Trade Polymarket Combos and Multi-Leg Parlays with Kairos

A Polymarket combo, also called a parlay, is a single position that combines bets on multiple independent prediction markets. Instead of buying YES on three separate markets individually, you buy a combo that pays off only if all three resolve YES — which means the price is lower and the potential payout is higher. Kairos routes combo orders through the Polymarket RFQ gateway, handles all the position tracking, and gives you clean endpoints to quote, execute, cash out, or redeem.

All combo endpoints require the API key triple (X-Client-Id / X-Api-Key / X-Api-Secret). Base URL: https://execution.kairos.trade.

How combos work

A combo bundles two or more Polymarket markets into a single token. The combo resolves as a winner only if every leg resolves in the direction you chose. Because the combined probability is lower than any individual leg, combo contracts trade at a significant discount — making them a capital-efficient way to express high-conviction multi-market views. Example: A combo on [Fed cuts in Q1] YES × [BTC above $100k by Feb] YES might price at 0.08 when the individual markets trade at 0.40 and 0.20 respectively.

Step 1 — Quote a combo

Always get a quote before executing. POST /combo/quote prices the combo via the RFQ gateway without committing any capital.

curl -X POST "https://execution.kairos.trade/combo/quote" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "legs": [
      {
        "market_id": "0xabc123",
        "outcome": "YES"
      },
      {
        "market_id": "0xdef456",
        "outcome": "YES"
      },
      {
        "market_id": "0xghi789",
        "outcome": "NO"
      }
    ],
    "size": 1000
  }'

import os
import httpx

API_HEADERS = {
    "X-Client-Id": os.environ["KAIROS_CLIENT_ID"],
    "X-Api-Key": os.environ["KAIROS_API_KEY"],
    "X-Api-Secret": os.environ["KAIROS_API_SECRET"],
}

payload = {
    "legs": [
        {"market_id": "0xabc123", "outcome": "YES"},
        {"market_id": "0xdef456", "outcome": "YES"},
        {"market_id": "0xghi789", "outcome": "NO"},
    ],
    "size": 1000,
}

resp = httpx.post(
    "https://execution.kairos.trade/combo/quote",
    json=payload,
    headers=API_HEADERS,
)
quote = resp.json()
print(f"Combo price: {quote['price']} — Cost: {quote['cost_usdc']} USDC")

Example response:

{
  "quote_id": "cqt_5nRa1bWcXzY8",
  "legs": [
    {"market_id": "0xabc123", "outcome": "YES", "individual_price": 0.40},
    {"market_id": "0xdef456", "outcome": "YES", "individual_price": 0.20},
    {"market_id": "0xghi789", "outcome": "NO",  "individual_price": 0.55}
  ],
  "size": 1000,
  "price": 0.044,
  "cost_usdc": 44.00,
  "max_payout_usdc": 1000.00,
  "implied_probability": 0.044,
  "fee_usdc": 0.22,
  "quote_expires_at": "2025-01-15T14:24:05Z"
}

The quote_id is valid for a short window (typically 30–60 seconds). Pass it to POST /combo/execute to lock in this price without re-quoting.

Step 2 — Execute the combo

Pass the quote_id from the previous step to execute at the quoted price. Omit quote_id to let Kairos re-quote at market on the fly.

curl -X POST "https://execution.kairos.trade/combo/execute" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "quote_id": "cqt_5nRa1bWcXzY8",
    "legs": [
      {"market_id": "0xabc123", "outcome": "YES"},
      {"market_id": "0xdef456", "outcome": "YES"},
      {"market_id": "0xghi789", "outcome": "NO"}
    ],
    "size": 1000
  }'

resp = httpx.post(
    "https://execution.kairos.trade/combo/execute",
    json={
        "quote_id": quote["quote_id"],
        "legs": payload["legs"],
        "size": 1000,
    },
    headers=API_HEADERS,
)
position = resp.json()
combo_id = position["combo_id"]
print(f"Combo executed: {combo_id} at price {position['executed_price']}")

Example response:

{
  "combo_id": "cbo_7gXp2mNkQwY3",
  "quote_id": "cqt_5nRa1bWcXzY8",
  "legs": [
    {"market_id": "0xabc123", "outcome": "YES"},
    {"market_id": "0xdef456", "outcome": "YES"},
    {"market_id": "0xghi789", "outcome": "NO"}
  ],
  "size": 1000,
  "executed_price": 0.044,
  "cost_usdc": 44.00,
  "status": "open",
  "created_at": "2025-01-15T14:23:05Z"
}

Combo execution routes through Polymarket’s RFQ gateway. Execution is not guaranteed if the quote has expired or if the RFQ gateway cannot find a maker for the requested leg combination.

Step 3 — View your combo positions

List all your open and historical combo positions:

curl "https://execution.kairos.trade/combo/positions" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET"

resp = httpx.get(
    "https://execution.kairos.trade/combo/positions",
    headers=API_HEADERS,
)
positions = resp.json()["positions"]
for p in positions:
    print(p["combo_id"], p["status"], f"size={p['size']}", f"current_value={p.get('current_value_usdc')}")

Example response snippet:

{
  "positions": [
    {
      "combo_id": "cbo_7gXp2mNkQwY3",
      "legs": [
        {"market_id": "0xabc123", "outcome": "YES", "resolved": false},
        {"market_id": "0xdef456", "outcome": "YES", "resolved": false},
        {"market_id": "0xghi789", "outcome": "NO",  "resolved": false}
      ],
      "size": 1000,
      "entry_price": 0.044,
      "current_price": 0.071,
      "current_value_usdc": 71.00,
      "unrealized_pnl_usdc": 27.00,
      "status": "open"
    }
  ]
}

Cash out an open combo position

If you want to exit before all legs resolve, sell your combo back to pUSD via the cash-out flow.

