gRPC-Web for .NET is now officially released. We announced experimental support in January and since then we’ve been making improvements based on feedback from early adopters.
With this release gRPC-Web graduates to a fully supported component of the grpc-dotnet project and is ready for production. Use gRPC in the browser with gRPC-Web and .NET today.
Getting started
Developers who are brand new to gRPC should check out Create a gRPC client and server in ASP.NET Core. This tutorial walks through creating your first gRPC client and server using .NET.
If you already have a gRPC app then the Use gRPC in browser apps article shows how to add gRPC-Web to a .NET gRPC server.
What are gRPC and gRPC-Web
gRPC is a modern high-performance RPC (Remote Procedure Call) framework. gRPC is based on HTTP/2, Protocol Buffers and other modern standard-based technologies. gRPC is an open standard and is supported by many programming languages, including .NET.
It is currently impossible to implement the gRPC HTTP/2 spec in the browser because there are no browser APIs with enough fine-grained control over requests. gRPC-Web is a standardized protocol that solves this problem and makes gRPC usable in the browser. gRPC-Web brings many of gRPC’s great features, like small binary messages and contract-first APIs, to modern browser apps.
New opportunities with gRPC-Web
gRPC-Web is designed to make gRPC available in more scenarios. These include:
- Call ASP.NET Core gRPC apps from the browser – Browser APIs can’t call gRPC HTTP/2. gRPC-Web offers a compatible alternative.
- JavaScript SPAs
- .NET Blazor Web Assembly apps
- Host ASP.NET Core gRPC apps in IIS and Azure App Service – Some servers, such as IIS and Azure App Service, currently can’t host gRPC services. While this is actively being worked on, gRPC-Web offers an interesting alternative that works in every environment today.
- Call gRPC from non-.NET Core platforms – HTTP/2 is not supported by HttpClient on all .NET platforms. gRPC-Web can be used to call gRPC services from Blazor and Xamarin.
gRPC is a registered trademark of the Linux foundation. Blazor is compatible with gRPC-web
We’ve worked with the Blazor team to make gRPC-Web a great end-to-end developer experience when used in Blazor WebAssembly apps. Not only will gRPC tooling automatically generate strongly typed clients for you to call gRPC services from your Blazor app, but gRPC offers significant performance benefits over JSON.
A great example of the performance benefits in action is Blazor’s default template app. The data transferred on the fetch data page is halved when gRPC is used instead of JSON. Data size is reduced from 627 bytes down to 309 bytes.
The performance gain here comes from gRPC’s efficient binary serialization over traditional text-based JSON. gRPC-Web is an exciting opportunity to improve rich browser-based apps.
Try gRPC-Web with ASP.NET Core today
For more information about gRPC-Web, check out the documention, or try out a sample app that uses gRPC-Web.
gRPC-Web for .NET is out on NuGet now:
- Grpc.AspNetCore.Web – Add gRPC-Web support to an ASP.NET Core gRPC service.
- Grpc.Net.Client.Web – Call gRPC-Web endpoints from .NET
We look forward to seeing what you create with .NET, gRPC and now gRPC-Web!
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James,
Is there a way with a .NET Core gRPC Service and using gRPC-Web to be hosted into IIS Express instead of Kestrel (In Visual Studio 2019)?
I tried to change the Properties of the project to IIS Express.
I followed this page below and I can see traffic in Krestel application/grpc-web
https://docs.microsoft.com/en-us/aspnet/core/grpc/browser?view=aspnetcore-3.1
Can you provide instructions?
Thank you.
Hello James
Does this not work with .net core 5 preview 7? I am struggling big time with trying to get this to work with
Blazor WebAssembly App (blazorwasm). I am creating a project like this
dotnet new blazorwasm and I try to add the needed packages and code but it seems GrpcChannel is not recognized
Thank you so much for any help you may give
Hi, wondering when gRPC-Web will be available on .Net 5? I have Blazor projects that use it. Thanks and keep up the great work!
Fantastico !!
can it run after cloudflare?
Great job ! I’m trying to host a grpc-web service into iis without success so far.
I was wondering if you have :
– complete code sample (client/server)
– how to publish the service into iis
– how to configure the application in iis (possibly using windows integrated security)
Thanks for your help.
Is possible to call gRPC services from a Xamarin Forms app? I didn't find any specific code example for xamarin. Trying to setting up locally a gRPC-Web server and a Xamarin Forms app, I'm not able to call the service from the Android emulator. I followed the documentation (after successfully made the intro gRPC tutorial) and I have also considered how to connect to local web services from emulator. Thanks
Is there any hope for a .Net Standard 2.0 compatible gRPC client so we can develop new services using .Net Core but allow them to be consumed by our older .Net Framework apps?
You will need to use Grpc.Core.
HttpClient in .NET Framework doesn’t support HTTP/2 and there are no plans to add it.
Isn’t the fact that HttpClient in .Net Framework doesn’t support HTTP/2 the same problem as the browser not supporting it? Wouldn’t the gRpc-Web solution work for .Net Framework also?
It is possible to create a grpc-web client for .NET Framework. In our case, Grpc.Net.Client uses netstandard2.1 specific APIs as part of its support for regular gRPC over HTTP/2. Supporting netstandard2.0 is not possible.
Can this be generically used with any js client like protobuf.js in a spa scenario?
And can we have a full sample with .Net Server and a JS SPA client?
How the server can create protobuf.js for JS Client?
Examples of gRPC-Web in a browser with a JavaScript client, and in a SPA (using Vue.js) are available here:
Fabulous stuff. Curious if the compression on the Blazor side is now operational, and, if it is, what the pattern might look like
var compressionproviders = new List(); compressionproviders.Add(new GzipCompressionProvider(System.IO.Compression.CompressionLevel.Optimal)); var channel = GrpcChannel.ForAddress("https://localhost:2494", new GrpcChannelOptions { HttpClient = httpClient, CompressionProviders = compressionproviders });Compression in Blazor is supported. It works exactly the same way compression does with a .NET gRPC client on .NET Core.