Open source & OCTA v2.0 aligned

Cap table management
built for founders

OpenCap Stack gives early-stage startups an open-source foundation for equity management — from seed-stage SAFE notes through Series A cap tables, 409A valuations, and AI-native tooling via MCP.

60+
API endpoints
29
MCP tools
100%
OCTA v2.0 aligned
Free
MIT licensed

See your cap table at a glance

Real-time ownership, share classes, and equity events — always up to date.

A
AcmeCo
HealthyLast updated just now
Total Raised
$2.1M
Diluted Shares
10.0M
Stakeholders
8
Share Price
$0.21
StakeholderTypeSharesOwnershipStatus
SR
Sarah Rodriguez
Founder4,200,000
42%
Active
TK
Tom Kim
Founder3,800,000
38%
Active
SR
Seed Round
Investor1,500,000
15%
Active
OP
Option Pool
ESOP500,000
5%
Reserved

10x cheaper than Carta or Cake Equity

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)

Trusted by founders building the future

Real companies managing real equity on OpenCap Stack.

“We manage our entire cap table — stakeholders, share classes, SAFEs, and equity grants — through OpenCap Stack. The MCP integration means I can query our ownership structure directly from Claude while working on fundraising docs.”
TM
Toby Morning
Founder & CEO, AINative Studio
“Switching from spreadsheets to OpenCap Stack was seamless. The employee portal gives our team full visibility into their equity without us having to field constant questions. And it's free — we were quoted $3,000/year by other platforms.”
C
Careers
Early-stage startup
Open source on GitHub
SOC 2 compliant infrastructure
OCTA v2.0 aligned
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

Everything your equity stack needs

A complete platform for managing equity from your first SAFE through complex cap table events — structured, auditable, and interoperable.

Cap Table Management

Full OCTA v2.0 schema compliance. Issue, track, and audit every share class, stakeholder, and equity event with industry-standard data structures.

SAFE Notes & Convertible Instruments

Model SAFE notes and convertible notes from first principles. Track conversion triggers, discount rates, valuation caps, and pro-rata rights across every round.

Dilution Modeling & Waterfall Analysis

Run scenario-based dilution models and waterfall analyses. Understand how new rounds, option pool refreshes, and conversion events affect every stakeholder.

409A Valuations & Vesting

Support your 409A valuation process with structured data exports. Configure cliff, linear, and custom vesting schedules with full audit trails for option grants.

MCP Server — AI-Native Cap Table

Manage your cap table from Claude, Cursor, or any MCP client. Query stakeholders, issue equity, and run dilution scenarios — all in natural language.

Document Storage & Audit Trail

Store board consents, stock agreements, and option grants with full version history. Every change is tracked, timestamped, and attributable.

REST API · Bearer auth · JSON
GET /api/v1/stakeholders
POST /api/v1/equity-grants
GET /api/v1/share-classes
POST /api/v1/safes
GET /api/v1/valuations/latest
# 60+ endpoints · Full OpenAPI spec
REST API

Build on the cap table API

60+ REST endpoints with JWT auth, rate limiting, and a full OpenAPI 3.0 spec. Integrate cap table data into your own tools, workflows, and AI agents.

Open-Cap-Stack/opencapstack

Open source. Self-hostable.
Free to start.

MIT licensed. Run it on your own infrastructure or use our managed cloud. Your equity data stays yours.

MIT LicenseSelf-hostableOCTA v2.0Docker ready

Ready to get started?

Set up your cap table in minutes. No credit card required for the free plan.