majiayu000 Manifold Markets Trading Skill
Real, working methods to bet on Manifold Markets using Mana (play money that can be donated to charity).
Setup
Get your API key from: https://manifold.markets/profile (API key section)
import os
import requests
API_URL = "https://api.manifold.markets/v0"
API_KEY = os.getenv("MANIFOLD_API_KEY")
def headers():
return {
"Authorization": f"Key {API_KEY}",
"Content-Type": "application/json"
}
Search Markets
def search_markets(query: str, limit: int = 10):
"""Search for markets"""
r = requests.get(f"{API_URL}/search-markets", params={
"term": query,
"limit": limit,
"filter": "open",
"sort": "liquidity"
})
r.raise_for_status()
markets = r.json()
for m in markets[:5]:
prob = m.get("probability", 0.5)
print(f"\nMarket: {m['question']}")
print(f"ID: {m['id']}")
print(f"Probability: {prob*100:.1f}%")
print(f"URL: {m.get('url', '')}")
return markets
markets = search_markets("AI")
Get Market by ID or Slug
def get_market(id_or_slug: str):
"""Get market details"""
# Try by ID first
r = requests.get(f"{API_URL}/market/{id_or_slug}")
if r.status_code == 404:
# Try by slug
r = requests.get(f"{API_URL}/slug/{id_or_slug}")
r.raise_for_status()
return r.json()
market = get_market("will-gpt5-be-released-before-2025")
print(f"Question: {market['question']}")
print(f"Probability: {market.get('probability', 0.5)*100:.1f}%")
Place a Bet
def place_bet(
market_id: str,
amount: int, # Mana amount to bet
outcome: str = "YES", # "YES" or "NO"
limit_prob: float = None # Optional limit order probability
):
"""
Place a bet on Manifold
Args:
market_id: The market ID (not slug!)
amount: Amount of Mana to bet
outcome: "YES" or "NO"
limit_prob: Optional - if set, creates a limit order at this probability
"""
payload = {
"contractId": market_id,
"amount": amount,
"outcome": outcome
}
if limit_prob is not None:
payload["limitProb"] = limit_prob
r = requests.post(f"{API_URL}/bet", headers=headers(), json=payload)
r.raise_for_status()
result = r.json()
print(f"Bet placed!")
print(f"Shares: {result.get('shares', 0):.2f}")
print(f"Probability after: {result.get('probAfter', 0)*100:.1f}%")
return result
# Market bet - buys at current price
result = place_bet(
market_id="abc123",
amount=100, # 100 Mana
outcome="YES"
)
# Limit order - only fills at 40% or below
result = place_bet(
market_id="abc123",
amount=100,
outcome="YES",
limit_prob=0.40
)
Cancel Bet (Limit Orders Only)
def cancel_bet(bet_id: str):
"""Cancel a limit order"""
r = requests.post(f"{API_URL}/bet/cancel/{bet_id}", headers=headers())
r.raise_for_status()
return True
cancel_bet("bet123")
Sell Shares
def sell_shares(
market_id: str,
outcome: str = "YES",
shares: float = None # None = sell all
):
"""
Sell shares in a market
Args:
market_id: The market ID
outcome: "YES" or "NO" - which shares to sell
shares: Number of shares to sell (None = all)
"""
payload = {
"contractId": market_id,
"outcome": outcome
}
if shares is not None:
payload["shares"] = shares
r = requests.post(f"{API_URL}/market/{market_id}/sell", headers=headers(), json=payload)
r.raise_for_status()
return r.json()
# Sell all YES shares
sell_shares("abc123", "YES")
# Sell specific amount
sell_shares("abc123", "YES", shares=50.0)
Get Your Bets
def get_my_bets(market_id: str = None):
"""Get your bets"""
params = {}
if market_id:
params["contractId"] = market_id
r = requests.get(f"{API_URL}/bets", headers=headers(), params=params)
r.raise_for_status()
bets = r.json()
for b in bets[:10]:
print(f"Bet: {b['outcome']} {b['amount']}M @ {b.get('probBefore', 0)*100:.0f}%")
return bets
bets = get_my_bets()
Get Your Positions
def get_positions():
"""Get current positions across all markets"""
# Get user info first
r = requests.get(f"{API_URL}/me", headers=headers())
r.raise_for_status()
user = r.json()
# Get bets to calculate positions
r = requests.get(f"{API_URL}/bets", headers=headers(), params={"limit": 1000})
bets = r.json()
# Aggregate by market
positions = {}
for bet in bets:
mid = bet["contractId"]
