Lore Commits
Overview
Every commit destroys decision context. You considered alternatives, evaluated tradeoffs, and chose one approach — but only the final diff survives. Lore reclaims this lost knowledge by encoding it as git trailers in commit messages.
Core principle: A commit is not a label for a diff — it's an atomic unit of institutional knowledge. Use git's native trailer format so decisions are machine-queryable, not buried in prose.
When to Use
- Any commit where you made non-obvious decisions
- When you rejected alternative approaches
- When external constraints shaped your implementation
- When future modifiers need warnings about fragile assumptions
- When test coverage has known gaps
When NOT to use: Trivial changes (typo fixes, formatting) where no real decisions were made.
The Format
<imperative summary line>
<optional body explaining the change>
Constraint: <external constraint that shaped this decision>
Rejected: <alternative> | <reason it was rejected>
Confidence: <high | medium | low>
Scope-risk: <narrow | moderate | broad>
Reversibility: <clean | moderate | difficult>
Directive: <warning or instruction for future modifiers>
Tested: <what was verified>
Not-tested: <known coverage gaps>
Related: <commit hash or description of related commit>All trailers are optional. Include only those that carry signal for this specific commit.
Trailer Vocabulary
| Trailer | Purpose | Example |
|---|---|---|
Constraint: | External limit that shaped the decision | Auth service does not support token introspection |
Rejected: | Alternative considered and why it was dropped. Use ` | ` to separate alternative from reason |
Confidence: | How sure you are this is right: high, medium, low | high |
Scope-risk: | Blast radius: narrow, moderate, broad | narrow |
Reversibility: | How easy to undo: clean, moderate, difficult | clean |
Directive: | Warning to future modifiers — what NOT to do or what to check first | Do not narrow 4xx handling without verifying upstream behavior |
Tested: | What was verified and how | Single expired token refresh (unit) |
Not-tested: | Known gaps in verification | Auth service cold-start > 500ms behavior |
Related: | Linked commits forming a decision chain | abc1234 (initial auth interceptor) |
You can repeat trailers (multiple Constraint:, multiple Rejected:, etc.).
You can extend the vocabulary with custom trailers when needed (e.g., Deadline:, Stakeholder:, Migration:).
Complete Example
Prevent silent session drops during long-running operations
The auth service returns inconsistent status codes on token
expiry, so the interceptor catches all 4xx responses and
triggers an inline refresh.
Constraint: Auth service does not support token introspection
Constraint: Must not add latency to non-expired-token paths
Rejected: Extend token TTL to 24h | security policy violation
Rejected: Background refresh on timer | race condition
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Error handling is intentionally broad (all 4xx)
-- do not narrow without verifying upstream behavior
Tested: Single expired token refresh (unit)
Not-tested: Auth service cold-start > 500ms behaviorWhy Git Trailers (Not Prose)
Agents naturally capture decision context as prose paragraphs. The problem: prose is not queryable.
Git trailers are a native git feature. Queryable with standard git tools:
# Query all constraints affecting a file
git log --all --grep="^Constraint:" -- path/to/file.ts
# Find all rejected approaches
git log --all --grep="^Rejected:" -- path/to/file.ts
# Find directives (warnings for future modifiers)
git log --all --grep="^Directive:" -- path/to/file.ts
# Check what's not tested
git log --all --grep="^Not-tested:" -- path/to/file.tsThis turns your git history into a queryable decision database at zero infrastructure cost.
Agent Workflow
When modifying code, before committing:
- Harvest context — What constraints did you face? What alternatives did you reject?
- Write the summary line — Imperative, focused on *why* not *what*
- Add body if the *how* needs explanation
- Append trailers — One per decision fact. Only include trailers that carry signal.
- Self-check — Would a future agent modifying this code benefit from knowing this?
Common Mistakes
| Mistake | Fix |
|---|---|
| Writing trailers as prose paragraphs | Use Key: value format on separate lines |
| Putting trailers before the body | Trailers must come after the body, separated by a blank line |
Omitting the reason in Rejected: | Always use `alternative |
| Adding trailers to trivial commits | Only add when real decisions were made |
| Duplicating diff content in trailers | Trailers capture what's NOT in the diff — the why, not the what |
Using Confidence: yes | Use the scale: high, medium, low |