hk-compound

/hk-compound — Compound a Pattern

Extract the transferable principle from what just happened and add it to the pattern library. The goal is not to document an incident — it's to name a reusable pattern that gets richer over time as more instances accumulate under it.

The unit: a pattern

A pattern is a named, transferable principle. It starts lean — a clear statement and one instance. It grows as you encounter more cases. The value compounds because each new instance sharpens the principle and makes it easier to recognize next time.

This is not a post-mortem filing system. Don't capture "what happened." Capture "what's the reusable insight, and how would I recognize this situation again?"

When to use

• You solved something and the principle behind the fix applies beyond this specific case
• You noticed a recurring shape across multiple situations
• You made a trade-off decision worth remembering the reasoning for
• You hit a gotcha that has a recognizable signal before you fall into it

Skip it for: one-off fixes with no transferable insight, trivial config, things that are obvious once you know them.

Context hint

<context_hint> #$ARGUMENTS </context_hint>

If the context hint above is empty, scan the conversation for the most significant learning — the thing that took the most investigation or had the most non-obvious outcome. Focus on extracting the transferable principle, not recapping the incident.

Process

Step 1: Extract the pattern

Spawn a haiku subagent to analyze the conversation. The subagent returns text only — no file writes.

Task(model: haiku, subagent_type: general-purpose)

Prompt: "You have access to the full conversation context. Extract:

1. PATTERN NAME: A short, memorable name for the principle (e.g., 'Verify Preconditions Before Flags', 'Information Density via Progressive Disclosure'). Not a description of what happened — a name for the reusable idea.

2. THE PRINCIPLE: 1-3 sentences. The transferable insight stated clearly enough that someone unfamiliar with the specific situation would understand and be able to apply it. No jargon without explanation.

3. WHY IT MATTERS: 1-2 sentences. What goes wrong when you ignore this? What do you gain by following it? Be concrete.

4. THE SIGNAL: How would you recognize that this pattern applies? What does the situation look like right before you need this? (If unclear from a single instance, say so — this can be added later.)

5. THIS INSTANCE: A brief description of what happened in this conversation that surfaced the pattern. Include specifics — error messages, file paths, code snippets — but keep it to a few lines. Date it.

6. TAGS: 3-5 lowercase hyphenated keywords for grep discovery.

Be concrete and specific. No filler. If you can't articulate a transferable principle — if it's just 'we fixed X by doing Y' with no broader lesson — say so."