> ## Documentation Index > Fetch the complete documentation index at: https://langchain-zh.cn/llms.txt > Use this file to discover all available pages before exploring further. # 沙盒 > 为基于沙盒环境的编码智能体构建类 IDE 的用户界面 export const PatternEmbed = ({pattern, theme, height, minHeight = 400, maxHeight = 700, className, defaultView = "preview", defaultSdk = "react", defaultLanguage = "js", showCodeTab = true, agentServer = "prod", onError, onReady}) => { var VALID_GUEST_TYPES = new Set(["READY", "RESIZE", "ERROR", "RUN_STARTED", "TRACE_URL", "THREAD_CLEARED"]); function stub() { return { safeParse: data => ({ success: true, data }), optional: () => stub(), min: () => stub(), url: () => stub() }; } var z = { object: _shape => stub(), literal: _value => stub(), string: () => stub(), number: () => stub(), boolean: () => stub(), enum: _values => stub(), array: _el => stub(), union: _schemas => stub(), record: (_key, _value) => stub(), discriminatedUnion: (_key, _schemas) => ({ safeParse(data) { if (data != null && typeof data === "object" && ("type" in data) && typeof data.type === "string" && VALID_GUEST_TYPES.has(data.type)) { return { success: true, data }; } return { success: false }; }, optional: () => stub(), min: () => stub(), url: () => stub() }) }; var SetThemeMessageSchema = z.object({ type: z.literal("SET_THEME"), theme: z.enum(["light", "dark"]) }); var SetPatternMessageSchema = z.object({ type: z.literal("SET_PATTERN"), slug: z.string() }); var ResetMessageSchema = z.object({ type: z.literal("RESET") }); var SetViewMessageSchema = z.object({ type: z.literal("SET_VIEW"), view: z.enum(["preview", "code"]) }); var SetLanguageMessageSchema = z.object({ type: z.literal("SET_LANGUAGE"), language: z.enum(["js", "python"]) }); var CodeFileSchema = z.object({ filename: z.string(), content: z.string() }); var UpdateCodeMessageSchema = z.object({ type: z.literal("UPDATE_CODE"), files: z.array(CodeFileSchema).min(1), entryFile: z.string() }); var TrackEventMessageSchema = z.object({ type: z.literal("TRACK_EVENT"), name: z.string(), properties: z.record(z.string(), z.union([z.string(), z.number(), z.boolean()])).optional() }); var HostToGuestMessageSchema = z.discriminatedUnion("type", [SetThemeMessageSchema, SetPatternMessageSchema, ResetMessageSchema, UpdateCodeMessageSchema, SetViewMessageSchema, SetLanguageMessageSchema, TrackEventMessageSchema]); var ReadyMessageSchema = z.object({ type: z.literal("READY"), framework: z.enum(["react", "vue", "angular", "svelte"]) }); var ResizeMessageSchema = z.object({ type: z.literal("RESIZE"), height: z.number() }); var ErrorMessageSchema = z.object({ type: z.literal("ERROR"), message: z.string(), stack: z.string().optional() }); var RunStartedMessageSchema = z.object({ type: z.literal("RUN_STARTED"), runId: z.string() }); var TraceUrlMessageSchema = z.object({ type: z.literal("TRACE_URL"), url: z.string().url(), runId: z.string() }); var ThreadClearedMessageSchema = z.object({ type: z.literal("THREAD_CLEARED") }); var GuestToHostMessageSchema = z.discriminatedUnion("type", [ReadyMessageSchema, ResizeMessageSchema, ErrorMessageSchema, RunStartedMessageSchema, TraceUrlMessageSchema, ThreadClearedMessageSchema]); var PreviewMessageSchema = z.union([HostToGuestMessageSchema, GuestToHostMessageSchema]); function isOriginAllowed(origin, allowedOrigins) { return allowedOrigins.includes("*") || allowedOrigins.includes(origin); } function createPreviewHost(iframe, options) { const {allowedOrigins} = options; const targetOrigins = options.targetOrigins ?? allowedOrigins; const listeners = new Map(); function postToGuest(message) { if (!iframe.contentWindow) return; for (const origin of targetOrigins) { iframe.contentWindow.postMessage(message, origin); } } function addListener(type, callback) { if (!listeners.has(type)) { listeners.set(type, new Set()); } listeners.get(type).add(callback); return () => { listeners.get(type)?.delete(callback); }; } function handleMessage(event) { if (!isOriginAllowed(event.origin, allowedOrigins)) return; const result = GuestToHostMessageSchema.safeParse(event.data); if (!result.success) return; const msg = result.data; const cbs = listeners.get(msg.type); if (!cbs) return; for (const cb of cbs) { switch (msg.type) { case "READY": cb(msg.framework); break; case "RESIZE": cb(msg.height); break; case "ERROR": cb(msg.message, msg.stack); break; case "RUN_STARTED": cb(msg.runId); break; case "TRACE_URL": cb(msg.url, msg.runId); break; case "THREAD_CLEARED": cb(); break; } } } window.addEventListener("message", handleMessage); return { setTheme(theme) { postToGuest({ type: "SET_THEME", theme }); }, setPattern(slug) { postToGuest({ type: "SET_PATTERN", slug }); }, setView(view) { postToGuest({ type: "SET_VIEW", view }); }, setLanguage(language) { postToGuest({ type: "SET_LANGUAGE", language }); }, updateCode(files, entryFile) { postToGuest({ type: "UPDATE_CODE", files, entryFile }); }, reset() { postToGuest({ type: "RESET" }); }, trackEvent(name, properties) { postToGuest({ type: "TRACK_EVENT", name, properties }); }, onReady(callback) { return addListener("READY", callback); }, onResize(callback) { return addListener("RESIZE", callback); }, onError(callback) { return addListener("ERROR", callback); }, onRunStarted(callback) { return addListener("RUN_STARTED", callback); }, onTraceUrl(callback) { return addListener("TRACE_URL", callback); }, onThreadCleared(callback) { return addListener("THREAD_CLEARED", callback); }, destroy() { window.removeEventListener("message", handleMessage); listeners.clear(); } }; } var PROD_BASE = "https://ui-patterns.langchain.com"; var SDK_LABELS = { react: "React", vue: "Vue", svelte: "Svelte", angular: "Angular" }; var SDK_LOCAL_HOSTS = { react: "http://localhost:4100", vue: "http://localhost:4200", svelte: "http://localhost:4300", angular: "http://localhost:4400" }; var SDK_PROD_HOSTS = { react: `${PROD_BASE}/react`, vue: `${PROD_BASE}/vue`, svelte: `${PROD_BASE}/svelte`, angular: `${PROD_BASE}/angular` }; var SDK_LOGOS = { react: ``, vue: ``, svelte: ``, angular: `` }; var PROD_AGENT_API_BASE = `${PROD_BASE}/api/langgraph`; function normalizeAgentServerBase(agentServer, useLocalPreview) { const trimmed = agentServer.trim(); if (useLocalPreview) { return "http://localhost:2024"; } if (trimmed === "prod") { return PROD_AGENT_API_BASE; } if (trimmed === "local") { return PROD_AGENT_API_BASE; } return PROD_AGENT_API_BASE; } function isLocalhost() { if (typeof window === "undefined") return false; const {hostname} = window.location; return hostname === "localhost" || hostname === "127.0.0.1" || hostname === "[::]"; } function detectPageTheme() { if (typeof document === "undefined") return "light"; const el = document.documentElement; if (el.classList.contains("dark")) return "dark"; if (el.getAttribute("data-theme") === "dark") return "dark"; if (el.style.colorScheme === "dark") return "dark"; return "light"; } var CACHE_KEY = "__lcPlaygroundIframeCache"; var iframeCache = globalThis[CACHE_KEY] ?? (() => { const m = new Map(); globalThis[CACHE_KEY] = m; return m; })(); var SDK_CACHE_KEY = "__lcPlaygroundSdkCache"; var sdkCache = globalThis[SDK_CACHE_KEY] ?? (() => { const m = new Map(); globalThis[SDK_CACHE_KEY] = m; return m; })(); var LANG_CACHE_KEY = "__lcPlaygroundLangCache"; var langCache = globalThis[LANG_CACHE_KEY] ?? (() => { const m = new Map(); globalThis[LANG_CACHE_KEY] = m; return m; })(); var VIEW_EYE_SVG = ``; var VIEW_CODE_SVG = ``; var CHEVRON_DOWN_SVG = ``; var TRACE_ICON_SVG = ``; var TRACE_SPINNER_SVG = ``; var EXTERNAL_LINK_SVG = ``; var DOWNLOAD_SVG = ``; var EXPAND_SVG = ``; var CLOSE_SVG = ``; var LANG_TS_SVG = ``; var LANG_PYTHON_SVG = ` `; var SDK_OPTIONS = Object.keys(SDK_LABELS).map(k => [k, SDK_LABELS[k]]); var EMBED_CSS = ` [data-lc-pe] .lc-tab{font-size:13px;font-family:inherit} [data-lc-pe] .lc-sdk-option{font-size:13px} [data-lc-pe] .lc-border{border-color:#B8DFFF} [data-lc-pe].dark .lc-border{border-color:#1A2740} [data-lc-pe] .lc-bg-surface{background-color:white} [data-lc-pe].dark .lc-bg-surface{background-color:#0B1120} [data-lc-pe] .lc-bg-wash{background-color:#F2FAFF} [data-lc-pe].dark .lc-bg-wash{background-color:#030710} [data-lc-pe] .lc-tab-active{background-color:#7FC8FF;color:#030710} [data-lc-pe] .lc-tab-inactive{background-color:transparent;color:#6B8299} [data-lc-pe] .lc-tab-inactive:hover{background-color:#E5F4FF;color:#030710} [data-lc-pe].dark .lc-tab-inactive:hover{background-color:#1A2740;color:#C8DDF0} [data-lc-pe] .lc-tab-trace{background-color:#FFF3E0;color:#E65100} [data-lc-pe].dark .lc-tab-trace{background-color:#3E2723;color:#FFB74D} [data-lc-pe] .lc-tab-trace:hover{background-color:#FFE0B2} [data-lc-pe].dark .lc-tab-trace:hover{background-color:#4E342E} [data-lc-pe] .lc-tab-trace-loading{background-color:transparent;color:#6B8299;cursor:not-allowed} [data-lc-pe] .lc-sdk-btn{border-color:#B8DFFF;background-color:white;font-size:13px;color:#030710} [data-lc-pe].dark .lc-sdk-btn{border-color:#1A2740;background-color:#0B1120;color:#C8DDF0} [data-lc-pe] .lc-sdk-btn:hover{background-color:#E5F4FF} [data-lc-pe].dark .lc-sdk-btn:hover{background-color:#1A2740} [data-lc-pe] .lc-dropdown{border-color:#B8DFFF;background-color:white;min-width:120px} [data-lc-pe].dark .lc-dropdown{border-color:#1A2740;background-color:#0B1120} [data-lc-pe] .lc-sdk-selected{background-color:#E5F4FF;color:#030710} [data-lc-pe].dark .lc-sdk-selected{background-color:#1A2740;color:#C8DDF0} [data-lc-pe] .lc-sdk-unselected{color:#6B8299} [data-lc-pe] .lc-sdk-unselected:hover{background-color:#F2FAFF;color:#030710} [data-lc-pe].dark .lc-sdk-unselected:hover{background-color:#1A2740;color:#C8DDF0} [data-lc-pe] .lc-spinner{border-color:#B8DFFF;border-top-color:#7FC8FF} [data-lc-pe].dark .lc-spinner{border-color:#1A2740;border-top-color:#7FC8FF} [data-lc-pe] .lc-error{background-color:rgb(178 125 117/0.1);border-color:rgb(178 125 117/0.3);color:#B27D75} [data-lc-pe] .lc-error-btn{border-color:rgb(178 125 117/0.3);background-color:white;color:#B27D75} [data-lc-pe].dark .lc-error-btn{background-color:#0B1120} [data-lc-pe] .lc-lang-switcher .lc-tab{padding:4px 8px} @media(max-width:639px){ [data-lc-pe] .lc-toolbar{flex-wrap:wrap;gap:8px} [data-lc-pe] .lc-tab-label{display:none} [data-lc-pe] .lc-tab{padding-left:10px;padding-right:10px} [data-lc-pe] .lc-sdk-btn{margin-left:auto} } [data-lc-pe] .lc-expand-btn{border:none;background:transparent;cursor:pointer;padding:6px;border-radius:6px;display:inline-flex;align-items:center;justify-content:center;color:#6B8299;transition:background-color 0.15s,color 0.15s} [data-lc-pe] .lc-expand-btn:hover{background-color:#E5F4FF;color:#030710} [data-lc-pe].dark .lc-expand-btn:hover{background-color:#1A2740;color:#C8DDF0} .lc-pe-backdrop{position:fixed;inset:0;z-index:9998;background:rgba(0,0,0,0.4);backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px)} `; const slotRef = useRef(null); const cardRef = useRef(null); const placeholderRef = useRef(null); const cachedRef = useRef(null); const useLocalPreview = agentServer === "local" || agentServer === "prod" && isLocalhost(); const agentQuery = agentServer !== "local" && agentServer !== "prod" ? `?agentServer=${encodeURIComponent(agentServer)}` : ""; const sdkCacheKey = `${agentServer}|${pattern}`; const [sdk, setSdkRaw] = useState(() => { const fromCache = sdkCache.get(sdkCacheKey); if (fromCache) return fromCache; const hosts = useLocalPreview ? SDK_LOCAL_HOSTS : SDK_PROD_HOSTS; let best = null; for (const [s, url] of Object.entries(hosts)) { const entry = iframeCache.get(`${url}|${agentQuery}`); if (entry?.lastActiveAt && (!best || entry.lastActiveAt > best.at)) { best = { sdk: s, at: entry.lastActiveAt }; } } if (best) return best.sdk; return defaultSdk; }); const setSdk = useCallback(s => { sdkCache.set(sdkCacheKey, s); setSdkRaw(s); }, [sdkCacheKey]); const [sdkDropdownOpen, setSdkDropdownOpen] = useState(false); const langCacheKey = `${agentServer}|${pattern}`; const [agentLang, setAgentLangRaw] = useState(() => langCache.get(langCacheKey) ?? defaultLanguage); const setAgentLang = useCallback(l => { langCache.set(langCacheKey, l); setAgentLangRaw(l); }, [langCacheKey]); const previewUrl = useLocalPreview ? SDK_LOCAL_HOSTS[sdk] : SDK_PROD_HOSTS[sdk]; const cacheKey = `${previewUrl}|${agentQuery}`; const [ready, setReady] = useState(() => iframeCache.get(cacheKey)?.ready ?? false); const [iframeHeight, setIframeHeight] = useState(() => iframeCache.get(cacheKey)?.lastHeight ?? minHeight); const [error, setError] = useState(null); const [activeView, setActiveView] = useState(() => iframeCache.get(cacheKey)?.lastView ?? defaultView); const [traceUrl, setTraceUrl] = useState(null); const [traceLoading, setTraceLoading] = useState(false); const [expanded, setExpanded] = useState(false); const expandedRef = useRef(false); expandedRef.current = expanded; const [pageTheme, setPageTheme] = useState(detectPageTheme); useEffect(() => { setPageTheme(detectPageTheme()); const observer = new MutationObserver(() => setPageTheme(detectPageTheme())); observer.observe(document.documentElement, { attributes: true, attributeFilter: ["class", "data-theme", "style"] }); return () => observer.disconnect(); }, []); const effectiveTheme = theme ?? pageTheme; useEffect(() => { if (document.getElementById("lc-pe-css")) return; const style = document.createElement("style"); style.id = "lc-pe-css"; style.textContent = EMBED_CSS; document.head.appendChild(style); }, []); const onErrorRef = useRef(onError); onErrorRef.current = onError; const onReadyRef = useRef(onReady); onReadyRef.current = onReady; const patternRef = useRef(pattern); patternRef.current = pattern; const themeRef = useRef(effectiveTheme); themeRef.current = effectiveTheme; const activeViewRef = useRef(activeView); activeViewRef.current = activeView; const agentLangRef = useRef(agentLang); agentLangRef.current = agentLang; useEffect(() => { let cached = iframeCache.get(cacheKey); if (cached?.hideTimer) { clearTimeout(cached.hideTimer); cached.hideTimer = void 0; } if (!cached) { const iframe2 = document.createElement("iframe"); iframe2.src = `${previewUrl}/${agentQuery}#/${patternRef.current}`; iframe2.setAttribute("sandbox", "allow-scripts allow-same-origin allow-forms"); iframe2.setAttribute("allow", "clipboard-write"); iframe2.title = `${patternRef.current} pattern`; iframe2.setAttribute("data-cache-key", cacheKey); Object.assign(iframe2.style, { position: "fixed", border: "none", visibility: "hidden", pointerEvents: "auto", zIndex: "1", borderRadius: "0 0 15px 15px" }); document.body.appendChild(iframe2); let iframeOrigin; try { iframeOrigin = new URL(previewUrl).origin; } catch { iframeOrigin = previewUrl; } const host2 = createPreviewHost(iframe2, { allowedOrigins: [iframeOrigin] }); cached = { iframe: iframe2, host: host2, ready: false, lastHeight: minHeight, lastView: defaultView, lastActiveAt: 0 }; iframeCache.set(cacheKey, cached); } cachedRef.current = cached; const {iframe, host} = cached; if (cached.ready) { setReady(true); setIframeHeight(cached.lastHeight); host.setTheme(themeRef.current); host.setPattern(patternRef.current); host.setLanguage(agentLangRef.current); if (activeViewRef.current !== "preview") { host.setView(activeViewRef.current); } cached.lastActiveAt = Date.now(); iframe.style.visibility = "visible"; } const unsubReady = host.onReady(() => { cached.ready = true; cached.lastActiveAt = Date.now(); setReady(true); host.setTheme(themeRef.current); host.setPattern(patternRef.current); host.setLanguage(agentLangRef.current); if (activeViewRef.current !== "preview") { host.setView(activeViewRef.current); } iframe.style.visibility = "visible"; onReadyRef.current?.(); }); const unsubResize = host.onResize(h => { if (expandedRef.current) return; const clamped = Math.min(maxHeight, Math.max(minHeight, h)); cached.lastHeight = clamped; setIframeHeight(clamped); }); const unsubError = host.onError((message, stack) => { setError(message); iframe.style.visibility = "hidden"; onErrorRef.current?.(message, stack); }); const unsubRunStarted = host.onRunStarted(() => { setTraceUrl(null); setTraceLoading(true); }); const unsubTraceUrl = host.onTraceUrl((url, _runId) => { setTraceUrl(url); setTraceLoading(false); }); const unsubThreadCleared = host.onThreadCleared(() => { setTraceUrl(null); setTraceLoading(false); }); function syncPosition() { const slot2 = slotRef.current; if (!slot2) return; const rect = slot2.getBoundingClientRect(); const {style} = iframe; style.top = `${rect.top}px`; style.left = `${rect.left}px`; style.width = `${rect.width}px`; style.setProperty("height", `${rect.height}px`, "important"); if (expandedRef.current) { style.zIndex = "10000"; } else { style.zIndex = "1"; } } syncPosition(); const ro = new ResizeObserver(syncPosition); if (slotRef.current) ro.observe(slotRef.current); document.addEventListener("scroll", syncPosition, { passive: true, capture: true }); window.addEventListener("resize", syncPosition, { passive: true }); let frameCount = 0; let rafId = 0; function initialSync() { syncPosition(); if (++frameCount < 5) rafId = requestAnimationFrame(initialSync); } rafId = requestAnimationFrame(initialSync); return () => { cancelAnimationFrame(rafId); ro.disconnect(); document.removeEventListener("scroll", syncPosition, { capture: true }); window.removeEventListener("resize", syncPosition); unsubReady(); unsubResize(); unsubError(); unsubRunStarted(); unsubTraceUrl(); unsubThreadCleared(); cachedRef.current = null; cached.hideTimer = setTimeout(() => { iframe.style.visibility = "hidden"; }, 200); }; }, [cacheKey, previewUrl, agentQuery, defaultView, minHeight, maxHeight]); useEffect(() => { requestAnimationFrame(() => window.dispatchEvent(new Event("resize"))); if (!expanded) return; const card = cardRef.current; const placeholder = placeholderRef.current; if (!card || !placeholder) return; const wrapper = document.createElement("div"); wrapper.setAttribute("data-lc-pe", ""); wrapper.className = `${effectiveTheme === "dark" ? "dark" : ""}`; document.body.appendChild(wrapper); const backdrop = document.createElement("div"); backdrop.className = "lc-pe-backdrop"; backdrop.addEventListener("click", () => setExpanded(false)); wrapper.appendChild(backdrop); wrapper.appendChild(card); Object.assign(card.style, { position: "fixed", zIndex: "9999", top: "50%", left: "50%", transform: "translate(-50%, -50%)", width: "min(70vw, calc(100vw - 48px))", height: "85vh", display: "flex", flexDirection: "column" }); const handleKeyDown = e => { if (e.key === "Escape") setExpanded(false); }; document.addEventListener("keydown", handleKeyDown); const pageWrapper = document.body.children[0]; const savedFilter = pageWrapper?.style.filter ?? ""; const savedPointerEvents = pageWrapper?.style.pointerEvents ?? ""; if (pageWrapper && pageWrapper !== wrapper) { pageWrapper.style.filter = "blur(4px)"; pageWrapper.style.pointerEvents = "none"; } requestAnimationFrame(() => window.dispatchEvent(new Event("resize"))); return () => { document.removeEventListener("keydown", handleKeyDown); if (pageWrapper && pageWrapper !