mcp: pre-initialize tools and resources on server startup

src/mcp/Server.zig

@@ -4,6 +4,7 @@ const lp = @import("lightpanda");
 
 const App = @import("../App.zig");
 const HttpClient = @import("../http/Client.zig");
+const protocol = @import("protocol.zig");
 const Self = @This();
 
 allocator: std.mem.Allocator,
@@ -15,6 +16,9 @@ browser: *lp.Browser,
 session: *lp.Session,
 page: *lp.Page,
 
+tools: []const protocol.Tool,
+resources: []const protocol.Resource,
+
 is_running: std.atomic.Value(bool) = .init(false),
 
 stdout_mutex: std.Thread.Mutex = .{},
@@ -40,9 +44,117 @@ pub fn init(allocator: std.mem.Allocator, app: *App) !*Self {
     self.session = try self.browser.newSession(self.notification);
     self.page = try self.session.createPage();
 
+    self.tools = try initTools(allocator);
+    self.resources = try initResources(allocator);
+
     return self;
 }
 
+fn initTools(allocator: std.mem.Allocator) ![]const protocol.Tool {
+    const tools = try allocator.alloc(protocol.Tool, 6);
+    errdefer allocator.free(tools);
+
+    tools[0] = .{
+        .name = "goto",
+        .description = "Navigate to a specified URL and load the page in memory so it can be reused later for info extraction.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "url": { "type": "string", "description": "The URL to navigate to, must be a valid URL." }
+            \\  },
+            \\  "required": ["url"]
+            \\}
+        , .{}),
+    };
+    tools[1] = .{
+        .name = "search",
+        .description = "Use a search engine to look for specific words, terms, sentences. The search page will then be loaded in memory.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "text": { "type": "string", "description": "The text to search for, must be a valid search query." }
+            \\  },
+            \\  "required": ["text"]
+            \\}
+        , .{}),
+    };
+    tools[2] = .{
+        .name = "markdown",
+        .description = "Get the page content in markdown format. If a url is provided, it navigates to that url first.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "url": { "type": "string", "description": "Optional URL to navigate to before fetching markdown." }
+            \\  }
+            \\}
+        , .{}),
+    };
+    tools[3] = .{
+        .name = "links",
+        .description = "Extract all links in the opened page. If a url is provided, it navigates to that url first.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "url": { "type": "string", "description": "Optional URL to navigate to before extracting links." }
+            \\  }
+            \\}
+        , .{}),
+    };
+    tools[4] = .{
+        .name = "evaluate",
+        .description = "Evaluate JavaScript in the current page context. If a url is provided, it navigates to that url first.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "script": { "type": "string" },
+            \\    "url": { "type": "string", "description": "Optional URL to navigate to before evaluating." }
+            \\  },
+            \\  "required": ["script"]
+            \\}
+        , .{}),
+    };
+    tools[5] = .{
+        .name = "over",
+        .description = "Used to indicate that the task is over and give the final answer if there is any. This is the last tool to be called in a task.",
+        .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, allocator,
+            \\{
+            \\  "type": "object",
+            \\  "properties": {
+            \\    "result": { "type": "string", "description": "The final result of the task." }
+            \\  },
+            \\  "required": ["result"]
+            \\}
+        , .{}),
+    };
+
+    return tools;
+}
+
+fn initResources(allocator: std.mem.Allocator) ![]const protocol.Resource {
+    const resources = try allocator.alloc(protocol.Resource, 2);
+    errdefer allocator.free(resources);
+
+    resources[0] = .{
+        .uri = "mcp://page/html",
+        .name = "Page HTML",
+        .description = "The serialized HTML DOM of the current page",
+        .mimeType = "text/html",
+    };
+    resources[1] = .{
+        .uri = "mcp://page/markdown",
+        .name = "Page Markdown",
+        .description = "The token-efficient markdown representation of the current page",
+        .mimeType = "text/markdown",
+    };
+
+    return resources;
+}
+
 pub fn deinit(self: *Self) void {
     self.is_running.store(false, .seq_cst);
 
@@ -51,6 +163,9 @@ pub fn deinit(self: *Self) void {
     self.notification.deinit();
     self.http_client.deinit();
 
+    self.allocator.free(self.tools);
+    self.allocator.free(self.resources);
+
     self.allocator.destroy(self);
 }
 

src/mcp/resources.zig

@@ -7,25 +7,10 @@ const protocol = @import("protocol.zig");
 const Server = @import("Server.zig");
 
 pub fn handleList(server: *Server, req: protocol.Request) !void {
-    const resources = [_]protocol.Resource{
-        .{
-            .uri = "mcp://page/html",
-            .name = "Page HTML",
-            .description = "The serialized HTML DOM of the current page",
-            .mimeType = "text/html",
-        },
-        .{
-            .uri = "mcp://page/markdown",
-            .name = "Page Markdown",
-            .description = "The token-efficient markdown representation of the current page",
-            .mimeType = "text/markdown",
-        },
-    };
-
     const result = struct {
         resources: []const protocol.Resource,
     }{
-        .resources = &resources,
+        .resources = server.resources,
     };
 
     try sendResult(server, req.id.?, result);

src/mcp/tools.zig

@@ -10,90 +10,11 @@ const protocol = @import("protocol.zig");
 const Server = @import("Server.zig");
 
 pub fn handleList(server: *Server, arena: std.mem.Allocator, req: protocol.Request) !void {
-    const tools = [_]protocol.Tool{
+    _ = arena;
-        .{
-            .name = "goto",
-            .description = "Navigate to a specified URL and load the page in memory so it can be reused later for info extraction.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "url": { "type": "string", "description": "The URL to navigate to, must be a valid URL." }
-                \\  },
-                \\  "required": ["url"]
-                \\}
-            , .{}),
-        },
-        .{
-            .name = "search",
-            .description = "Use a search engine to look for specific words, terms, sentences. The search page will then be loaded in memory.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "text": { "type": "string", "description": "The text to search for, must be a valid search query." }
-                \\  },
-                \\  "required": ["text"]
-                \\}
-            , .{}),
-        },
-        .{
-            .name = "markdown",
-            .description = "Get the page content in markdown format. If a url is provided, it navigates to that url first.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "url": { "type": "string", "description": "Optional URL to navigate to before fetching markdown." }
-                \\  }
-                \\}
-            , .{}),
-        },
-        .{
-            .name = "links",
-            .description = "Extract all links in the opened page. If a url is provided, it navigates to that url first.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "url": { "type": "string", "description": "Optional URL to navigate to before extracting links." }
-                \\  }
-                \\}
-            , .{}),
-        },
-        .{
-            .name = "evaluate",
-            .description = "Evaluate JavaScript in the current page context. If a url is provided, it navigates to that url first.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "script": { "type": "string" },
-                \\    "url": { "type": "string", "description": "Optional URL to navigate to before evaluating." }
-                \\  },
-                \\  "required": ["script"]
-                \\}
-            , .{}),
-        },
-        .{
-            .name = "over",
-            .description = "Used to indicate that the task is over and give the final answer if there is any. This is the last tool to be called in a task.",
-            .inputSchema = try std.json.parseFromSliceLeaky(std.json.Value, arena,
-                \\{
-                \\  "type": "object",
-                \\  "properties": {
-                \\    "result": { "type": "string", "description": "The final result of the task." }
-                \\  },
-                \\  "required": ["result"]
-                \\}
-            , .{}),
-        },
-    };
-
     const result = struct {
         tools: []const protocol.Tool,
     }{
-        .tools = &tools,
+        .tools = server.tools,
     };
 
     try sendResult(server, req.id.?, result);