commit-trailers

A format for adding decision notes to Git commit messages. Git is the version-control system that records code changes over time.

In plain words
What is it for?
It is for recording scope risk, architectural constraints, rejected approaches, and known testing gaps in searchable commit history.
Why use it?
It preserves why a change was made, what risks it has, which alternatives were rejected, and what was not tested, so future developers can understand the project history.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/xeldaralz/everything-claude-unity/commit-trailers
Any agent
npx skills add XeldarAlz/everything-claude-unity --skill commit-trailers
Clone the repo
git clone --depth 1 https://github.com/XeldarAlz/everything-claude-unity

Made for: Claude Code, Codex.

Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 621 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00037 $0.00621
Opus 5 $0.00018 $0.00311
Sonnet 5 $0.00007 $0.00124
Haiku 4.5 $0.00004 $0.00062

Measured 2d ago against content hash 900218e54f1a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

commit-trailers scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/core/commit-trailers/SKILL.md · 88 lines

How it starts

The opening of the file, as written. The whole thing — 88 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Structured Commit Trailers

When creating git commit messages, append structured trailers that capture decision context. This metadata makes architectural decisions searchable in git history and helps future developers understand why changes were made the way they were.

Trailers

Required (every commit)

Scope-risk: — How much of the project does this change affect?

  • low — isolated change, single file or tightly scoped feature
  • medium — touches multiple systems or changes shared interfaces
  • high — modifies shared infrastructure, serialization format, or build pipeline

Conditional (include when applicable)

Constraint: — Architectural constraints that were respected during this change. Reference the rule or convention by name.

Rejected: — Alternatives that were considered and rejected, with brief reason. Helps future developers avoid re-exploring dead ends.

Not-tested: — Known gaps in test coverage or scenarios that weren't verified. Use none if everything is covered.

Format Rules

  • Trailers go after a blank line at the end of the commit message body
  • One trailer per line
  • Keep each trailer under 100 characters
  • Scope-risk is always present
  • Omit Constraint if no specific constraints were relevant
  • Omit Rejected if no alternatives were considered
  • Omit Not-tested for trivial changes; include it for anything non-trivial

Examples

Simple feature addition

Add object pooling for projectiles

Replaces Instantiate/Destroy cycle with a pre-warmed pool of 32.
Pool size is configurable via SerializeField on SpawnSystem.

Scope-risk: low
Constraint: no-alloc-in-update — pool grows only in Awake
Rejected: addressables-pool — overkill for single prefab type
Not-tested: pool exhaustion when max size exceeded during boss fight

Bug fix

Fix enemy health not resetting on respawn

EnemyModel.Health was not reset in ObjectPool.OnGet callback.
Added explicit reset in EnemySystem.OnSpawn().

Scope-risk: low
Not-tested: none

Read the full file on GitHub · 88 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 88 lines · 37 tokens per session scan A 900218e54f1a

Subscribe to this mod's changes

commit-trailers is a skill published in the GitHub repository XeldarAlz/everything-claude-unity (21 stars, last pushed 4mo ago), licensed MIT. It adds 37 tokens to every session and 621 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.