== wrapper) { pageWrapper.style.filter = savedFilter; pageWrapper.style.pointerEvents = savedPointerEvents; } card.style.cssText = ""; placeholder.appendChild(card); wrapper.remove(); requestAnimationFrame(() => window.dispatchEvent(new Event("resize"))); }; }, [expanded, effectiveTheme]); useEffect(() => { if (!ready || !cachedRef.current) return; setError(null); cachedRef.current.host.setPattern(pattern); }, [pattern, ready]); useEffect(() => { if (!ready || !cachedRef.current) return; cachedRef.current.host.setTheme(effectiveTheme); }, [effectiveTheme, ready]); useEffect(() => { if (!ready || !cachedRef.current) return; cachedRef.current.host.setLanguage(agentLang); }, [agentLang, ready]); const switchView = useCallback(view => { setActiveView(view); if (cachedRef.current) { cachedRef.current.lastView = view; if (cachedRef.current.ready) { cachedRef.current.host.setView(view); if (view === "code") { cachedRef.current.host.trackEvent("code_tab_clicked", { pattern }); } } } }, [pattern]); const sdkButtonRef = useRef(null); useEffect(() => { if (!sdkDropdownOpen || !sdkButtonRef.current) return; const isDark = effectiveTheme === "dark"; const rect = sdkButtonRef.current.getBoundingClientRect(); const dropdown = document.createElement("div"); Object.assign(dropdown.style, { position: "fixed", top: `${rect.bottom + 4}px`, right: `${window.innerWidth - rect.right}px`, zIndex: expandedRef.current ? "10001" : "10", minWidth: "120px", borderRadius: "8px", border: `1px solid ${isDark ? "#1A2740" : "#B8DFFF"}`, backgroundColor: isDark ? "#0B1120" : "white", boxShadow: "0 4px 12px rgba(0,0,0,0.15)", padding: "4px 0" }); for (const [value, label] of SDK_OPTIONS) { const isSelected = value === sdk; const btn = document.createElement("button"); btn.type = "button"; Object.assign(btn.style, { display: "flex", alignItems: "center", gap: "6px", width: "100%", textAlign: "left", padding: "6px 12px", fontSize: "13px", cursor: "pointer", border: "none", fontWeight: isSelected ? "500" : "normal", backgroundColor: isSelected ? isDark ? "#1A2740" : "#E5F4FF" : "transparent", color: isSelected ? isDark ? "#C8DDF0" : "#030710" : "#6B8299" }); btn.innerHTML = `${SDK_LOGOS[value]}${label}`; btn.addEventListener("mouseenter", () => { if (!isSelected) { btn.style.backgroundColor = isDark ? "#1A2740" : "#F2FAFF"; btn.style.color = isDark ? "#C8DDF0" : "#030710"; } }); btn.addEventListener("mouseleave", () => { if (!isSelected) { btn.style.backgroundColor = "transparent"; btn.style.color = "#6B8299"; } }); btn.addEventListener("click", () => { setSdk(value); setSdkDropdownOpen(false); cachedRef.current?.host.trackEvent("sdk_switched", { sdk: value, pattern }); }); dropdown.appendChild(btn); } document.body.appendChild(dropdown); const handleClose = e => { if (!dropdown.contains(e.target) && !sdkButtonRef.current?.contains(e.target)) { setSdkDropdownOpen(false); } }; const timer = setTimeout(() => document.addEventListener("mousedown", handleClose), 0); return () => { clearTimeout(timer); document.removeEventListener("mousedown", handleClose); dropdown.remove(); }; }, [sdkDropdownOpen, sdk, effectiveTheme, setSdk, pattern]); const handleReset = useCallback(() => { cachedRef.current?.host.reset(); if (cachedRef.current?.ready) { cachedRef.current.host.setPattern(pattern); } }, [pattern]); const resolvedHeight = height ?? Math.min(maxHeight, Math.max(minHeight, iframeHeight)); const heightStyle = typeof resolvedHeight === "number" ? `${resolvedHeight}px` : resolvedHeight; useEffect(() => { if (!expanded) { slotRef.current?.style.setProperty("height", heightStyle, "important"); } else { slotRef.current?.style.removeProperty("height"); } }, [heightStyle, expanded]); const tabBase = "lc-tab inline-flex items-center gap-1.5 px-3.5 py-1.5 rounded-lg border-none font-medium cursor-pointer transition-all duration-150"; const tabActiveClass = `${tabBase} lc-tab-active shadow-sm`; const tabInactiveClass = `${tabBase} lc-tab-inactive`; const tabTraceActiveClass = `${tabBase} lc-tab-trace`; const tabTraceLoadingClass = `${tabBase} lc-tab-trace-loading`; const toolbar = showCodeTab &&
{(traceUrl || traceLoading) && !useLocalPreview && { if (!traceUrl) e.preventDefault(); else cachedRef.current?.host.trackEvent("trace_tab_clicked", { pattern }); }} className={traceUrl ? tabTraceActiveClass : tabTraceLoadingClass} aria-disabled={!traceUrl}> Trace {traceUrl && } }
{activeView === "code" &&
}
{} {}
; const slot =
{!ready && !error &&
} {error &&
Preview Error

{error}

}
; return
{toolbar} {slot}
