/arnold:check

Compare your docs to your code. Find drift. This is the signature command - the feature nobody else has.

When to use it

Run /arnold:check after writing code, before a PR review, or at the start of a new session. Any time you want to know if docs and code still agree.

Usage

arnold · terminal

> /arnold:check

🦕 ARNOLD CHECK REPORT ━━━━━━━━━━━━━━━━━━━━━━ Scanned: 4 feature docs, 23 source files 🔴 DRIFT DETECTED ━━━━━━━━━━━━━━━━━ 1. auth: Session timeout 📄 Docs say: "Sessions expire after 24 hours" 💻 Code has: SESSION_TTL = 72 * 60 * 60 → Docs say 24hr, code says 72hr. Which is right? 2. booking: Capacity limit 📄 Docs say: "Maximum 20 spots per class" 💻 Code has: MAX_CAPACITY = 30 → Docs say 20, code says 30. 🟢 ALIGNED ━━━━━━━━━━ ✓ auth: Rate limit is 5 attempts per minute ✓ payments: Stripe is the payment processor ✓ booking: Users cannot book the same class twice 🟡 GAPS ━━━━━━━ ○ calendar-sync: Flow documentation missing ○ calendar-sync: Acceptance criteria not defined Run /arnold:resolve to fix drift items.

What it does

Reads every doc in your docs/ folder - overviews, flows, edge cases, criteria
Reads every source file in your codebase
Compares them - looking for specific claims in docs that contradict the code
Reports findings in three categories:
- 🔴 DRIFTED - Docs say one thing, code says another
- 🟢 ALIGNED - Docs and code agree
- 🟡 GAPS - Something is documented but has no code, or vice versa
Creates a snapshot so future /arnold:diff checks are instant

How drift detection works

Arnold doesn't just do a text diff. It understands claims - specific, verifiable statements in your docs like "sessions expire after 24 hours" or "maximum 20 spots per class." It then searches the codebase for evidence that confirms or contradicts each claim.

Each drift item includes:

The feature and specific field that drifted
What the docs say (with doc file reference)
What the code has (with source file and line number)
A human-readable summary of the mismatch

Arnold checks are thorough but fast. Snapshots from previous checks make subsequent runs near-instant.

Tips

Run /arnold:check at the start of every coding session. It's your "where do things stand" command.

After a check, use /arnold:resolve to fix drift items
Use /arnold:diff for a quick snapshot-based check between full checks
Check output gets better as your docs get more specific and concrete