Componentpedia / Listings / Ocelot

Ocelot is a .NET API gateway. This project is aimed at people using .NET running a microservices (service-oriented) architecture that needs a unified point of entry into their system. However, it will work with anything that speaks HTTP(S) and runs on any platform that ASP.NET Core supports.

Ocelot consists of a series of ASP.NET Core middlewares arranged in a specific order. Ocelot custom middlewares manipulate the HttpRequest object into a state specified by its configuration until it reaches a request builder middleware, where it creates a HttpRequestMessage object, which is used to make a request to a downstream service. The middleware that makes the request is the last thing in the Ocelot pipeline. It does not call the next middleware. The response from the downstream service is retrieved as the request goes back up the Ocelot pipeline. There is a piece of middleware that maps the HttpResponseMessage onto the HttpResponse object, and that is returned to the client. That is basically it, with a bunch of other features!

Ocelot is designed to work with ASP.NET Core and it targets net9.0 STS and net8.0, net10.0 LTS target framework monikers (TFMs). ¹ Install Ocelot package and its dependencies using the .NET CLI:

dotnet add package Ocelot

All versions are available on NuGet.

• RST-sources: This includes the source code for the documentation (in reStructuredText format, .rst files), which is up to date for the current development. And the rendered HTML documentation is available here.
• Read the Docs: This official website, in HTML format, contains a wealth of information and will be helpful if you want to understand the features that Ocelot currently offers. The rendered HTML documentation, which is currently in development, is available here.
• Ask Ocelot Guru: It is an AI focused on Ocelot, designed to answer your questions. ²

The primary features—Configuration and Routing—are always utilized by users, even in a minimal app setup, without customizations or extra configurations. Ocelot's capabilities are categorized into three main groups of features: solid, hybrid, and feature-family groups, which are explained below.

• Solid features are unique to Ocelot. They do not contain subfeatures and are not related to other features.
• Hybrid features, on the other hand, have multiple relationships with other features and can be part of other features.
• Feature families are large groups that consist of multiple subfeatures.

Feature groups are explained in the table below

Ocelot customizations can be configured using Metadata, developed with Delegating Handlers, and in advanced scenarios, they can be developed and then configured with Middleware Injection. For further details, refer to the Documentation.

Welcome to Ocelot's minimalist folder organization! Our repository follows a clean, flat structure that makes it easy to navigate and contribute. Here's where everything lives:

Ocelot/
├── 📦 src/                 # Main library source code (Ocelot NuGet package)
│   ├── Configuration/       # Configuration system & builders
│   ├── DependencyInjection/ # IoC setup & extension methods
│   ├── Authentication/      # Auth middleware & schemes
│   ├── RateLimiting/        # Rate limiting policies
│   ├── Routing/             # Core routing logic
│   └── ...                  # Other features (Caching, Load Balancing, etc.)
│
├── 🧪 unit/                    # Unit tests (fast, isolated tests)
│   └── Ocelot.UnitTests.csproj  # Component-level test suite
│
├── ✅ acceptance/              # Integration tests (end-to-end scenarios)
│   └── Ocelot.Acceptance.csproj # Full pipeline test suite
│
├── 📊 benchmark/               # Performance benchmarking
│   └── Ocelot.Benchmarks.csproj # Using BenchmarkDotNet
│
├── 🚀 manual/                  # Manual testing & demo apps
│   └── Ocelot.ManualTest.csproj # Sample applications
│
├── 🛠️ testing/                 # Shared test infrastructure (Ocelot.Testing NuGet package)
│   └── Ocelot.Testing.csproj    # Common test utilities & helpers
│
├── 📖 docs/                    # Documentation source files (https://ocelot.readthedocs.io website)
│   ├── *.rst files              # reStructuredText documentation
│   └── make.* scripts           # Terminal build scripts for generating HTML docs
│
├── 📚 samples/                 # Example projects & demonstrations
│
├── ⚙️ .config/                 # Build & versioning configuration
│   └── dotnet-tools.json        # CI and local building tools configuration
│
├── 🔧 .github/                 # GitHub-specific settings
│   ├── steps/                   # CI/CD terminal scripts for GitHub Actions steps
│   ├── workflows/               # CI/CD pipelines (GitHub Actions)
│   └── *.md files               # Markdown configuration supporting GitHub process
│
└── 📋 Root Configuration       # Solution & project files
    ├── Ocelot.slnx              # Visual Studio 2026+ solution (Ocelot development)
    ├── Ocelot.Samples.slnx      # Visual Studio 2026+ solution (Ocelot samples)
    ├── .editorconfig            # Code style & formatting rules
    ├── build.cake               # Cake build automation (Release workflow only)
    └── ReleaseNotes.md          # Template for release notes (used in GitHub Actions)

1. New to Ocelot?

   • Start with src/DependencyInjection/ to understand the startup flow
   • Read docs/ for architecture and feature documentation

2. Want to run tests?

   • Unit tests: dotnet test unit/Ocelot.UnitTests.csproj --verbosity quiet
   • Acceptance tests: dotnet test acceptance/Ocelot.Acceptance.csproj

3. Need to benchmark?

   • cd benchmark && dotnet run -c Release

4. Contributing?

   • Place code in appropriate folder (usually src/FeatureName/)
   • Add tests in parallel structure under unit/ or acceptance/
   • Submit a pull request! 🎉

You can see what we are working on in the backlog. We love to receive contributions from the community, so please keep them coming. Pull requests, issues, and commentary welcome!

Please complete the relevant template for issues and pull requests. Sometimes it's worth getting in touch with us to discuss changes before doing any work in case this is something we are already doing or it might not make sense. We can also give advice on the easiest way to do things

Finally, we mark all existing issues as .⁷ If you want to contribute for the first time, we suggest looking at a