if mid not in positions:
positions[mid] = {"yes": 0, "no": 0, "invested": 0}
if bet["outcome"] == "YES":
positions[mid]["yes"] += bet.get("shares", 0)
else:
positions[mid]["no"] += bet.get("shares", 0)
if not bet.get("isSold", False):
positions[mid]["invested"] += bet["amount"]
return positions, user.get("balance", 0)
positions, balance = get_positions()
print(f"Balance: {balance} Mana")
for mid, pos in positions.items():
if pos["yes"] > 0 or pos["no"] > 0:
print(f"Market {mid}: YES={pos['yes']:.1f}, NO={pos['no']:.1f}")
Get Balance
def get_balance():
"""Get your Mana balance"""
r = requests.get(f"{API_URL}/me", headers=headers())
r.raise_for_status()
user = r.json()
return user.get("balance", 0)
balance = get_balance()
print(f"Balance: {balance} Mana")
Complete Trading Bot Example
#!/usr/bin/env python3
"""
Manifold arbitrage bot - finds mispriced markets
"""
import os
import time
import requests
API_URL = "https://api.manifold.markets/v0"
API_KEY = os.getenv("MANIFOLD_API_KEY")
def h():
return {"Authorization": f"Key {API_KEY}", "Content-Type": "application/json"}
def search(query):
r = requests.get(f"{API_URL}/search-markets",
params={"term": query, "limit": 20, "filter": "open"})
return r.json()
def bet(market_id, amount, outcome, limit_prob=None):
payload = {"contractId": market_id, "amount": amount, "outcome": outcome}
if limit_prob:
payload["limitProb"] = limit_prob
r = requests.post(f"{API_URL}/bet", headers=h(), json=payload)
return r.json()
def get_balance():
r = requests.get(f"{API_URL}/me", headers=h())
return r.json().get("balance", 0)
# Strategy: Buy extreme probabilities (likely to revert)
MIN_LIQUIDITY = 1000 # Only trade liquid markets
while True:
try:
balance = get_balance()
print(f"\nBalance: {balance} Mana")
# Search trending markets
markets = search("2024")
for m in markets:
prob = m.get("probability", 0.5)
liquidity = m.get("totalLiquidity", 0)
if liquidity < MIN_LIQUIDITY:
continue
# Buy YES on very low probability (< 10%)
if prob < 0.10:
print(f"LOW: {m['question'][:50]} at {prob*100:.1f}%")
if balance > 50:
bet(m["id"], 50, "YES", limit_prob=0.15)
# Buy NO on very high probability (> 90%)
elif prob > 0.90:
print(f"HIGH: {m['question'][:50]} at {prob*100:.1f}%")
if balance > 50:
bet(m["id"], 50, "NO", limit_prob=0.85)
time.sleep(300) # Check every 5 minutes
except Exception as e:
print(f"Error: {e}")
time.sleep(60)
Multiple Choice Markets
def bet_multiple_choice(market_id: str, answer_id: str, amount: int):
"""Bet on a multiple choice market"""
payload = {
"contractId": market_id,
"amount": amount,
"answerId": answer_id
}
r = requests.post(f"{API_URL}/bet", headers=headers(), json=payload)
r.raise_for_status()
return r.json()
# Get market with answers
market = get_market("who-will-win-2024-election")
for answer in market.get("answers", []):
print(f"{answer['text']}: {answer['probability']*100:.1f}% (ID: {answer['id']})")
# Bet on specific answer
bet_multiple_choice("market123", "answer456", 100)
Create a Market
def create_market(
question: str,
description: str = "",
close_time: int = None, # Unix timestamp
initial_prob: float = 0.5,
ante: int = 100 # Initial liquidity
):
"""Create a new binary market"""
payload = {
"outcomeType": "BINARY",
"question": question,
"description": description,
"initialProb": int(initial_prob * 100),
"ante": ante
}
if close_time:
payload["closeTime"] = close_time * 1000 # Milliseconds
r = requests.post(f"{API_URL}/market", headers=headers(), json=payload)
r.raise_for_status()
return r.json()
# Create market
new_market = create_market(
question="Will it rain tomorrow in NYC?",
initial_prob=0.3,
ante=100
)
print(f"Created: {new_market['url']}")
Important Notes
- Mana is play money - Can be donated to charity
- No limit on bets - Unlike real money markets
- Market maker AMM - Prices move based on bets
- Limit orders - Use
limitProbfor better prices - API rate limits - Be gentle, ~60 requests/minute
- Shares ≠ Mana - Shares vary based on probability