8fa2961ffc* basic-host: filter non-ui tools * basic-host: filter app-only tools, prioritize UI tools - Filter out tools with visibility: ['app'] from host tool list - Sort tools to show UI-enabled tools first, then alphabetically - Add local isToolVisibleToModel helper in basic-host
530 lines
17 KiB
TypeScript
530 lines
17 KiB
TypeScript
import { getToolUiResourceUri, McpUiToolMetaSchema } from "@modelcontextprotocol/ext-apps/app-bridge";
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import type { Tool } from "@modelcontextprotocol/sdk/types.js";
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import { Component, type ErrorInfo, type ReactNode, StrictMode, Suspense, use, useEffect, useMemo, useRef, useState } from "react";
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import { createRoot } from "react-dom/client";
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import { callTool, connectToServer, hasAppHtml, initializeApp, loadSandboxProxy, log, newAppBridge, type ServerInfo, type ToolCallInfo, type ModelContext, type AppMessage } from "./implementation";
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import styles from "./index.module.css";
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/**
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* Check if a tool is visible to the model (not app-only).
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* Tools with `visibility: ["app"]` should not be shown in tool lists.
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*/
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function isToolVisibleToModel(tool: { _meta?: Record<string, unknown> }): boolean {
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const result = McpUiToolMetaSchema.safeParse(tool._meta?.ui);
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if (!result.success) return true; // default: visible to model
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const visibility = result.data.visibility;
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if (!visibility) return true; // default: visible to model
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return visibility.includes("model");
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}
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/** Compare tools: UI-enabled first, then alphabetically by name. */
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function compareTools(a: Tool, b: Tool): number {
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const aHasUi = !!getToolUiResourceUri(a);
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const bHasUi = !!getToolUiResourceUri(b);
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if (aHasUi && !bHasUi) return -1;
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if (!aHasUi && bHasUi) return 1;
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return a.name.localeCompare(b.name);
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}
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/**
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* Extract default values from a tool's JSON Schema inputSchema.
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* Returns a formatted JSON string with defaults, or "{}" if none found.
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*/
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function getToolDefaults(tool: Tool | undefined): string {
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if (!tool?.inputSchema?.properties) return "{}";
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const defaults: Record<string, unknown> = {};
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for (const [key, prop] of Object.entries(tool.inputSchema.properties)) {
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if (prop && typeof prop === "object" && "default" in prop) {
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defaults[key] = prop.default;
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}
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}
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return Object.keys(defaults).length > 0
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? JSON.stringify(defaults, null, 2)
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: "{}";
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}
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// Host passes serversPromise to CallToolPanel
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interface HostProps {
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serversPromise: Promise<ServerInfo[]>;
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}
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type ToolCallEntry = ToolCallInfo & { id: number };
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let nextToolCallId = 0;
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function Host({ serversPromise }: HostProps) {
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const [toolCalls, setToolCalls] = useState<ToolCallEntry[]>([]);
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const [destroyingIds, setDestroyingIds] = useState<Set<number>>(new Set());
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const requestClose = (id: number) => {
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setDestroyingIds((s) => new Set(s).add(id));
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};
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const completeClose = (id: number) => {
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setDestroyingIds((s) => {
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const next = new Set(s);
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next.delete(id);
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return next;
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});
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setToolCalls((calls) => calls.filter((c) => c.id !== id));
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};
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return (
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<>
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{toolCalls.map((info) => (
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<ToolCallInfoPanel
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key={info.id}
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toolCallInfo={info}
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isDestroying={destroyingIds.has(info.id)}
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onRequestClose={() => requestClose(info.id)}
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onCloseComplete={() => completeClose(info.id)}
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/>
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))}
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<CallToolPanel
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serversPromise={serversPromise}
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addToolCall={(info) => setToolCalls([...toolCalls, { ...info, id: nextToolCallId++ }])}
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/>
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</>
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);
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}
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// CallToolPanel renders the unified form with Suspense around ServerSelect
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interface CallToolPanelProps {
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serversPromise: Promise<ServerInfo[]>;
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addToolCall: (info: ToolCallInfo) => void;
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}
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function CallToolPanel({ serversPromise, addToolCall }: CallToolPanelProps) {
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const [selectedServer, setSelectedServer] = useState<ServerInfo | null>(null);
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const [selectedTool, setSelectedTool] = useState("");
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const [inputJson, setInputJson] = useState("{}");
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// Filter out app-only tools, prioritize tools with UIs
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const toolNames = selectedServer
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? Array.from(selectedServer.tools.values())
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.filter((tool) => isToolVisibleToModel(tool))
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.sort(compareTools)
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.map((tool) => tool.name)
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: [];
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const isValidJson = useMemo(() => {
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try {
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JSON.parse(inputJson);
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return true;
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} catch {
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return false;
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}
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}, [inputJson]);
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const handleServerSelect = (server: ServerInfo) => {
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setSelectedServer(server);
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// Filter out app-only tools, prioritize tools with UIs
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const visibleTools = Array.from(server.tools.values())
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.filter((tool) => isToolVisibleToModel(tool))
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.sort(compareTools);
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const firstTool = visibleTools[0]?.name ?? "";
