--- name: til description: "Teach ONE concept from THIS session — a term that flew past, the idea behind a fixed mistake, or a tool that did silent work — and save it to the Obsidian vault's TIL/ folder in the same turn. Use when the user says 'til', '/til', ';til', 'what did I learn', or asks for the one thing worth learning from the session — also appropriate at session close alongside other closing rituals." --- # til The user is a builder who ships real things without formal CS background. Terms fly past in every session; they usually search them alone afterward. This skill closes that gap: one concept per run, taught properly, from THIS session — not generic trivia. Every lesson is also written to the Obsidian vault so the vocabulary accumulates instead of scrolling away. ## The contract: chat AND vault, same turn The lesson always lands in two places in the same turn: 1. The full lesson text in chat, where the user reads it now. 2. The identical text as a note in the vault, where it accumulates. Never chat-only. Never save-only. Never ask permission before saving, never defer the save to "after you confirm" — teach and write in one pass, then show the footer with the note path. ## Picking the one thing Priority order — take the first that applies: 1. A term or concept that appeared 2+ times in the session that the user never used in their own words (they worked around it). 2. The concept behind a mistake that was made and fixed — teach the why, not the blame. 3. A tool, pattern, or piece of syntax that was used silently and did real work (e.g. a flag, an atomic write, a data structure choice). 4. Fallback only: a genuinely good fun fact connected to the session's language, tool, or history. One thing. If two are tempting, save the second for the next run — say "there's another one banked for next time" and nothing more. Before teaching, list the TIL folder (see below) and skip any term that already has a note. If the top pick is already there, drop to the next priority. ## How to teach it - Name the term first, exactly as it's written, so it can be searched. - One or two short paragraphs. Plain English. Every jargon word used in the explanation must itself be explained or dropped. - Analogies are welcome — audio production, DJing, signal flow, and physical-world analogies land better than CS metaphors. - End with one line: why it mattered in THIS session specifically. - Close with: "Want the deeper version?" — and only expand if asked. The deep version may go longer, show code, and link docs. ## Writing the note **Where.** The vault is at: ``` /Users/kika_hub/_KIKA_MAIN/Kika's_Obsidian ``` Write directly to `TIL/` at the vault root with the filesystem (Write tool). Create `TIL/` if it doesn't exist. Only if the path above is gone, fall back to the `kika-obsidian-mcp` tools, and only then ask for the vault path (once, then reuse it). **Filename.** `YYYY-MM-DD-.md` — lowercase, spaces and dots to hyphens, no other punctuation. Two notes on the same day for the same term shouldn't happen (the dedupe check runs first); if it somehow does, append `-2`. **Contents.** Frontmatter first so Obsidian Bases can filter on it: ```markdown --- term: date: project: source: session tags: [til] --- # **Why it mattered here:** ``` Do not expand, re-word, or add sections the chat answer didn't have. The note is a record of what was taught, not a second draft of it. If the user asks for the deeper version afterward, append it to the same note under a `## Deeper` heading — don't create a second file. Nothing else goes in the vault. No index file, no MOC, no daily-note edits, no backlinks the user didn't ask for. ## Output footer Last line in chat, always, greppable: ``` TIL: — ``` Then one short line with the note path, e.g. `→ TIL/2026-08-18-idempotent.md`. No commentary on the save itself. ## Hard rules - Exactly one concept. Never a list. Never "3 things you learned." - Chat and vault get the same lesson in the same turn — see the contract. - Default length: two paragraphs max. Expansion only on request. - Must come from the actual session content. If the session was trivial, say so and use priority 4 — never invent relevance. - Never condescend. The user ships production apps; missing vocabulary is not missing ability. - Never overwrite an existing TIL note. Check the folder, pick a fresh term, or append under `## Deeper` — those are the only two options. - If the vault write fails, still teach the lesson in chat and say the save failed in one line. Never swallow the error, never retry loops.