Agent.NET

Elegant agent workflows for .NET, designed in F#.

Typed. Declarative. Durable.

---

What is Agent.NET?

Agent.NET is an F#‑native authoring layer built on top of the Microsoft Agent Framework.
MAF provides a powerful, low‑level foundation for building agent systems — durable state, orchestration primitives, tool execution, and a flexible runtime model.

Agent.NET builds on those capabilities with a higher‑level, ergonomic workflow DSL designed for clarity, composability, and developer experience.
Where MAF offers the essential building blocks, Agent.NET provides the expressive authoring model that makes agent workflows feel natural to write and reason about.

What can you do with Agent.NET?

1. Create chat agents with tools (ChatAgent)

Simple interface: string -> Task<string>. Tools are plain F# functions with metadata from XML docs.

let agent =
    ChatAgent.create "You are a helpful assistant."
    |> ChatAgent.withTools [searchTool; calculatorTool]
    |> ChatAgent.build chatClient

let! text = agent.Chat("Summarize the latest quarterly report.")

Learn more ->

2. Create typed agents as functions (TypedAgent<'input,'output>)

Wrap a ChatAgent with format/parse functions for use in workflows or anywhere you'd call a service.

let analyzeAgent: TypedAgent<CustomerMessage, SentimentResult> = 
    TypedAgent.create formatCustomerMessage parseSentimentResult chatAgent

let! sentiment = analyzeAgent.Invoke message

Learn more ->

3. Create workflows (workflow)

Strongly typed orchestration mixing deterministic .NET code with LLM calls. Run in-process or on Azure Durable Functions.

let myWorkflow = workflow {
    step loadData
    fanOut analyst1 analyst2 analyst3
    fanIn summarize
}

Learn more ->

---

🚀 Durable Workflows in Azure (Minimal Example)

Agent.NET workflows run anywhere — in‑memory for local execution, or durably on Azure using Durable Functions.

From the Samples.DurableFunctions project:

/// A durable trade approval workflow defined with Agent.NET
let tradeApprovalWorkflow =
    workflow {
        name "TradeApprovalWorkflow"
        step analyzeStock
        step sendForApproval
        awaitEvent "TradeApproval" eventOf<ApprovalDecision>
        step executeTrade
    }

You can host this workflow inside an Azure Durable Functions orchestrator written in F# or C#.

F# orchestrator

module TradeApprovalWorkflow

open Microsoft.DurableTask
open Microsoft.Azure.Functions.Worker
open AgentNet.Durable

[<Function("TradeApprovalOrchestrator")>]
let orchestrator ([<OrchestrationTrigger>] ctx: TaskOrchestrationContext) =
    let request = ctx.GetInput<TradeRequest>()
    Workflow.Durable.run ctx request tradeApprovalWorkflow

C# orchestrator

Call a workflow defined in your F# project:

using Microsoft.DurableTask;
using Microsoft.Azure.Functions.Worker;
using AgentNet.Durable;

public static class TradeApprovalOrchestrator
{
    [Function("TradeApprovalOrchestrator")]
    public static Task<TradeResult> Run([OrchestrationTrigger] TaskOrchestrationContext context)
    {
        var request = context.GetInput<TradeRequest>();
        return Workflow.Durable.run(context, request, tradeApprovalWorkflow);
    }
}

This is the final shape:

• Declarative workflow definition — one expression per workflow
• Typed steps — plain .NET functions (with or without agents)
• Explicit suspension via awaitEvent (human-in-the-loop, external events)
• Durable execution powered by MAF and Azure Durable Functions
• Minimal host surface — the orchestrator simply runs the workflow

---

Installation

AgentNet — Agents and in-process workflows

dotnet add package AgentNet

AgentNet.Durable — Azure Durable Function workflows

dotnet add package AgentNet.Durable

---

Features

Railway‑Oriented Programming (tryStep)

tryStep brings typed early‑exit semantics into the workflow DSL. Use it when a step may return a Result and you want the workflow to short‑circuit on Error.

Learn more →

Tools: Quotation-Based Metadata Extraction

The <@ @> quotation syntax captures your function and extracts all metadata automatically:

/// <summary>Searches the knowledge base</summary>
/// <param name="query">The search query</param>
/// <param name="maxResults">Maximum number of results to return</param>
let searchKnowledge (query: string) (maxResults: int) : string =
    KnowledgeBase.search query maxResults

let searchTool = Tool.createWithDocs <@ searchKnowledge @>
// Extracts:
//   Name: "searchKnowledge"
//   Description: "Searches the knowledge base"
//   Parameters: [{Name="query"; Description="The search query"; Type=string}
//                {Name="maxResults"; Description="Maximum number of results"; Type=int}]

Why quotations?

