State Management Tutorial¶

This tutorial will teach you how to work with state in SemanticKernel.Graph. You'll learn how to use KernelArguments and GraphState, manage data flow between nodes, and leverage the powerful state management features.

What You'll Learn¶

How state flows through your graph
Using KernelArguments for input and output
Working with GraphState for enhanced state management
State validation and versioning
Best practices for state design

Prerequisites¶

Before starting, ensure you have: * Completed the First Graph Tutorial * Basic understanding of SemanticKernel.Graph concepts * A configured LLM provider

Understanding State in Graphs¶

What is State?¶

State in SemanticKernel.Graph represents the data that flows through your workflow. It's like a backpack that gets passed from node to node, collecting and carrying information throughout the execution.

State Components¶

Input State: Initial data when the graph starts
Intermediate State: Data modified by each node during execution
Output State: Final state containing all results and intermediate data

Basic State Management¶

Creating Input State¶

using Microsoft.SemanticKernel;
using SemanticKernel.Graph.Extensions;

// Basic state with simple values
var state = new KernelArguments
{
    ["userName"] = "Alice",
    ["userAge"] = 30,
    ["preferences"] = new[] { "AI", "Machine Learning", "Graphs" }
};

// State with complex objects
var userProfile = new
{
    Name = "Bob",
    Department = "Engineering",
    Skills = new[] { "C#", ".NET", "AI" }
};

var stateWithObjects = new KernelArguments
{
    ["userProfile"] = userProfile,
    ["requestId"] = Guid.NewGuid().ToString(),
    ["timestamp"] = DateTimeOffset.UtcNow
};

Reading State in Nodes¶

var analysisNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Analyze this user profile:
        Name: {{$userProfile.Name}}
        Department: {{$userProfile.Department}}
        Skills: {{$userProfile.Skills}}

        Provide insights about their technical background and suggest learning paths.
    ")
);

Writing to State¶

var processingNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Process the user profile and provide:
        1. Technical assessment
        2. Learning recommendations
        3. Career suggestions

        Format as JSON with keys: assessment, recommendations, career
    ")
);

// Store the result in a specific key
processingNode.StoreResultAs("analysis");

Enhanced State with GraphState¶

What is GraphState?¶

GraphState is an enhanced wrapper around KernelArguments that provides additional features like: * State versioning and validation * Execution history tracking * Metadata management * Serialization capabilities

Using GraphState¶

using SemanticKernel.Graph.State;

// Create enhanced state
var graphState = new GraphState(new KernelArguments
{
    ["input"] = "Hello World",
    ["metadata"] = new Dictionary<string, object>
    {
        ["source"] = "tutorial",
        ["version"] = "1.0"
    }
});

// Access state with enhanced features
var input = graphState.GetValue<string>("input");
var metadata = graphState.GetValue<Dictionary<string, object>>("metadata");

// Add execution metadata
graphState.AddExecutionStep("NodeName", "Processing input", DateTimeOffset.UtcNow);

State Flow Between Nodes¶

Building a State-Aware Graph¶

using Microsoft.SemanticKernel;
using SemanticKernel.Graph;
using SemanticKernel.Graph.Extensions;
using SemanticKernel.Graph.Nodes;

class Program
{
    static async Task Main(string[] args)
    {
        var builder = Kernel.CreateBuilder();
        builder.AddOpenAIChatCompletion("gpt-4", Environment.GetEnvironmentVariable("OPENAI_API_KEY"));
        builder.AddGraphSupport();
        var kernel = builder.Build();

        // Create nodes that work with state
        var inputNode = new FunctionGraphNode(
            kernel.CreateFunctionFromPrompt(@"
                Analyze this text: {{$input}}
                Provide:
                1. Sentiment (positive/negative/neutral)
                2. Key topics
                3. Word count

