Modular Context | Karpathy LLM Knowledge Base + Gmail & G-Cal

Your Obsidian vault as LLM-native knowledge base + multi-account Google Workspace (Gmail, Calendar, Drive, Docs, Sheets, Slides) exposed as 25 MCP tools for Claude Code. Local-first, encrypted, no telemetry.

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What is this?

Two things in one plugin:

1. LLM Knowledge Base — Your Obsidian vault structured as Sources → Wiki → Schema (Karpathy-aligned framing). Multi-terminal Claude Code + Codex with skills sidebar, agent tracking, session glyphs. Your second brain seen by LLMs as a first-class context.

2. G-Suite MCP Server — Multi-account Google Workspace (Gmail, Calendar, Drive, Docs, Sheets, Slides) exposed as 25 native tools for Claude Code (gmail_search, drive_list_files, docs_create_doc, sheets_append_row, slides_read_presentation, …). OAuth 2.0 + PKCE desktop flow, tokens encrypted via Electron safeStorage (OS keychain), no telemetry, no cloud.

One install, one onboarding, two productivity frontiers.

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Architecture

                    🦀  LLM KNOWLEDGE BASE
                    ┌────────────────────────┐
                    │   Sources · Wiki ·     │
                    │   Schema  (vault)      │
                    └───────┬────────▲───────┘
                            │        │
                 feed every │        │ write digest /
                 new session│        │ synthesise back
                            ▼        │
           ╔═════════════════════════╧════════════════════╗
           ║     🦀  CLAUDE CODE  (sessions · terminals)  ║
           ║                                              ║
           ║     ⟲  inbox digest loop                     ║
           ║     ⟲  meeting prep loop                     ║
           ║     ⟲  synthesise-files loop                 ║
           ╚═══════════╦════════════════════╦═════════════╝
                       │                    │
                pulls  │                    │  pushes
                       ▼                    ▼
           ┌──────────────────────────────────────────┐
           │   🦀  mcp-google   (stdio · Node)        │
           └───────────┬──────────────────────┬───────┘
                       ▼                      ▼
                    🦀  GOOGLE WORKSPACE (multi-account · 25 tools)
                    ├─ Gmail    ✓ 4   ← search → send/draft/labels
                    ├─ GCal     ✓ 6   ← list   → create/update/delete/freebusy
                    ├─ Drive    ✓ 4   ← list/search → download/upload
                    ├─ Docs     ✓ 3   ← read   → create/update
                    ├─ Sheets   ✓ 5   ← read   → write/append/create
                    └─ Slides   ✓ 3   ← read   → create/add-slide

        ── configured by ──▶  🦀  Modular Context Plugin
                               (infra · OAuth · sidecar)

Architecture decisions (full ADRs in docs/adrs/):

• ADR-001 — Hybrid OAuth: Quick Connect (shared client) + BYO (user-provided client)
• ADR-002 — Electron safeStorage token storage (OS keychain)
• ADR-003 + addendum — MCP server stdio lifecycle + plaintext credentials sidecar
• ADR-005 — Multi-account storage model (per-account folder + index)

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Features

LLM Knowledge Base

• Multi-terminal split layouts — single, side-by-side, stacked, 2×2, 2×3, 2×4. Up to 8 sessions.
• Claude Code + Codex — toggle AI provider in settings; auto-launch on new terminal.
• Skills sidebar — 3 primary skills (full-width), rest in secondary grid. One-click launches.
• Agent tracker — Working / To Review / Standby states per session.
• Session glyphs — unique geometric shape per terminal. Skills inherit their icon.
• Compact mode — 48px icon-only sidebar, maximum terminal real estate.
• Fullscreen overlay — terminal fills Obsidian; sidebar docks right. Esc to exit.
• Real PTY — zsh in a pseudo-terminal, not a basic runner.
• Wiki-link autocomplete — [[ inside terminal searches vault notes.
• Drag-and-drop — Finder / Obsidian → terminal as shell-escaped paths.
• Session persistence — tab names, glyphs, layouts survive restarts.
• Smart Session Restore — on reopen, picker modal classifies saved sessions (Needs attention / Idle / Archive) instead of silent auto-resume. You choose what materializes — no accidental skill re-runs.
• Auto-onboarding — first install triggers a setup agent that scaffolds your vault.

G-Suite MCP Server (v2.1 — 25 tools)

• Multi-account — unlimited Google accounts in parallel (Testing mode: up to 100 test users per account)
• 25 tools for Claude Code across 6 Workspace products (Gmail ×4, Calendar ×6, Drive ×4, Docs ×3, Sheets ×5, Slides ×3 — see table below)
• Zero telemetry — no metrics, no crash reports, no external calls beyond OAuth + Google API
• Local-first — tokens encrypted via OS keychain (macOS Keychain / Windows DPAPI / Linux libsecret via libsecret)
• Auto-refresh — 50-minute timer per account, 5-minute expiry buffer
• Error taxonomy — TOKEN_EXPIRED, ACCOUNT_NOT_FOUND, SCOPE_OUTDATED, RATE_LIMITED, PERMISSION_DENIED, QUOTA_EXCEEDED, NETWORK_ERROR
• Hot reload — server re-reads credentials per tool call, zero-downtime refresh

