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fix(mcp): bound stdio probe handshake by the probe timeout #1988

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fix(mcp): bound stdio probe handshake by the probe timeout #1988

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27 changes: 23 additions & 4 deletions src/Netclaw.Cli/Mcp/McpCommand.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -861,7 +861,10 @@ internal static async Task<McpProbeResult> ProbeServerAsync(

try
{
await using var client = await CreateOneOffClientAsync(serverName, entry);
// Bound the connect handshake by the probe budget so a slow/cold stdio
// server (e.g. npx cold start) fails fast instead of hanging on the SDK's
// 60s default InitializationTimeout.
await using var client = await CreateOneOffClientAsync(serverName, entry, initializationTimeout: ProbeTimeout);
var tools = await client.ListToolsAsync(cancellationToken: timeoutCts.Token);
return new McpProbeResult(McpProbeStatus.Connected, tools.Count, null);
}
Expand Down Expand Up @@ -891,13 +894,21 @@ internal static async Task<McpProbeResult> ProbeServerAsync(
{
return new McpProbeResult(McpProbeStatus.Unreachable, 0, "connection timed out");
}
catch (TimeoutException) when (!ct.IsCancellationRequested)
{
// The MCP SDK throws TimeoutException when the initialization handshake
// exceeds InitializationTimeout. Map it to Unreachable so a slow/cold stdio
// server is reported deterministically instead of escaping as a crash.
return new McpProbeResult(McpProbeStatus.Unreachable, 0, "connection timed out");
}
catch (Exception ex) when (ex is IOException or SocketException)
{
return new McpProbeResult(McpProbeStatus.Unreachable, 0, "connection failed");
}
}

internal static async Task<McpClient> CreateOneOffClientAsync(McpServerName serverName, McpServerEntry entry)
internal static async Task<McpClient> CreateOneOffClientAsync(
McpServerName serverName, McpServerEntry entry, TimeSpan? initializationTimeout = null)
{
IClientTransport transport;

Expand Down Expand Up @@ -932,7 +943,7 @@ internal static async Task<McpClient> CreateOneOffClientAsync(McpServerName serv
transport = new HttpClientTransport(options, McpHttpClientFactory.Shared);
}

return await McpClient.CreateAsync(transport, new McpClientOptions
var clientOptions = new McpClientOptions
{
ClientInfo = new()
{
Expand All @@ -942,7 +953,15 @@ internal static async Task<McpClient> CreateOneOffClientAsync(McpServerName serv
WebsiteUrl = "https://netclaw.dev",
Description = "Open-source autonomous operations agent built on Akka.NET",
},
});
};

// When the caller supplies a budget (the probe does), bound the initialization
// handshake by it instead of the SDK's 60s default so slow/cold stdio servers
// fail fast and deterministically.
if (initializationTimeout is not null)
clientOptions.InitializationTimeout = initializationTimeout.Value;

return await McpClient.CreateAsync(transport, clientOptions);
}

// ── Config file helpers (delegated to ConfigFileHelper) ──
Expand Down
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