switched from config.json to secrets

BlogWriter.csproj

@@ -7,6 +7,7 @@
     <TargetFramework>net10.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
+    <UserSecretsId>162971f9-9e16-430b-9879-eef4676fe8c8</UserSecretsId>
   </PropertyGroup>
 
   <ItemGroup>
@@ -17,6 +18,9 @@
     </PackageReference>
     <PackageReference Include="Microsoft.Extensions.AI" Version="10.7.0" />
     <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="10.7.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration" Version="10.0.10" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="10.0.10" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="10.0.10" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="10.0.10" />
     <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="10.0.10" />
     <PackageReference Include="OpenAI" Version="2.11.0" />

Program.cs

@@ -2,32 +2,34 @@
 using System.Diagnostics;
 using System.Net.Http.Headers;
 using System.Net.Http.Json;
-using System.Text.Json;
 using BlogWriter;
 using Microsoft.Extensions.AI;
+using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.Logging;
 using OpenAI;
 
-const string fileName = "config.json";
-
-using var stream = File.OpenRead(fileName);
-using var document = JsonDocument.Parse(stream);
-JsonElement config = document.RootElement;
+// Secrets come from the .NET user-secrets store in development and from
+// environment variables in CI/production (env vars win on key collisions).
+IConfiguration config = new ConfigurationBuilder()
+    .AddUserSecrets<Program>()
+    .AddEnvironmentVariables()
+    .Build();
 
-string? GetValue(string key) =>
-    config.TryGetProperty(key, out JsonElement value) ? value.GetString() : null;
+string GetRequired(string key) =>
+    config[key] ?? throw new InvalidOperationException(
+        $"Missing configuration value '{key}'. Set it with: dotnet user-secrets set \"{key}\" \"<value>\"");
 
-Environment.SetEnvironmentVariable("OPENAI_API_KEY", GetValue("API_KEY"));
-Environment.SetEnvironmentVariable("OPENAI_BASE_URL", GetValue("OPENAI_API_BASE"));
-Environment.SetEnvironmentVariable("TAVILY_API_KEY", GetValue("TAVILY_API_KEY"));
+string openAiApiKey = GetRequired("API_KEY");
+string openAiApiBase = GetRequired("OPENAI_API_BASE");
+string tavilyApiKey = GetRequired("TAVILY_API_KEY");
 
 string modelName = "gpt-4o-mini";
 
 var openAIClient = new OpenAIClient(
-    new ApiKeyCredential(Environment.GetEnvironmentVariable("OPENAI_API_KEY")!),
+    new ApiKeyCredential(openAiApiKey),
     new OpenAIClientOptions
     {
-        Endpoint = new Uri(Environment.GetEnvironmentVariable("OPENAI_BASE_URL")!)
+        Endpoint = new Uri(openAiApiBase)
     });
 
 // Build the IChatClient pipeline once and share it across all agents.
@@ -64,7 +66,7 @@
 
 var tavilyHttpClient = new HttpClient { BaseAddress = new Uri("https://api.tavily.com/") };
 tavilyHttpClient.DefaultRequestHeaders.Authorization =
-    new AuthenticationHeaderValue("Bearer", Environment.GetEnvironmentVariable("TAVILY_API_KEY"));
+    new AuthenticationHeaderValue("Bearer", tavilyApiKey);
 
 AIFunction tavilyTool = AIFunctionFactory.Create(
     async (string query) =>

README.md

@@ -1,2 +1,24 @@
 # Demo code associated with series of blog posts on https://jesseliberty.com
-
+
+## Configuration
+
+Secrets are read from the .NET [user-secrets](https://learn.microsoft.com/aspnet/core/security/app-secrets) store in
+development and from environment variables in CI/production. There is no `config.json` file.
+
+Set the required values once per machine:
+
+```pwsh
+dotnet user-secrets set "API_KEY" "<your-openai-api-key>"
+dotnet user-secrets set "OPENAI_API_BASE" "https://aibe.mygreatlearning.com/openai/v1"
+dotnet user-secrets set "TAVILY_API_KEY" "<your-tavily-api-key>"
+```
+
+Alternatively, provide the same keys as environment variables (`API_KEY`, `OPENAI_API_BASE`, `TAVILY_API_KEY`);
+environment variables override user secrets.
+
+Then run:
+
+```pwsh
+dotnet run
+```
+