Brainis has a lot of surface area, but it is built from five repeating ideas.
1. OS modules
An OS is a department-grade tool: Revenue OS is a full CRM, Hiring OS is a full applicant tracking system, People OS is a full HR platform. All 11 share the same data layer, so a candidate hired in Hiring OS becomes an employee in People OS without an export, and a closed deal in Revenue OS can raise an invoice in Finance OS.
Some former standalone modules now live inside a parent OS: People OS absorbed Payroll, Performance, Learning, Rewards, and Wellness; Hiring OS absorbed recruitment marketing; Operations absorbed Delivery, Customer Success, and Knowledge.
2. Cortex
Cortex is the AI brain across every module. It answers questions grounded in your data, runs plays (pre-built analyses and workflows), generates deliverables, and can operate on a schedule through Autopilot. Cortex is a layer, not a module: it sees across departments, which is what makes cross-cutting questions like "which deals are at risk because delivery slipped" answerable.
3. Agents
Three kinds of AI workers exist, and the distinction matters:
| Kind | What it is | Where |
|---|---|---|
| AI Agents | Agents you build or install from the marketplace | Command Center, Agents |
| AI Managers | Built-in autonomous managers per OS | Command Center, AI Managers |
| Cortex Fleet | The run log of everything AI has done | Cortex, Fleet |
See Agents overview.
4. Credits
AI work costs credits; your plan covers everything else. One credit covers roughly 2,000 tokens of AI processing. A quick Cortex answer costs about 2 credits; a deep analysis costs about 10. Every plan includes a monthly allowance, and top-up packs never expire. See How credits work.
5. Governed autonomy
Every AI-originated write goes through one gateway that checks autonomy level, permission scope, risk, and budget, then records the action in an audit chain with undo where possible. You set how independent the AI is per module or per agent with authority contracts. See Authority contracts.
Tip: If you remember one thing: every plan includes every module, AI work costs credits, and you control how much the AI may do on its own.