• Function name becomes tool name (rename the function, tool updates automatically)
• Parameter names preserved (no "arg0", "arg1")
• XML docs become descriptions (documentation lives with the code)
• Type information retained for schema generation

If you prefer manual descriptions:

let searchTool =
    Tool.create <@ searchKnowledge @>
    |> Tool.describe "Searches the knowledge base for relevant documents"

ChatAgent: Pipeline-Style Configuration

Build agents using a clean pipeline:

let stockAdvisor =
    ChatAgent.create """
        You are a stock market analyst. You help users understand
        stock performance, analyze trends, and compare investments.
        Always provide balanced, factual analysis.
        """
    |> ChatAgent.withName "StockAdvisor"
    |> ChatAgent.withTool getStockInfoTool
    |> ChatAgent.withTool getHistoricalPricesTool
    |> ChatAgent.withTool calculateVolatilityTool
    |> ChatAgent.withTools [compareTool; analysisTool]  // Add multiple at once
    |> ChatAgent.build chatClient

Use your agent:

// Async chat
let! response = stockAdvisor.Chat("Compare AAPL and MSFT performance")

// Access the underlying config if needed
printfn $"Agent: {stockAdvisor.Config.Name}"

TypedAgent: Structured Input/Output for Workflows

While ChatAgent works with strings (string -> Task<string>), workflows often need typed data flowing between steps. TypedAgent wraps a ChatAgent with format/parse functions to enable strongly-typed workflows.

For a minimal example of wrapping a ChatAgent into a TypedAgent and using it in a workflow, see the Quick Start. The example below shows a more involved stock comparison scenario.

// Domain types for your workflow
type StockPair = { Stock1: StockData; Stock2: StockData }
type AnalysisResult = { Pair: StockPair; Analysis: string }

// Define a function to format the typed input into a prompt.
let formatStockPair (pair: StockPair) =
    $"""Compare these two stocks:
    {pair.Stock1.Symbol}: {pair.Stock1.Info}
    {pair.Stock2.Symbol}: {pair.Stock2.Info}"""

// Define a function that the AI can use to return a typed output.
let parseAnalysisResult (pair: StockPair) (response: string) =
    { Pair = pair; Analysis = response }

// Create the typed agent
let typedAnalyst = TypedAgent.create formatStockPair parseAnalysisResult stockAnalystAgent

Using TypedAgent standalone:

// Invoke with typed input, get typed output
let! result = typedAnalyst.Invoke(stockPair)
printfn $"Analysis: {result.Analysis}"

Using TypedAgent in workflows:

The real power is using TypedAgent as a strongly-typed step in a workflow:

let comparisonWorkflow = workflow {
    step fetchBothStocks   // async/task function
    step typedAnalyst      // TypedAgent works directly
    step generateReport    // sync function (returns Task.fromResult)
}

let input = { Symbol1 = "AAPL"; Symbol2 = "MSFT" }
let! report = Workflow.InProcess.run input comparisonWorkflow

The workflow is fully type-safe: the compiler ensures each step's output type matches the next step's input type. Steps can be named for debugging/logging, or unnamed for brevity.

Workflows: Computation Expression for Orchestration

The workflow CE generalizes the patterns from the Quick Start to more complex multi-agent scenarios. Orchestrate complex multi-agent scenarios with elegant, readable syntax.

The step operation directly accepts:

• Task functions ('a -> Task<'b>)
• Async functions ('a -> Async<'b>)
• TypedAgents (TypedAgent<'a,'b>)
• Other workflows (WorkflowDef<'a,'b>)

No wrapping required—just pass them in. The compiler ensures each step's output type matches the next step's input type, catching mismatches at compile time.

