Using CurlDotNet from PowerShell and .NET scripts

CurlDotNet is a .NET assembly, so PowerShell can load it with Add-Type and run curl commands through [CurlDotNet.Curl]::Execute(...), with no curl.exe and none of PowerShell’s native-argument quoting rules. The same command strings work unchanged in C# projects and .csx scripts.

Add-Type -Path "$HOME/.curldotnet/9.8.0/lib/net8.0/CurlDotNet.dll"
$r = [CurlDotNet.Curl]::Execute('curl -H "Accept: application/json" https://httpbin.org/json')
($r.Body | ConvertFrom-Json).slideshow.title

Guides

Guide	What it covers
Install CurlDotNet for PowerShell	Downloading the package, which DLL to load in PowerShell 7 and in Windows PowerShell 5.1, dotnet add package, #r "nuget: CurlDotNet" and #:package
Run curl commands from PowerShell	[CurlDotNet.Curl]::Execute, reading .StatusCode, .Headers and .Body, ConvertFrom-Json, here-strings, errors
curl vs Invoke-WebRequest vs Invoke-RestMethod	The curl alias in 5.1, why pasted commands break, how CurlDotNet’s parser handles backtick continuations and Windows-style \" escapes
curl flavors: bash, CMD, PowerShell and Invoke-WebRequest	CurlFlavor.PowerShell for curl.exe commands, CurlFlavor.InvokeWebRequest for -Uri/-Headers @{} syntax, how Auto tells them apart, and the bytes each sends
Paste a curl command from API docs	GitHub, Stripe and OpenAI-style commands, run unchanged in C# or PowerShell
Convert curl to PowerShell code	Curl.ToPowershellCode for native Invoke-RestMethod code, and what to add by hand

Quick start in three steps

1. Get the DLL. Download CurlDotNet from nuget.org and extract it (a .nupkg is a zip file). The install guide has copy-paste commands for PowerShell 7 and Windows PowerShell 5.1.
2. Load it. Add-Type -Path <folder>/lib/net8.0/CurlDotNet.dll for PowerShell 7.4+, or lib/net48 for Windows PowerShell 5.1.
3. Run a command. Put the curl command in single quotes (or a @' ... '@ here-string) and pass it to [CurlDotNet.Curl]::Execute.

$cmd = @'
curl -X POST https://httpbin.org/post `
  -H "Content-Type: application/json" `
  -d '{"name":"Ada"}'
'@
$r = [CurlDotNet.Curl]::Execute($cmd)
"$($r.StatusCode) $(($r.Body | ConvertFrom-Json).json.name)"

Which tool for which job

You want to…	Use
Write idiomatic PowerShell from scratch	Invoke-RestMethod
Run a curl command from docs exactly as written	[CurlDotNet.Curl]::Execute
Turn a curl command into a dependency-free script	[CurlDotNet.Curl]::ToPowershellCode
Use the same request in PowerShell and in a C# app	CurlDotNet in both
Script in C# instead of PowerShell	dotnet script with #r "nuget: CurlDotNet, 9.8.0"

What to expect

• The result is a CurlDotNet.Core.CurlResult: .StatusCode, .IsSuccess, .Body, .Headers, .IsBinary, .BinaryData.
• HTTP errors (404, 500) do not throw unless you pass -f; network failures and timeouts do.
• As with curl.exe, there is no timeout unless you pass -m (whole transfer) or --connect-timeout.
• Like curl.exe, every request sends User-Agent: curl/8.7.1 and Accept: */* unless you pass -A or -H.

C# guides

The task-by-task C# guides (POST JSON, auth, uploads, downloads, timeouts, ASP.NET Core and more) are in How to do common curl tasks in C#.

About CurlDotNet

A pure C# implementation of curl’s command-line behavior on top of HttpClient, for netstandard2.0, .NET Framework 4.7.2 and 4.8, and .NET 8, 9 and 10. MIT licensed, written by Jacob Mellor, sponsored by Iron Software. Source and issues: github.com/jacob-mellor/curl-dot-net.