Save to Obsidian: Knowledge Router + Session Logger

Every time the user says "save to my brain", this skill does two things in one shot:

1. Knowledge extraction. Pulls out the knowledge worth keeping (lessons, decisions, ideas, insights) and files each piece in the right vault section.
2. Session log. Writes a record of the session in 06 Session Logs/: what was done, why, with which tools, and what is still open.

The user says it once. The vault gets smarter and the session is on record.

When to save (the save signal)

Saving is not automatic. Finishing a task does not trigger a save. Save when:

• The user asks. "Save it", "guárdalo", "log this", "save the session".
• You offer it once, at the end of a session that produced something real, and the user says yes. Real means: a decision with reasons, a lesson learned the hard way, a new process, a new piece of the system, a pattern that repeated, or a strategy.

Never save in the middle of a session "just in case", and never offer more than once. If the same kind of work has happened 3 or more times, offer to turn it into a skill instead of saving it again.

Triggers / Activadores

English: "save to my brain" · "save it" · "save the session" · "save this conversation" · "log this" · "session summary" · "save to the vault"

Español: "guárdalo en mi cerebro" · "guárdalo" · "guarda la sesión" · "guarda esta conversación" · "registra esto" · "resumen de sesión" · "guarda en la bóveda"

The main phrase is configurable in CLAUDE.md as {{TRIGGER_PHRASE_SAVE}}.

Load order (every time)

1. This skill: routing, extraction, session log.
2. obsidian-power-user: formatting, linking, Obsidian conventions. The link rules below override anything there that conflicts.
3. Verify the vault path (next section).
4. Get the real date and time from the clock: date "+%Y-%m-%d %H:%M". Never guess it.
5. Work.

Vault location

The vault path is in CLAUDE.md as {{VAULT_PATH}}; its name is {{VAULT_NAME}}.

Verify before writing anything:

ls "{{VAULT_PATH}}/00 Inbox" 2>/dev/null

If it does not exist: ask the user to confirm the location or grant access to the folder. Never write somewhere else as a workaround, and never leave files in the working directory and call it done. If the user has the kit but never ran second-brain-init, suggest that first.

Vault structure (00 to 09)

Sections are found by their number prefix, so a user who renames "01 Personal Knowledge" to "01 Company Knowledge" keeps everything working.

{{VAULT_NAME}}/
├── 00 Inbox/                <- Only when nothing else fits yet
├── 01 Personal Knowledge/   <- People/, Places/, Routines/, Lessons Learned/
├── 02 Strategy/             <- Vision/, Goals/, Decision Log/, North Star/
├── 03 Ideas & Notes/        <- Ideas, plus References/ (saved sources and web clips)
├── 04 Learning/             <- Books/, Courses/, AI & Tech/, Business/
├── 05 AI System/            <- Skills/, Integrations/, Architecture/
├── 06 Session Logs/         <- Session logs and project checkpoints
├── 07 Assets/               <- Finished outputs: reports, dashboards, documents
├── 08 Projects/             <- Working notes of active projects, one folder each
├── 09 MOCs/                 <- Maps of Content and project Doors
├── Archives/                <- Old or replaced notes. Nothing is ever deleted
├── Excalidraw/              <- Drawings
└── Templates/               <- The user's templates. This skill never writes here

THE LINK RULES (non-negotiable)

Broken links are the most common way a vault rots. These rules exist so it never does.

1. Forbidden characters in file names: # ^ [ ] | : Obsidian cannot link a note whose name has one of them. Write No.1 instead of #1, (Draft) instead of [Draft], and a comma or a hyphen instead of a colon.
2. Every link must resolve. Before writing [[Target]], check that a note with that name exists (search the vault by file name). A link to nothing is a broken promise.
3. No placeholder links. If the related note does not exist yet, either create it as a short stub (frontmatter plus two lines, status: stub) so the link resolves, or do not write the link. Never leave red links on purpose.
4. Link by name, never by path. Write [[Note Name]], never [[../folder/note]].
5. Every new note enters the graph connected. At least 2 outgoing links that resolve, and at least 1 incoming link: add it to the matching MOC in 09 MOCs/, or to the *See also:* line of a related note.