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setSelectedTool(firstTool);
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// Set input JSON to tool defaults (if any)
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setInputJson(getToolDefaults(server.tools.get(firstTool)));
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};
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const handleToolSelect = (toolName: string) => {
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setSelectedTool(toolName);
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// Set input JSON to tool defaults (if any)
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setInputJson(getToolDefaults(selectedServer?.tools.get(toolName)));
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};
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const handleSubmit = () => {
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if (!selectedServer) return;
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const toolCallInfo = callTool(selectedServer, selectedTool, JSON.parse(inputJson));
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addToolCall(toolCallInfo);
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};
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return (
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<div className={styles.callToolPanel}>
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<form onSubmit={(e) => { e.preventDefault(); handleSubmit(); }}>
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<label>
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Server
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<Suspense fallback={<select disabled><option>Loading...</option></select>}>
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<ServerSelect serversPromise={serversPromise} onSelect={handleServerSelect} />
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</Suspense>
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</label>
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<label>
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Tool
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<select
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className={styles.toolSelect}
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value={selectedTool}
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onChange={(e) => handleToolSelect(e.target.value)}
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>
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{selectedServer && toolNames.map((name) => (
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<option key={name} value={name}>{name}</option>
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))}
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</select>
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</label>
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<label>
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Input
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<textarea
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className={styles.toolInput}
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aria-invalid={!isValidJson}
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value={inputJson}
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onChange={(e) => setInputJson(e.target.value)}
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/>
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</label>
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<button type="submit" disabled={!selectedTool || !isValidJson}>
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Call Tool
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</button>
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</form>
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</div>
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);
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}
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// ServerSelect calls use() and renders the server <select>
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interface ServerSelectProps {
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serversPromise: Promise<ServerInfo[]>;
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onSelect: (server: ServerInfo) => void;
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}
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function ServerSelect({ serversPromise, onSelect }: ServerSelectProps) {
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const servers = use(serversPromise);
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const [selectedIndex, setSelectedIndex] = useState(0);
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useEffect(() => {
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if (servers.length > selectedIndex) {
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onSelect(servers[selectedIndex]);
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}
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}, [servers]);
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if (servers.length === 0) {
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return <select disabled><option>No servers configured</option></select>;
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}
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return (
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<select
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value={selectedIndex}
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onChange={(e) => {
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const newIndex = Number(e.target.value);
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setSelectedIndex(newIndex);
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onSelect(servers[newIndex]);
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}}
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>
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{servers.map((server, i) => (
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<option key={i} value={i}>{server.name}</option>
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))}
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</select>
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);
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}
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interface ToolCallInfoPanelProps {
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toolCallInfo: ToolCallInfo;
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isDestroying?: boolean;
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onRequestClose?: () => void;
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onCloseComplete?: () => void;
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}
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function ToolCallInfoPanel({ toolCallInfo, isDestroying, onRequestClose, onCloseComplete }: ToolCallInfoPanelProps) {
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const isApp = hasAppHtml(toolCallInfo);
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// For non-app tool calls, close immediately when isDestroying becomes true
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useEffect(() => {
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if (isDestroying && !isApp) {
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onCloseComplete?.();
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}
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}, [isDestroying, isApp, onCloseComplete]);
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return (
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<div
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className={styles.toolCallInfoPanel}
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style={isDestroying ? { opacity: 0.5, pointerEvents: "none" } : undefined}
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>
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{/* For non-app tools, show input/output side by side */}
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{!isApp && (
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<div className={styles.inputInfoPanel}>
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<h2>
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<span>{toolCallInfo.serverInfo.name}</span>
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<span className={styles.toolName}>{toolCallInfo.tool.name}</span>
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{onRequestClose && !isDestroying && (
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<button
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className={styles.closeButton}
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onClick={onRequestClose}
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title="Close"
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>
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×
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</button>
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)}
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</h2>
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<JsonBlock value={toolCallInfo.input} />
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</div>
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)}
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<div className={isApp ? styles.appOutputPanel : styles.outputInfoPanel}>
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{/* For apps, show header above the app: ServerName:tool_name */}
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{isApp && (
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<div className={styles.appHeader}>
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<span>{toolCallInfo.serverInfo.name}:<span className={styles.toolName}>{toolCallInfo.tool.name}</span></span>
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{onRequestClose && !isDestroying && (
