polymarket-mert-sniper

SKILL.md

---
name: polymarket-mert-sniper
description: Near-expiry conviction trading on Polymarket. The skill scans markets in their final minutes, filters for strongly-skewed splits (60/40+), and places bounded trades against the under-priced side. Defaults — $10 max per trade, 5 trades/run, 8-minute expiry window, dry-run unless `--live`.
metadata:
  author: Simmer (@simmer_markets)
  version: "1.3.6"
  displayName: Mert Sniper
  difficulty: advanced
  attribution: Strategy inspired by @mert — https://x.com/mert/status/2020216613279060433
---
# Mert Sniper

Near-expiry conviction trading on Polymarket. The skill scans markets in their final minutes of pricing, filters for strongly-skewed splits, and places bounded trades against the under-priced side.

> 🚨 **Framework, not a production trading system.** Read [DISCLAIMER.md](./DISCLAIMER.md) before connecting to a wallet with real funds. Dry-run is the default; `--live` is required for any real-USDC trade. Defaults: $10 max per trade, 60/40 split minimum, 8-minute expiry window, 5 trades per scan cycle — adjust deliberately before scaling.

> **This is a template.** The default logic (expiry + split filter) is a starting point — remix it with your own filters, timing rules, or market selection criteria. The skill handles all the plumbing (market discovery, trade execution, safeguards). Your agent provides the alpha.

> Strategy attribution: [@mert](https://x.com/mert/status/2020216613279060433) — see source thread for the original methodology (topic filter, near-expiry timing, strong-split entry).

> **News-recency veto.** Optional guard that checks Simmer's macro-news schedule before order placement and skips matching news-resolution markets inside the first 30 seconds after CPI, BLS jobs/unemployment, FOMC, nonfarm payrolls, or quarterly earnings events. Continuous-feed crypto Up/Down markets are not blocked by this veto. Default is off until internal positive backfill coverage exists; set `enable_news_veto=true` to enable it.

## When to Use This Skill

Use this skill when the user wants to:
- Trade markets that are about to resolve (last-minute conviction bets)
- Filter by topic (e.g. only SOL/crypto markets)
- Cap bet size (e.g. never more than $10)
- Only trade when odds are strongly skewed (e.g. 60/40 or better)
- Run an automated expiry-sniping strategy

## Setup Flow

1. **Install the Simmer SDK**
   ```bash
   pip install simmer-sdk
   ```

2. **Ask for Simmer API key**
   - Get it from simmer.markets/dashboard -> SDK tab
   - Store in environment as `SIMMER_API_KEY`

3. **Ask for wallet private key** (required for live trading)
   - This is the private key for their Polymarket wallet (the wallet that holds USDC)
   - Store in environment as `WALLET_PRIVATE_KEY`
   - The SDK uses this to sign orders client-side automatically — no manual signing needed

4. **Ask about settings** (or confirm defaults)
   - Market filter: Which markets to scan (default: all)
   - Max bet: Maximum per trade (default $10)
   - Expiry window: How close to resolution (default 8 minutes)
   - Min split: Minimum odds skew (default 60/40)

5. **Save settings to config.json or environment variables**

## Configuration

| Setting | Environment Variable | Default | Description |
|---------|---------------------|---------|-------------|
| Market filter | `SIMMER_MERT_FILTER` | (all) | Tag or keyword filter (e.g. `solana`, `crypto`) |
| Max bet | `SIMMER_MERT_MAX_BET_USD` | 10.00 | Maximum USD per trade |
| Expiry window | `SIMMER_MERT_EXPIRY_MINUTES` | 8 | Only trade markets resolving within N minutes |
| Min split | `SIMMER_MERT_MIN_SPLIT` | 0.60 | Only trade when YES or NO >= this (e.g. 0.60 = 60/40) |
| Max trades/run | `SIMMER_MERT_MAX_TRADES_PER_RUN` | 5 | Maximum trades per scan cycle |
| Smart sizing % | `SIMMER_MERT_SIZING_PCT` | 0.05 | % of balance per trade |
| Fee buffer | `SIMMER_MERT_FEE_BUFFER` | 0.02 | Extra alpha required above entry fee; only applies when `SIMMER_MERT_MIN_EDGE` is set |
| Declared edge | `SIMMER_MERT_MIN_EDGE` | 0.00 | Your signal's claimed edge above market price (probability units). At 0 (default): fee is logged but gate is advisory only. Set to X to block trades where entry fee > X — e.g. `0.05` requires your signal to clear at least 5¢ above market after fees |
| News-recency veto | `SIMMER_MERT_ENABLE_NEWS_VETO` | false | Skip matching news-resolution markets within 30s of scheduled macro/news releases |

