ui: add browser get_info tool (#27251)

* ui: add browser get_info tool

* format

* nits

* Update tools/ui/src/lib/stores/tools.svelte.ts

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

---------

Co-authored-by: Aleksander Grygier <aleksander.grygier@gmail.com>

tools/ui/src/lib/constants/browser-info.ts

@@ -0,0 +1,36 @@
+import { CLI_FLAGS } from './cli-flags.constants';
+import { BuiltInTool, JsonSchemaType, ToolCallType } from '$lib/enums';
+import type { OpenAIToolDefinition } from '$lib/types';
+
+export const BROWSER_INFO_TOOL_NAME = BuiltInTool.GET_INFO;
+
+/** UA token to OS name, first match wins - Android and iOS UAs also carry the Linux / Mac OS X tokens */
+export const BROWSER_INFO_OS_UA_PATTERNS: readonly [RegExp, string][] = [
+	[/Windows NT/, 'Windows'],
+	[/Android/, 'Android'],
+	[/iPhone|iPad|iPod/, 'iOS'],
+	[/CrOS/, 'ChromeOS'],
+	[/Mac OS X/, 'macOS'],
+	[/Linux/, 'Linux']
+];
+
+export const BROWSER_INFO_OS_UNKNOWN = 'unknown';
+
+/** Sent to the model as the `note` field of the tool result, next to the OS name */
+export const BROWSER_INFO_NOTE = `This environment is browser-only, it cannot read or modify local files, and it cannot run shell commands. To get local file access, tell user to launch llama-server with the ${CLI_FLAGS.AGENT} argument.`;
+
+export function buildBrowserInfoToolDefinition(): OpenAIToolDefinition {
+	return {
+		function: {
+			description:
+				'Get runtime info (OS name), may call when user asks about local files or shell commands',
+			name: BROWSER_INFO_TOOL_NAME,
+			parameters: {
+				properties: {},
+				required: [],
+				type: JsonSchemaType.OBJECT
+			}
+		},
+		type: ToolCallType.FUNCTION
+	};
+}

tools/ui/src/lib/constants/cli-flags.constants.ts

@@ -1,4 +1,5 @@
 export const CLI_FLAGS = {
+	AGENT: '--agent',
 	API_KEY: '--api-key',
 	MCP_PROXY: '--ui-mcp-proxy',
 	SLOTS: '--slots',

tools/ui/src/lib/constants/index.ts

@@ -59,3 +59,4 @@ export * from './uri-template.constants';
 export * from './url.constants';
 export * from './working-directory.constants';
 export * from './read-media';
+export * from './browser-info';