                Format as JSON with keys: sentiment, topics, wordCount
            ")
        ).StoreResultAs("analysis");

        var decisionNode = new ConditionalGraphNode("RouteBySentiment",
            state => state.GetValueOrDefault("analysis", "").ToString().Contains("positive"));

        var positiveNode = new FunctionGraphNode(
            kernel.CreateFunctionFromPrompt(@"
                The analysis shows positive sentiment: {{$analysis}}
                Generate an encouraging response with suggestions for next steps.
            ")
        ).StoreResultAs("response");

        var negativeNode = new FunctionGraphNode(
            kernel.CreateFunctionFromPrompt(@"
                The analysis shows negative sentiment: {{$analysis}}
                Provide empathetic support and constructive feedback.
            ")
        ).StoreResultAs("response");

        var summaryNode = new FunctionGraphNode(
            kernel.CreateFunctionFromPrompt(@"
                Create a summary of this interaction:
                Input: {{$input}}
                Analysis: {{$analysis}}
                Response: {{$response}}

                Format as a concise summary paragraph.
            ")
        ).StoreResultAs("summary");

        // Build the graph
        var graph = new GraphExecutor("StateManagementExample");

        graph.AddNode(inputNode);
        graph.AddNode(decisionNode);
        graph.AddNode(positiveNode);
        graph.AddNode(negativeNode);
        graph.AddNode(summaryNode);

        // Connect with conditional routing
        graph.Connect(inputNode, decisionNode);
        graph.Connect(decisionNode, positiveNode, 
            edge => edge.When(state => state.GetValueOrDefault("analysis", "").ToString().Contains("positive")));
        graph.Connect(decisionNode, negativeNode, 
            edge => edge.When(state => !state.GetValueOrDefault("analysis", "").ToString().Contains("positive")));
        graph.Connect(positiveNode, summaryNode);
        graph.Connect(negativeNode, summaryNode);

        graph.SetStartNode(inputNode);

        // Execute with different inputs
        var testInputs = new[]
        {
            "I love working with AI and machine learning!",
            "I'm struggling with this programming problem.",
            "The weather is beautiful today and I feel great!"
        };

        foreach (var input in testInputs)
        {
            Console.WriteLine($"\n=== Testing with: {input} ===");

            var state = new KernelArguments { ["input"] = input };
            var result = await graph.ExecuteAsync(state);

            Console.WriteLine($"Sentiment: {result.GetValueOrDefault("analysis", "No analysis")}");
            Console.WriteLine($"Response: {result.GetValueOrDefault("response", "No response")}");
            Console.WriteLine($"Summary: {result.GetValueOrDefault("summary", "No summary")}");
        }
    }
}

State Validation and Type Safety¶

Type-Safe State Access¶

// Use extension methods for type-safe access
var state = new KernelArguments
{
    ["count"] = 42,
    ["name"] = "Alice",
    ["isActive"] = true
};

// Type-safe retrieval with defaults
var count = state.GetValueOrDefault<int>("count", 0);
var name = state.GetValueOrDefault<string>("name", "Unknown");
var isActive = state.GetValueOrDefault<bool>("isActive", false);

// Try to get values with type checking
if (state.TryGetValue<int>("count", out var safeCount))
{
    Console.WriteLine($"Count is: {safeCount}");
}

State Validation¶

var validationNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Validate this user data:
        Name: {{$userName}}
        Age: {{$userAge}}
        Email: {{$userEmail}}

        Return JSON with validation results:
        {
            "isValid": boolean,
            "errors": [string],
            "warnings": [string]
        }
    ")
).StoreResultAs("validation");

// Add validation logic
var decisionNode = new ConditionalGraphNode("IsValidUser",
    state => 
    {
        var validation = state.GetValueOrDefault("validation", "");
        return validation.ToString().Contains("\"isValid\": true");
    });

Advanced State Patterns¶

State Accumulation¶

var accumulationNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Based on the current conversation history: {{$conversationHistory}}
        And the new input: {{$newInput}}

        Update the conversation with the new interaction.
        Return the updated conversation history.
    ")
).StoreResultAs("conversationHistory");

// Initialize with empty history
var state = new KernelArguments
{
    ["conversationHistory"] = new List<string>(),
    ["newInput"] = "Hello, I need help with AI"
};

State Transformation¶

var transformNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Transform this data structure: {{$rawData}}

        Extract and structure the following information:
        - Key insights
        - Action items
        - Priority levels

        Return as structured JSON.
    ")
).StoreResultAs("structuredData");