Get a cash-out quote

curl -X POST "https://execution.kairos.trade/combo/cash-out-quote" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "combo_id": "cbo_7gXp2mNkQwY3",
    "size": 1000
  }'

resp = httpx.post(
    "https://execution.kairos.trade/combo/cash-out-quote",
    json={"combo_id": "cbo_7gXp2mNkQwY3", "size": 1000},
    headers=API_HEADERS,
)
co_quote = resp.json()
print(f"Cash-out price: {co_quote['price']} — Proceeds: {co_quote['proceeds_usdc']} USDC")

Example response:

{
  "cash_out_quote_id": "coq_2xKj9mQpLvT4",
  "combo_id": "cbo_7gXp2mNkQwY3",
  "size": 1000,
  "price": 0.069,
  "proceeds_usdc": 69.00,
  "fee_usdc": 0.35,
  "quote_expires_at": "2025-01-15T15:01:05Z"
}

Execute the cash-out

curl -X POST "https://execution.kairos.trade/combo/cash-out" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "cash_out_quote_id": "coq_2xKj9mQpLvT4",
    "combo_id": "cbo_7gXp2mNkQwY3",
    "size": 1000
  }'

resp = httpx.post(
    "https://execution.kairos.trade/combo/cash-out",
    json={
        "cash_out_quote_id": co_quote["cash_out_quote_id"],
        "combo_id": "cbo_7gXp2mNkQwY3",
        "size": 1000,
    },
    headers=API_HEADERS,
)
print(resp.json())

Example response:

{
  "combo_id": "cbo_7gXp2mNkQwY3",
  "status": "closed",
  "proceeds_usdc": 69.00,
  "closed_at": "2025-01-15T15:00:45Z"
}

Redeem a winning combo

When all legs resolve in your favour, redeem the combo to collect your pUSD payout:

curl -X POST "https://execution.kairos.trade/combo/redeem" \
  -H "X-Client-Id: $KAIROS_CLIENT_ID" \
  -H "X-Api-Key: $KAIROS_API_KEY" \
  -H "X-Api-Secret: $KAIROS_API_SECRET" \
  -H "Content-Type: application/json" \
  -d '{
    "combo_id": "cbo_7gXp2mNkQwY3"
  }'

resp = httpx.post(
    "https://execution.kairos.trade/combo/redeem",
    json={"combo_id": "cbo_7gXp2mNkQwY3"},
    headers=API_HEADERS,
)
result = resp.json()
print(f"Redeemed: {result['payout_usdc']} USDC")

Example response:

{
  "combo_id": "cbo_7gXp2mNkQwY3",
  "status": "redeemed",
  "payout_usdc": 1000.00,
  "redeemed_at": "2025-01-20T18:00:00Z"
}

Redemption is only available after all legs have resolved and the combo is in a winning state. Attempting to redeem a combo with unresolved or losing legs returns a 409 Conflict error.

Combo lifecycle overview

quote → execute → [monitor] → cash-out (early exit)
                            ↘ redeem (all legs WIN)
                            ↘ expires worthless (any leg loses)

Combo status values

Status	Meaning
`open`	All legs are still unresolved; position is live
`partial`	One or more legs have resolved correctly so far
`winning`	All legs resolved in your favour; ready to redeem
`losing`	At least one leg resolved against you; combo expires worthless
`closed`	You cashed out before full resolution
`redeemed`	You redeemed a winning combo and received payout

Full Python workflow

import httpx

BASE = "https://execution.kairos.trade"
HEADERS = {**API_HEADERS, "Content-Type": "application/json"}

LEGS = [
    {"market_id": "0xabc123", "outcome": "YES"},
    {"market_id": "0xdef456", "outcome": "YES"},
    {"market_id": "0xghi789", "outcome": "NO"},
]

# 1. Quote
quote = httpx.post(f"{BASE}/combo/quote", json={"legs": LEGS, "size": 1000}, headers=HEADERS).json()
print(f"Quote: {quote['price']} — expires {quote['quote_expires_at']}")

# 2. Execute
position = httpx.post(f"{BASE}/combo/execute", json={
    "quote_id": quote["quote_id"], "legs": LEGS, "size": 1000,
}, headers=HEADERS).json()
combo_id = position["combo_id"]
print(f"Position opened: {combo_id}")

# 3. Later — cash out
co_quote = httpx.post(f"{BASE}/combo/cash-out-quote", json={
    "combo_id": combo_id, "size": 1000,
}, headers=HEADERS).json()

result = httpx.post(f"{BASE}/combo/cash-out", json={
    "cash_out_quote_id": co_quote["cash_out_quote_id"],
    "combo_id": combo_id,
    "size": 1000,
}, headers=HEADERS).json()
print(f"Cashed out for {result['proceeds_usdc']} USDC")

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Trade Polymarket Combos and Multi-Leg Parlays with Kairos

How combos work

Step 1 — Quote a combo

Step 2 — Execute the combo

Step 3 — View your combo positions

Cash out an open combo position

Get a cash-out quote

Execute the cash-out

Redeem a winning combo

Combo lifecycle overview

Full Python workflow

Trading

Cross-Venue Routing

​How combos work

​Step 1 — Quote a combo

​Step 2 — Execute the combo

​Step 3 — View your combo positions

​Cash out an open combo position

​Get a cash-out quote

​Execute the cash-out

​Redeem a winning combo

​Combo lifecycle overview

​Full Python workflow

Trading

Cross-Venue Routing

How combos work

Step 1 — Quote a combo

Step 2 — Execute the combo

Step 3 — View your combo positions

Cash out an open combo position

Get a cash-out quote

Execute the cash-out

Redeem a winning combo

Combo lifecycle overview

Full Python workflow