Developer Platform

Build on CapSign

Full API access to equity, governance, treasury, and documents. Integrate CapSign into your workflows — or let your AI agents do it.

Platform APIs

Everything you need to integrate

A complete API surface for managing organizations programmatically — built for both traditional integrations and autonomous AI agents.

RESTful API
Full CRUD operations for every resource — organizations, equity, documents, governance, treasury, and more.
Webhooks
Real-time event notifications for proposal votes, document signatures, equity transfers, and all platform activity.
OAuth 2.0 & API Keys
Industry-standard authentication with granular permission scopes. Role-based access for teams and agents.
AI Agent Support
Purpose-built agent role with scoped permissions. Agents can propose actions but governance controls execution.

Quick Start

A few lines of code

Manage organizations, issue equity, run governance, and more — all from your codebase or your AI agent.

Your ApplicationTypeScript
import { CapSign } from '@capsign/sdk';

const client = new CapSign({
  apiKey: process.env.CAPSIGN_API_KEY,
});

// Create an organization
const org = await client.organizations.create({
  name: 'Acme Corp',
  entityType: 'corporation',
  jurisdiction: 'DE',
});

// Issue equity
const shares = await client.equity.issue({
  orgId: org.id,
  class: 'Common Stock',
  shares: 10_000_000,
  parValue: 0.0001,
});

// Create a governance proposal
const proposal = await client.governance.propose({
  orgId: org.id,
  type: 'board_resolution',
  title: 'Approve Series A',
  description: 'Authorize issuance of Series A Preferred',
  votingPeriod: '7d',
});
Your AI AgentTypeScript
// AI Agent integration
const client = new CapSign({
  apiKey: process.env.AGENT_API_KEY,
  role: 'agent', // Scoped permissions
});

// Agent proposes a treasury action
const proposal = await client.governance.propose({
  orgId: 'org_abc123',
  type: 'treasury_transfer',
  amount: 50_000,
  recipient: 'vendor_xyz',
  reason: 'Q1 vendor payment - auto-detected from invoice',
});
// → Requires human approval before execution

// Agent generates monthly report
const report = await client.reports.generate({
  orgId: 'org_abc123',
  type: 'investor_update',
  period: '2026-Q1',
});

Resources

Everything you need to get started

Ready to build?

Get your API key and start integrating CapSign into your applications today.