Simmer MCP server

Simmer SDK

Simmer is the leading prediction market harness for AI agents. Autonomous agents place trades on venues like Polymarket, Kalshi and Hyperliquid through a unified API — with self-custody wallets, safety rails, and smart context.

• AI-native trading platform — designed for autonomous agents, with full support for manual trading too. Users install trading skills and let their agents trade autonomously.
• $SIM simulated trading — paper-trade with virtual currency before risking real funds.
• Multi-venue — trade Polymarket, Kalshi and Hyperliquid through one unified API.

What's in this repo

Installation

pip install simmer-sdk

Get your API key from simmer.markets/dashboard.

Quick Start

OpenClaw Skill Pattern (recommended)

Most Simmer users run trading skills inside OpenClaw. The standard pattern uses a lazy singleton client and reads config from environment variables:

import os
from simmer_sdk import SimmerClient

SKILL_SLUG = "my-skill-slug"   # Must match your ClawHub slug
TRADE_SOURCE = f"sdk:{SKILL_SLUG}"

_client = None
def get_client(live: bool = False):
    global _client
    if _client is None:
        venue = os.environ.get("TRADING_VENUE", "sim")
        # `live` controls paper vs real execution and is a constructor arg, not a
        # per-trade flag. live=False => paper preview (no real order placed).
        _client = SimmerClient(api_key=os.environ["SIMMER_API_KEY"], venue=venue, live=live)
    return _client

def run(live: bool = False):
    client = get_client(live)

    # Find markets. Unfiltered browse is windowed to the newest ~1,000 active
    # markets — filter with sort="volume", q="...", or tags="..." to reach the rest.
    markets = client.get_markets(status="active", sort="volume", limit=20)

    # Get trading context (safeguards, slippage, conflict detection)
    ctx = client.get_market_context(markets[0].id)

    # Trade — always tag source and skill_slug
    if not ctx.conflict and ctx.recommended_action != "hold":
        result = client.trade(
            market_id=markets[0].id,
            side="yes",
            

Set environment variables:

export SIMMER_API_KEY=sk_live_...
export TRADING_VENUE=sim            # sim | polymarket | kalshi
export WALLET_PRIVATE_KEY=0x...    # Required for Polymarket self-custody

Default to dry-run. Skills should require --live to execute real trades. Paper-trade with $SIM until your edge is consistent, then graduate to real money.

Raw SDK

For developers building custom integrations:

from simmer_sdk import SimmerClient

client = SimmerClient(api_key="sk_live_...")

# Browse markets (unfiltered browse is windowed to the newest ~1,000 active
# markets — use sort="volume", q="...", or tags="..." for discovery)
markets = client.get_markets(sort="volume", limit=10)
for m in markets:
    print(f"{m.question}: {m.current_probability:.1%}")

Shortened. The full README is on GitHub.