Sequential Pipelines

let reportWorkflow = workflow {
    step researcher      // Gather information
    step analyst         // Analyze findings
    step writer          // Write the report
    step editor          // Polish and refine
}

C# MAF equivalent

var builder = new WorkflowBuilder(researcherExecutor);
builder.AddEdge(researcherExecutor, analystExecutor);
builder.AddEdge(analystExecutor, writerExecutor);
builder.AddEdge(writerExecutor, editorExecutor);
builder.WithOutputFrom(editorExecutor);
var workflow = builder.Build();

Parallel Fan-Out / Fan-In

Process data in parallel, then combine results:

let claimsWorkflow = workflow {
    step extractClaims
    fanOut 
        checkPolicy 
        assessRisk 
        detectFraud
    fanIn aggregateResults
    step generateReport
}
    
let report = Workflow.runSync claimData claimsWorkflow

Note: fanOut supports 2-5 direct arguments. For 6+ branches, use list syntax with the + operator, which converts each item to a unified Step type (enabling mixed executors, functions, angents, and workflows in the same list):

fanOut [+analyst1; +analyst2; +analyst3; +analyst4; +analyst5; +analyst6]

C# MAF equivalent

var builder = new WorkflowBuilder(extractClaimsExecutor);
builder.AddEdge(extractClaimsExecutor, checkPolicyExecutor);
builder.AddEdge(extractClaimsExecutor, assessRiskExecutor);
builder.AddEdge(extractClaimsExecutor, detectFraudExecutor);
builder.AddEdge(checkPolicyExecutor, aggregateResultsExecutor);
builder.AddEdge(assessRiskExecutor, aggregateResultsExecutor);
builder.AddEdge(detectFraudExecutor, aggregateResultsExecutor);
builder.AddEdge(aggregateResultsExecutor, generateReportExecutor);
builder.WithOutputFrom(generateReportExecutor);
var workflow = builder.Build();

Conditional Routing

Route to different agents based on content:

type Priority = Urgent | Normal | LowPriority

let triageWorkflow = workflow {
    step classifier
    route (function
        | Urgent -> urgentHandler
        | Normal -> standardHandler
        | LowPriority -> batchHandler)
}

C# MAF equivalent

// Create transitions with explicit filters
var urgentTransition = new Transition(
    classifierExecutor,
    urgentHandlerExecutor
);
urgentTransition.Filter = result => result is Urgent;

var normalTransition = new Transition(
    classifierExecutor,
    standardHandlerExecutor
);
normalTransition.Filter = result => result is Normal;

var lowTransition = new Transition(
    classifierExecutor,
    batchHandlerExecutor
);
lowTransition.Filter = result => result is LowPriority;

// Add transitions to the workflow
builder.AddTransition(urgentTransition);
builder.AddTransition(normalTransition);
builder.AddTransition(lowTransition);

// Declare possible outputs
builder.WithOutputFrom(
    urgentHandlerExecutor,
    standardHandlerExecutor,
    batchHandlerExecutor
);

var workflow = builder.Build();

Resilience: Retry, Timeout, Fallback

Build fault-tolerant workflows:

let resilientWorkflow = workflow {
    step primaryAgent
    retry 3                              // Retry up to 3 times
    timeout (TimeSpan.FromSeconds 30.0)  // Timeout after 30s
    fallback backupAgent                 // Use backup if all else fails
}

Combine resilience with other operations:

let robustAnalysis = workflow {
    step loadData
    fanOut analyst1 analyst2 analyst3
    retry 2
    fanIn combiner
    timeout (TimeSpan.FromMinutes 5.0)
    fallback cachedResults
}

C# MAF + Polly equivalent

var retryPolicy = Policy
    .Handle<Exception>()
    .WaitAndRetryAsync(3, attempt =>
        TimeSpan.FromSeconds(Math.Pow(2, attempt)));

var timeoutPolicy = Policy
    .TimeoutAsync(TimeSpan.FromSeconds(30));

var fallbackPolicy = Policy<string>
    .Handle<Exception>()
    .FallbackAsync(cachedResult);

var combinedPolicy = Policy.WrapAsync(fallbackPolicy, timeoutPolicy, retryPolicy);

// Then wire into your executor...