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<button
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className={styles.closeButton}
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onClick={onRequestClose}
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title="Close"
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>
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×
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</button>
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)}
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</div>
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)}
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<ErrorBoundary>
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<Suspense fallback="Loading...">
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{
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isApp
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? <AppIFramePanel
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toolCallInfo={toolCallInfo}
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isDestroying={isDestroying}
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onTeardownComplete={onCloseComplete}
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/>
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: <ToolResultPanel toolCallInfo={toolCallInfo} />
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}
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</Suspense>
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</ErrorBoundary>
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</div>
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</div>
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);
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}
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function JsonBlock({ value }: { value: object }) {
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return (
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<pre className={styles.jsonBlock}>
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<code>{JSON.stringify(value, null, 2)}</code>
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</pre>
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);
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}
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interface CollapsiblePanelProps {
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icon: string;
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label: string;
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content: string;
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badge?: string;
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defaultExpanded?: boolean;
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}
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function CollapsiblePanel({ icon, label, content, badge, defaultExpanded = false }: CollapsiblePanelProps) {
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const [expanded, setExpanded] = useState(defaultExpanded);
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return (
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<div
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className={styles.collapsiblePanel}
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onClick={() => setExpanded(!expanded)}
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title={expanded ? "Click to collapse" : "Click to expand"}
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>
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<div className={styles.collapsibleHeader}>
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<span className={styles.collapsibleLabel}>{icon} {label}</span>
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<span className={styles.collapsibleSize}>
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{badge ?? `${content.length} chars`}
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</span>
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<span className={styles.collapsibleToggle}>
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{expanded ? "▼" : "▶"}
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</span>
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</div>
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{expanded ? (
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<pre className={styles.collapsibleFull}>{content}</pre>
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) : (
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<div className={styles.collapsiblePreview}>
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{content.slice(0, 100)}{content.length > 100 ? "…" : ""}
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</div>
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)}
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</div>
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);
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}
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interface AppIFramePanelProps {
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toolCallInfo: Required<ToolCallInfo>;
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isDestroying?: boolean;
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onTeardownComplete?: () => void;
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}
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function AppIFramePanel({ toolCallInfo, isDestroying, onTeardownComplete }: AppIFramePanelProps) {
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const iframeRef = useRef<HTMLIFrameElement | null>(null);
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const appBridgeRef = useRef<ReturnType<typeof newAppBridge> | null>(null);
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const [modelContext, setModelContext] = useState<ModelContext | null>(null);
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const [toolResult, setToolResult] = useState<object | null>(null);
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const [messages, setMessages] = useState<AppMessage[]>([]);
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useEffect(() => {
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const iframe = iframeRef.current!;
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// First get CSP and permissions from resource, then load sandbox
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// CSP is set via HTTP headers (tamper-proof), permissions via iframe allow attribute
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toolCallInfo.appResourcePromise.then(({ csp, permissions }) => {
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loadSandboxProxy(iframe, csp, permissions).then((firstTime) => {
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// The `firstTime` check guards against React Strict Mode's double
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// invocation (mount → unmount → remount simulation in development).
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// Outside of Strict Mode, this `useEffect` runs only once per
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// `toolCallInfo`.
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if (firstTime) {
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const appBridge = newAppBridge(toolCallInfo.serverInfo, iframe, {
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onContextUpdate: setModelContext,
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onMessage: (msg) => setMessages((prev) => [...prev, msg]),
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});
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appBridgeRef.current = appBridge;
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initializeApp(iframe, appBridge, toolCallInfo);
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}
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});
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});
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// Track tool result for display
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toolCallInfo.resultPromise.then(setToolResult).catch(() => {});
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}, [toolCallInfo]);
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// Graceful teardown: wait for guest to respond before unmounting
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// This follows the spec: "Host SHOULD wait for a response before tearing
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// down the resource (to prevent data loss)."
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useEffect(() => {
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if (!isDestroying) return;
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if (!appBridgeRef.current) {
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// Bridge not ready yet (e.g., user closed before iframe loaded)
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onTeardownComplete?.();
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return;
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}
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log.info("Sending teardown notification to MCP App");
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appBridgeRef.current.teardownResource({})
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.catch((err) => {
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log.warn("Teardown request failed (app may have already closed):", err);
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})
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.finally(() => {
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onTeardownComplete?.();
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});
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}, [isDestroying, onTeardownComplete]);
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// Format content blocks - handle text, images, resources, etc.
