@juicesharp/rpiv-args

Pass arguments to a skill the way you pass them to a shell command. rpiv-args adds $1, $2, $ARGUMENTS and friends to Pi Agent skill bodies, and runs !`cmd` and ```! blocks so real command output is in the prompt before the model reads it. It is for anyone who writes Pi skills and wants to parameterize them instead of keeping one hard-coded copy per case.

Install

pi install npm:@juicesharp/rpiv-args

Restart your Pi session.

Quick start

Create .pi/skills/deploy/SKILL.md in your project (or ~/.pi/agent/skills/deploy/SKILL.md for a personal skill) and put a placeholder in the body:

---
name: deploy
description: Deploy a service to an environment
---

Deploy service $1 to $2.
Current branch: !`git branch --show-current`

Invoke it with arguments:

/skill:deploy api production

The model receives the body with $1 as api, $2 as production, the real branch name in place of the git command, and a trailing Skill input: api production line marking your raw input.

What you get

• Skills take arguments like shell commands — positionals, $ARGUMENTS and ${@:N:L} slices, split with shell-style quoting, so /skill:deploy "staging server" --force puts staging server in $1.
• Command output lands in the prompt, not in a tool call — inline !`git status -s` and ```! blocks execute first and the model reads the evidence instead of deciding to go fetch it.
• Installing it is a no-op for existing skills — a body with no placeholder and no shell syntax emits text byte-identical to Pi's built-in expansion, pinned by a regression test.
• The model stops reading your argument as a new instruction — arguments are emitted under an explicit Skill input: label and a skill-invocation protocol is prepended to the system prompt every turn.
• Runaway commands can't hang the turn or flood the context — every command is capped at 120 s by default and output is tail-truncated to 50 KB / 2000 lines; errors are inlined so the rest of the body still gets through.
• Commands run in the order you wrote them — strictly sequential, never parallel, so !`mkdir x` then !`ls x` behaves.
• Skill-relative paths keep working — ${SKILL_DIR} always resolves to the skill file's own directory, however the skill was installed; ${SESSION_ID} gives the current session id.

Configuration

rpiv-args reads no config file and no environment variables. The one knob is per-skill frontmatter, in the skill's own SKILL.md:

Key	What it does	Default
shell-timeout	Ceiling in seconds for each !`cmd` / ```! command in that skill. 0 disables the timer.	120

Shell commands always run in the Pi session's working directory, not the skill directory.

Reference

• Placeholders and variables — every placeholder and runtime variable, indexing and slicing rules, quoting, and what substitution deliberately does not do.
• Authoring skills — choosing $ARGUMENTS over positionals, empty-argument behaviour, frontmatter, and a worked example with the exact text the model receives.
• Shell substitution — shell syntax, execution order, timeouts, error strings, output budgets, and Windows / PowerShell authoring.
• How it works — the three event hooks, the transformation pipeline, both emit paths, the skill index, and the paths that are not covered.

Requirements

• A Pi Agent host. No API key, no model selection, no native modules — nothing here calls a model.
• A POSIX shell or PowerShell for !`cmd` / ```! blocks. Commands run through sh -c on macOS and Linux and powershell.exe -Command on Windows, where POSIX-only tools such as grep, sed and awk are not aliased — see Shell substitution.

Related

• @juicesharp/rpiv-pi — the umbrella package. Its /rpiv-setup command installs rpiv-args along with the rest of the family, and its lane transcript hides the Skill input: line from the displayed conversation.

License

MIT — see LICENSE.