brief-light

brief-light is a skill for Claude Code from HAX-Studio/mnemonica. It costs 69 tokens per session (749 once invoked), scanned A, original, MIT.

A quick, bounded introduction to a software project and the systems it contains, based on its Mnemonica knowledge index and selected parts of its module files. Mnemonica is a project documentation system organized into modular files.

In plain words
What is it for?
Use it to get oriented on a project, learn its purpose and main systems, or catch up quickly while keeping the amount of reading predictable.
Why use it?
It helps someone understand an unfamiliar codebase without reading every documentation file in full.

Skill for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: mentions CLAUDE.md.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the mnemonica plugin — 8 skills shipped together

Good fit Use it to get oriented on a project, learn its purpose and main systems, or catch up quickly while keeping the amount of reading predictable.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add HAX-Studio/mnemonica
Claude Code
/plugin install mnemonica

Made for: Claude Code.

Or install mnemonica, the plugin that ships this one along with the rest of its 8 skills.

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 brief-light

README.md
[![agentmods](https://agentmods.dev/badge/skills/hax-studio/mnemonica/brief-light/github.svg)](https://agentmods.dev/skills/hax-studio/mnemonica/brief-light)
Your own site
<a href="https://agentmods.dev/skills/hax-studio/mnemonica/brief-light"><img src="https://agentmods.dev/badge/skills/hax-studio/mnemonica/brief-light/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 brief-light

Your own site · 80×15
<a href="https://agentmods.dev/skills/hax-studio/mnemonica/brief-light"><img src="https://agentmods.dev/badge/skills/hax-studio/mnemonica/brief-light.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 749 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.
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 $0.00069 $0.00749
Opus 5 $0.00034 $0.00375
Sonnet 5 $0.00014 $0.00150
Haiku 4.5 $0.00007 $0.00075

Measured 9d ago against content hash cbbe8d0773a6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

brief-light 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 9d 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/brief-light/SKILL.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Mnemonica: brief-light

Give a real, substantive orientation to a project — not two sentences, but not the full depth of brief-full either — by reading the CLAUDE.md index plus a bounded slice of each module file, so the cost stays predictable regardless of how large any individual module has grown. This skill never writes anything.

If the user's invocation includes extra wording (for example, "focus the brief on the payments system"), treat it as narrowing which modules to cover — it cannot turn this into an unbounded read of every module file in full; that is what brief-full is for.

Step 1: Check whether Mnemonica is installed

Run ${CLAUDE_PLUGIN_ROOT}/scripts/check-index-integrity.sh <project-root>. Exit 2 (NO_MNEMONICA_BLOCK) means there is no index to brief from — tell the user and suggest mnemonica:setup, and stop. Exit 1 means some module files are missing; note which ones, but continue — a brief can still be useful with partial coverage.

Step 2: Read the module index and README

Read the module index from .claude/CLAUDE.md. Read README.md at the project root if it exists, for the project's own framing of what it is (name, purpose, how it runs) — this skill only reads README.md, never writes it, same as every other Mnemonica skill.

Step 3: Read a bounded slice of each module

For each module file that exists on disk, read roughly its first 40 lines (or its first major heading section, whichever is shorter) — not the whole file. This is what keeps brief-light light: cost stays roughly constant per module regardless of how long any one of them has grown. Do not read further just because a file looks interesting; that tradeoff is what brief-full exists for.

Step 4: Check freshness

Check whether <project-root> is inside a git working tree.

  • No git: if knowledge/.mnemonica-state.json exists, read its last_run_utc for the only freshness signal available; otherwise say freshness can't be assessed.
  • Git available: run ${CLAUDE_PLUGIN_ROOT}/skills/audit-light/scripts/diff-since-checkpoint.sh <project-root> purely to read its output — never act on what it reports as changed. Exit 2/3/4 all mean "no reliable freshness signal, docs may not reflect recent work" — say that plainly rather than guessing. On success, read COMMITS_BEHIND and mention it if it is more than a handful of commits.

Read the full file on GitHub · 58 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. 9d ago First seen · 58 lines · 69 tokens per session scan A cbbe8d0773a6

Subscribe to this mod's changes

brief-light is a skill published in the GitHub repository HAX-Studio/mnemonica (3 stars, last pushed 1mo ago), licensed MIT. It adds 69 tokens to every session and 749 once invoked, about $0.0003 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 2026-08-31.

Related

Other skills, from other repositories

create-request

Create, update, or scan per-task request tickets for progress tracking. These are date-prefixed non-lifecycle docs under requests/, NOT feature-level requirements (use /req-analyze for those). Use when: tracking task progress, updating completion status, scanning incomplete requests, checking request status dashboard.…

sd0xdev/sd0x-harness · 112 tokens

recap-doc

Post-development recap document generator. Use when: AI/Codex has implemented a feature and the user needs a guided walkthrough of what changed and why, with blind-spot detection and anticipated questions. Not for: Q&A follow-up (use /recap-ask), technical share-out for teammates (use /tech-brief), or generic code…

sd0xdev/sd0x-harness · 114 tokens

runbook

Generate and update feature release runbooks from existing docs and codebase. Use when: creating operational runbook, release handbook, deployment checklist, pre-release preparation. Not for: incident response (v2), code review (use codex-code-review), architecture design (use architecture).

sd0xdev/sd0x-harness · 59 tokens

jira

Jira integration — view issues, generate branches, create tickets, transition status. Use when: user mentions Jira ticket key (XX-123), says /jira, wants to create branch from ticket, create a new ticket, or update Jira status. Not for: GitHub issues (use issue-analyze).

sd0xdev/sd0x-harness · 64 tokens

repo-intake

Project initialization inventory (one-time). Use when: first onboarding a project, rebuilding cache after structural changes. Not for: day-to-day development (read cache directly), finding specific files (use code-explore). Output: project map with entrypoints + test map + next steps.

sd0xdev/sd0x-harness · 60 tokens

request-tracking

Request tracking knowledge base. Use when: querying request status, managing document references, tracking progress. Not for: creating requests (use create-request), tech specs (use tech-spec). Output: status report + progress tracking.

sd0xdev/sd0x-harness · 48 tokens