apply-feature-knowledge

name	apply-feature-knowledge
description	Consumption algorithm for FEATURE_KNOWLEDGE variable — pre-computed feature context
user-invocable	false
allowed-tools	Read

Apply Feature Knowledge

Iron Law

Pre-computed context, not a cage. Verify against current code — always.

A feature knowledge captures patterns AS THEY WERE when last written. Code evolves. Use the feature knowledge as a starting point, not gospel truth. When something feels off, Read the actual files. Code is authoritative; feature knowledge is supplementary.

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3-Step Algorithm

Step 1: Read the Feature Knowledge

When FEATURE_KNOWLEDGE is provided and is not (none):

1. Read each feature knowledge section (separated by --- Feature knowledge: {slug} --- headers)
2. Absorb: architecture, data flow, key patterns, anti-patterns, gotchas
3. Note integration points that relate to your current task

Step 2: Apply to Current Task

1. Patterns as defaults: Follow documented patterns unless you have a specific reason not to
2. Anti-patterns as warnings: Check your work against documented anti-patterns
3. Gotchas as checklists: Verify each gotcha doesn't apply to your changes
4. Integration points: Ensure your changes respect documented boundaries
5. Key files: Use as starting points for exploration

Step 3: Verify Against Current Code

The feature knowledge may not reflect recent changes:

• If the feature knowledge doesn't address your specific area, explore further
• When an assertion seems outdated: Read the relevant source files to confirm — code wins
• When you find a contradiction between the KB and actual code, trust the code
• Note discrepancies in your output when they matter for the task

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Skip Guard

When FEATURE_KNOWLEDGE is (none), empty, or not provided — skip this skill entirely. Do not mention feature knowledge or its absence in your output.

Freshness Model

Feature knowledge uses write-through + verify-on-read for freshness:

• KBs are written at the point a documented area changes (not on a background schedule)
• Readers verify key assertions against current code rather than relying on staleness markers
• When in doubt, Read the file — that resolves any uncertainty immediately

Concatenation Format

Multiple feature knowledge entries are concatenated with slug headers:

--- Feature knowledge: payments ---
[full KNOWLEDGE.md content]

--- Feature knowledge: auth ---
[full KNOWLEDGE.md content]