The frontmatter contract

Every note this skill writes carries the same properties, so search, filters and the health check can trust them:

---
title: "Decision, Raised Beds"
type: decision          # from the closed list in .brain/vocabulary.json
project: garden         # optional; when used, it must be in the project list
date: 2026-10-02        # YYYY-MM-DD, real date
time: "14:35"           # HH:MM, real time from the clock, never guessed
description: "One line that says what this note is and when to read it."
tags: [garden, decisions]   # lowercase, no spaces, no accents, no #
status: active          # active | done | superseded | parked | stub | draft
aliases:
  - "Raised bed decision"
source: "Conversation, 2026-10-02"
---

The closed lists live in {{VAULT_PATH}}/.brain/vocabulary.json. Types: session, decision, lesson, idea, learning, reference, person, process, architecture, integration, moc, door, checkpoint, health, note. If a note needs a new type, status or project, add it to that file first (tell the user), then use it.

Validate before calling it saved. If python3 is available, run:

python3 "{{VAULT_PATH}}/.brain/tools/check_frontmatter.py" "<the note>.md"

It must print 0 with problems. If it lists a problem, fix the note and run it again. Without Python, check the required keys, the lists and the date and time format by reading the note back.

The description is the most valuable line in the note: the search ranks it high and the AI reads it to decide whether to open the note. Write it for a stranger.

PART 1: Knowledge extraction

Step 1. Review the conversation

The whole conversation is the source. If the user pointed at something ("save the part about pricing"), focus there. Otherwise scan everything.

Step 2. Extract the nuggets

Filter hard. For each piece ask: "Would this be useful in a conversation three months from now?"

Content type beats topic. A skill about marketing is still a skill, so it goes to 05 AI System/Skills/, not to 04 Learning/. What it IS beats what it is ABOUT.

For everything else, route by topic:

Do not save as nuggets: troubleshooting that only mattered today (session log), file paths and debugging detail (session log), what a skill file already says, anything already in the vault, or the conversation verbatim.

Step 3. Search before you write

Look for an existing note on the same topic first. If python3 and the index exist:

python3 "{{VAULT_PATH}}/.brain/tools/brain_search.py" "<topic words>"

Otherwise search file names and text in the relevant section.

• A related note exists: update it. Add the new knowledge and the date.
• It already says the same: skip it.
• Never create "v2" copies, never leave .bak copies next to a note. One note per topic, kept current.

Step 4. Write the notes

File names: YYYY-MM-DD Type, Short Title.md for dated notes, a plain descriptive name for evergreen notes. No forbidden characters.

• 2026-10-02 Lesson, Define Success Before Starting.md
• 2026-10-02 Decision, Move Tasks to Obsidian.md
• What My Best Clients Have in Common.md

Body:

# [Title]

> [!info] Context / Contexto
> One or two sentences on why this came up.

[The knowledge itself, specific, with numbers and names, in the user's voice.
[[Wikilinks]] inline wherever a concept, person or decision has its own note.]

*See also: [[Related Note 1]] | [[Related Note 2]]*

By type, add:

• Lesson: > [!warning] What happened / Qué pasó and > [!tip] Takeaway / Aprendizaje.
• Decision: > [!quote] Decision / Decisión, then Why, then Considered and rejected.
• Idea: > [!note] The idea / La idea, then Why it could work, then Open questions.

Step 5. Link it into the graph

1. Link forward to existing notes (each target verified, rule 2).
2. Link backward: add the new note to the *See also:* line or related: property of the notes it relates to.
3. Register it in the matching MOC in 09 MOCs/. If a section passes about 7 notes on one theme and has no MOC, propose one to the user.
4. Notes created in the same save link to each other.
5. Use [[Note#Heading]] or [[Note^block-id]] to point at a precise spot, and [[Note|natural words]] when the title reads badly inline.

Promotion: how knowledge moves up

The brain compounds by promoting what repeats, not by piling up notes.

