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name: refactor-structural-duplication license: MIT description: > Identify structurally duplicate logic (pipeline-spine duplication) across semantically distinct modules. Use when multiple implementations share the same orchestration skeleton (e.g., bounds→shape→chunking→reduction→wrap), and unification may require subtle abstraction. Produces a duplication map and a safe extraction/refactor plan. metadata: author: Jordan Godau references: - 01_INTENT.md - 02_DEFINTIONS.md - 03_PROCEDURE.md - 04_REFACTOR_PLAN_TEMPLATE.md - 05_OUTPUT_TEMPLATE.md keywords: - duplication - structural - pipeline - spine - extraction - abstraction - unification - drift

Instructions

Read all references in references/ before starting.

Goal

Detect and report structural duplication across modules (not copy/paste), especially where:

• different domain concepts remain correctly separate, but
• the underlying processing pipeline is parallel/duplicated, risking drift.

When unification likely requires subtle abstraction, produce a staged plan that can be executed safely.

Scope

• This skill does not enforce “thin public facades” or restructure public APIs.
• This skill does identify shared pipeline spines and propose extraction targets and abstraction seams.

Signals

Activate when any of the following are true:

• Multiple modules implement similar orchestration stages (even with different operators).
• There are parallel implementations of structurally similar functionality in the codebase.
• The agent (or a developer) is about to re-implement “the same infrastructure again” for a new product.

Procedure

Follow references/03_PROCEDURE.md.

Output

Produce a single Markdown report using references/05_OUTPUT_TEMPLATE.md. If abstraction is needed, include a staged plan using references/04_REFACTOR_PLAN_TEMPLATE.md.