persona

persona is a skill for Claude Code from mehrad-dm/mastermind. It costs 84 tokens per session (1,145 once invoked), scanned A, original, MIT.

A writing guide for adapting code to the documented public style of a named engineer. It treats style as a set of observable choices about structure, naming, abstraction, comments, tests, and error handling.

In plain words
What is it for?
Use it when asking for code influenced by a public engineer's open-source work, talks, or writing, with sources supporting the chosen style.
Why use it?
It gives style-based requests a verifiable basis instead of guessing what a real person would write.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the mastermind plugin — 32 skills, 4 agents, 1 hook shipped together

Good fit Use it when asking for code influenced by a public engineer's open-source work, talks, or writing, with sources supporting the chosen style.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mehrad-dm/mastermind/persona
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.

Any agent
npx skills add mehrad-dm/mastermind --skill persona
Clone the repo
git clone --depth 1 https://github.com/mehrad-dm/mastermind

Made for: Claude Code.

Or install mastermind, the plugin that ships this one along with the rest of its 32 skills, 4 agents, 1 hook.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for persona

README.md
[![agentmods](https://agentmods.dev/badge/skills/mehrad-dm/mastermind/persona/github.svg)](https://agentmods.dev/skills/mehrad-dm/mastermind/persona)
Your own site
<a href="https://agentmods.dev/skills/mehrad-dm/mastermind/persona"><img src="https://agentmods.dev/badge/skills/mehrad-dm/mastermind/persona/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for persona

Your own site · 80×15
<a href="https://agentmods.dev/skills/mehrad-dm/mastermind/persona"><img src="https://agentmods.dev/badge/skills/mehrad-dm/mastermind/persona.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 84 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,145 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00084 $0.01145
Opus 5.5 $0.00034 $0.00458
Sonnet 5.5 $0.00017 $0.00229
Haiku 4.5 $0.00008 $0.00114

Measured 15d ago against content hash b048ea1cc25a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

persona 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 15d 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.

skills/persona/SKILL.md · 64 lines

How it starts

The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Persona: write in the documented style of a named engineer

The user names an engineer they admire and MasterMind writes the code in that person's documented public style. Works on any code, any project, not just your own. It's a lens on taste, not a new rulebook.

What a persona actually is: the recurring, public choices that make someone's code recognizable: which primitives they reach for, how they name and factor things, their stance on abstraction vs. directness, comments, tests, error handling, and the principles they've published in talks/posts/OSS. Build the lens from real, verifiable public work: their open-source repos, their writing, their documented positions, not vibes.

Four rules, none skippable:

  1. Documented, not fabricated. Apply only style you can ground in their real public work, grounded means a resolvable primary-source link in the output (see the citation gate below). If you don't actually know how they'd write something, say so and fall back to signature / mentors.md / house style, never invent "they would do X" or put words/opinions in a real person's mouth. Honesty over performance.
  2. Style is a lens; correctness is not up for grabs. A persona shapes taste: naming, structure, idiom. core/rigor.md, security, and a11y always outrank it. "They'd skip the null-check" is not a licence to ship a bug. If the persona and correctness conflict, correctness wins and you say why.
  3. In the style of: not impersonation. The output is "written in the documented style of X," never a claim that X wrote it, endorsed it, or was involved. No fabricated quotes, no forged attribution, no signing their name to a commit. It's a stylistic homage, stated as one.
  4. Known engineers only, from public record. This is for public figures with a documented body of work. A private colleague's style is signature (quarantine-gated): never profile a named private individual here.

How to apply: name the 3–6 load-bearing traits of their public style, write the code through them, and in one line tell the user which traits you leaned on (e.g. "leaned on: small pure functions, minimal deps, teaching-comments, per their public work"). Prefer their principles over surface mannerisms: a persona is how someone decides, not just how they format. It composes with the active field: persona sets taste, the field pack supplies the stack, rigor supplies the gate.

Citation gate: every trait ships a resolvable link, or it doesn't ship:

  • No citation, no trait. Each trait carries a URL to a primary source in the output: their repo/file/commit, their book, their talk, their own post, a style guide they authored. An actual link the user can click, not "as documented by X". A trait you cannot cite does not go in the output: dropped, not softened, not hedged, not caveated.
  • Verify, don't assert. If you can reach the web in this session, actually fetch each link and confirm it resolves and says what you claim: a check you run, not one you report. If you can't, say so, cite only sources you can name precisely enough for the user to check by hand (exact repo + path, book + chapter, talk + title/year), and mark the set unverified. Never write "I checked / read / verified" for a check you didn't run.
  • No sources, no persona. If you can't find primary sources for the named person at all, say so plainly and stop, don't synthesize a plausible style from their fame or reputation. Fall back to signature (rules from the user's actual codebase) or house style / mentors.md, and tell the user which.

A stereotype ("they'd use lots of patterns") is the failure mode; the cited habit is the goal.

Their own words stay theirs: propose, never rewrite unasked (~/.mastermind/engineering/core/rigor.md → Stay in scope).

Read the full file on GitHub · 64 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 15d ago Changed · +2 lines · +84 tokens per session b048ea1cc25a
  2. 1mo ago First seen · 62 lines · 0 tokens per session scan A 762d0701ea4e

Subscribe to this mod's changes

persona is a skill published in the GitHub repository mehrad-dm/mastermind (23 stars, last pushed 6d ago), licensed MIT. It adds 84 tokens to every session and 1,145 once invoked, about $0.0003 per session on Opus 5.5. 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.