Automating .NET Framework Support Checks: A Programmatic Approach

Side project idea I

Developer Karen Payne presents a technical solution for programmatically verifying if a .NET application version is currently supported. The implementation leverages official Microsoft release metadata to provide real-time framework status updates.

Why This Matters

In technical environments, relying on manual documentation for framework lifecycles often leads to security vulnerabilities when versions reach ‘End of Life’ unnoticed. By automating this check via the official release-metadata API, engineers can integrate support-phase validation directly into their CI/CD pipelines or application startup routines, ensuring compliance with support standards and reducing technical debt.

Key Insights

• Microsoft maintains a public JSON feed for .NET release metadata at dotnetcli.azureedge.net (2026).
• Mapping non-standard JSON properties like ‘support-phase’ is achieved using the JsonPropertyNameAttribute in System.Text.Json.
• The TargetFrameworkAttribute can be extracted via reflection to identify the specific framework version of a running assembly.
• Asynchronous stream processing with JsonSerializer.DeserializeAsync allows for memory-efficient parsing of large metadata files.
• Support phases are categorized as ‘active’ or ‘not active,’ providing a binary state for automated decision-making.

Working Examples

Service to fetch and deserialize .NET release metadata from Microsoft’s edge servers.

public static class DotNetReleaseService
{
private static readonly HttpClient _httpClient = new();
public static async Task<List<ReleaseIndexItem>> GetReleaseIndexAsync(CancellationToken cancellationToken = default)
{
const string url = "https://dotnetcli.azureedge.net/dotnet/release-metadata/releases-index.json";
using HttpResponseMessage response = await _httpClient.GetAsync(url, cancellationToken);
response.EnsureSuccessStatusCode();
await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
var root = await JsonSerializer.DeserializeAsync<ReleasesIndexRoot>(stream, Options, cancellationToken);
return root?.ReleasesIndex ?? [];
}
public static JsonSerializerOptions Options => new() { PropertyNameCaseInsensitive = true };
}

Extension method to extract the semantic version from the assembly’s target framework attribute.

public static Version? GetTargetFrameworkVersion(this Assembly assembly)
{
var framework = assembly.GetCustomAttribute<TargetFrameworkAttribute>()?.FrameworkName;
if (string.IsNullOrWhiteSpace(framework)) return null;
const string marker = "Version=v";
var id = framework.IndexOf(marker, StringComparison.OrdinalIgnoreCase);
if (id >= 0)
{
var versionText = framework[(id + marker.Length)..].Trim();
var comma = versionText.IndexOf(',');
if (comma >= 0) versionText = versionText[..comma];
return Version.TryParse(versionText, out var v) ? v : null;
}
return null;
}

Practical Applications

• Use Case: Automated auditing tools can scan microservice repositories to flag dependencies on frameworks that are no longer in an active support phase.
• Pitfall: Ignoring exception handling in HttpClient requests can cause application startup failures if the Microsoft metadata endpoint is unreachable.
• Use Case: Corporate compliance dashboards can use this logic to generate reports on the ‘End of Life’ status of all deployed internal applications.
• Pitfall: Failing to use a CancellationToken in asynchronous calls can lead to blocked threads and poor resource management during network latency.

References:

• https://dev.to/karenpayneoregon/side-project-idea-i-32g8