; }; 编码智能体需要的不仅仅是一个聊天窗口。它们需要一个文件浏览器、代码查看器、差异面板，一个 IDE 体验。这种模式将一个深度智能体连接到一个[沙盒](/oss/python/deepagents/sandboxes)，使其能够在隔离环境中读取、写入和执行代码，然后通过自定义 API 服务器暴露沙盒文件系统，以便前端在智能体工作时实时显示文件。 ## 架构 沙盒模式包含三层： 1. **带有沙盒后端的深度智能体：** 智能体从沙盒自动获取文件系统工具（`read_file`、`write_file`、`edit_file`、`execute`） 2. **自定义 API 服务器** — 一个通过 `langgraph.json` 的 `http.app` 字段暴露的 FastAPI 应用，提供前端可以调用的文件浏览端点 3. **IDE 前端：** 一个三面板布局（文件树、代码/差异查看器、聊天），在智能体进行更改时实时同步文件 ```mermaid theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} %%{ init: { "fontFamily": "monospace", "flowchart": { "curve": "curve" } } }%% graph LR UI["IDE 前端"] API["API 服务器"] AGENT["createDeepAgent()"] SANDBOX["沙盒"] UI --"useStream()"--> AGENT UI --"/api/sandbox/:threadId/*"--> API AGENT --"read/write/execute"--> SANDBOX API --"ls / read"--> SANDBOX classDef blueHighlight fill:#DBEAFE,stroke:#2563EB,color:#1E3A8A; classDef greenHighlight fill:#DCFCE7,stroke:#16A34A,color:#14532D; classDef purpleHighlight fill:#EDE9FE,stroke:#7C3AED,color:#4C1D95; classDef orangeHighlight fill:#FEF3C7,stroke:#D97706,color:#92400E; class UI blueHighlight; class AGENT greenHighlight; class SANDBOX purpleHighlight; class API orangeHighlight; ``` ## 沙盒生命周期 在深入代码之前，了解沙盒的作用域策略很重要。作用域策略决定了谁共享一个沙盒、沙盒的存活时间以及运行时如何解析它。 ### 线程作用域的沙盒（推荐） 每个 LangGraph 线程都有自己的沙盒。沙盒 ID 存储在线程的元数据中，并通过后端工厂的 `runtime.configurable.thread_id` 解析。这是大多数应用程序的推荐方法： * 对话是隔离的 — 一个线程中的文件更改不会影响另一个线程 * 沙盒状态在页面重新加载时保持不变（相同线程 = 相同沙盒） * 清理很简单：当线程被删除时，其沙盒也可以被删除 ```mermaid theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} sequenceDiagram participant FE as 前端 participant LG as LangGraph API participant HTTP as API 服务器 participant SB as 沙盒 Note over FE: 页面加载 FE->>LG: POST /threads LG-->>FE: threadId FE->>HTTP: GET /api/sandbox/:threadId/tree HTTP->>LG: threads.get(threadId) → metadata.sandbox_id alt 尚无沙盒 HTTP->>SB: LangSmithSandbox.create() HTTP->>LG: threads.update(threadId, metadata.sandbox_id) else 已有沙盒 HTTP->>SB: connect(sandbox_id) end HTTP-->>FE: 文件树 Note over FE: 用户发送消息 FE->>LG: POST /threads/:threadId/runs/stream LG->>LG: 后端工厂从 runtime 读取 thread_id LG->>SB: 连接到同一沙盒 ``` ### 智能体作用域的沙盒 同一助手下的所有线程共享一个沙盒。适用于希望更改在不同对话间持续的持久化项目环境： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} def sandbox_backend_factory(runtime): assistant_id = runtime.config.get("configurable", {}).get("assistant_id") return get_or_create_sandbox_for_assistant(assistant_id) ``` ### 用户作用域的沙盒 每个用户在所有线程中拥有自己的沙盒。需要自定义身份验证和用户识别： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} def sandbox_backend_factory(runtime): user_id = runtime.config.get("configurable", {}).get("user_id") return get_or_create_sandbox_for_user(user_id) ``` ### 会话作用域的沙盒（客户端） 对于没有 LangGraph 线程的简单应用，前端可以生成一个会话 ID 并直接传递。这种方法不会在浏览器会话间持久化，最适合演示或原型设计： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} import uuid import urllib.parse import urllib.request session_id = str(uuid.uuid4()) query = urllib.parse.urlencode({"sessionId": session_id}) urllib.request.urlopen(f"http://localhost:2024/api/sandbox/tree?{query}") ``` 本指南的其余部分使用**线程作用域的沙盒**作为主要示例。 ## 设置智能体 ### 选择沙盒提供商 Deep Agents 支持多个[沙盒提供商](/oss/python/integrations/sandboxes)。任何实现 `SandboxBackendProtocol` 的提供商都可以使用： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} from deepagents import create_deep_agent from deepagents.sandbox import LangSmithSandbox # 或 DaytonaSandbox 等 sandbox = LangSmithSandbox.create() agent = create_deep_agent(model="anthropic:claude-sonnet-4-5", backend=sandbox) ``` 智能体会自动获取文件系统工具（`read_file`、`write_file`、`edit_file`、`ls`、`glob`、`grep`）和一个用于运行 shell 命令的 `execute` 工具。无需工具配置。 ### 为线程作用域的沙盒使用后端工厂 不要在模块级别创建沙盒（这将在所有线程间共享并可能过期），而是使用一个**后端工厂**，在运行时按线程解析沙盒。工厂接收一个 `BackendRuntime` 对象，其中包含来自当前 LangGraph 运行的 `configurable.thread_id`： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} from deepagents import create_deep_agent from deepagents.sandbox import LangSmithSandbox def sandbox_backend_factory(runtime): thread_id = runtime.config.get("configurable", {}).get("thread_id") if not thread_id: raise ValueError("No thread_id — agent must run on a thread") return get_or_create_sandbox_for_thread(thread_id) agent = create_deep_agent( model="anthropic:claude-sonnet-4-5", backend=sandbox_backend_factory, ) ``` ### 初始化沙盒 在智能体运行之前，使用 `uploadFiles` 将项目文件填充到沙盒中： 对于 **LangSmith** 沙盒，容器镜像和资源限制来自[沙盒模板](/langsmith/sandbox-templates)。在创建沙盒时传递 `templateName`（参见上面的 `getOrCreateSandboxForThread`）。`uploadFiles` 在运行时在该镜像之上初始化或更新项目文件。 ```ts theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} const SEED_FILES: Record = { "package.json": JSON.stringify({ name: "my-app", version: "1.0.0" }, null, 2), "src/index.js": 'console.log("Hello");', }; const encoder = new TextEncoder(); await sandbox.uploadFiles( Object.entries(SEED_FILES).map(([path, content]) => [`/app/${path}`, encoder.encode(content)]), ); ``` 上传 `package.json` 后，运行 `sandbox.execute("cd /app && npm install")`，以便在智能体开始之前安装依赖项。 ## 添加文件浏览 API 智能体可以读取和写入文件，但前端也需要直接访问来浏览沙盒文件系统。添加一个自定义的 [FastAPI](https://fastapi.tiangolo.com) API 服务器，并通过 `langgraph.json` 中的 `http.app` 字段暴露它。 ### 创建 API 服务器 沙盒 API 端点使用线程 ID 作为 URL 路径参数。