• A reference graduates. When a saved clip in References/ gets the user's own thoughts, their links, or is cited by other notes, move it to its real home (01, 02 or 04) and fix the links that pointed to it.
• Many connections become a doctrine. When about five notes keep circling the same principle, write one canonical note for it in 05 AI System/Architecture/ and link it from a MOC, so the next session reads the principle instead of rediscovering it.
• A growing theme gets a MOC. Propose it first; never invent a new top-level section on your own.

PART 2: Session log

Every save gets a session log in 06 Session Logs/, even when no nuggets were extracted. Name: YYYY-MM-DD Session, Short Title.md (add (2), (3) for more sessions the same day).

---
title: "Session, [Short Title]"
type: session
date: YYYY-MM-DD
time: "HH:MM"
description: "One line: what this session did and why it matters."
tags: [session, topic-tag]
status: done
---

# Session, [Short Title]

> [!info] Session details
> **Date:** YYYY-MM-DD HH:MM · **Length:** about 45 min · **Started by:** the user's opening request

## What we accomplished / Lo que logramos
A short narrative (2 to 4 paragraphs) with [[links]] to the notes, tools and people involved.

## Key decisions / Decisiones clave
> [!quote] [Decision]
> **Decision:** ... **Why:** ... **Alternatives:** ...

## Outputs
- **[Output]**: what it is and where it lives

## Tools and sources used
- **[Tool]**: what it was used for

## Lessons / Aprendizajes
> [!tip] Takeaways
> What surprised us. If nothing: "Clean session, nothing notable."

## Open items / Pendientes
- [ ] Item with enough context to act on later

## Knowledge saved
- [[Note Title]] → section

Scale the detail to the session: a 15-minute task gets a short log. Quote the user's memorable lines. Keep their mix of English and Spanish as they said it.

If the session belongs to a project with a Door (09 MOCs/Door, <Project>.md), link the Door from the log. Updating the Door itself is the job of close-session.

Step 6. Tell the user what was saved

Saved to {{VAULT_NAME}}:
- [Note] → 02 Strategy / Decision Log
- [Note] (updated) → 01 Personal Knowledge / Lessons Learned
- Session log → 06 Session Logs
All notes pass the frontmatter check.

In Spanish when that is the user's language ("Guardado en ...", "Todas las notas pasan la revisión del frontmatter"). If nothing was worth extracting, say so and save only the log. If the search index exists, end by refreshing it: python3 "{{VAULT_PATH}}/.brain/tools/brain_index.py" --quiet.

Edge cases

• Short session: skip extraction if there is nothing, and write a condensed log.
• Sensitive data: the vault is private, so include it, unless the user asks not to.
• Several unrelated tasks: one sub-heading per task in the log.
• Vault not reachable: say so and ask for access. Never write elsewhere.
• Long conversation: if the start fell out of context, use the host's transcript tools to recover it before extracting.
• Spanish-speaking user: headings, callouts and prose in Spanish; property names and tags stay in English, because the tools read them.

Vault hygiene (non-negotiable)

1. Knowledge and session records only. No temp files, no drafts for elsewhere.
2. No duplicates and no "v2" files. Update the original.
3. Never delete. Old or replaced notes move to Archives/, with status: superseded.
4. No .bak copies inside the vault. A manual backup goes to Archives/Backups/<date>/.
5. No orphans: 2 or more resolving links out, 1 or more in.
6. Templates/ is read-only for this skill; Excalidraw/ is only for drawings.
7. Session logs complement knowledge notes; they never replace them.
8. Real date and time on every note, validated frontmatter on every note.
9. The link rules above override everything else.

Changelog

• 2.0.0 (2026-10-02): The link rules (forbidden characters, no broken or placeholder links, link by name, MOC registration). The frontmatter contract with closed lists in .brain/vocabulary.json, real time on every note, and validation with check_frontmatter.py. The save signal. Search before writing with brain_search.py. Promotion (references, doctrines, MOCs). Never delete, no .bak files. Sections 07 to 09 and Archives. File names without dashes.
• 1.0.0 (2026-05-29): First public version.