Grille Process

Overview

This skill covers process_run — Grille's tool for spawning Windows executables directly, without a shell intermediary. Apply it whenever Claude needs to run build tools, version control commands, deployment scripts, or any allowlisted binary on the local machine.

process_run is distinct from ps_run (PowerShell cmdlets) and docker_exec (commands inside containers). Use this tool for native Windows executables.

Tools

• process_run — Execute an allowlisted Windows executable with arguments. Captures stdout and stderr. 30-second default timeout, 300-second maximum. Output capped at 10 MB. Python stdout is automatically decoded as UTF-8 — no sys.stdout.reconfigure() needed in inline -c scripts.

Patterns

Always include .exe (or .cmd) in the executable name:

✅ "cargo.exe"
✅ "git.exe"
✅ "npm.cmd"
✅ "az.cmd"
❌ "cargo"    ← will fail — no shell to resolve the extension
❌ "git"      ← will fail

Standard build workflow:

grille:process_run
  executable="cargo.exe"
  args=["build", "--release"]
  working_dir="C:\\dev\\myapp"

Git operations:

grille:process_run
  executable="git.exe"
  args=["log", "--oneline", "-10"]
  working_dir="C:\\dev\\myapp"

Git for Windows deadlock prevention is baked into Grille internally (stdin: null prevents MSYS2 PTY initialization from hanging). No action needed by Claude.

Deploy — copy built binary:

grille:process_run
  executable="xcopy.exe"
  args=["C:\\dev\\myapp\\target\\release\\myapp.exe",
        "C:\\Users\\<user>\\AppData\\Local\\MyApp\\", "/Y"]

Constraints

• Do not attempt to use cmd.exe, powershell.exe (5.1), wscript.exe, cscript.exe, mshta.exe, regsvr32.exe, rundll32.exe, certutil.exe, or msiexec.exe. These LOLBins are hardcoded denials in Grille — they cannot be unblocked by any configuration. Use ps_run for PowerShell 7 (pwsh.exe) cmdlets instead.
• Do not omit the .exe or .cmd extension. Grille spawns executables via tokio::process::Command without a shell. Shell extension resolution (.cmd, .bat, .ps1) does not apply. The extension must be explicit.
• Do not attempt git push via Grille. Git push requires SSH agent access, which is inaccessible from a Grille subprocess context. Push manually from a terminal.

⛔ git push cannot work via Grille. STOP — push manually from a terminal window.

• Do not use process_run for PowerShell cmdlets. Use ps_run (the powershell module). process_run has powershell.exe on its LOLBin deny list.

⛔ For PowerShell cmdlets, STOP — use ps_run via the grille-powershell skill. Calling process_run with powershell.exe is a hardcoded denial and will always fail.

• Executable must be in process_allowed in grille.toml. If a binary is not in the allowlist, the call is denied and logged. Check grille_info or grille.toml to see the current allowlist.
• Arguments are passed as a list, never shell-concatenated. Do not construct shell pipelines or use shell metacharacters (|, >, &&). Each argument is a discrete array element.

Examples

Example 1: Build and check for errors

grille:process_run
  executable="cargo.exe"
  args=["build", "--release"]
  working_dir="C:\\dev\\myapp"

→ Check stdout/stderr for "error[" lines
→ On success: Finished release in Xs

Example 2: Check git status before a commit

grille:process_run
  executable="git.exe"
  args=["status", "--short"]
  working_dir="C:\\dev\\myapp"

→ Review modified/untracked files
→ Follow with: git.exe add / git.exe commit
→ Push manually from terminal (SSH agent not accessible via Grille)