pi-skill-guard

A pi extension that intercepts "tool not found" errors: injects skill documentation for matching skill names and falls back to bash for unknown tools with a command argument.

Install

pi install npm:pi-skill-guard

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What it does

The extension intercepts tool errors via the message_end event and silently fixes them before the LLM sees a failure. Two guard cases:

1. Skill documentation injection

When the model calls a tool name that matches an available skill (e.g. brave-search), the extension replaces the "not found" error with the skill's SKILL.md content.

Before: Tool brave-search not found (error) After: Full SKILL.md content injected as a successful tool result

2. Bash command execution

When the model calls an unknown tool that has a command argument, the extension executes it via pi's built-in bash tool. Supports optional timeout (number or string).

Before: Tool my-script not found (error) After: Actual bash execution result with proper truncation and temp file management

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Related

For field alias normalization (edit / write / read argument correction), see pi-arg-corrector.

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Architecture

All interception happens in the message_end event, which fires after each message is finalized and allows replacing the message in place. Each tool call is tracked by ID to prevent double-handling across the replacement chain.

• session_start: loads skills, caches file paths
• turn_end: clears handled-tool-call tracking
• message_end: inspects error results, applies guards