How To Build The ULTIMATE AI Company Brain (Obsidian + Claude Code)
Your second brain is single-player. This is the multiplayer version.
This one was fun to make. I spend the whole film playing Althea, Director of RevOps at RMBL, a fictional company that makes roller coaster management software and is trying to get a new water park product into every deal. Althea starts where most ops people actually start: a folder full of call notes, a CRM export, somebody's pricing scratchpad. One prompt into Claude Code and that mess becomes a clean, interlinked Obsidian vault, the Karpathy LLM-wiki pattern, with a graph view you can wander around all day. You can build that part in an afternoon, and I show you how.
Then the leap. I point Claude Code at GTM Brain, our public repo, run /start, and it connects the vault to Day.ai. It reads the initiative I care about, drives attach rates on the new product, audits the whole sales team against it, and catches that Mason, the new rep, has no agent at all. A few approvals later the rollout ships: Mason gets an agent built from what's working across the team, everyone's call prep quietly learns when to bring up the new product, and every change lands in a change set I can roll back. One shared brain, every agent owned by a human, deployed from my terminal.
What Shipped
Your Agent Learns Your Voice Automatically
Day AI now builds a personal Email Writing skill for every user — automatically. Once your Gmail finishes syncing, your agent reads dozens of your real sent emails, studies how you actually write — tone, length, greetings, sign-offs — and rewrites its own drafting instructions in your voice. You get a `/email` skill without setting anything up. No style-guide homework, no prompt engineering.
The skill also knows your email templates. It lists each one by name with guidance on when to use it, and pulls the current version at draft time — so when you edit a template, every future draft picks up the change. And because it's a normal skill, you can refine it in plain language: tell your agent "make my emails shorter" or "stop using exclamation points" and the skill updates.
Also shipped
Skills can include other skills: A skill can now reference up to five other skills belonging to the same agent, folding their instructions in at run time. Keep your "Email Voice" guidance in one skill, include it from "End of Day Email" and "Follow-up Drafts", and refining the voice once improves everything that uses it.
Widescreen mode: Press Ctrl/⌘+W to let chat, Pages, and Home stretch to the full width of your window instead of a centered column. Toggle it back the same way.
Markdown uploads in chat: You can now attach `.md` files in chat alongside the other supported file types, and your agent reads them directly.
Copy and export Pages: Pages get Copy page and Download as Markdown actions in the panel menu — pasting into Docs or Notion keeps the formatting, and plain-text editors get clean markdown. Individual tables get their own Copy action too, preserving headers, colors, and column widths when pasted into another Page.
Better folder browsing: Folder cards in Pages now show relative last-updated times, wrap longer titles instead of truncating them, and can be sorted by folder order, name, or last updated — and inline folder expansion now actually shows the folder's contents.
Decision tree charts: Ask your agent to diagram branching logic — lead qualification flows, routing rules, playbooks — and it renders a proper decision tree with labeled branches, exportable and embeddable in Pages like every other chart.
New connectors — Crossbeam, Sumble, Common Room, and Guru: Four new MCP connectors join the roster. Connect them from Workspace Integrations with per-user OAuth and your agent can work with partner ecosystem data (Crossbeam), technographic data (Sumble), community signals (Common Room), and verified company knowledge (Guru) directly.
Top-N dashboard tables: Table widgets accept an optional row limit applied after sorting, so you can build an honest "Top 20 deals by amount" table — with the header showing "Top 20 of 312" so nobody mistakes it for the full list.
MCP tools from Slack: Your agent can now use your connected MCP tools when you talk to it in Slack — always-allowed tools run silently in 1:1 DMs, and tools that need permission post an approval card right in the Slack thread with Approve/Deny buttons. In shared channels, every connector call asks first and the card discloses where the result will be posted. [needs context: confirm rollout scope — currently enabled for select workspaces]
Know someone else who should check out Day AI? Shoot them this link: https://day.ai/demo
