fix: Standardize OpenAI API key environment variable naming (#1001) (#2629)

- Replace OPENAI_APIKEY with OPENAI_API_KEY across all samples
- Replace AZURE_FOUNDRY_OPENAI_APIKEY with AZURE_FOUNDRY_OPENAI_API_KEY
- Ensures consistency with OpenAI's standard naming convention
- Applies to .NET and Python samples

Fixes #1001

Co-authored-by: Alexander Zarei <alzarei@users.noreply.github.com>

Author: alzarei

agent-samples/openai/OpenAIAssistants.yaml

@@ -11,7 +11,7 @@ model:
         topP: 0.95
     connection:
         kind: ApiKey
-        key: =Env.OPENAI_APIKEY
+        key: =Env.OPENAI_API_KEY
 outputSchema:
     properties:
         language:

agent-samples/openai/OpenAIChat.yaml

@@ -11,7 +11,7 @@ model:
         topP: 0.95
     connection:
         kind: ApiKey
-        key: =Env.OPENAI_APIKEY
+        key: =Env.OPENAI_API_KEY
 outputSchema:
     properties:
         language:

agent-samples/openai/OpenAIResponses.yaml

@@ -11,7 +11,7 @@ model:
         topP: 0.95
     connection:
         kind: ApiKey
-        key: =Env.OPENAI_APIKEY
+        key: =Env.OPENAI_API_KEY
 outputSchema:
     properties:
         language:

dotnet/samples/GettingStarted/AgentProviders/Agent_With_AzureFoundryModel/Program.cs

@@ -12,7 +12,7 @@
 using OpenAI.Chat;
 
 var endpoint = Environment.GetEnvironmentVariable("AZURE_FOUNDRY_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_FOUNDRY_OPENAI_ENDPOINT is not set.");
-var apiKey = Environment.GetEnvironmentVariable("AZURE_FOUNDRY_OPENAI_APIKEY");
+var apiKey = Environment.GetEnvironmentVariable("AZURE_FOUNDRY_OPENAI_API_KEY");
 var model = Environment.GetEnvironmentVariable("AZURE_FOUNDRY_MODEL_DEPLOYMENT") ?? "Phi-4-mini-instruct";
 
 // Since we are using the OpenAI Client SDK, we need to override the default endpoint to point to Azure Foundry.

dotnet/samples/GettingStarted/AgentProviders/Agent_With_AzureFoundryModel/README.md

@@ -27,7 +27,7 @@ Set the following environment variables:
 $env:AZURE_FOUNDRY_OPENAI_ENDPOINT="https://ai-foundry-<myresourcename>.services.ai.azure.com/openai/v1/"
 
 # Optional, defaults to using Azure CLI for authentication if not provided
-$env:AZURE_FOUNDRY_OPENAI_APIKEY="************"
+$env:AZURE_FOUNDRY_OPENAI_API_KEY="************"
 
 # Optional, defaults to Phi-4-mini-instruct
 $env:AZURE_FOUNDRY_MODEL_DEPLOYMENT="Phi-4-mini-instruct"

dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/Program.cs

@@ -11,7 +11,7 @@
 using OpenAI;
 using OpenAI.Assistants;
 
-var apiKey = Environment.GetEnvironmentVariable("OPENAI_APIKEY") ?? throw new InvalidOperationException("OPENAI_APIKEY is not set.");
+var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY") ?? throw new InvalidOperationException("OPENAI_API_KEY is not set.");
 var model = Environment.GetEnvironmentVariable("OPENAI_MODEL") ?? "gpt-4o-mini";
 
 const string JokerName = "Joker";

dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIAssistants/README.md

@@ -11,6 +11,6 @@ Before you begin, ensure you have the following prerequisites:
 Set the following environment variables:
 
 ```powershell
-$env:OPENAI_APIKEY="*****" # Replace with your OpenAI API key
+$env:OPENAI_API_KEY="*****" # Replace with your OpenAI API key
 $env:OPENAI_MODEL="gpt-4o-mini"  # Optional, defaults to gpt-4o-mini
 ```

dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIChatCompletion/Program.cs

@@ -7,7 +7,7 @@
 using OpenAI;
 using OpenAI.Chat;
 
-var apiKey = Environment.GetEnvironmentVariable("OPENAI_APIKEY") ?? throw new InvalidOperationException("OPENAI_APIKEY is not set.");
+var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY") ?? throw new InvalidOperationException("OPENAI_API_KEY is not set.");
 var model = Environment.GetEnvironmentVariable("OPENAI_MODEL") ?? "gpt-4o-mini";
 
 AIAgent agent = new OpenAIClient(

dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIChatCompletion/README.md

@@ -8,6 +8,6 @@ Before you begin, ensure you have the following prerequisites:
 Set the following environment variables:
 
 ```powershell
-$env:OPENAI_APIKEY="*****" # Replace with your OpenAI api key
+$env:OPENAI_API_KEY="*****" # Replace with your OpenAI api key
 $env:OPENAI_MODEL="gpt-4o-mini"  # Optional, defaults to gpt-4o-mini
 ```

dotnet/samples/GettingStarted/AgentProviders/Agent_With_OpenAIResponses/Program.cs

@@ -6,7 +6,7 @@
 using OpenAI;
 using OpenAI.Responses;
 
-var apiKey = Environment.GetEnvironmentVariable("OPENAI_APIKEY") ?? throw new InvalidOperationException("OPENAI_APIKEY is not set.");
+var apiKey = Environment.GetEnvironmentVariable("OPENAI_API_KEY") ?? throw new InvalidOperationException("OPENAI_API_KEY is not set.");
 var model = Environment.GetEnvironmentVariable("OPENAI_MODEL") ?? "gpt-4o-mini";
 
 AIAgent agent = new OpenAIClient(