A private, automated knowledge system

Keep what matters.
Let the system organise it.

Second Brain turns the things you save, write, read, and plan into a connected Obsidian knowledge system, with automation doing the repetitive work and you staying in control.

See how the system works ↘
CAPTUREApple NotesSaved articlesGoogle contextAI captures
SBSecond BrainProcess · connect · organise
USEConnected notesTodoist actionsDaily contextSearch & recall

For people who save a lot, want to use what they learn and are tired of organising everything by hand.

Knowledge workersKeep projects, people, decisions, references, and open questions connected.
Builders and researchersTurn scattered reading and working context into durable, source-linked understanding.
Obsidian power usersAdd automation without giving up local Markdown, human edits, or control of the graph.
01 · HOW IT WORKS

Capture once.
Keep compounding.

01

Capture

Bring in selected notes, saved content, calendar context, files, and deliberate AI captures.

02

Filter

The system checks what changed and brings in only useful new material, so old content and noise stay out.

03

Understand

AI extracts evidence, proposes relationships, and drafts targeted updates to the right notes.

04

Validate

Deterministic rules verify evidence, ownership, links, expected state, and safe Markdown before writing.

05

Use

Search the graph, review changes, receive meaningful tasks and digests, and keep the knowledge working.

02 · CAPABILITIES

One system for notes, saved articles, tasks and useful context.

Together, these tools keep a folder of notes organised, connected and ready to use.

01

Apple Notes ↔ Obsidian

A signed Mac worker keeps selected Apple Notes and Markdown in sync while Apple data stays on the Mac.

02

Connected knowledge

Evidence becomes structured claims, relationships, decisions, tensions, and links instead of another pile of isolated notes.

03

Read-only Google context

Selected Gmail, Drive, and Calendar context can inform the system without granting write authority back to Google.

04

Turn saved articles into notes

Saved articles and bookmarks become short notes with links to the source, so the reading backlog becomes useful knowledge.

05

Todoist task delivery

Useful next actions are delivered to a dedicated Todoist destination without turning every note into a task.

06

Search and recall

A private index makes the vault searchable from approved tools while the underlying notes remain yours.

07

Promotion state

Every derived note keeps source lineage and moves through a visible review state before it becomes knowledge, reference, or archive.

08

Insight-focused digest

Telegram highlights bounded decisions, connections, tensions, and experiments instead of repeating queue maintenance.

09

Choose an approved AI provider

The system can use different approved AI providers without changing the safety checks or ownership of the vault.

10

Obsidian Control Panel

Everyday source, output, writing, and style settings live where the knowledge lives: inside Obsidian.

11

Whole-system health

Separate checks cover managed notes, human maps, generated captures, source collections, connectors, sync, and backups without publishing private content.

12

Verified backups

Encrypted snapshots and isolated restore checks protect the vault without testing recovery against the live copy.

03 · WHY IT MATTERS

The value is not more notes. It is less cognitive housekeeping.

Remember the useful parts.Important context survives inboxes, tabs, feeds, and fleeting moments of attention.

See connections earlier.New evidence is routed toward the people, projects, ideas, and decisions it can actually change.

Reduce maintenance.Routine collection, organisation, validation, backup, and health checks happen without a manual nightly ritual.

Stay in control.Human edits, local Markdown, explicit approvals, and reversible writes remain more important than model confidence.

04 · ARCHITECTURE

Cloud automation.
Local authority.

MAC

What stays on the Mac

Apple data, the Obsidian vault, signed validation, and final writes stay on the Mac.

  • Apple Notes sync
  • Obsidian vault
  • Checked changes
  • Local rollback
N8N

What automation handles

Private workflows collect approved non-Apple context, schedule work, call AI models and prepare focused suggestions.

  • Read-only connectors
  • Model routing
  • Retries and cursors
  • Health and digests
05 · DISPOSITION STRUCTURE

Organised by meaning,
not by where it came from.

The system separates raw sources from durable knowledge. New evidence is reconciled against what is already known, then routed to a small set of maintained note roles.

