MCP tool-use execution loop for autonomous agent runs

Autonomous agents with MCP tools now run a bounded tool-use loop: the model may call tools (executed via the gateway, results fed back) until it returns a final answer. Gated/DraftOnly agents get the tool catalog as data but never auto-call — a human-in-the-loop agent never autonomously reaches an external tool. Extends IModelClient with tool definitions and a tool-use conversation, adds the OpenAI-compatible tool serialization/parsing plus a deterministic "tooluse" stub client, and records every tool call in the run trace. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-15 15:20:48 +03:30
parent a9d4d691f0
commit c8d9af6191
5 changed files with 285 additions and 16 deletions
@@ -0,0 +1,94 @@
+using System.Net;
+using System.Text;
+using TeamUp.Modules.Integrations.Ai;
+using TeamUp.SharedKernel.Ai;
+using Xunit;
+
+namespace TeamUp.IntegrationTests;
+
+/// <summary>
+/// The model-client tool-use plumbing: the OpenAI-compatible adapter serializes tools + a tool-use
+/// conversation and parses tool calls out of the reply; the deterministic "tooluse" stub drives the
+/// loop (ask for a tool, then answer once a result is present).
+/// </summary>
+public sealed class ModelClientToolTests
+{
+    [Fact]
+    public async Task OpenAi_adapter_sends_tools_and_parses_tool_calls()
+    {
+        const string reply =
+            """{"choices":[{"message":{"role":"assistant","content":null,"tool_calls":[{"id":"call_abc","type":"function","function":{"name":"search_issues","arguments":"{\"q\":\"bug\"}"}}]}}]}""";
+        var handler = new CapturingHandler(reply);
+        var client = new OpenAiCompatibleModelClient(new HttpClient(handler));
+
+        var request = new ModelRequest(
+            "openai", "gpt-4o", "sk-test", null, "find bugs", MaxTokens: 512,
+            Tools: [new ModelTool("search_issues", "Search the tracker.", """{"type":"object"}""")],
+            Messages: [new ModelMessage("user", "find bugs")]);
+
+        var completion = await client.CompleteAsync(request);
+
+        Assert.True(completion.Success);
+        var call = Assert.Single(completion.ToolCalls!);
+        Assert.Equal("call_abc", call.Id);
+        Assert.Equal("search_issues", call.Name);
+        Assert.Contains("bug", call.ArgumentsJson);
+
+        // The outgoing body carries the tool definition and the conversation.
+        Assert.Contains("\"tools\"", handler.LastBody);
+        Assert.Contains("search_issues", handler.LastBody);
+        Assert.Contains("find bugs", handler.LastBody);
+    }
+
+    [Fact]
+    public async Task OpenAi_adapter_returns_plain_text_when_no_tool_calls()
+    {
+        const string reply = """{"choices":[{"message":{"role":"assistant","content":"Here are the bugs."}}]}""";
+        var client = new OpenAiCompatibleModelClient(new HttpClient(new CapturingHandler(reply)));
+
+        var completion = await client.CompleteAsync(new ModelRequest("openai", "gpt-4o", "sk", null, "hi"));
+
+        Assert.True(completion.Success);
+        Assert.Equal("Here are the bugs.", completion.Text);
+        Assert.Null(completion.ToolCalls);
+    }
+
+    [Fact]
+    public async Task ToolUse_stub_asks_for_a_tool_then_answers_once_a_result_is_present()
+    {
+        var stub = new ToolUseStubModelClient();
+        List<ModelTool> tools = [new ModelTool("lookup", null, "{}")];
+
+        var first = await stub.CompleteAsync(new ModelRequest(
+            "tooluse", "m", "", null, "do it", Tools: tools, Messages: [new ModelMessage("user", "do it")]));
+        var toolCall = Assert.Single(first.ToolCalls!);
+        Assert.Equal("lookup", toolCall.Name);
+        Assert.Null(first.Text);
+
+        var second = await stub.CompleteAsync(new ModelRequest(
+            "tooluse", "m", "", null, "do it", Tools: tools,
+            Messages:
+            [
+                new ModelMessage("user", "do it"),
+                new ModelMessage("assistant", null, first.ToolCalls),
+                new ModelMessage("tool", "the result", ToolCallId: toolCall.Id),
+            ]));
+
+        Assert.Null(second.ToolCalls);
+        Assert.Contains("do it", second.Text!);
+    }
+
+    private sealed class CapturingHandler(string responseJson) : HttpMessageHandler
+    {
+        public string LastBody { get; private set; } = string.Empty;
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            LastBody = await request.Content!.ReadAsStringAsync(cancellationToken);
+            return new HttpResponseMessage(HttpStatusCode.OK)
+            {
+                Content = new StringContent(responseJson, Encoding.UTF8, "application/json"),
+            };
+        }
+    }
+}