这确保前端始终访问当前对话的正确沙盒，使用与智能体后端工厂相同的 `getOrCreateSandboxForThread` 函数： ```python theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} # src/api/server.py from fastapi import FastAPI, Query, Path from utils import get_or_create_sandbox_for_thread app = FastAPI() @app.get("/api/sandbox/{thread_id}/tree") async def list_tree( thread_id: str = Path(...), path: str = Query("/app"), ): sandbox = await get_or_create_sandbox_for_thread(thread_id) result = await sandbox.aexecute( f"find {path} -printf '%y\\t%s\\t%p\\n' 2>/dev/null | sort" ) entries = [] for line in result.output.strip().split("\n"): if not line: continue type_char, size_str, full_path = line.split("\t") entries.append({ "name": full_path.split("/")[-1], "type": "directory" if type_char == "d" else "file", "path": full_path, "size": int(size_str), }) return {"path": path, "entries": entries, "sandbox_id": sandbox.id} @app.get("/api/sandbox/{thread_id}/file") async def read_file( thread_id: str = Path(...), path: str = Query(...), ): sandbox = await get_or_create_sandbox_for_thread(thread_id) results = await sandbox.adownload_files([path]) return {"path": path, "content": results[0].content.decode()} ``` 智能体的后端工厂和 API 服务器都调用相同的 `getOrCreateSandboxForThread` 函数。这确保它们对于给定线程始终解析到相同的沙盒。线程元数据中的沙盒 ID 是单一事实来源 — 无需内存缓存。 ### 配置 `langgraph.json` 注册智能体图和 API 服务器。`http.app` 字段告诉 LangGraph 平台在默认路由旁边提供你的自定义路由： :::python ```json theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} { "graphs": { "coding_agent": "./src/agents/my_agent.py:agent" }, "env": ".env", "http": { "app": "./src/api/server.py:app" } } ``` ::> 你的自定义路由可在与 LangGraph API 相同的主机上使用。对于使用 `langgraph dev` 的本地开发，地址是 `http://localhost:2024`。 在 `http.app` 中定义的自定义路由优先于默认的 LangGraph 路由。这意味着如果需要，你可以覆盖内置端点，但注意不要意外覆盖像 `/threads` 或 `/runs` 这样的路由。 ## 构建前端 前端有三个面板：文件树侧边栏、代码/差异查看器和聊天面板。它使用 `useStream` 进行智能体对话，并使用自定义 API 端点进行文件浏览。 ### 线程创建 页面加载时创建一个 LangGraph 线程，并将其 ID 持久化在 `sessionStorage` 中，以便页面重新加载时重新连接到同一个沙盒： ```tsx theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} const THREAD_KEY = "sandbox-thread-id"; function IDEPreview() { const [threadId, setThreadId] = useState( () => sessionStorage.getItem(THREAD_KEY), ); const updateThreadId = useCallback((id: string | null) => { setThreadId(id); if (id) sessionStorage.setItem(THREAD_KEY, id); else sessionStorage.removeItem(THREAD_KEY); }, []); const stream = useStream({ apiUrl: AGENT_URL, assistantId: "coding_agent", threadId, onThreadId: updateThreadId, }); // 首次挂载时创建线程 useEffect(() => { if (threadId) return; stream.client.threads.create().then((t) => updateThreadId(t.thread_id)); }, [stream.client, threadId, updateThreadId]); // 将 threadId 传递给沙盒文件钩子 const { tree, files } = useSandboxFiles(threadId); // ... } ``` “新建线程”按钮清除存储的 ID，以便下次挂载时创建一个新线程（和新沙盒）： ```tsx theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} function handleNewThread() { stream.switchThread(null); updateThreadId(null); } ``` ### 文件状态管理 跟踪沙盒文件系统的两个快照：原始状态（智能体运行前）和当前状态（实时更新）。线程 ID 包含在 API URL 中，以确保请求始终命中正确的沙盒： ```ts theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} const AGENT_URL = "http://localhost:2024"; async function fetchTree(threadId: string): Promise { const res = await fetch( `${AGENT_URL}/api/sandbox/${encodeURIComponent(threadId)}/tree?filePath=/app`, ); const data = await res.json(); return data.entries.filter((e: FileEntry) => !e.path.includes("node_modules")); } async function fetchFile(threadId: string, path: string): Promise { const res = await fetch( `${AGENT_URL}/api/sandbox/${encodeURIComponent(threadId)}/file?filePath=${encodeURIComponent(path)}`, ); const data = await res.json(); return data.content ?? null; } ``` ### 实时文件同步 IDE 体验的关键是在**智能体工作时**更新文件，而不是在它完成后。监视流消息中来自文件修改工具的 `ToolMessage` 实例。当 `write_file` 或 `edit_file` 工具调用完成时，刷新该特定文件。当 `execute` 完成时，刷新所有文件（因为 shell 命令可能修改任何文件）： ```tsx React theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} import { useStream } from "@langchain/react"; import { ToolMessage, AIMessage } from "langchain"; const FILE_MUTATING_TOOLS = new Set(["write_file", "edit_file", "execute"]); export function IDEPreview() { const stream = useStream({ apiUrl: AGENT_URL, assistantId: "coding_agent", }); const processedIds = useRef(new Set()); useEffect(() => { // 从 AI 消息构建文件修改工具调用的映射 const toolCallMap = new Map(); for (const msg of stream.messages) { if (!AIMessage.isInstance(msg)) continue; for (const tc of msg.tool_calls ?? []) { if (tc.id && FILE_MUTATING_TOOLS.has(tc.name)) { toolCallMap.set(tc.id, { name: tc.name, args: tc.args }); } } } // 当出现文件修改工具的 ToolMessage 时，刷新 for (const msg of stream.messages) { if (!ToolMessage.isInstance(msg)) continue; const id = msg.id ?? msg.tool_call_id; if (!id || processedIds.current.has(id)) continue; const call = toolCallMap.get(msg.tool_call_id); if (!call) continue; processedIds.current.add(id); if (call.name === "write_file" || call.name === "edit_file") { refreshSingleFile(call.args.path); } else if (call.name === "execute") { refreshAllFiles(); } } }, [stream.messages]); } ``` ```vue Vue theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} ``` ```svelte Svelte theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} ``` ```ts Angular theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} import { Component, effect } from "@angular/core"; import { useStream } from "@langchain/angular"; import { ToolMessage, AIMessage } from "langchain"; const FILE_MUTATING_TOOLS = new Set(["write_file", "edit_file", "execute"]); @Component({ selector: "app-ide-preview", template: ``, }) export class IdePreviewComponent { stream = useStream({ apiUrl: AGENT_URL, assistantId: "coding_agent", }); private processedIds = new Set(); constructor() { effect(() => { const messages = this.stream.messages(); const toolCallMap = new Map(); for (const msg of messages) { if (AIMessage.isInstance(msg)) { for (const tc of (msg as AIMessage).tool_calls ?? []) { if (tc.id && FILE_MUTATING_TOOLS.has(tc.name)) { toolCallMap.set(tc.id, { name: tc.name, args: tc.args }); } } } } for (const msg of messages) { if (!ToolMessage.isInstance(msg)) continue; const id = (msg as ToolMessage).id ?? (msg as ToolMessage).tool_call_id; if (!id || this.processedIds.has(id)) continue; const call = toolCallMap.get((msg as ToolMessage).tool_call_id); if (!call) continue; this.processedIds.add(id); if (call.name === "write_file" || call.name === "edit_file") { this.refreshSingleFile(call.args.path); } else if (call.name === "execute") { this.refreshAllFiles(); } } }); } } ``` ### 检测更改的文件 在每次智能体运行之前，对当前文件内容进行快照。文件刷新后，与快照进行比较以识别哪些文件发生了更改： ```ts theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} function detectChanges(current: FileSnapshot, original: FileSnapshot): Set { const changed = new Set(); for (const [path, content] of Object.entries(current)) { if (original[path] !== content) changed.add(path); } for (const path of Object.keys(original)) { if (!(path in current)) changed.add(path); } return changed; } ``` 当用户选择一个已更改的文件时，默认显示差异视图，以便他们立即看到智能体修改的内容。 ### 显示差异 使用适合框架的差异库来渲染统一差异： | 框架 | 库 | 组件 | | ------- | -------------------------------------------------------------------------- | -------------------------------------------------------------- | | React | [`@pierre/diffs`](https://diffs.com) | 使用 `parseDiffFromFile` 的 `` | | Vue | [`@git-diff-view/vue`](https://github.com/MrWangJustToDo/git-diff-view) | 使用来自 `@git-diff-view/file` 的 `generateDiffFile` 的 `` | | Svelte | [`@git-diff-view/svelte`](https://github.com/MrWangJustToDo/git-diff-view) | 使用来自 `@git-diff-view/file` 的 `generateDiffFile` 的 `` | | Angular | [`ngx-diff`](https://github.com/rars/ngx-diff) | 带有 `[before]` 和 `[after]` 的 `` | 使用 `@pierre/diffs`（React）的示例： ```tsx theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} import { FileDiff } from "@pierre/diffs/react"; import { parseDiffFromFile } from "@pierre/diffs"; function DiffPanel({ original, current, fileName }) { const diff = parseDiffFromFile( { name: fileName, contents: original }, { name: fileName, contents: current }, ); return ( ); } ``` ### 已更改文件摘要 显示所有已修改文件的摘要，包含行级别的添加/删除计数。这为用户提供了智能体影响的快速概览 — 类似于 `git status`： ```tsx theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}} function ChangedFilesSummary({ changedFiles, files, originalFiles, onSelect }) { const stats = [...changedFiles].map((path) => { const oldLines = (originalFiles[path] ?? "").split("\n"); const newLines = (files[path] ?? "").split("\n"); // 通过比较行来计算添加/删除 return { path, additions, deletions }; }); return (

{stats.length} 个文件已更改

{stats.map((file) => ( ))}
); } ``` ## 三面板布局 IDE 布局将三个面板并排排列： | 面板 | 宽度 | 用途 | | ------- | --------- | -------------- | | 文件树 | 固定（208px） | 浏览沙盒文件，查看更改指示器 | | 代码 / 差异 | 灵活 | 查看文件内容或统一差异 | | 聊天 | 固定（320px） | 与智能体交互 | ```tsx theme={"theme":{"light":"catppuccin-latte","dark":"catppuccin-mocha"}}
``` 文件树显示 VS Code 风格的图标（使用 [`@iconify-json/vscode-icons`](https://www.npmjs.com/package/@iconify-json/vscode-icons)），并在已修改的文件上显示琥珀色圆点。选择已修改的文件会自动切换到差异标签页。 ## 使用场景 沙盒适用于以下情况： * **编码智能体**：创建、修改和运行代码的智能体需要一个超越聊水的可视化界面 * **代码审查工作流**：智能体建议更改，用户在接受前审查差异 * **教程或学习应用**：AI 助手逐步帮助用户构建项目，在上下文中显示更改 * **原型设计工具**：用户用自然语言描述功能，并实时观看智能体实现它们 ## 最佳实践 * **在生产应用中使用线程作用域的沙盒**。将沙盒 ID 存储在线程元数据中，并通过后端工厂的 `runtime.configurable.thread_id` 解析。这避免了模块级别的状态，并保持每个对话的沙盒隔离。 * **在智能体后端工厂和 API 服务器之间共享 `getOrCreateSandboxForThread`**。两者都应以相同的方式解析沙盒 — 通过线程元数据 — 这样就有了单一事实来源，无需内存缓存。 * **将 `threadId` 持久化在 `sessionStorage` 中**，以便页面重新加载时重新连接到同一线程和沙盒，而不是创建新的。 * **在每个相关的工具调用时同步文件**，而不仅仅是在运行完成时。这使 IDE 感觉是实时的。监视 `write_file`、`edit_file` 和 `execute` 工具消息并立即刷新。 * **对于已更改的文件，默认显示差异视图**。当用户点击智能体修改的文件时，首先显示差异 — 这是他们关心的内容。 * **为只读操作显示简洁的工具结果**。不要在聊天中转储 `read_file` 的完整输出，而是显示像 `Read router.js L1-42` 这样的一行摘要。为修改工具保留完整的输出显示。 * **用真实项目初始化沙盒**。从空沙盒开始会让人感到困惑。上传一个可工作的启动项目，以便用户（和智能体）立即获得上下文。 * **从文件树中过滤掉 `node_modules`**。没有人想浏览成千上万的依赖文件。获取树时过滤掉它们。 ***
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