Composition: Nest Workflows

Workflows are composable - nest them freely:

let innerWorkflow = workflow {
    step stepA
    step stepB
}

// Direct nesting - just pass the workflow!
let outerWorkflow = workflow {
    step preprocess
    step innerWorkflow
    step postprocess
}

// Or use toExecutor when you want explicit naming
let namedOuter = workflow {
    step preprocess
    step (Workflow.toExecutor "InnerStep" innerWorkflow)
    step postprocess
}

C# MAF equivalent

// Build the inner workflow
var innerBuilder = new WorkflowBuilder(stepAExecutor);
innerBuilder.AddEdge(stepAExecutor, stepBExecutor);
innerBuilder.WithOutputFrom(stepBExecutor);
var innerWorkflow = innerBuilder.Build();

// Convert the inner workflow into an executor
var innerExecutor = new WorkflowExecutor("InnerStep", innerWorkflow);

// Build the outer workflow
var outerBuilder = new WorkflowBuilder(preprocessExecutor);
outerBuilder.AddEdge(preprocessExecutor, innerExecutor);
outerBuilder.AddEdge(innerExecutor, postprocessExecutor);
outerBuilder.WithOutputFrom(postprocessExecutor);

var outerWorkflow = outerBuilder.Build();

Running Workflows

// Synchronous
let result = Workflow.runSync "initial input" myWorkflow

// Asynchronous
let! result = Workflow.InProcess.run "initial input" myWorkflow

Railway-Oriented Programming with tryStep

Workflows often need to perform validation or business‑rule checks that may fail.
tryStep brings Railway-Oriented Programming directly into the main workflow DSL, giving you short‑circuiting error handling without switching to a different computation expression or monadic style.

When a tryStep returns:

• Ok value → the workflow continues with value
• Error err → the workflow exits immediately, returning Error err from tryRun

This gives you the classic “railway switch” behavior with minimal ceremony.

Example

// Custom error type for the workflow
type ProcessingError =
    | ParseError of string
    | ValidationError of string

let parse (raw: string) =
    if raw.Length > 0
    then Ok { Id = "doc"; Content = raw }
    else Error (ParseError "Empty input")
    |> Task.fromResult

let validate (doc: Document) =
    if doc.Content.Contains("valid")
    then Ok { Doc = doc; IsValid = true; Errors = [] }
    else Error (ValidationError "Missing 'valid' keyword")
    |> Task.fromResult

let save (validated: ValidatedDoc) =
    printfn "Saving Document"
    { Doc = validated; WordCount = 1; Summary = "Saved" }
    |> Task.fromResult

let documentWorkflow = workflow {
    tryStep parse
    tryStep validate
    step save
}

Running the workflow

let! result = Workflow.InProcess.tryRun documentWorkflow

• If any tryStep returns Error, the workflow stops immediately
• tryRun returns Result<'ok, 'err>
• run (without Result) throws an internal early‑exit signal instead — useful for Durable orchestrators

Why tryStep feels so natural

• No monadic boilerplate — you stay in the main workflow CE
• No type contagion — only the steps that need Result use it
• Clear, predictable control flow — early exit is explicit and typed
• Works everywhere — InProcess and Durable runners share the same semantics

Step types supported by tryStep

• Functions returning Task<Result<'o,'e>> or Async<Result<'o,'e>>
• TypedAgent<'i,'o> (automatically wrapped in Ok)
• Any normal step can follow a tryStep — the workflow only exits when a tryStep returns Error

---

API Reference

Types

Type	Description
ToolDef	Tool definition with name, description, parameters, and MethodInfo
ParamInfo	Parameter metadata: name, description, and type
ChatAgentConfig	Agent configuration: name, instructions, and tools
ChatAgent	Built agent with Chat: string -> Task<string> and ChatFull: string -> Task<ChatResponse>
TypedAgent<'i,'o>	Typed wrapper around ChatAgent with format/parse functions
ChatResponse	Full response with Text and Messages list
ChatMessage	Message with Role and Content
ChatRole	Union type: User, Assistant, System, Tool
Executor<'i,'o>	Workflow step that transforms input to output
WorkflowDef<'i,'o>	Composable workflow definition

Tool Functions

Function	Description
Tool.create	Creates a tool from an F# function using a quotation.
Tool.createWithDocs	Creates a tool and extracts XML documentation from the quoted function.
Tool.describe	Overrides or adds a description for a tool.

Agent Functions

Function	Description
ChatAgent.create	Creates a chat agent configuration with the given instruction string.
ChatAgent.withName	Assigns a display name to the agent.
ChatAgent.withTool	Adds a single tool to the agent configuration.
ChatAgent.withTools	Adds multiple tools to the agent configuration.
ChatAgent.build	Builds a ChatAgent using an IChatClient and the configuration.
TypedAgent.create	Wraps a ChatAgent with format/parse functions for typed input/output.
TypedAgent.invoke	Invokes a typed agent: structured input in, structured output out.

