Trader Guide

The end-to-end path for placing a parlay. Unlike CLOB orders, parlays are placed by sending a Solana transaction yourself — the Platform API mirrors the resulting state for reads, but it does not accept the bet.

1. Pick your legs

A leg is one market plus a YES/NO pick. Between 2 and 10 of them.

Before adding a market, check it’s eligible:

• Status open, and not past end_time
• Old enough to have a full TWAP window of price history — at least one hour, and never less than the averaging window
• Outcome probability inside the configured band (hard bounds: 1%–99%)
• Deep enough and traded enough to price — the vault sets minimum liquidity and volume floors
• Traded recently enough that the TWAP isn’t stale
• Not the same market as another leg
• Not in the same event as another leg

Every threshold above is admin-tunable config, not a constant. Read them from the parlay config account rather than hardcoding — the deployed floor is not necessarily the hard bound.

The webapp greys out ineligible markets before you can add them. If you’re building your own client, mirror these client-side — every one is also enforced on-chain, but failing there costs a transaction.

Note

Parlay legs are AMM markets. CLOB order-book markets cannot currently be used as legs. → CLOB Markets as Legs

→ Leg Eligibility

The correlation rule

You cannot put two legs from the same event on one slip. “Team A wins” and “Team A wins by 2+” are almost the same bet; multiplying their probabilities as if independent would price the slip far below its true risk. The program rejects it with SameEventCorrelation.

2. Read the multiplier

combined   = p₀ × p₁ × … × pₙ
multiplier = 1 / combined
payout     = stake × multiplier

Legs	Each at	Combined	Multiplier
2	50%	0.25	4×
3	50%	0.125	8×
3	50% / 40% / 25%	0.05	20×
4	30%	0.0081	123×
5	20%	0.00032	3,125×

The multiplier compounds fast. So does the chance of missing: five legs at 20% each land together 0.032% of the time.

3. Set your stake

Within the configured bounds — typically $1 minimum. The resulting payout must clear config.max_payout and fit the vault’s exposure headroom, so a large stake on a long slip can be rejected even when the stake itself is fine.

If you hit ExposureLimitExceeded, reduce the stake. The vault is protecting its solvency, not rejecting you.

4. Set min_payout — and actually set it

create_parlay takes a min_payout slippage floor. If the computed payout comes out below it, the transaction reverts with SlippageExceeded rather than filling you at a worse multiplier.

Caution

Set min_payout to a real floor — e.g. 98% of the payout you previewed.

A preview computed from spot prices can differ from what the program computes, because legs are priced off the one-hour TWAP. Passing min_payout = 1 accepts whatever the chain arrives at.

5. Place it

Send a create_parlay transaction to the high-market-parlay program.

Parlay PDA   seeds = ["parlay", user_pubkey, user_seq_le_bytes]

Parameter	Meaning
legs	Vec<LegInput> — one { selected_outcome } per leg
stake	Micro-USDC
min_payout	Your slippage floor
user_seq	Your per-user sequence number

The market references travel in remaining_accounts, length exactly 2 × legs.len():

Range	Accounts
[0..N]	Market accounts, in leg order
[N..2N]	MarketEventLink PDAs, derived per leg’s market_id

The user_seq race

The PDA is keyed on (user, user_seq), deliberately — two users can both create their first parlay in the same slot without racing a global counter. But you can race yourself: two browser tabs both computing max(existing) + 1 will collide.

Handle it: on an “account already in use” error, increment user_seq and retry. The webapp retries up to four times.

The stake transfers from your USDC ATA into the parlay vault in the same transaction.

6. Track it

curl -s https://prod-api.gomarket.io/api/parlays/user/ \
  -H "Authorization: Bearer $JWT"

curl -s https://prod-api.gomarket.io/api/parlays/user/?status=active \
  -H "Authorization: Bearer $JWT"

curl -s https://prod-api.gomarket.io/api/parlays/{parlay_id}/ \
  -H "Authorization: Bearer $JWT"

The detail endpoint is scoped to the caller — you cannot read someone else’s slip, and a parlay that isn’t yours returns the same 404 as one that doesn’t exist.

Status	Meaning	Claimable
active	At least one leg still pending	—
won	All legs terminal, none lost	yes — payout
lost	A leg lost; nothing to collect	no
voided	Every leg’s market cancelled	yes — stake refund
refunded	Admin already paid the stake back	no
claimed	Paid out	no

voided and refunded are easy to confuse: voided still owes you a claim, refunded has already been settled.

7. Settle the legs

Legs don’t settle themselves. Once a leg’s market is Resolved or Cancelled, anyone can call settle_leg(leg_index) — you, an operator, an indexer.

Error	Means
MarketNotResolved (6013)	Too early — the market isn’t terminal yet
LegNotPending (6033)	Already settled; harmless

Settling is idempotent through that second check, so a retry loop is safe.

8. Claim — and don’t wait

claim_parlay is signed by you and accepts two statuses:

Won      fee = floor(potential_payout × fee_bps_at_create / 10_000)
         net = potential_payout − fee

Voided   net = stake       fee = 0      // every leg's market cancelled

The vault pays net to your USDC ATA and, for a winner, fee to the treasury in the same transaction. Status flips to Claimed.

fee_bps_at_create is snapshotted when you placed the slip — an admin fee change in between cannot touch what you pay.

Winnings expire

A won slip does not stay claimable forever. parlay.claim_deadline is set at create time from config.claim_deadline_secs. Once it passes, an admin can call void_parlay on your winner: the stake is refunded and the winnings are forfeited.

The deadline exists so unclaimed winners don’t lock vault exposure indefinitely. It is the one way a winning parlay pays less than it should — claim promptly.

What can go wrong

Error	Code	What to do
ExposureLimitExceeded	6011	Reduce the stake — the vault is near its limit
PayoutExceedsMax	6010	Reduce the stake or shorten the slip
StakeTooLow / StakeTooHigh	6008/6009	Stake outside the configured bounds
MarketNotOpen	6012	A leg’s market closed while you were building
ProbabilityOutOfRange	6014	A leg sits outside the configured band
SameEventCorrelation	6005	Two legs from one event
DuplicateMarket	6004	Same market twice
SlippageExceeded	6042	The TWAP price moved past your min_payout
Paused	6000	Parlay creation is paused
TooFewLegs / TooManyLegs	6002/6003	Outside 2–max_legs

Full list: Error Codes.

Suggested slips

The Platform API serves curated templates:

curl -s https://prod-api.gomarket.io/api/markets/parlay-suggestions/

In the webapp these are previews. Demo legs carry a synthetic negative market ID and no market address, and are blocked from submission — they exist to show the shape of a combo, not to be placed.

Things a parlay cannot do

• Be sold or exited. No secondary market, no partial close. Once placed, it runs to settlement.
• Be transferred. The Parlay account is bound to your pubkey; only you can claim.
• Be repriced. probability_at_entry is written once. Later market moves don’t change your multiplier, in either direction.