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const formatContentBlock = (c: { type: string; [key: string]: unknown }) => {
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switch (c.type) {
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case "text":
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return (c as { type: "text"; text: string }).text;
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case "image":
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return `<image: ${(c as { mimeType?: string }).mimeType ?? "unknown"}>`;
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case "audio":
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return `<audio: ${(c as { mimeType?: string }).mimeType ?? "unknown"}>`;
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case "resource":
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return `<resource: ${(c as { resource?: { uri?: string } }).resource?.uri ?? "unknown"}>`;
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default:
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return `<${c.type}>`;
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}
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};
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// Format context for display
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const contextText = modelContext?.content?.map(formatContentBlock).join("\n") ?? "";
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const contextJson = modelContext?.structuredContent
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? JSON.stringify(modelContext.structuredContent, null, 2)
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: "";
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const fullContext = [contextText, contextJson].filter(Boolean).join("\n\n");
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const inputJson = JSON.stringify(toolCallInfo.input, null, 2);
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const resultJson = toolResult ? JSON.stringify(toolResult, null, 2) : null;
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// Format messages
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const formatMessage = (m: AppMessage) => {
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const content = m.content.map(formatContentBlock).join("\n");
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return `[${m.role}] ${content}`;
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};
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const messagesText = messages.map(formatMessage).join("\n\n");
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return (
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<div className={styles.appIframePanel}>
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<CollapsiblePanel icon="📥" label="Tool Input" content={inputJson} />
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<iframe ref={iframeRef} />
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{resultJson && (
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<CollapsiblePanel icon="📤" label="Tool Result" content={resultJson} />
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)}
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{messages.length > 0 && (
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<CollapsiblePanel
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icon="💬"
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label="Messages"
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content={messagesText}
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badge={`${messages.length} message${messages.length > 1 ? "s" : ""}`}
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/>
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)}
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{modelContext && (
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<CollapsiblePanel icon="📋" label="Model Context" content={fullContext} />
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)}
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</div>
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);
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}
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interface ToolResultPanelProps {
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toolCallInfo: ToolCallInfo;
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}
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function ToolResultPanel({ toolCallInfo }: ToolResultPanelProps) {
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const result = use(toolCallInfo.resultPromise);
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return <JsonBlock value={result} />;
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}
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interface ErrorBoundaryProps {
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children: ReactNode;
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}
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interface ErrorBoundaryState {
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hasError: boolean;
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error: unknown;
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}
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class ErrorBoundary extends Component<ErrorBoundaryProps, ErrorBoundaryState> {
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state: ErrorBoundaryState = { hasError: false, error: undefined };
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// Called during render phase - must be pure (no side effects)
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// Note: error is `unknown` because JS allows throwing any value
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static getDerivedStateFromError(error: unknown): ErrorBoundaryState {
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return { hasError: true, error };
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}
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// Called during commit phase - can have side effects (logging, etc.)
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componentDidCatch(error: unknown, errorInfo: ErrorInfo): void {
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log.error("Caught:", error, errorInfo.componentStack);
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}
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render(): ReactNode {
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if (this.state.hasError) {
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const { error } = this.state;
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const message = error instanceof Error ? error.message : String(error);
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return <div className={styles.error}><strong>ERROR:</strong> {message}</div>;
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}
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return this.props.children;
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}
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}
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async function connectToAllServers(): Promise<ServerInfo[]> {
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const serverUrlsResponse = await fetch("/api/servers");
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const serverUrls = (await serverUrlsResponse.json()) as string[];
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// Use allSettled to be resilient to individual server failures
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const results = await Promise.allSettled(
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serverUrls.map((url) => connectToServer(new URL(url)))
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);
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const servers: ServerInfo[] = [];
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for (let i = 0; i < results.length; i++) {
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const result = results[i];
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if (result.status === "fulfilled") {
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servers.push(result.value);
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} else {
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console.warn(`[HOST] Failed to connect to ${serverUrls[i]}:`, result.reason);
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}
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}
|
||
|
||
if (servers.length === 0 && serverUrls.length > 0) {
|
||
throw new Error(`Failed to connect to any servers (${serverUrls.length} attempted)`);
|
||
}
|
||
|
||
return servers;
|
||
}
|
||
|
||
createRoot(document.getElementById("root")!).render(
|
||
<StrictMode>
|
||
<ErrorBoundary>
|
||
<Host serversPromise={connectToAllServers()} />
|
||
</ErrorBoundary>
|
||
</StrictMode>,
|
||
);
|