Plume.Anthropic 0.1.0-rc.1

Plume 🪶

The minimalist, resilient AI client for .NET. One unified API. Multiple providers. Built-in failover.

Package	Version
Plume
Plume.OpenAI
Plume.Anthropic
Plume.Google
Plume.Ollama

using var http = new HttpClient();
var ai = PlumeClient.CreateBuilder()
    .Use(new OpenAIProvider(http, new() { ApiKey = "sk-..." }))
    .WithDefaultModel("gpt-4o-mini")
    .Build();

string answer = await ai.AskAsync("What is the capital of France?");

That's it. From zero to a working LLM call in two lines. No KernelBuilder, no plugins, no ceremony.

Why Plume?

The .NET AI ecosystem is dominated by heavyweight frameworks designed for enterprise. Plume is for the rest of us:

• Tiny. Core package has minimal dependencies. No Azure SDK pulled in transitively.
• Multi-provider. OpenAI, Anthropic Claude, Google Gemini, Ollama — same API, swap at will.
• Resilient by default. Provider down? Plume fails over silently to the next one. Your app keeps responding.
• Async-first. IAsyncEnumerable streaming. CancellationToken everywhere. Modern .NET 8+.
• AOT-ready. Source-generated JSON, trim-safe, Native AOT compatible.

Install

dotnet add package Plume
dotnet add package Plume.OpenAI       # optional
dotnet add package Plume.Anthropic    # optional
dotnet add package Plume.Google       # optional
dotnet add package Plume.Ollama       # optional

Install only the providers you use. Plume itself does not depend on any specific provider.

Quick start (DI / ASP.NET)

using Plume.DependencyInjection;
using Plume.OpenAI;

builder.Services.AddPlume(options =>
{
    options.UseOpenAI(builder.Configuration["OpenAI:ApiKey"]!);
    options.DefaultModel = "gpt-4o-mini";
});

// Anywhere in your app:
public class SummaryService(IPlumeClient ai)
{
    public Task<string> Summarize(string text) =>
        ai.AskAsync($"Summarize in 2 lines: {text}");
}

Streaming

await foreach (var chunk in ai.StreamAsync("Write a haiku about rain"))
    Console.Write(chunk);

Multi-turn conversations

var chat = ai.NewChat(system: "You are a senior C# code reviewer.");

await chat.AskAsync("Review: public string Hi() => \"hi\";");
await chat.AskAsync("How can I make it more idiomatic?");

// Persist or restore
foreach (var message in chat.History)
    SaveToDatabase(message);

Failover — the killer feature

using Plume.Anthropic;
using Plume.OpenAI;
using Plume.Google;
using Plume.Ollama;

builder.Services.AddPlume(options =>
{
    options.UseAnthropic(anthropicKey);          // primary
    options.FallbackToOpenAI(openAiKey);         // if Anthropic fails transiently
    options.FallbackToGoogle(googleKey);         // then Google
    options.FallbackToOllama();                  // local last resort

    options.DefaultModel = "claude-sonnet-4";
});

If Anthropic returns 429 or 503, Plume silently fails over to OpenAI, then Google, then your local Ollama. Your application keeps responding. No code changes, no try/catch. This is the gap nothing else in the .NET ecosystem fills.

What counts as transient (failover happens):

• HTTP 429 (rate limit) — uses Retry-After if provided
• HTTP 503/504/502/408 (server unavailable, gateway timeout)
• HttpRequestException (network failure)
• Timeouts

What does NOT count as transient (failover does NOT happen):

• HTTP 4xx other than 429 (bad request, auth failure, not found)
• Cancellation requested by your CancellationToken

Provider-specific options (strongly typed)

var answer = await ai.AskAsync("Generate a story",
    new AskOptions
    {
        Temperature = 0.9,
        Extensions = new OpenAIExtensions
        {
            FrequencyPenalty = 0.5,
            Seed = 42
        }
    });

IntelliSense works. Compile-time safety. No stringly-typed dictionaries. Provider-specific extensions are silently ignored if the request fails over to a different provider — so you can use them safely with failover enabled.

Supported providers

Samples

Runnable end-to-end samples live in samples/. Each is a single-file program — clone the repo, set the relevant *_API_KEY env var, and dotnet run.

Status

🚧 v0.1.0-alpha — under active development, API may evolve before 1.0.

The roadmap:

Contributing

Issues and PRs welcome.

License

MIT. Use it freely in commercial projects.

Built with ❤️ for .NET developers who want their AI code to read like it was written, not generated.