Persistent Living Artifact Mutation Pattern

Overview

When executing multi-phase engineering tasks, poorly designed agents generate new markdown files for every status update (plan_v1.md, plan_v2.md, revised_plan.md, final_summary.md).

Creating duplicate files pollutes repository search indices, degrades RAG vector embeddings, confuses subagents with conflicting historical drafts, and wastes thousands of generation tokens.

The Persistent Living Artifact Pattern enforces a single canonical document per domain (e.g. implementation_plan.md, walkthrough.md) and updates it via in-place differential edits (replace_file_content), maintaining a pristine single source of truth.

Duplicate Proliferation vs. Single Living Artifact