01CAPTUREDNotes, messages, files, events, saves

Immutable source references preserve where each useful observation came from without copying the source again.

02SYNTHESISEDClaims, actions, tensions, decisions

Evidence is typed, ranked, and held for bounded review. Generation alone never makes a note canonical.

03DISPOSITIONPromoted · referenced · archived

Useful material strengthens a decision, thread, map, connection, or reusable knowledge note; everything else stays reference or leaves the queue.

The maintained graph

Roles describe what a note does in the system. Exact paths remain the identity, so similarly named notes in different areas never collapse into one.

PeopleRelationships, commitments, recent developments, and follow-ups.
ThreadsActive projects, decisions, blockers, next actions, and material history.
PositionsSupported beliefs, preferences, principles, and values as they evolve.
DomainsHigh-level navigation, responsibilities, and current priorities.
ReferenceSelected context and dependable source material worth keeping close.
KnowledgeReusable concepts, methods, explanations, and durable understanding.
ConnectionsEvidence-backed patterns, influences, contradictions, and cross-domain links.
LogDated records that preserve chronology without crowding the knowledge graph.
HUMAN-OWNEDYour writing, annotations, and corrections
+
AUTOMATION-MANAGEDA replaceable area for automated summaries

Automation can update only its managed region. Everything outside it is verified byte-for-byte before and after a transaction.

06 · SAFE AI ACCESS

A safe, limited way for AI tools to use your notes.

Approved AI tools can search the Second Brain, read one chosen note or save one item you explicitly ask to keep. They cannot browse the Mac or roam through the live vault.

search_second_brain

Find relevant knowledge

Searches the private index at a chosen depth, returning the most relevant results and only the requested content.

READ-ONLY
get_second_brain_note

Read a selected note

Retrieves one exact note after the client has identified it through search. It cannot browse arbitrary files.

READ-ONLY
keep_in_second_brain

Save an explicit capture

Creates one new AI Capture only when you clearly ask to keep something. It cannot update or delete existing knowledge.

CREATE-ONLY
AI clientExplicit tool request
→
OAuth-protected MCPIdentity and narrow tool list
→
Fixed private workflowsNo workflow discovery
→
Derived read indexSearch, read, or one capture
WHAT MCP CAN DO
  • Search indexed Markdown
  • Read one exact result
  • Create one explicit AI Capture
  • Confirm exactly what happened
WHAT MCP CANNOT DO
  • Discover or execute arbitrary workflows
  • Read credentials or provider configuration
  • Refresh, publish, update, or delete the vault
  • Bypass local validation or human ownership

An AI Capture is not automatically accepted as truth. It first enters a create-only inbox. After it reaches the original local vault, the Mac validates its metadata and may extract supported durable context at lower model-interpretation authority.

07 · BUILT-IN BOUNDARIES

Automation stops when it cannot prove a change is safe.

Your notes stay yours

Obsidian remains the source of truth. Automation proposes and validates; it does not silently seize ownership.

AI is not the final authority

AI models return suggestions. Clear code checks the allowed scope, evidence, links and current file state before anything can change.

No change means no model call

Frequent checks stop early when nothing is new, so freshness does not automatically mean more token usage.

Every part can fail safely

A connector, model or summary failure preserves the last valid state instead of replacing it with an empty or uncertain result.

08 · ROADMAP

Useful now.
Still getting smarter.

01

Available now

Local Apple Notes sync, Obsidian as the write authority, source lineage, explicit promotion queues, cross-domain maps, read-only context collection, private search, model routing, insight digests, health reporting, and verified backups.

02

Owner-guided next

Reviewing proposed knowledge, rating useful insights, and choosing which connections change a decision remain deliberately human actions.

03

Further ahead

A productised Apple Notes Sync app, broader connector packs, safer collaborative review, easier self-hosted installation, and more useful knowledge-health and reflection surfaces.

SB

Make saved knowledge more useful without adding more maintenance.

Second Brain is a self-hosted system for people who want AI help without giving up their notes, judgement or privacy.

Explore Drew's Digest ↗ View the source on GitHub ↗