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3 primary skills (post-onboarding)

Skill	Purpose	Uses
Synthesise Files	Turn raw files (transcripts, notes, backlog) into vault modules — categorize, tag, update, reweave neighbors	Your vault, optional _transcripts-backlog/
WhatsApp Digest	Analyze WhatsApp groups for action items, blindspots, staleness vs vault	macOS WhatsApp.app
Gmail + G-Suite	Inbox sweep, stale follow-ups, calendar gap analysis, meeting prep, doc extraction, sheet logging, deck prep	MCP tools below

All three write artifacts to _workspace/{YYYY-MM}/w{N}/. Secondary skills (Pulse, Brief, Log, Reweave, Graph, Graduate, Ideas, Vault-Audit) available in sidebar grid.

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25 MCP tools

Gmail (4)

Tool	Purpose
gmail_search	Query with Gmail syntax (is:unread, from:X, after:2026-04-01). Optional body extraction.
gmail_draft	Create draft — not sent. User opens webUrl in Gmail UI to send.
gmail_send	Send immediately. Skip draft for trusted, scripted sends.
gmail_modify_labels	Add/remove labels — system presets (INBOX, UNREAD, STARRED, IMPORTANT, SPAM, TRASH) + custom labels by name.

Calendar (6)

Tool	Purpose
calendar_list_calendars	Enumerate all calendars user has access to.
calendar_list_events	Events in time range.
calendar_create_event	Create event (sendUpdates: "none" default — no auto-invite spam).
calendar_update_event	Patch existing (only provided fields changed).
calendar_delete_event	Delete.
calendar_freebusy	Query busy windows across multiple calendars — ideal for "find time to meet".

Drive (4)

Tool	Purpose
drive_list_files	List with Drive query syntax filter, pagination, ordering.
drive_search	Full-text search across file content + names. Optional mimeType filter. Excludes trashed.
drive_download_file	Get file content. Google-native files auto-exported as text; binary returned as base64.
drive_upload_file	Create file with content + optional parentFolderId. Supports utf-8 / base64.

Docs (3)

Tool	Purpose
docs_read_doc	Plain-text extraction from doc body (walks paragraphs + tables).
docs_create_doc	New doc with title + optional initialContent.
docs_update_doc	mode: "append" (at document end) or mode: "replace" (wipe body + insert).

Sheets (5)

Tool	Purpose
sheets_list_sheets	Spreadsheet metadata + list of sheet tabs.
sheets_read_range	Read A1-notation range. Supports majorDimension + valueRenderOption.
sheets_write_range	Overwrite values at range. USER_ENTERED parses formulas + dates.
sheets_append_row	Append row(s) to data region end.
sheets_create_spreadsheet	New spreadsheet with optional initial sheet titles.

Slides (3)

Tool	Purpose
slides_read_presentation	Metadata + plain-text summary per slide.
slides_create_presentation	New presentation with title.
slides_add_slide	Insert slide with layout (BLANK / TITLE / TITLE_AND_BODY / SECTION_HEADER / TITLE_AND_TWO_COLUMNS / CAPTION_ONLY).

Every tool accepts optional account param (email, case-insensitive). Omit → primary account. Unknown email → ACCOUNT_NOT_FOUND error.

OAuth scopes required (10 total): gmail.modify, calendar, drive.file, drive.metadata.readonly, documents, spreadsheets, presentations, plus OIDC openid email profile.

Google Cloud setup: Enable 6 APIs in your OAuth project — Gmail, Calendar, Drive, Docs, Sheets, Slides. Missing API returns PERMISSION_DENIED with direct enable link.

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Install

Plugin

Requires Obsidian ≥ 0.15 and macOS (Linux + Windows may work; untested).

Via BRAT (Beta Reviewer plugin, recommended for now):

1. Install BRAT from Community Plugins
2. Cmd+P → "BRAT: Add a beta plugin" → klemensgc/modular-context-obsidian-plugin
3. Enable in Settings → Community plugins

Manual:

1. Download main.js, manifest.json, styles.css, mcp-server.js from latest release
2. Copy to <vault>/.obsidian/plugins/modular-context/
3. Enable plugin in Settings → Community plugins → Modular Context

MCP server

Auto-installed on first Google Workspace: Connect. Plugin copies bundled binary to ~/.modular-context/mcp-google/dist/index.js (~100 MB one-time).

