how

Files (3)

• SKILL.md
• explainer-prompt.md · references/
• explorer-prompt.md · references/

SKILL.md (first lines)

# How

Explore the codebase to answer "how does X work?" questions. Produce architectural explanations at the level of a senior engineer onboarding onto a subsystem, enough to build a working mental model, not so much that it reads like annotated source code.

Every spawn is a Task subagent with `subagent_type: generalPurpose` and `readonly: true`. Explorers use the `how explorer` line in the `mstack-models.mdc` rule (default `claude-sonnet-5-5-high`), and every explainer uses the `how explainer` line (default `claude-opus-5-5-xhigh`). Set `model` to that line's value, or to the default if the rule or the line is missing. Leave `model` unset when the value is `auto` or `inherit-parent`. If the Task tool rejects a slug, use the default and say so. If it rejects the default, use the closest valid slug of the same family from its error message.

## 0. Check the `kb` resource

Read the `kb` resource when it is set. Pick the role that fits the question. Read the KB index recorded in the env file, then the index of that role's folder, then the note. When a note covers the question, cite it and explore only the gap. Pass the note paths to every explorer and explainer. When `kb` or the role is missing or `not set`, say so in one line, skip this step, and ask once per session whether the user has one (`../ateam-mode/references/resources.md`).

## 1. Assess complexity

If the scope is ambiguous, state your interpretation and explore. The user can redirect.

- **Simple** (a single module, a small utility, a narrow question such as "how does function X work"): no explorers. Spawn one explainer that explores and explains in one pass, built from `references/explainer-prompt.md` without the explorer-findings section. Go to step 4.
- **Complex** (a subsystem spanning multiple files or services, a cross-cutting feature, a full architectural overview): go to step 2.

When in doubt, take the simple path.

## 2. Explore (complex only)

Decompose the question into 2 to 4 angles, each a distinct slice of the subsystem. Spawn all explorers in a single message, each with `references/explorer-prompt.md` and its angle filled in.

## 3. Synthesize (complex only)

Once all explorers have returned, spawn one explainer with `references/explainer-prompt.md` and every explorer's findings filled in.

## 4. Present

Present the explainer's output. Light edits for clarity or context from the conversation are fine. Do not rewrite it.

## Output format

The explanation uses the sections defined in `references/explainer-prompt.md`, dropping any that do not apply: Overview, Key Concepts, How It Works, Where Things Live, Gotchas.

From anhminhnguyenhoang/mstack, MIT.

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