ElBruno.HuggingFace.Downloader

📥 ElBruno.HuggingFace.Downloader

A .NET library and CLI tool to download files (ONNX models, tokenizers, voice presets, etc.) from Hugging Face Hub repositories with progress reporting, caching, and authentication support.

Features

• 📦 Download any file from public or private Hugging Face repositories
• 📊 Rich progress reporting with stages (Checking → Downloading → Validating → Complete)
• 🔑 HF_TOKEN authentication for gated/private repositories (env var or explicit)
• 🔒 Atomic writes using temp files to avoid partial/corrupt downloads
• 🔁 Resumable downloads using HTTP range requests for interrupted large files
• 📌 Revision pinning with resolved commit metadata and optional expected commit enforcement
• ✅ Required vs optional files — optional files fail silently
• 🧾 Manifest-based bundles with SHA-256 and size validation
• 📏 HEAD requests to resolve total download size before starting
• ⏭️ Skip existing files — only downloads what's missing
• 🖥️ Cross-platform cache directory helpers (Windows, Linux, macOS)
• 💉 DI-friendly with IServiceCollection extension methods
• 📝 ILogger integration for structured logging

📦 NuGet Packages

Package	Version	Downloads	Description
ElBruno.HuggingFace.Downloader			Core library for downloading files from Hugging Face Hub repositories
ElBruno.HuggingFace.Downloader.Cli			CLI tool (hfdownload) for managing Hugging Face downloads

Installation

Library (NuGet)

dotnet add package ElBruno.HuggingFace.Downloader

CLI Tool

dotnet tool install -g ElBruno.HuggingFace.Downloader.Cli

Once installed, use the hfdownload command:

# Download model files
hfdownload download sentence-transformers/all-MiniLM-L6-v2 onnx/model.onnx tokenizer.json

# Download a specific tag into a revision-aware cache directory
hfdownload download sentence-transformers/all-MiniLM-L6-v2 onnx/model.onnx --revision v1.0

# Restart from scratch instead of resuming a preserved partial download
hfdownload download sentence-transformers/all-MiniLM-L6-v2 onnx/model.onnx --no-resume

# Ensure a manifest-defined bundle with integrity validation
hfdownload download --manifest ./phi4-bundle.json -o ./models/phi4

# Check if files exist locally
hfdownload check sentence-transformers/all-MiniLM-L6-v2 onnx/model.onnx tokenizer.json

# List cached models
hfdownload list

# Delete a cached model
hfdownload delete sentence-transformers/all-MiniLM-L6-v2

# See all commands
hfdownload --help

See the full CLI Reference for all commands and options.

Quick Start (Library)

1) Download model files

using ElBruno.HuggingFace;

using var downloader = new HuggingFaceDownloader();

var request = new DownloadRequest
{
    RepoId = "sentence-transformers/all-MiniLM-L6-v2",
    LocalDirectory = "./models/miniLM",
    RequiredFiles = ["onnx/model.onnx", "tokenizer.json"],
    OptionalFiles = ["tokenizer_config.json", "vocab.txt"],
    Revision = "refs/pr/42"
};

await downloader.DownloadFilesAsync(request);

Console.WriteLine($"Resolved commit: {request.ResolvedCommitSha}");

2) Ensure a manifest-based bundle with SHA-256 validation

var manifest = new ModelBundleManifest
{
    RepoId = "microsoft/Phi-4-mini-instruct-onnx",
    Revision = "main",
    Files =
    [
        new ModelBundleFile
        {
            Path = "onnx/model.onnx",
            Size = 123456789,
            Sha256 = "0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef"
        },
        new ModelBundleFile
        {
            Path = "tokenizer.json",
            Required = false
        }
    ]
};

var bundle = await downloader.EnsureBundleAsync(manifest, "./models/phi4");
Console.WriteLine(bundle.ResolvedManifestPath);

Manifest-driven bundle downloads validate existing files before reuse, re-download corrupted files, and write a resolved manifest to ./models/phi4/.hf.bundle.resolved.json.

3) Pin a branch or tag to the expected commit

var request = new DownloadRequest
{
    RepoId = "my-org/my-model",
    LocalDirectory = "./models/pinned",
    RequiredFiles = ["model.onnx"],
    Revision = "main",
    ExpectedCommitSha = "1234567890abcdef1234567890abcdef12345678"
};

await downloader.DownloadFilesAsync(request);
Console.WriteLine(request.ResolvedCommitSha);

4) Check if files are already downloaded

bool ready = downloader.AreFilesAvailable(
    ["onnx/model.onnx", "tokenizer.json"],
    "./models/miniLM");

if (!ready)
{
    var missing = downloader.GetMissingFiles(
        ["onnx/model.onnx", "tokenizer.json"],
        "./models/miniLM");
    Console.WriteLine($"Missing {missing.Count} files");
}

5) Track download progress

var progress = new Progress<DownloadProgress>(p =>
{
    if (p.Stage == DownloadStage.Downloading)
        Console.Write($"\r⬇️ [{p.CurrentFile}] {p.PercentComplete:F0}% (reused {ByteFormatHelper.FormatBytes(p.ResumedBytes)})");
    else
        Console.WriteLine($"{p.Stage}: {p.Message}");
});

await downloader.DownloadFilesAsync(new DownloadRequest
{
    RepoId = "sentence-transformers/all-MiniLM-L6-v2",
    LocalDirectory = "./models/miniLM",
    RequiredFiles = ["onnx/model.onnx", "tokenizer.json"],
    Progress = progress
});

6) Authentication (Private/Gated Repos)

Set the HF_TOKEN environment variable, or pass it explicitly:

var downloader = new HuggingFaceDownloader(new HuggingFaceDownloaderOptions
{
    AuthToken = "hf_your_token_here"
});

7) Dependency Injection

builder.Services.AddHuggingFaceDownloader(options =>
{
    options.Timeout = TimeSpan.FromMinutes(60);
});

// Then inject HuggingFaceDownloader in your services
public class MyModelService(HuggingFaceDownloader downloader)
{
    public async Task EnsureModelAsync()
    {
        await downloader.DownloadFilesAsync(new DownloadRequest
        {
            RepoId = "my-org/my-model",
            LocalDirectory = DefaultPathHelper.GetDefaultCacheDirectory("MyApp"),
            RequiredFiles = ["model.onnx", "tokenizer.json"]
        });
    }
}

Direct downloads also write ./models/.../.hf.download.resolved.json so callers can inspect the requested revision and resolved commit later.

Documentation

Related Projects

• ElBruno.PersonaPlex — Integrates this downloader to auto-download ONNX models for NVIDIA's PersonaPlex-7B-v1 full-duplex speech-to-speech model

Building from Source

git clone https://github.com/elbruno/ElBruno.HuggingFace.Downloader.git
cd ElBruno.HuggingFace.Downloader
dotnet build ElBruno.HuggingFace.Downloader.slnx
dotnet test ElBruno.HuggingFace.Downloader.slnx

Requirements

• .NET 8.0 SDK or later

🤝 Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

📄 License

This project is licensed under the MIT License — see the LICENSE file for details.

👋 About the Author

Hi! I'm ElBruno 🧡, a passionate developer and content creator exploring AI, .NET, and modern development practices.

Made with ❤️ by ElBruno

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