter } from "./client";
+import { starter as serverStarter } from "./server";
+
+const register = () => {
+  registerClient("pglite", clientStarter);
+  registerServer("pglite", serverStarter);
+};
+
+export default register;

src/lib/applications/pglite/server.ts

@@ -0,0 +1,113 @@
+import { Server } from "@modelcontextprotocol/sdk/server/index.js";
+import {
+  CallToolRequestSchema,
+  ListResourcesRequestSchema,
+  ListToolsRequestSchema,
+  ReadResourceRequestSchema,
+} from "@modelcontextprotocol/sdk/types.js";
+import { Transport } from "@modelcontextprotocol/sdk/shared/transport.js";
+import { PGlite } from "@electric-sql/pglite";
+
+const mainDb = new PGlite("idb://xp-main-pgdata");
+
+export const starter = async (transport: Transport) => {
+  const server = new Server(
+    {
+      name: "pglite-server",
+      version: "1.0.0",
+    },
+    {
+      capabilities: {
+        resources: {},
+        tools: {},
+      },
+    }
+  );
+
+  const SCHEMA_PATH = "schema";
+
+  server.setRequestHandler(ListResourcesRequestSchema, async () => {
+    const result = await mainDb.query(
+      "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'"
+    );
+    return {
+      resources: (result.rows as any[]).map((row) => ({
+        uri: new URL(`${row.table_name}/${SCHEMA_PATH}`).href,
+        mimeType: "application/json",
+        name: `"${row.table_name}" database schema`,
+      })),
+    };
+  });
+
+  server.setRequestHandler(ReadResourceRequestSchema, async (request) => {
+    const resourceUrl = new URL(request.params.uri);
+
+    const pathComponents = resourceUrl.pathname.split("/");
+    const schema = pathComponents.pop();
+    const tableName = pathComponents.pop();
+
+    if (schema !== SCHEMA_PATH) {
+      throw new Error("Invalid resource URI");
+    }
+
+    const result = await mainDb.query(
+      "SELECT column_name, data_type FROM information_schema.columns WHERE table_name = $1",
+      [tableName]
+    );
+
+    return {
+      contents: [
+        {
+          uri: request.params.uri,
+          mimeType: "application/json",
+          text: JSON.stringify(result.rows, null, 2),
+        },
+      ],
+    };
+  });
+
+  server.setRequestHandler(ListToolsRequestSchema, async () => {
+    return {
+      tools: [
+        {
+          name: "query",
+          description: "Run a read-only SQL query",
+          inputSchema: {
+            type: "object",
+            properties: {
+              sql: { type: "string" },
+            },
+          },
+        },
+      ],
+    };
+  });
+
+  server.setRequestHandler(CallToolRequestSchema, async (request) => {
+    if (request.params.name === "query") {
+      const sql = request.params.arguments?.sql as string;
+
+      try {
+        await mainDb.query("BEGIN TRANSACTION READ ONLY");
+        const result = await mainDb.query(sql);
+        return {
+          content: [
+            { type: "text", text: JSON.stringify(result.rows, null, 2) },
+          ],
+          isError: false,
+        };
+      } catch (error) {
+        throw error;
+      } finally {
+        mainDb
+          .query("ROLLBACK")
+          .catch((error) =>
+            console.warn("Could not roll back transaction:", error)
+          );
+      }
+    }
+    throw new Error(`Unknown tool: ${request.params.name}`);
+  });
+
+  await server.connect(transport);
+};