// BUILT FROM PRIMITIVES, NOT SCREENS

Your equity stack is a live system, not a stack of forms.

Cap table, SAFE notes, dilution, and 409A — four composable primitives your team and your AI operate directly. Open source. OCTA v2.0 aligned.

get started free →explore the API
OPEN SOURCE/OCTA v2.0/FREE TO START/MCP NATIVE
CAPTABLE.RUN — COMPOSED FROM PRIMITIVESlive
CAP TABLE
10M shares · 3 classes
SAFE
$500K at $10M cap
DILUTION
62% founders · 28% investors
409A
$0.21 FMV · pending
> captable  recorded Series A close · 2,500,000 shares   2m
> safe     converted $500K SAFE at $10M cap         12m
> dilution  modeled post-money ownership · 4 scenarios ⏸ review
// TRUSTED BY FOUNDERS AT
AINativeSpaceTimeCareers
// FOUR PRIMITIVES

Everything else is just these four, composed.

PRIMITIVE / CAP TABLE
Your equity, structured
Every share class, stakeholder, and equity event tracked with full OCTA v2.0 compliance. Always audit-ready, always up to date.
PRIMITIVE / SAFE NOTES
Living instruments
Track conversion triggers, discount rates, valuation caps, and pro-rata rights across every round. Automatic cap table impact modeling.
PRIMITIVE / DILUTION
Scenario modeling
Run waterfall analyses and dilution scenarios. See how new rounds, option pool refreshes, and conversions affect every stakeholder.
PRIMITIVE / 409A
Compliance, automated
Support your 409A valuation process with structured data exports. Configure vesting schedules with full audit trails for option grants.
// COMPOSE YOUR EQUITY STACK

Issue, model, comply. No rigid workflow builder.

01 / issue
Issue equity your way
Create share classes, grant stock options, record SAFEs — structured from day one with OCTA schema compliance built in.
02 / model
See the future
Run dilution scenarios, waterfall analyses, and cap table projections. Know the impact of every round before you sign the term sheet.
03 / comply
Stay audit-ready
409A support, 83(b) tracking, vesting automation, and full document version control. Every change logged and attributable.
60+
API endpoints
29
MCP tools
100%
OCTA v2.0 aligned
$0
to get started
“We manage our entire cap table — stakeholders, share classes, SAFEs, and equity grants — through OpenCap Stack. The MCP integration means I query ownership directly from Claude while working on fundraising docs.”
Toby Morning
Founder & CEO, AINative Studio
// AI-NATIVE CAP TABLE

Manage your cap table from Claude or Cursor

The OpenCap Stack MCP server gives any MCP-compatible AI client direct access to your cap table. Issue equity grants, query dilution scenarios, and run waterfall analyses — all in natural language.

  • 29 MCP tools covering stakeholders, SAFEs, grants, valuations, and more
  • Works with Claude, Cursor, and any MCP-compatible client
  • Skill auto-installs to Claude Code on npm install
  • Full audit trail — every AI action is logged
install the MCP server →
terminal
$ npm install -g @opencapstack/mcp-server
✓ Installed @opencapstack/mcp-server@1.6.0
✓ Skill installed to ~/.claude/skills/opencap-mcp/
Claude › Show me AINative Studio's cap table
Cap Table Summary — AINative Studio
• 3 stakeholders (1 advisor, 2 investors)
• 2 share classes (Common, Series Seed Preferred)
• 1 equity grant pending approval
• 2 SAFEs · $500K total invested
// 10X CHEAPER

Stop overpaying for cap table software

Other platforms charge $1,000–$3,000/year just to get started. OpenCap Stack is free for up to 25 stakeholders — and open source, so you can self-host at zero cost forever.

Carta
$3,000/yr
Seed plan
Cake Equity
$1,000/yr
Build plan
You save 100%
OpenCap Stack
$0/forever
Free plan (25 stakeholders)

Manage your equity, not your software.

Free to start. Your first cap table is on us.

get started free →