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
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.