execution

A governed tool for running local commands and managing development environments. It supports Windows, Linux, and Mac, including Python virtual environments and pip package operations.

In plain words
What is it for?
It helps create and validate virtual environments, manage command policies, run pip safely, and handle approved command overrides.
Why use it?
It adds command allowlists, blocklists, safety checks, isolation, and human approval to local execution. This helps control what an agent can run and install.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/layer1labs/specsmith/execution
Any agent
npx skills add layer1labs/specsmith --skill execution
Clone the repo
git clone --depth 1 https://github.com/layer1labs/specsmith

Made for: Claude Code, Codex.

Per session 15 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 704 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00015 $0.00704
Opus 5 $0.00008 $0.00352
Sonnet 5 $0.00003 $0.00141
Haiku 4.5 $0.00002 $0.00070

Measured yesterday against content hash 53833c4a2359, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

execution scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/execution/SKILL.md · 117 lines

How it starts

The opening of the file, as written. The whole thing — 117 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Local Execution Management

This skill enables specsmith projects to manage local command execution and environment management while maintaining governance compliance across Windows, Linux, and Mac platforms.

Requirements Covered

  • REQ-089: Local Command Execution Policy
  • REQ-090: Local Command Whitelist Management
  • REQ-091: Local Command Blacklist Management
  • REQ-092: Local Command Override Capability
  • REQ-093: Pip Execution Override
  • REQ-094: Pip Execution Safety Checks
  • REQ-095: Virtual Environment Creation
  • REQ-096: Virtual Environment Management
  • REQ-097: Virtual Environment Validation
  • REQ-098: Virtual Environment Warning System
  • REQ-099: Local Environment Isolation
  • REQ-100: Execution Policy Configuration

Integration Capabilities

Platform Features

  • Cross-platform command execution with platform-specific considerations
  • Local environment isolation and management
  • Virtual environment creation and management
  • Pip execution safety with workspace-local enforcement
  • Whitelist and blacklist management for commands
  • Override capability with human approval

Governance Requirements

  • Human approval required for all local command execution
  • Configuration management with governance controls
  • Security best practices enforcement for execution
  • Resource monitoring and logging for execution activities

Platform-Specific Considerations

Windows

  • Path handling with Windows-specific conventions
  • PowerShell and CMD integration
  • Windows-specific environment variables
  • File system permissions and access controls
  • Registry and system integration considerations

Linux

  • POSIX-compliant path handling
  • Shell integration (bash, zsh, fish)
  • Package manager integration (apt, yum, pacman)
  • System service management
  • File permissions and ownership

macOS

  • Darwin-specific path handling
  • macOS application integration
  • Homebrew and MacPorts package management
  • System preferences and security frameworks
  • AppleScript and automation support

Read the full file on GitHub · 117 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. yesterday First seen · 117 lines · 15 tokens per session scan A 53833c4a2359

Subscribe to this mod's changes

execution is a skill published in the GitHub repository layer1labs/specsmith (7 stars, last pushed 29d ago), licensed MIT. It adds 15 tokens to every session and 704 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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