Ars Contexta is a Claude Code plugin that creates a personalized knowledge system from a conversation about how someone thinks and works, using connected Markdown files, note-processing skills, hooks, navigation maps, and templates. It is for people who want an owned, persistent second brain tailored to their domain. The catalogue entries are its generated skills, hooks, agent, and plugin workflow.
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.
/plugin marketplace add agenticnotetaking/arscontexta/plugin install arscontextaWrote 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.
[](https://agentmods.dev/skills/agenticnotetaking/arscontexta/health)<a href="https://agentmods.dev/skills/agenticnotetaking/arscontexta/health"><img src="https://agentmods.dev/badge/skills/agenticnotetaking/arscontexta/health.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00100 | $0.07132 |
| Opus 5 | $0.00050 | $0.03566 |
| Sonnet 5 | $0.00020 | $0.01426 |
| Haiku 4.5 | $0.00010 | $0.00713 |
Grade A, and why
health 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 6d 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.
How it starts
The opening of the file, as written. The whole thing — 761 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Runtime Configuration (Step 0 — before any processing)
Read these files to configure domain-specific behavior:
-
ops/derivation-manifest.md— vocabulary mapping, folder names, platform hints- Use
vocabulary.notesfor the notes folder name - Use
vocabulary.inboxfor the inbox folder name - Use
vocabulary.notefor the note type name in output - Use
vocabulary.topic_mapfor MOC/topic map references - Use
vocabulary.topic_mapsfor plural form
- Use
-
ops/config.yaml— processing depth, thresholds -
Three-space reference —
${CLAUDE_PLUGIN_ROOT}/reference/three-spaces.mdfor boundary rules (load only for full and three-space modes) -
Templates — read template files to understand required schema fields for validation
If these files don't exist (pre-init invocation or standalone use), use universal defaults:
- notes folder:
notes/ - inbox folder:
inbox/ - topic map: topic maps in notes/
EXECUTE NOW
Target: $ARGUMENTS
Parse the invocation mode immediately:
| Input | Mode | Categories Run |
|---|---|---|
empty or quick |
Quick | 1 (Schema), 2 (Orphans), 3 (Links) |
full |
Full | All 8 categories |
three-space |
Three-Space | 5 (Three-Space Boundaries) only |
Execute these steps:
- Detect mode from arguments
- Scan the vault — inventory all note files, {vocabulary.topic_map} files, inbox items, ops files
- Run each applicable diagnostic category in order (1-8)
- Classify each result as PASS, WARN, or FAIL using the thresholds below
- Surface condition-based maintenance signals (check against threshold table)
- Generate the health report with specific file paths, counts, and recommended actions
- Write report to
ops/health/YYYY-MM-DD-report.md
START NOW. Reference below explains each diagnostic category in detail.
Platform Adaptation
Checks adapt to what the platform supports:
- If semantic search (qmd) is not configured, skip semantic-dependent checks and note their absence
- If hooks are not available, note that validation is convention-only (no automated enforcement)
- If self/ directory does not exist (disabled by config), skip self-space checks but verify ops/ absorbs self-space content correctly
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.
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.
- 6d ago First seen · 761 lines · 100 tokens per session scan A 3ac7b6c3d5b1
health is a skill published in the GitHub repository agenticnotetaking/arscontexta (3,485 stars, last pushed 6mo ago), licensed MIT. It adds 100 tokens to every session and 7,132 once invoked, about $0.0005 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 2026-08-30.
Other skills, from other repositories
llm-wiki
Build and maintain an LLM-curated personal knowledge base — the "LLM Wiki" pattern from Andrej Karpathy's April 2026 gist. Use this skill whenever the user wants to ingest a source (paper, article, transcript, PDF, notes) into a persistent compounding knowledge base, ask a question against accumulated notes, lint or…
migrate
Scan the project and migrate existing documentation into OKF format. Use when the user wants to populate the knowledge base from existing docs, README, schemas, API specs, runbooks, or any structured project knowledge. Trigger on "migrate to okf", "populate the knowledge base", "scan my docs", "convert docs to okf"…
ingest
Create or update a single OKF concept file from raw input. Use when the user wants to document a specific table, metric, API, service, or concept in the knowledge base — even if they say "add this to the okf", "documenta essa tabela", "cria um conceito pra isso", "adiciona no knowledge base", "register this API", or…
claude-mega-brain
OKF knowledge navigation. ALWAYS use this skill the moment a block appears in session context — it means the project has documented concepts and you must consult them before answering questions about data, schemas, metrics, APIs, or systems. Also trigger when the user asks about a table, column, metric definition…
init
Initialize OKF knowledge base files in the current project. Use when the user wants to start documenting their project for claude-mega-brain, or when the user says "init mega brain", "setup the knowledge base", "cria o okf", "inicializa o mega brain", "quero usar o mega brain", "criar a estrutura do knowledge base"…
init
Initialize a personal Trove, a local file-based knowledge index for Claude Code. Use when the user says start/set up/create my trove, or when they want to remember things but no trove exists yet. Scaffolds the trove directory, INDEX.md and entries/ folder at user scope (/.claude/trove, follows you everywhere) or…