## Quick Commands

```bash
# Check account balance and positions
python scripts/status.py

# Detailed position list
python scripts/status.py --positions
```

**API Reference:**
- Base URL: `https://api.simmer.markets`
- Auth: `Authorization: Bearer $SIMMER_API_KEY`
- Portfolio: `GET /api/sdk/portfolio`
- Positions: `GET /api/sdk/positions`

## Running the Skill

```bash
# Dry run (default -- shows opportunities, no trades)
python mert_sniper.py

# Execute real trades
python mert_sniper.py --live

# Filter to specific markets
python mert_sniper.py --filter solana

# Custom expiry window (5 minutes)
python mert_sniper.py --expiry 5

# With smart position sizing (uses portfolio balance)
python mert_sniper.py --live --smart-sizing

# Check positions only
python mert_sniper.py --positions

# View config
python mert_sniper.py --config

# Disable safeguards (not recommended)
python mert_sniper.py --no-safeguards
```

## How It Works

Each cycle the script:
1. Fetches active markets from Simmer API (optionally filtered by tag/keyword)
2. Filters to markets resolving within the expiry window (default 8 minutes)
3. Checks the price split -- only trades when one side >= min_split (default 60%)
4. Determines direction: backs the favored side (higher probability)
5. **Fee logging**: prints entry-fee cost per market (`POLY_FEE_RATE_CRYPTO × p × (1-p)`, entry only — redemption is free). If `SIMMER_MERT_MIN_EDGE > 0`, gates out markets where declared edge < entry fee + buffer
6. **Safeguards**: Checks context for flip-flop warnings, slippage, market status
7. **Execution**: Places trade on the favored side, capped at max bet
8. Reports summary of scanned, filtered, and traded markets

## Example Output

```
🎯 Mert Sniper - Near-Expiry Conviction Trading
==================================================

  [DRY RUN] No trades will be executed. Use --live to enable trading.

  Configuration:
  Filter:        solana
  Max bet:       $10.00
  Expiry window: 8 minutes
  Min split:     60/40
  Max trades:    5
  Smart sizing:  Disabled
  Safeguards:    Enabled

  Fetching markets (filter: solana)...
  Found 12 active markets

  Markets expiring within 8 minutes: 2

  SOL highest price on Feb 10?
     Resolves in: 1m 34s
     Split: YES 72% / NO 28%
     Side: YES (72% >= 60%)
     [DRY RUN] Would buy $10.00 on YES

  Summary:
  Markets scanned: 12
  Near expiry:     2
  Strong split:    1
  Trades executed: 0

  [DRY RUN MODE - no real trades executed]
```

## Troubleshooting

**"No markets found"**
- Check your filter -- try without a filter first
- Markets may not be available (check simmer.markets)

**"No markets expiring within window"**
- Increase expiry window: `--expiry 10` (10 minutes)
- Or run more frequently (cron every minute)

**"Split too narrow"**
- Lower the min split: `--set min_split=0.55`
- This trades more often but with less conviction

**"Resolves in: 17h" on 15-min markets**
- Polymarket's `endDate` is the event-level end-of-day, not the individual market close time
- For 15-min crypto markets (e.g. "BTC Up or Down - Feb 8, 11PM ET"), the actual close time is in the question text but not in the API
- This is a Polymarket data limitation — widen the expiry window (`--expiry 1080`) as a workaround, or use the split filter to find conviction opportunities regardless of timing

**"External wallet requires a pre-signed order"**
- `WALLET_PRIVATE_KEY` is not set in the environment
- The SDK signs orders automatically when this env var is present — no manual signing code needed
- Fix: `export WALLET_PRIVATE_KEY=0x<your-polymarket-wallet-private-key>`
- Do NOT attempt to sign orders manually or modify the skill code — the SDK handles it

**"Balance shows $0 but I have funds on Polygon"**
- Polymarket V2 (live 2026-04-28) uses **pUSD** (PolyUSD, 1:1 backed by USDC.e). If your wallet holds USDC.e, migrate at [simmer.markets/dashboard](https://simmer.markets/dashboard?ref=sdk-skill&utm_campaign=sdk-skill) with one click (~30s)
- If you bridged native USDC (Circle), swap to USDC.e first, then migrate to pUSD
- Full migration guide: [docs.simmer.markets/v2-migration](https://docs.simmer.markets/v2-migration)

**"API key invalid"**
- Get new key from simmer.markets/dashboard -> SDK tab