@firstpick/pi-extension-conditional-system-prompts

Conditionally appends the local Windows policy and a short, fail-closed routing bridge to the enabled subagent-governance skill.

Install

pi install npm:@firstpick/pi-extension-conditional-system-prompts

Pi discovers conditional-system-prompts.ts through the package manifest. The subagent-governance skill must also be enabled when the subagent tool is available.

Behavior

Before an agent starts, the extension applies these conditions:

Condition	Appended content
Pi is running on Windows	Local APPEND_WINDOWS.md from the configured agent directory
Selected tools include subagent	Built-in bridge requiring the parent to load subagent-governance with read

When both conditions apply, the Windows prompt is appended first, followed by the governance bridge. Existing system-prompt content is retained. Only the Windows file is read and cached.

The governance bridge preserves progressive disclosure rather than duplicating policy text. Before injecting it, the extension resolves the advertised <location> for subagent-governance from <available_skills> and verifies that both its SKILL.md and Pi adapter are readable and non-empty. The bridge directs the parent to that adapter and keeps the installed pi-subagents skill authoritative for runtime mechanics.

Configuration and requirements

• Maintain APPEND_WINDOWS.md only when Windows routing is needed.
• Enable subagent-governance through Pi settings or a package entry.
• Reload Pi after changing the extension, settings, skill, or Windows prompt.

No external subagent-policy prompt file is required or read.

Security and privacy

• The Windows prompt stays local; this package does not send its contents anywhere.
• The extension reads only APPEND_WINDOWS.md and only when Pi is running on Windows.
• Treat that file as trusted configuration because its content is appended to the system prompt.
• The governance bridge contains no private data and does not read the skill body itself.

Failure behavior and limitations

A Windows turn requires APPEND_WINDOWS.md; a missing or unreadable file propagates the file-read error. Non-Windows turns never read it.

A turn with subagent selected receives the skill bridge without reading an external prompt. If the enabled governance skill is missing from the current system prompt, or its advertised SKILL.md or Pi adapter is unavailable, unreadable, or empty, the extension injects a model-visible configuration-error policy requiring delegation to stop until configuration is restored.

The extension validates availability, not policy semantics. It does not manage settings or replace hard fanout enforcement; runtime fanout guards remain separate.

Development

npm test
npm run check
npm run smoke
npm pack --dry-run --json

Tests cover selected-tool routing, Windows ordering, Windows caching, fail-closed bridge language, and Windows-only missing-file behavior.

License

MIT