Create Agent Provider Package

This skill guides you through creating a new Agent Provider NuGet package for the AgentFrameworkToolkit. Agent Providers enable integration with different LLM services (e.g., Anthropic, OpenAI, Google, Mistral).

Quick Decision Guide

Choose implementation approach:

1. •

   OpenAI-Compatible Provider - If the LLM service has an OpenAI-compatible API:

   • •Examples: OpenRouter, XAI (Grok), Cohere
   • •See: OpenAI-Compatible Template
   • •Faster implementation (reuses existing OpenAI code)
2. •

   Custom Provider - If the LLM service has a unique API:

   • •Examples: Anthropic (Claude), Google (Gemini), GitHub Models, Mistral
   • •See: Custom Provider Template
   • •Full control, follows standard patterns

Core Provider Components

Most provider packages include these components (OpenAI-compatible providers reuse AgentFrameworkToolkit.OpenAI.AgentOptions):

1. Connection Class (<Provider>Connection)

• •Manages API credentials and configuration
• •Creates and configures the SDK client
• •Supports network timeout and custom endpoints (if applicable)
• •Provides raw HTTP call inspection hooks (if possible)

2. Agent Factory (<Provider>AgentFactory)

• •Creates agent instances from options (or from simplified overloads)
• •Builds the inner ChatClientAgent (custom providers)
• •Applies middleware via AgentFrameworkToolkit.MiddlewareHelper

3. Agent Options (<Provider>AgentOptions) (custom providers only)

• •Configuration for agent creation (model, instructions, tools, max tokens, etc.)
• •Provider-specific settings (e.g., thinking budget)
• •Middleware configuration (raw HTTP/tool inspection, tool-calling middleware, OpenTelemetry, logging)

4. Agent Wrapper (<Provider>Agent)

• •Inherits from AIAgent
• •Delegates to an inner agent instance
• •Exposes an InnerAgent property

5. Chat Models Constants (<Provider>ChatModels) (only if provider is specific. if it offers multiple LLMs don't include such)

• •Constants for available model IDs
• •Makes model selection discoverable

Implementation Steps

Step 1: Project Setup

mkdir src/AgentFrameworkToolkit.<Provider>

Important repo conventions (don’t fight the build system):

• •src/* projects inherit defaults from Directory.Build.props (currently net8.0).
• •NuGet packaging defaults are imported via nuget-package.props in each src/* .csproj.
• •Central package versions are in Directory.Packages.props (no versions in .csproj).

Step 2: Implement Core Components

Follow existing providers:

• •OpenAI-compatible: src/AgentFrameworkToolkit.OpenRouter/, src/AgentFrameworkToolkit.XAI/, src/AgentFrameworkToolkit.Cohere/
• •Custom: src/AgentFrameworkToolkit.Anthropic/, src/AgentFrameworkToolkit.GitHub/, src/AgentFrameworkToolkit.Google/, src/AgentFrameworkToolkit.Mistral/

Step 3: Add Service Extensions

Create ServiceCollectionExtensions.cs for dependency injection using the repo naming convention:

• •Add<Provider>AgentFactory(this IServiceCollection services, string apiKey)
• •Add<Provider>AgentFactory(this IServiceCollection services, <Provider>Connection connection)

Step 4: Write Tests (Integration Tests)

Provider tests live in development/Tests/ and make real API calls. See Testing Guide for the repo’s concrete pattern.

Quick checklist:

1. •Add provider project references:
   • •development/Tests/Tests.csproj
   • •development/Sandbox/Sandbox.csproj
2. •Add provider to the shared test harness:
   • •Add a value to AgentProvider enum in development/Tests/TestBase.cs
   • •Add a case to GetAgentForScenarioAsync(...) in development/Tests/TestBase.cs
3. •Create development/Tests/<Provider>Tests.cs:
   • •Call the shared scenario tests (SimpleAgentTestsAsync, NormalAgentTestsAsync, etc.)
   • •Add DI tests for Add<Provider>AgentFactory(...)
4. •Add a sandbox runner in development/Sandbox/Providers/<Provider>.cs and optionally wire it in development/Sandbox/Program.cs
5. •Add your API key to user-secrets:
   • •Update development/Secrets/Secrets.cs and development/Secrets/SecretsManager.cs
   • •Set the secret using dotnet user-secrets for the development/Secrets/Secrets.csproj project

Step 5: Repository Integration

1. •Add the project to AgentFrameworkToolkit.slnx under /Packages/
2. •Add any new SDK package versions to Directory.Packages.props
3. •Update documentation:
   • •Main README.md provider table
   • •Provider-specific src/AgentFrameworkToolkit.<Provider>/README.md
   • •CHANGELOG.md

Step 6: Validation

dotnet build --configuration Release

Key Architectural Patterns

Middleware Configuration (custom providers)

Use the shared helper instead of re-implementing ordering rules:

• •AgentFrameworkToolkit.MiddlewareHelper.ApplyMiddleware(...)

Agent Factory Pattern (custom providers)

public class <Provider>AgentFactory
{
    public <Provider>Connection Connection { get; }

    public <Provider>AgentFactory(string apiKey);
    public <Provider>AgentFactory(<Provider>Connection connection);

    public <Provider>Agent CreateAgent(<Provider>AgentOptions options)
    {
        // 1. Get SDK client from connection
        // 2. Build IChatClient (or use SDK-provided one)
        // 3. Create ChatClientAgent
        // 4. Apply middleware via MiddlewareHelper
        // 5. Wrap in provider-specific agent
    }
}

Common Pitfalls

1. •Missing XML documentation (warnings are errors in this repo)
2. •Putting versions in .csproj instead of Directory.Packages.props
3. •Forgetting to update AgentFrameworkToolkit.slnx and README.md
4. •Forgetting to add provider to development/Tests/TestBase.cs test harness
5. •Hardcoding API keys instead of using user-secrets (development/Secrets/SecretsManager.cs)

Reference Documentation

• •OpenAI-Compatible Provider Template
• •Custom Provider Template
• •Unit Testing Guide
• •Provider Implementation Checklist