How to use the .NET (C#) plugin

Run C# scripts and dotnet CLI commands from Kestra workflows using dotnet-script inside a .NET SDK container.

Authentication

This plugin has no authentication properties. Use environment variables for secrets (e.g., connection strings, API keys) passed via env on the task, or use {{ secret('SECRET_NAME') }} in your script body.

Tasks

Script

Runs an inline C# script defined in the script property. The script is written to a temporary .csx file and executed with dotnet-script.

dotnet-script is installed automatically via dotnet tool install -g dotnet-script before each run. To avoid the installation overhead, use a custom containerImage that already includes dotnet-script.

NuGet package references work out of the box — place #r "nuget: PackageName,Version" directives at the top of your script. The first run with a new package reference triggers a NuGet restore which may take 30–60 seconds.

Required properties:

• script — inline C# script body in .csx format

Optional:

• containerImage — defaults to mcr.microsoft.com/dotnet/sdk: 10.0
• beforeCommands — shell commands to run before the script (e.g., set environment variables)
• inputFiles — additional files to stage alongside the script
• outputFiles — glob patterns for files to capture into Kestra internal storage
• taskRunner — override the execution environment (default: Docker)

Commands

Runs arbitrary shell commands sequentially inside a .NET SDK container. Use this task when script files live in namespace files or are cloned from a Git repository, or when you need raw dotnet CLI access (e.g., dotnet build, dotnet test).

dotnet-script is not pre-installed in the default image. Add the following to beforeCommands when running .csx files:

beforeCommands: 
  - dotnet tool install -g dotnet-script --ignore-failed-sources || true
  - export PATH="$PATH: $HOME/.dotnet/tools"

Required properties:

• commands — list of shell commands to execute in order

Optional:

• containerImage — defaults to mcr.microsoft.com/dotnet/sdk: 10.0
• beforeCommands, inputFiles, namespaceFiles, outputFiles, taskRunner — same as Script

Triggers

ScriptTrigger

Polls on an interval by running an inline .NET script the same way the Script task does, and starts an execution when exitCondition matches. The script runs in a fresh container on every poll, so keep it quick.

Required properties:

• script: inline .NET script body
• exitCondition: either exit N, which matches when the script exits with code N, or a regex (with substring fallback) matched against the vars the script emits with : : {"outputs": {...}}: :

Optional:

• interval: time between polls, defaults to PT60S
• edge: defaults to true, so the trigger fires only when the condition changes from not matching to matching. The previous result is kept in the namespace KV store under a key starting with trigger-edge-. Set to false to fire on every matching poll
• containerImage: defaults to mcr.microsoft.com/dotnet/sdk: 10.0

The trigger outputs are available as {{ trigger.timestamp }}, {{ trigger.condition }}, {{ trigger.exitCode }} and {{ trigger.vars }}. A failed run has no vars, so only an exit N condition can match a failure.

CommandsTrigger

Same behavior as ScriptTrigger, but runs a list of shell commands the way the Commands task does. Required properties are commands and exitCondition; interval, edge and containerImage work as above.