Borrow infrastructure and own domain behavior
The team spends maintenance effort on behavior that makes its product useful.
Why
Agents create private infrastructure forks to satisfy constraints that the product never required.
Installation
Terminal
npx --yes @principle-driven/[email protected] add borrow-infrastructure-own-domain-behaviorThe CLI uses your prefix, assigns the next local number, and updates your agent index. CLI installation guide ↗
The Markdown preview uses the catalog token. Your installed file uses its local token.
# PDD-10 — Borrow infrastructure and own domain behavior
Token: PDD-10
Version: v1
## Rule
Use maintained packages for established infrastructure problems. Keep domain rules and product behavior under your ownership.
Before you fork or replace a package, try its public APIs and extension points.
Before you create custom infrastructure, name the product requirement that existing packages cannot reasonably satisfy. Account for ongoing maintenance.
Remove constraints that come only from the proposed implementation.
### Exceptions
A concrete product requirement can justify a fork or custom mechanism. Record why supported alternatives fail and who owns future maintenance.
A small domain function does not need a dependency merely because a package exists. Compare the actual complexity and cost.
## Rationale
Agents invent implementation constraints and use them to justify private infrastructure forks. The team inherits maintenance without a product requirement.
## History
- v1 (2026-10-05): Published to focus custom code on product requirements instead of unnecessary infrastructure forks.