Simmer Market Maker

Places GTC limit orders on both sides (bid/ask) of liquid Polymarket markets. Finds active markets with >$10k 24h volume, mid-range prices, and ample time to...

Security Scan

The skill's code and instructions match a Polymarket market‑making purpose, but there are manifest/metadata inconsistencies and a few provenance gaps you should verify before trusting live trades or providing an API key.

Purpose & Capability

The SKILL.md and market_maker.py implement a Polymarket market‑maker using a Simmer SDK and a Polymarket CLOB endpoint; the required simmer SDK and SIMMER_API_KEY are coherent with that purpose. However, the top-level registry metadata in the evaluation header claimed no required env vars while clawhub.json and SKILL.md both require SIMMER_API_KEY — a manifest inconsistency that reduces trust in the package metadata.

Instruction Scope

Runtime instructions and code stay within the stated domain: fetching markets, computing midpoints (via CLOB endpoint), cancelling and placing GTC orders, and managing a small config. There are no instructions to read unrelated host files, crawl shell history, or exfiltrate arbitrary data to unknown endpoints. The only network targets are the Simmer API (via simmer-sdk/_request) and Polymarket CLOB at clob.polymarket.com.

Install Mechanism

No install script is included (instruction-only install), and required dependency is a pip package (simmer-sdk) — which is an expected delivery method. There are no arbitrary downloads or extract actions in the skill files. Still, the package lacks a homepage and the owner/publish provenance is weak; you should verify the simmer-sdk package source and integrity before installing.

Credentials

The skill requires a single API key (SIMMER_API_KEY) and an optional TRADING_VENUE — both reasonable for a trading bot. The concern is the manifest mismatch: some registry metadata claimed no required env vars while the bundled clawhub.json and SKILL.md require SIMMER_API_KEY. That mismatch could cause users to miss that they're exposing an API key to this code. Also confirm what rights the SIMMER API key grants (trading vs read-only) before using it for live trades.

Persistence & Privilege

The skill is not flagged always:true and is user-invocable only; it does not request system‑wide privileges. It uses load_config/update_config to manage its own config files (normal). Autonomous invocation is allowed by default but not combined here with other high‑risk flags.

What to consider before installing

This skill appears to implement what it claims (a Polymarket market maker) and only needs a Simmer API key and the simmer-sdk package — both reasonable for trading. However: 1) the package lacks an external homepage and the registry metadata is inconsistent about required environment variables, so verify the source and trust the owner before installing; 2) inspect the simmer-sdk package (where network/trade calls are implemented) to confirm it doesn't do unexpected work or store your API key insecurely; 3) check what permissions the SIMMER_API_KEY grants (ensure it isn't broader than necessary, e.g., doesn't grant withdrawals); 4) run in paper/sim mode first (TRADING_VENUE=sim and --dry run) and review logs; 5) consider running in an isolated environment and rotate the API key after initial tests. If you want, I can list the specific lines that access external endpoints and the exact manifest mismatches to help you audit further.

Polymarket Market Maker

A market-making strategy that places GTC (Good-Till-Cancelled) limit orders on both sides of liquid Polymarket prediction markets, capturing the bid/ask spread.

Strategy

1. Market Selection: Finds active markets with:

   • 24h volume > $10,000 (liquid enough to fill)
   • Price (YES probability) between 0.15 and 0.85 (avoids near-certain outcomes)
   • Resolves > 4 hours away (enough time to get fills)
   • No taker fees (is_paid=False) — 10% fee kills the edge

2. Pricing: Fetches the live CLOB midpoint for each market and quotes:

   • YES buy limit at mid - 0.02 (2¢ below mid)
   • NO buy limit at (1 - mid) - 0.02 (2¢ below NO mid)

3. Order Management: Cancels existing open orders before placing new ones each run.

4. Limits: Max $5 per order, max 3 markets per run.

Requirements

Environment variables (required):

Variable	Required	Description
SIMMER_API_KEY	✅ Yes	Your Simmer API key — get it at simmer.markets/dashboard → SDK tab
TRADING_VENUE	Optional	polymarket (default) or sim for paper trading with virtual $SIM

Python dependency: simmer-sdk — install with pip install simmer-sdk

Setup

export SIMMER_API_KEY=sk_live_...         # required
export TRADING_VENUE=sim                   # optional: paper mode with $SIM
pip install simmer-sdk

Usage

# Dry run (default)
python market_maker.py

# Live trading
python market_maker.py --live

# Show current positions
python market_maker.py --positions

# Show config
python market_maker.py --config

# Set config
python market_maker.py --set max_order_usd=10.0

Config (env vars)

Env Var	Default	Description
SIMMER_MM_MAX_ORDER_USD	5.0	Max USD per limit order
SIMMER_MM_MAX_MARKETS	3	Max markets per run
SIMMER_MM_MIN_VOL_24H	10000	Min 24h volume filter
SIMMER_MM_SPREAD_OFFSET	0.02	How far below mid to quote (2¢)
SIMMER_MM_MIN_PRICE	0.15	Min YES price to consider
SIMMER_MM_MAX_PRICE	0.85	Max YES price to consider
SIMMER_MM_MIN_HOURS_TO_RESOLVE	4	Min hours to resolution