Files
2026-07-13 12:58:18 +08:00

84 lines
3.8 KiB
C#

using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using OpenAI;
// MCP Apps agent.
//
// This agent has no bespoke tools — the CopilotKit runtime is wired with
// `mcpApps: { servers: [...] }` (see `src/app/api/copilotkit-mcp-apps/route.ts`)
// pointing at a public MCP server (default: Excalidraw). The runtime
// auto-applies the MCP Apps middleware which exposes the remote MCP
// server's tools to this agent at request time and emits the activity
// events that CopilotKit's built-in `MCPAppsActivityRenderer` renders in
// the chat as a sandboxed iframe.
//
// Reference parity with:
// showcase/integrations/langgraph-python/src/agents/mcp_apps_agent.py
public sealed class McpAppsAgentFactory
{
private const int HarnessMaxContextWindowTokens = 128_000;
private const int HarnessMaxOutputTokens = 8_192;
private const string SystemPrompt =
"You draw simple diagrams in Excalidraw via the MCP tool.\n\n" +
"SPEED MATTERS. Produce a correct-enough diagram fast; do not optimize " +
"for polish. Target: one tool call, done in seconds.\n\n" +
"When the user asks for a diagram:\n" +
"1. Call `create_view` ONCE with 3-5 elements total: shapes + arrows + " +
" an optional title text.\n" +
"2. Use straightforward shapes (rectangle, ellipse, diamond) with plain " +
" `label` fields (`{\"text\": \"...\", \"fontSize\": 18}`) on them.\n" +
"3. Connect with arrows. Endpoints can be element centers or simple " +
" coordinates — you don't need edge anchors / fixedPoint bindings.\n" +
"4. Include ONE `cameraUpdate` at the END of the elements array that " +
" frames the whole diagram. Use an approved 4:3 size (600x450 or " +
" 800x600). No opening camera needed.\n" +
"5. Reply with ONE short sentence describing what you drew.\n\n" +
"Every element needs a unique string `id` (e.g. \"b1\", \"a1\", \"title\"). " +
"Standard sizes: rectangles 160x70, ellipses/diamonds 120x80, 40-80px " +
"gap between shapes.\n\n" +
"Do NOT:\n" +
"- Call `read_me`. You already know the basic shape API.\n" +
"- Make multiple `create_view` calls.\n" +
"- Iterate or refine. Ship on the first shot.\n" +
"- Add decorative colors / fills / zone backgrounds unless the user " +
" explicitly asks for them.\n" +
"- Add labels on arrows unless crucial.\n\n" +
"If the user asks for something specific (colors, more elements, " +
"particular layout), follow their lead — but still in ONE call.";
private readonly OpenAIClient _openAiClient;
private readonly ILogger _logger;
public McpAppsAgentFactory(OpenAIClient openAiClient, ILoggerFactory loggerFactory)
{
ArgumentNullException.ThrowIfNull(openAiClient);
ArgumentNullException.ThrowIfNull(loggerFactory);
_openAiClient = openAiClient;
_logger = loggerFactory.CreateLogger<McpAppsAgentFactory>();
}
public AIAgent CreateMcpAppsAgent()
{
// gpt-4o-mini for speed — Excalidraw element emission is simple JSON
// and we bias hard toward sub-30s generation.
var chatClient = _openAiClient.GetChatClient("gpt-4o-mini").AsIChatClient();
return chatClient.AsHarnessAgent(
HarnessMaxContextWindowTokens,
HarnessMaxOutputTokens,
new HarnessAgentOptions
{
Name = "McpAppsAgent",
Description = "MCP Apps demo agent — draws Excalidraw diagrams via remote MCP tools.",
ChatOptions = new ChatOptions
{
Instructions = SystemPrompt,
MaxOutputTokens = HarnessMaxOutputTokens,
Tools = [],
},
});
}
}