Style Fingerprint Skill
The #1 complaint about AI drafts is "it doesn't sound like me." This skill fixes it at the root: it studies writing the user has actually shipped, extracts the mechanical, imitable features of their voice, and writes a style card into the Brain — after which every brain-aware skill drafts in their register instead of the model's default.
What This Skill Produces
- A style card (~200-300 words, structured) capturing the user's voice as reproducible rules, not adjectives
- Before/after proof: one paragraph rewritten from model-default into the fingerprinted voice, so the user can verify the card works
- The card saved to
brain/knowledge/style.md (with the user's approval), plus a one-line pointer in context.md voice section
Required Inputs
Ask for (if not already provided):
- 3-5 samples the user wrote and shipped — real emails, updates, PRD sections, posts. More samples of the same genre beat variety. Politely reject samples the user merely approved but didn't write — an edited-by-committee doc fingerprints the committee.
- The target register if samples span several (exec formal vs team casual) — or fingerprint each as a named variant
Extraction Method
Analyse mechanics, not impressions. For each dimension, extract a rule an imitator could follow:
Then verify: rewrite one neutral paragraph in the extracted voice and check it against the samples. If it reads generic, the card is adjectives, not rules — extract harder.
Output Format
Style card: [name / register variant] — fingerprinted [date] from [n] samples
Rhythm: [rules]
Register: [rules]
Structure: [rules]
Signature moves: [phrases/patterns, quoted from samples]
Emphasis & numbers: [rules]
Never: [the banned list]
Calibration line: (one sentence from the samples that is peak them — future skills imitate toward this)
Proof — same paragraph, twice:
[model-default version]
[fingerprinted version]
📥 Save to Brain: propose writing this card to brain/knowledge/style.md and adding a voice: see knowledge/style.md pointer in context.md. Show the write, get a yes, then use ../professional-brain/scripts/brain_write.py … --commit. Brain-aware skills read context.md voice on every run — the fingerprint takes effect immediately and everywhere.
Quality Checks
Anti-Patterns
Example Trigger Phrases
- "Learn my writing style."
- "Make outputs sound like me."
- "Build a voice profile."