microsoft/semantic-kernel · error · InvalidOperationException

AZURE_OPENAI_ENDPOINT is not set.

Error message

AZURE_OPENAI_ENDPOINT is not set.

What it means

The Azure OpenAI Responses ReasoningModel migration sample throws InvalidOperationException when AZURE_OPENAI_ENDPOINT is missing. This sample uses a reasoning model (default deployment o4-mini) via the Responses API to transform a React component. Reasoning models have different token and parameter characteristics that the Responses API exposes.

Source

Thrown at dotnet/samples/AgentFrameworkMigration/AzureOpenAIResponses/Step02_ReasoningModel/Program.cs:15

// Copyright (c) Microsoft. All rights reserved.

using Azure.AI.OpenAI;
using Azure.Identity;
using Microsoft.Agents.AI;
using Microsoft.Extensions.AI;
using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.Agents.OpenAI;
using Microsoft.SemanticKernel.ChatCompletion;
using OpenAI.Responses;

#pragma warning disable OPENAI001 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
#pragma warning disable SKEXP0110 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.

var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
var deploymentName = System.Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "o4-mini";
var userInput =
    """
    Instructions:
    - Given the React component below, think about it and change it so that nonfiction books have red
        text. 
    - Return only the code in your reply
    - Do not include any additional formatting, such as markdown code blocks
    - For formatting, use four space tabs, and do not allow any lines of code to 
        exceed 80 columns
    const books = [
        { title: 'Dune', category: 'fiction', id: 1 },
        { title: 'Frankenstein', category: 'fiction', id: 2 },
        { title: 'Moneyball', category: 'nonfiction', id: 3 },
    ];
    export default function BookList() {
        const listItems = books.map(book =>
        <li>

View on GitHub (pinned to c028a0c7dc)

Solutions

1. Set AZURE_OPENAI_ENDPOINT to your Azure OpenAI resource URL
2. Set AZURE_OPENAI_DEPLOYMENT_NAME to a reasoning model deployment (defaults to o4-mini)
3. Ensure the reasoning model (e.g. o4-mini) is deployed in your Azure OpenAI resource
4. Run az login for AzureCliCredential

Example fix

// before
var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");

// after
var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
if (string.IsNullOrWhiteSpace(endpoint))
    throw new InvalidOperationException(
        "AZURE_OPENAI_ENDPOINT is not set. Deploy a reasoning model (e.g. o4-mini) first.");

var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT");
var deployment = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "o4-mini";
if (string.IsNullOrWhiteSpace(endpoint))
{
    Console.Error.WriteLine("AZURE_OPENAI_ENDPOINT is not set. Deploy a reasoning model (e.g. o4-mini).");
    return;
}

static bool IsAzureOpenAIEndpointConfigured() =>
    !string.IsNullOrWhiteSpace(Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT"));

try
{
    var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
        ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
}
catch (InvalidOperationException ex) when (ex.Message.Contains("AZURE_OPENAI_ENDPOINT"))
{
    Console.Error.WriteLine(ex.Message);
    return;
}

When it happens

Trigger: Running AzureOpenAIResponses/Step02_ReasoningModel without AZURE_OPENAI_ENDPOINT. The throw at line 15 fires before the React component prompt is sent.

Common situations: The o4-mini deployment does not exist in the Azure OpenAI resource (AZURE_OPENAI_DEPLOYMENT_NAME defaults to o4-mini here, not gpt-4o); reasoning models may not be available in all regions; the Responses API preview may not be enabled on the resource.

Related errors

• AZURE_OPENAI_ENDPOINT is not set.
• AZURE_OPENAI_ENDPOINT is not set.
• AZURE_OPENAI_ENDPOINT is not set.
• AZURE_OPENAI_ENDPOINT is not set.
• AZURE_OPENAI_ENDPOINT is not set.

AI-assisted analysis of microsoft/semantic-kernel@c028a0c7dc (2026-08-13). Data as JSON: /api/errors/e0eb2235316e498d. Report an issue: GitHub.