Axial
Repository F# setup
open System
open System.IO
open System.Threading
open System.Threading.Tasks
open Axial
open Axial.Console
open Axial.FileSystem
open Axial.PlatformService
open Axial.Process

Processes

Axial.Process lets a command-line program start an external command without giving up typed failures, cancellation, or cleanup. You describe the command first, choose what happens to its input and output, then run it.

Start with a script

For a small command-line program, describe commands, connect them, choose where output goes, then call run:

open Axial.Process
open Axial.Process.DSL // Short pipeline helpers: cwd, env, timeout, =>, capture, run

Process.command $"git log --oneline -20"
|> cwd repository
|> env "NO_COLOR" "1"
|> timeout (TimeSpan.FromSeconds 5)
=> cmd $"head -5"
|> capture
|> run

Process.command (and DSL cmd) preserves each interpolation hole as one native argument. cwd, env, and timeout return updated command specifications. => connects stdout to the next command's stdin. capture creates a Flow that retains stdout and stderr; none of those steps starts a child process. The final run starts the Flow with live clock, filesystem, console, and process services. It returns 0 on success, or writes a redacted error and returns an appropriate nonzero exit code. Use it at a .NET command-line application's outermost boundary.

For a server, worker, or application Flow, see run a process in an application Flow. That guide explains the explicit process capability, live wiring, test fakes, and the difference between Process.toFlow and Flow.run.

Choose how the command communicates

Need DSL Full API What you receive
Inspect output after the command exits capture Process.capture ProcessResult: stdout, stderr, bytes, exit codes, and timing
Show output as it arrives console Process.console Structured completion data
React to output before completion stream Process.stream A backpressured stream of output and completion events
Send final output elsewhere writeTo / appendTo Process.stdout / Process.stderr A configured command

New process specifications capture stdout and stderr by default. capture makes that choice explicit and replaces a prior output policy. Output capture and destinations explains bounded capture, files, console forwarding, and tees. Streaming output covers long-running commands and incremental handling.

What Axial owns

The process service starts the native topology; Axial owns its lifetime. A timeout or interruption terminates every started stage, including partially started pipelines, before the enclosing Flow finishes. Expected process problems remain ProcessError values instead of becoming unstructured exceptions.

Guides