learn

learn is a skill for Claude Code from letrplB/second-brain. It costs 38 tokens per session (1,102 once invoked), scanned A, original, MIT.

An end-to-end command for turning a source into linked, checked notes in a personal research vault.

In plain words
What is it for?
Use it to extract claims from papers or other sources, connect them to existing notes, audit the links, archive the source, and print a summary.
Why use it?
It removes the need to run separate extraction, linking, checking, and archiving steps by hand.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions subagents.

Part of the second-brain plugin — 10 skills shipped together

Good fit Use it to extract claims from papers or other sources, connect them to existing notes, audit the links, archive the source, and print a summary.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/letrplb/second-brain/learn
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 letrplB/second-brain --skill learn
Clone the repo
git clone --depth 1 https://github.com/letrplB/second-brain

Made for: Claude Code.

Or install second-brain, the plugin that ships this one along with the rest of its 10 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 learn

README.md
[![agentmods](https://agentmods.dev/badge/skills/letrplb/second-brain/learn/github.svg)](https://agentmods.dev/skills/letrplb/second-brain/learn)
Your own site
<a href="https://agentmods.dev/skills/letrplb/second-brain/learn"><img src="https://agentmods.dev/badge/skills/letrplb/second-brain/learn/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 learn

Your own site · 80×15
<a href="https://agentmods.dev/skills/letrplb/second-brain/learn"><img src="https://agentmods.dev/badge/skills/letrplb/second-brain/learn.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 38 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,102 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 $0.00038 $0.01102
Opus 5.5 $0.00015 $0.00441
Sonnet 5.5 $0.00008 $0.00220
Haiku 4.5 $0.00004 $0.00110

Measured 1mo ago against content hash 6f313e52c976, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

learn 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 1mo 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/learn/SKILL.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/learn

Intent. End-to-end ingestion. The user-facing composite for "learn this source properly."

What it does (default mode)

Sequential, all inline:

  1. /extract <source>. Atomic claim notes written to notes/claims/. Paper note created in notes/papers/.
  2. For each new claim, /connect <claim>. Sequential pass. Forward + backward links + MOC membership.
  3. For each new claim, /audit <claim> (quick mode). Schema + link check. Skip cold-read in this loop.
  4. Move source. From inbox/<source> to archive/<YYYY-MM-DD>-<source-slug>/<source>. Untouched copy preserved.
  5. Print summary. Claims created, links added, MOCs touched, audit issues, archive path.

If extraction returns 0 claims, stop after step 1 and report.

Deep mode (--deep)

For papers and other dense sources where parallelism helps and the model genuinely needs full audit including cold-read.

  1. /extract <source>. Same as above — inline; the lead does extraction.
  2. Spawn one subagent per new claim. Each subagent does:
    • /connect <its-claim> (full forward + backward + MOC)
    • /audit <its-claim> --mode=full (schema + link + cold-read) Each subagent is fresh-context for its own claim. One claim, one subagent, end-to-end — not one subagent per phase.
  3. Lead waits for all subagents. Collects their summaries.
  4. Cross-connect pass (lead, inline). Walk the new claim set; for each claim, check whether it should link to another new claim whose note didn't exist when its sibling's connect ran. Add missed sibling links.
  5. Move source, print summary.

Subagent count cap: N (claims) × 1. Hard cap of 16 concurrent (Task tool platform limit). If extraction returned >16 claims, queue: spawn first 16, wait for all, then spawn next batch.

When to use which mode

Source class Mode
Tweet, single-paragraph note default. Often 0–1 claim; sequential is fine.
Blog essay (≤2K words) default. 3–8 claims; sequential takes < a minute.
Long essay / chapter (~3–8K words) default unless user wants thorough audit.
Paper (peer-reviewed, dense) --deep recommended.
Anything where the user said "thorough" or "deep" --deep.

Read the full file on GitHub · 98 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. 1mo ago First seen · 98 lines · 38 tokens per session scan A 6f313e52c976

Subscribe to this mod's changes

learn is a skill published in the GitHub repository letrplB/second-brain (1 stars, last pushed 5mo ago), licensed MIT. It adds 38 tokens to every session and 1,102 once invoked, about $0.0002 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 2026-08-31.

Related

Other skills, from other repositories

shodh-memory

Persistent memory system for AI agents. Use this skill to remember context across conversations, recall relevant information, and build long-term knowledge. Activate when you need to store decisions, learnings, errors, or context that should persist beyond the current session.

varun29ankuS/shodh-memory · 53 tokens

curate

Power-user audit of Wenlan's pending surfaces: accept or dismiss pending revisions (conflicts/merges), or audit pending captures (not yet confirmed). Most users want /brief for revisions; that handles the daily flow. Use /wenlan curate only for explicit deep-walk audits after bulk imports, or to walk the full queue…

wenlan-app/wenlan · 106 tokens

pages

Browse, open, or print distilled pages, reusing the wenlan pages CLI for the actual open (one implementation on your PATH, no setup). /wenlan pages opens the page when one matches, or shows a small native picker when 2-4 match. /wenlan pages --print reads the page here instead of opening an editor. /wenlan pages lists…

wenlan-app/wenlan · 105 tokens

forget

Delete a memory from Wenlan by ID. Destructive and cannot be undone — prefer /capture with supersedes for corrections. Invoked as /wenlan forget .

wenlan-app/wenlan · 43 tokens

llm-wiki

Build and maintain an LLM-curated knowledge base from papers, articles, transcripts, notes and project findings. Ingest sources into linked Markdown, answer questions with citations, lint or upgrade a wiki, and preserve useful synthesis across sessions and agents. Also capture verified task experience, consolidate…

praneybehl/llm-wiki-plugin · 130 tokens

raytsystem-save

Stage a cited synthesis as a typed raytsystem DRAFT bundle and escaped preview. Use for SAVE, preserving a verified query answer, preparing a knowledge proposal, or creating a reviewable draft; never treat SAVE as canonical promotion or publication.

romarayt/raytsystem-public-os · 53 tokens