Minimal Code

Resist the urge to write more than necessary.

Principles

• YAGNI. You aren't gonna need it. No speculative parameters, no "for future extensibility" hooks, no configuration for cases that don't exist.
• KISS. The simplest thing that could possibly work. If there's a one-line solution and a three-class solution, the one-liner wins until there's a concrete reason it doesn't.
• DRY when it actually repeats. Three occurrences before you extract a helper. Two might be coincidence. One is always coincidence.
• Flat over nested. Shallow call graphs, few layers, fewer indirections. Each extra layer is a place a future reader has to stop and look up.
• Delete more than you add, when you can. Touching a function is a chance to remove dead code that the function actually owns. (But not code it doesn't own — see surgical-edit.)

Heuristics

Dependencies

• Can the standard library do this? Use it.
• Is a dependency already present that covers this? Use it.
• A new dependency needs: justification in the plan, license check, maintenance check, bundle/runtime impact.

Abstractions

• New class? Only if there's state and behavior and multiple call sites.
• New interface/protocol? Only if there are or will soon be multiple implementations — not "might be someday."
• New module? Only if the code doesn't fit the theme of an existing one.

Configuration

• Hardcode first, extract to config when a second value appears.
• Feature flags for actual rollouts, not for "maybe someday."

Indirection

• Don't wrap a library call in a function that does nothing but call it.
• Don't add a factory when a constructor works.
• Don't add a service layer when the call site is the only caller.

The "one-function rule"

Before adding a new class, ask: would a single function do? Before adding a new module, ask: would a single function in an existing module do? Before adding a new file, ask: would three lines in an existing file do?

Lines-of-code signal

Track LOC delta per task (the /ship command reports it). A steady upward trend without feature growth is a signal of over-engineering. A feature that shrinks the codebase is a win.

What this skill must NOT do

• Don't celebrate removing code that's actually load-bearing.
• Don't delete tests to hit a LOC target.
• Don't over-minimize to the point of one-letter variable names and uncommented dense logic.

References

• skills/surgical-edit/SKILL.md