Method executeToolAndRespond

go/session.go:1496–1553

executeToolAndRespond executes a tool handler and sends the result back via RPC.

(requestID, toolName, toolCallID string, arguments any, handler ToolHandler, traceparent, tracestate string)

// executeToolAndRespond executes a tool handler and sends the result back via RPC.
func (s *Session) executeToolAndRespond(requestID, toolName, toolCallID string, arguments any, handler ToolHandler, traceparent, tracestate string) {
	ctx := contextWithTraceParent(context.Background(), traceparent, tracestate)
	defer func() {
		if r := recover(); r != nil {
			errMsg := fmt.Sprintf("tool panic: %v", r)
			s.RPC.Tools.HandlePendingToolCall(ctx, &rpc.HandlePendingToolCallRequest{
				RequestID: requestID,
				Error:     &errMsg,
			})
		}
	}()

	invocation := ToolInvocation{
		SessionID:    s.SessionID,
		ToolCallID:   toolCallID,
		ToolName:     toolName,
		Arguments:    arguments,
		TraceContext: ctx,
	}

	result, err := handler(invocation)
	if err != nil {
		errMsg := err.Error()
		s.RPC.Tools.HandlePendingToolCall(ctx, &rpc.HandlePendingToolCallRequest{
			RequestID: requestID,
			Error:     &errMsg,
		})
		return
	}

	textResultForLLM := result.TextResultForLLM
	if textResultForLLM == "" {
		textResultForLLM = fmt.Sprintf("%v", result)
	}

	// Default ResultType to "success" when unset, or "failure" when there's an error.
	effectiveResultType := result.ResultType
	if effectiveResultType == "" {
		if result.Error != "" {
			effectiveResultType = "failure"
		} else {
			effectiveResultType = "success"
		}
	}

	rpcResult := &rpc.ExternalToolTextResultForLlm{
		TextResultForLlm: textResultForLLM,
		ToolTelemetry:    result.ToolTelemetry,
		ResultType:       &effectiveResultType,
	}
	if result.Error != "" {
		rpcResult.Error = &result.Error
	}
	s.RPC.Tools.HandlePendingToolCall(ctx, &rpc.HandlePendingToolCallRequest{
		RequestID: requestID,
		Result:    rpcResult,
	})
}