State Persistence and Checkpointing¶

Basic Checkpointing¶

// Enable checkpointing in your graph options
builder.AddGraphSupport(options =>
{
    options.Checkpointing.Enabled = true;
    options.Checkpointing.Interval = 3; // Checkpoint every 3 nodes
});

// State is automatically saved and can be restored
var checkpointManager = kernel.GetRequiredService<ICheckpointManager>();
var savedState = await checkpointManager.SaveCheckpointAsync(graphId, executionId, state);

State Serialization¶

// State can be serialized for external storage
var serializedState = JsonSerializer.Serialize(state, new JsonSerializerOptions
{
    WriteIndented = true
});

// And deserialized back
var restoredState = JsonSerializer.Deserialize<KernelArguments>(serializedState);

Best Practices¶

1. Use Descriptive Keys¶

// Good
state["userProfile"] = userData;
state["analysisResults"] = analysis;

// Avoid
state["data"] = userData;
state["result"] = analysis;

2. Validate State at Key Points¶

var validationNode = new ConditionalGraphNode("ValidateState",
    state => 
    {
        // Check required fields exist
        var required = new[] { "userProfile", "analysisResults" };
        return required.All(key => state.ContainsKey(key));
    });

3. Use Type-Safe Access¶

// Use extension methods for safety
var count = state.GetValueOrDefault<int>("count", 0);
var name = state.GetValueOrDefault<string>("name", "Unknown");

4. Structure Complex State¶

// Group related data
state["user"] = new
{
    Profile = userProfile,
    Preferences = userPreferences,
    History = userHistory
};

5. Handle State Errors Gracefully¶

var errorHandlerNode = new FunctionGraphNode(
    kernel.CreateFunctionFromPrompt(@"
        Handle this error gracefully: {{$error}}
        Provide a user-friendly message and recovery suggestions.
    ")
).StoreResultAs("errorResponse");

Common State Patterns¶

Configuration State¶

var configState = new KernelArguments
{
    ["maxRetries"] = 3,
    ["timeout"] = TimeSpan.FromSeconds(30),
    ["logLevel"] = "Information"
};

Session State¶

var sessionState = new KernelArguments
{
    ["sessionId"] = Guid.NewGuid().ToString(),
    ["startTime"] = DateTimeOffset.UtcNow,
    ["userContext"] = userContext
};

Workflow State¶

var workflowState = new KernelArguments
{
    ["currentStep"] = "analysis",
    ["completedSteps"] = new[] { "input", "validation" },
    ["nextSteps"] = new[] { "processing", "output" }
};

Troubleshooting State Issues¶

Common Problems¶

State Not Persisting Between Nodes¶

System.Collections.Generic.KeyNotFoundException: The given key 'result' was not present in the dictionary.

Solution: Ensure nodes are properly storing results using StoreResultAs() or manual state assignment.

Type Conversion Errors¶

System.InvalidCastException: Unable to cast object of type 'System.String' to type 'System.Int32'.

Solution: Use type-safe access methods like GetValueOrDefault<T>() or validate types before casting.

State Corruption¶

System.Text.Json.JsonException: The JSON value could not be converted to KernelArguments.

Solution: Check state serialization/deserialization logic and ensure all objects are serializable.

Next Steps¶

Now that you understand state management, explore these advanced topics:

Conditional Nodes Guide: Master conditional logic and routing
Checkpointing Tutorial: Learn about state persistence and recovery
Error Handling Guide: Handle state errors and exceptions
Advanced Patterns: Discover complex state management patterns

Concepts and Techniques¶

This tutorial covers several key concepts:

State: Data that flows through the graph, maintaining context across execution steps
KernelArguments: The base state container that holds key-value pairs
GraphState: Enhanced state wrapper with versioning, validation, and metadata
State Flow: How data moves between nodes and transforms during execution
State Validation: Ensuring data integrity and type safety throughout the workflow

Prerequisites and Minimum Configuration¶

To complete this tutorial, you need: * SemanticKernel.Graph package installed and configured * LLM Provider with valid API keys * Basic understanding of graph concepts from the first tutorial * .NET 8.0+ runtime environment