/azure-ai

Azure OpenAI — .NET SDK Quick Reference

Condensed from azure-ai-openai-dotnet. Full patterns (function calling, structured outputs, RAG with Search) in the azure-ai-openai-dotnet plugin skill if installed.

Install

dotnet add package Azure.AI.OpenAI

Quick Start

using Azure.AI.OpenAI;
using OpenAI.Chat;
var azureClient = new AzureOpenAIClient(new Uri(endpoint), credential);
ChatClient chatClient = azureClient.GetChatClient("gpt-4o-mini");

Non-Obvious Patterns

• Client hierarchy: AzureOpenAIClient.GetChatClient() / GetEmbeddingClient() / GetImageClient() / GetAudioClient()
• Reasoning models (o1): use DeveloperChatMessage instead of SystemChatMessage, set ReasoningEffortLevel
• RAG: #pragma warning disable AOAI001 then options.AddDataSource(new AzureSearchChatDataSource{...})
• Structured outputs: ChatResponseFormat.CreateJsonSchemaFormat(...)

Best Practices

1. Use Entra ID in production — avoid API keys
2. Reuse client instances — create once, share across requests
3. Handle rate limits — implement exponential backoff for 429 errors
4. Stream for long responses — use CompleteChatStreamingAsync
5. Set appropriate timeouts for long completions
6. Use structured outputs for consistent response format
7. Monitor token usage via completion.Usage for cost management
8. Validate tool call arguments before execution