microsoft/teams.net
Publicmirrored from https://github.com/microsoft/teams.netAvailable
core/samples/A2ABot/A2A/A2AClient.cs
56lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. |
| 2 | // Licensed under the MIT License. |
| 3 | |
| 4 | using System.Text.Json; |
| 5 | using A2A; |
| 6 | |
| 7 | namespace A2ABot.A2A; |
| 8 | |
| 9 | // Outbound A2A. Resolves the peer's AgentCard once (so callers can read |
| 10 | // its live description) and ships HandoffMessage payloads as DataParts. |
| 11 | // Knows nothing about Teams, LLMs, or proactive messaging. |
| 12 | internal sealed class A2AClient(IHttpClientFactory factory, Config config) |
| 13 | { |
| 14 | private readonly SemaphoreSlim _initLock = new(1, 1); |
| 15 | private volatile CachedPeer? _cached; |
| 16 | |
| 17 | private sealed record CachedPeer(AgentCard Card, global::A2A.A2AClient Client); |
| 18 | |
| 19 | public async Task<AgentCard> GetPeerCardAsync(CancellationToken ct) |
| 20 | { |
| 21 | if (_cached is not null) return _cached.Card; |
| 22 | |
| 23 | await _initLock.WaitAsync(ct); |
| 24 | try |
| 25 | { |
| 26 | if (_cached is not null) return _cached.Card; |
| 27 | |
| 28 | HttpClient http = factory.CreateClient("a2a"); |
| 29 | A2ACardResolver resolver = new(new Uri(config.PeerUrl), http); |
| 30 | AgentCard card = await resolver.GetAgentCardAsync(ct); |
| 31 | |
| 32 | global::A2A.A2AClient client = new(new Uri(card.SupportedInterfaces[0].Url), http); |
| 33 | _cached = new CachedPeer(card, client); |
| 34 | return card; |
| 35 | } |
| 36 | finally |
| 37 | { |
| 38 | _initLock.Release(); |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | public async Task SendHandoffAsync(HandoffMessage payload, CancellationToken ct) |
| 43 | { |
| 44 | await GetPeerCardAsync(ct); |
| 45 | |
| 46 | await _cached!.Client.SendMessageAsync(new SendMessageRequest |
| 47 | { |
| 48 | Message = new Message |
| 49 | { |
| 50 | MessageId = Guid.NewGuid().ToString("N"), |
| 51 | Role = Role.User, |
| 52 | Parts = [Part.FromData(JsonSerializer.SerializeToElement(payload))], |
| 53 | } |
| 54 | }, ct); |
| 55 | } |
| 56 | } |
| 57 | |