About

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!

Install

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.

Documentation

• 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]

Features

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.

:file_folder: Repository Structure

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:

:dart: Quick Overview

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)

:book: Folder Guide

:world_map: Where to Find Things

:rocket: Getting Started

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! :tada:

Contributing

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

Notes

[^1]: Starting with version 21 and higher, the solution's code base supports Multitargeting as SDK-style projects. It should be easier for teams to migrate to the currently supported .NET 8, 9 and 10 frameworks. Also, new features will be available for all .NET SDKs that we support via multitargeting. Find out more here: Target frameworks in SDK-style projects [^2]: Ocelot Guru is an unofficial tool to get answers regarding Ocelot: please consider it an advanced search tool. Thus, we have an official Questions & Answers category in the Discussions space. [^3]: Retry policies only via Polly library referenced within the Ocelot.QualityOfService.Polly extension package, a former Ocelot.Provider.Polly package. [^4]: Previously, the Aggregation feature was called Request Aggregation in versions 23.4.3 and earlier. Internally, within the Ocelot team, this feature is referred to as Multiplexer. [^5]: Ocelot supports the following service discovery providers: (1) Consul through the Ocelot.Discovery.Consul extension package, (2) Kubernetes via the Ocelot.Provider.Kubernetes extension package, and (3) Netflix Eureka, which utilizes the Steeltoe.Discovery.Eureka package referenced within the Ocelot.Discovery.Eureka extension package. Additionally, Ocelot supports (4) Azure Service Fabric for service discovery, along with special modes such as Dynamic Routing and Custom Providers. [^6]: Ocelot does not directly support GraphQL. Developers can easily integrate the GraphQL for .NET library. [^7]: See all labels for the repository, which are useful for searching and filtering.