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Repo structure

Monorepo with three packages:

modular-context-obsidian-plugin/
├── packages/
│   ├── plugin/        ← Obsidian plugin (main.ts, manifest, features + MCP client glue)
│   ├── mcp-google/    ← standalone MCP server (25 Google Workspace tools, Node)
│   ├── shared/        ← portable types + AgentTracker + PTY helper + UI primitives
│   └── app/           ← experimental standalone Electron app (WIP, not shipped)
├── README.md          ← you are here
├── banner.png
└── package.json       ← monorepo scripts (build:shared → build:mcp-google → build:plugin)

• packages/plugin/CHANGELOG.md — user-facing release notes (v1.0 → v2.0)
• packages/plugin/RELEASE-v2.0.0.md — v2.0 release highlights
• packages/mcp-google/README.md — MCP server docs (25 tools, accounts, env contract)
• packages/mcp-google/CHANGELOG.md — MCP server version history
• Skill library: separate repo klemensgc/modular-context-skills — plugin auto-syncs

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Connect Google Workspace

Two paths:

• Quick Connect (no GCP setup) — use the shared OAuth client bundled with the pre-built release. Comment your email on #3 — Quick Connect: request test-user access to be added as a test user (usually within 24h). Then skip to step 5 below.
• BYO (your own GCP project) — full control, no test-user limit. Follow all 6 steps below.

6 steps (BYO path)

1. Create GCP OAuth Client

   • Google Cloud Console → new project (e.g. modular-context-gcp)
   • Enable APIs: Gmail API, Google Calendar API
   • OAuth consent screen → External, Testing mode → add scopes: gmail.modify, calendar, plus openid, email, profile
   • Add yourself as test user
   • Create credentials → OAuth 2.0 Client ID → Desktop app
   • Copy Client ID + Client Secret

2. Fill .env.local in the plugin's build folder:

   GOOGLE_OAUTH_CLIENT_ID=...
   GOOGLE_OAUTH_CLIENT_SECRET=...
   

3. Rebuild (npm run build in packages/plugin) if self-building. Pre-built release uses the shared Quick Connect client.

4. Reload plugin — Cmd+P → "Reload app without saving"

5. Connect — Cmd+P → "Google Workspace: Connect (or add account)" → browser OAuth → authorize → done

6. Add more accounts — "Google Workspace: Add another account" any time

The plugin writes .mcp.json to your vault root + per-account sidecars to ~/.modular-context/mcp-google/accounts/{filename}/. Restart Claude Code session to pick up the MCP server.

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Plugin commands

Command	Purpose
Google Workspace: Connect (or add account)	Launch OAuth flow for new/additional account
Google Workspace: Add another account	Alias for above — clearer intent
Google Workspace: Reconnect (upgrade scopes)	Nuke tokens, re-auth all accounts with current scope set
Google Workspace: Disconnect all accounts	Remove all credentials + .mcp.json entry
Google Workspace: Status	List connected accounts, expiry times, scope status
Google Workspace: Show MCP server logs	Open ~/.modular-context/mcp-google/logs/server.log

Plus 5+ non-Google commands for terminal / skill management. See Command Palette.

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Security

• Tokens encrypted via Electron safeStorage (OS keychain). Never leave disk in plaintext.
• Credentials sidecar for MCP server: plaintext JSON at 0600 perms in user-scope folder (comparable to ~/.aws/credentials, ~/.config/gcloud/). Plugin may re-encrypt in v2.1 (see ADR-003 addendum).
• No telemetry. No crash reports. No metrics. Zero phone-home.
• Logs scrub tokens, emails, subjects via regex on every line.
• Multi-account isolation. Each account has separate credentials; MCP server honors account param strictly.

Full threat model in docs/adrs/ADR-003-addendum-shared-state.md.

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What's new in v2.0

• 3 primary skills reorganization — Synthesise Files (was "Ingest Data"), WhatsApp Digest, Gmail + Calendar
• New gsuite-analysis skill — orchestrates 10 MCP tools with 4 playbook patterns
• Graduated v1.5 / v1.6 / v1.7 beta milestones: OAuth + storage + MCP server + multi-account + full control
• OAuth scope upgrade: gmail.modify + calendar full (replaces gmail.readonly, gmail.send, calendar.events)
• mcp-google-workspace @ 1.1.0 stable (from 1.1.0-beta.1)
• New tools: gmail_send, gmail_modify_labels, calendar_list_calendars, calendar_update_event, calendar_delete_event, calendar_freebusy
• Smart Session Restore Picker — replaces silent auto-resume on plugin reopen. Modal classifies saved sessions into Needs attention / Idle / Archive buckets; you pick what materializes. No accidental skill re-runs, no hidden respawns.

Full list in packages/plugin/CHANGELOG.md.

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Troubleshooting

Issue	Fix
Notice: "Reconnect required for {email}"	Google Workspace: Reconnect (upgrade scopes) — scopes changed
TOKEN_EXPIRED from MCP tool	User revoked access or refresh token rotated — Reconnect
ACCOUNT_NOT_FOUND	Account not connected — Add another account
MCP server not visible in Claude Code	Restart Claude Code session. .mcp.json loaded at session start.
Plugin reloaded but old behavior	Hard reload: Cmd+P → "Reload app without saving" (not just disable+enable)
Server logs empty	Normal — server only runs when Claude Code calls a tool. Not a daemon.

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Contributing

Plugin: modular-context-obsidian-plugin

Skills library: modular-context-skills (separate repo, auto-synced)

PRs welcome. Issues welcome. No support contract, but I read everything.

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License

MIT © klemensgc / receptionOS