Workflow CE Keywords

Keyword	Description
step	Add a step to the workflow
tryStep	Execute a step that returns Result; short‑circuits the workflow on Error
fanOut	Execute multiple executors in parallel
fanIn	Combine parallel results into one
route	Conditional routing based on pattern matching
retry	Retry failed steps N times
timeout	Fail if step exceeds duration
fallback	Use alternative executor on failure
backoff	Set retry delay strategy

Workflow Functions

Function	Description
Workflow.InProcess.run	Runs a workflow in‑process and returns the final output. Throws on tryStep errors.
Workflow.InProcess.tryRun	Runs a workflow in‑process and returns Result<'output,'error> with early‑exit handling.
Workflow.Durable.run	Runs a workflow inside a Durable Functions orchestrator. Throws on tryStep errors.
Workflow.Durable.tryRun	Durable‑safe version of tryRun; returns Result<'output,'error> instead of throwing.
Workflow.Durable.tryRunIgnore	Use when your Durable orchestrator delegates to a workflow but doesn’t need to return a value. This avoids Durable’s restriction on serializing F# discriminated unions.

---

XML Documentation Format

For Tool.createWithDocs to extract parameter descriptions, use explicit <summary> tags:

/// <summary>Searches for documents matching the query</summary>
/// <param name="query">The search query string</param>
/// <param name="limit">Maximum results to return</param>
let search (query: string) (limit: int) : string = ...

Note: F# requires <summary> tags when using <param> tags. Without <summary>, the param tags become part of the summary text.

---

Examples

See the StockAdvisorFS sample project for a complete example including:

• Multiple tools with XML documentation
• Agent configuration
• Real-world usage patterns

---

Workflow: A Semantic Layer for MAF

Agent.NET's workflow CE is a semantic layer for Microsoft Agent Framework (MAF). Define your workflow once in expressive F#, then choose how to run it:

let stockAnalysisWF = workflow {
    step fetchStockData
    fanOut technicalAnalysis fundamentalAnalysis sentimentAnalysis
    fanIn synthesizeReports
    step generateRecommendation
}

// In-memory execution (quick-running workflows)
let! result = Workflow.InProcess.run input stockAnalysisWF

// MAF durable execution (long-running, durable workflows)
let! result = Workflow.Durable.run ctx input stockAnalysisWF

Why a Semantic Layer?

Direct MAF (C#)	Agent.NET Workflow (F#)
Verbose executor classes	Normal F# functions
Manual graph wiring	Declarative step, fanOut, fanIn
Stringly-typed edges	Compiler-enforced type transitions
Resilience via Polly boilerplate	Built-in retry, timeout, fallback

Two Execution Modes

Agent.NET supports both execution models from a single workflow definition:

Mode	API	Description
In-memory	Workflow.InProcess.run	Used for short-lived workflows executed within the current process.
MAF Durable	Workflow.Durable.run	Runs on MAF's durable runtime (backed by Azure Durable Functions) with automatic checkpointing, replay, and fault tolerance.

Same workflow. Your choice of execution model.

---

Dependencies

Both packages depend only on abstractions, keeping Agent.NET lightweight, platform‑agnostic, and free of Azure‑specific hosting requirements.

AgentNet

Built on the core Microsoft Agent Framework abstractions.

• Microsoft.Agents.AI — agent primitives
• Microsoft.Agents.AI.Workflows — workflow graph + in‑memory execution
• Microsoft.Extensions.AI.Abstractions — AI service abstractions for .NET

AgentNet.Durable

Adds durable execution by targeting the Durable Task abstractions.

• Microsoft.DurableTask.Abstractions — durable orchestration primitives
• Microsoft.Agents.AI.Workflows — shared workflow graph model

---

License

MIT License - see LICENSE for details.

---

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.

---

Roadmap

Workflow State Management

The current WorkflowContext.State mechanism needs rework — each step currently receives a fresh context, so state changes don't propagate between steps. A future release will provide proper state management that integrates with MAF's serialization for durable workflows.

Feature	Status	Description
State propagation fix	Planned	Rework WorkflowContext so state set in one step is available to subsequent steps
Strongly-typed state	Planned	Workflow.InProcess.runWithState and Workflow.Durable.runWithState for passing typed state between steps with a friendlier API. Also allows initializing workflows with predefined state.

---

Built with F# and a belief that AI tooling should be elegant.