How

Portability (required)

This skill is part of the portable pstack pack.

1. Read the pstack capability contract and the adapter for the active coding agent before delegation.
2. Use explore for read-only tracing, parallel for independent exploration slices, and review for architectural criticism.
3. Do not use a write-capable helper for this skill. Every helper is instructed not to edit files.
4. Resolve models through model_role; never require a vendor-specific model identifier.
5. When helper spawning is unavailable, run the same steps on the lead agent and state that fan-out was collapsed.

Purpose

Answer questions about how a subsystem works at the level of a senior engineer onboarding into it. Build a useful mental model rather than an annotated source dump.

There are two modes: