paperclob-mcp

MCP server for PaperBook — a Polymarket-wire-compatible paper CLOB plus the honest simulator: replay your strategy against recorded real Polymarket books and get a founded verdict (real_edge / phantom / no_edge / inconclusive) instead of a flattering paper PnL.

Every other paper-trading sim fills you at the prices you see. This one fills you at the prices that would actually have filled — after latency, against the tape as it was at arrival. The difference (adverse selection) is where most backtested "edges" die.

Install

pip install paperclob-mcp

Claude Code

claude mcp add paperclob -- paperclob-mcp

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "paperclob": {
      "command": "paperclob-mcp"
    }
  }
}

Tools

Live paper CLOB (paper money — registering grants $10,000; no real funds):

Honest simulator (recorded real tape, fillable-lens grading):

Credentials

Account and session secrets are held in the MCP process's memory only — never logged, never returned to the model. To reuse a live account across restarts, set in the server environment:

PAPERCLOB_API_KEY / PAPERCLOB_SECRET / PAPERCLOB_PASSPHRASE

PAPERCLOB_BASE_URL overrides the API host (default https://paperclob.com).

The verdict, honestly

get_sim_report returns three lenses, each edge_real = realized win rate − avg price paid ($-weighted): paper (the book you saw — flattering), honest_persist, and honest_fillable (the lens — the price you could actually transact). The verdict is decided on honest_fillable with a 40-fill gate. A green verdict is necessary, not sufficient, for real edge.

The always-current API contract is at https://paperclob.com/llms-full.txt. Paper money only; not affiliated with Polymarket; nothing here is financial advice.