Documentation

Breakpoint Engine is the OPM (Option Pricing Method) valuation engine your AI agents work with — explore, pause, and mutate capital structure in real time. It connects to ChatGPT, Claude, Cursor, and any MCP-capable client as a Model Context Protocol server: hosted cloud connector or open-source local build.

Connect your AI assistant

Same cloud endpoint for every client: https://cloud.breakpointengine.com/mcp (Streamable HTTP + Auth0 OAuth). Create an account, buy a pack, then follow the guide for your host:

• ChatGPT — custom MCP connector (Developer mode). Successor to ChatGPT plugins.
• Claude — claude.ai custom connectors, Claude Code CLI, and Claude Desktop.
• Cursor & VS Code — cloud HTTP MCP (mcp.json + Connect / OAuth) or private local Docker stdio.

Overview of both paths: MCP connectors · Get started.

Use the engine

• Cap table input format — the JSON your agent sends in: preferred terms, common, options, warrants, debt, and market assumptions, with a worked example.
• Tool reference — all opm_* MCP tools, resources, streaming, and conventions.
• Methodology — what the engine computes and where judgment stays with you.
• Pricing — Round, Portfolio, and Practice work-unit packs; local build unmetered.

Machine-readable discovery

• /llms.txt and /llms-full.txt — agent briefs
• /.well-known/mcp.json — MCP server discovery
• /pricing.json and /api/site.json — structured data
• Cloud MCP endpoint: https://cloud.breakpointengine.com/mcp (MCP Streamable HTTP, OAuth 2.1)

Frequently asked questions

Is there a Breakpoint Engine ChatGPT plugin?

ChatGPT plugins were retired by OpenAI. Breakpoint Engine connects to ChatGPT as a custom MCP connector instead — same capability, current mechanism. See the ChatGPT setup guide at /docs/chatgpt.

What is Breakpoint Engine?

A stateless financial-engineering engine for private-company equity valuation — classic OPM forwardsolve, equity and volatility backsolve, breakpoint schedules, and interactive scenario transactions — exposed to AI agents over the Model Context Protocol (MCP).

Does Breakpoint Engine store my cap table?

No. The engine is computation, not custody. Cap tables are passed as tool inputs, computed on, and never retained. Scenario transactions are ephemeral and process-local.

Is the output a 409A valuation opinion?

No. Breakpoint Engine supplies the math under a valuation — breakpoints, allocations, backsolves. Assumptions, judgment, and any professional opinion remain with you or your valuation firm.

How do I connect it to my AI assistant?

Add the cloud MCP connector (https://cloud.breakpointengine.com/mcp, OAuth sign-in) in ChatGPT, Claude, or Cursor — or build the open-source engine locally and connect over stdio. Per-client guides: /docs/chatgpt, /docs/claude, /docs/cursor.