Create Order

Creates a buy/sell order for prediction market positions. Requires signed order data.

POST /orders

Create Order

cURL

curl --request POST \
  --url https://api.limitless.exchange/orders \
  --header 'Content-Type: application/json' \
  --header 'lmts-api-key: <api-key>' \
  --data '
{
  "order": {
    "salt": "1778155025318314496",
    "maker": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "signer": "0x742d35Cc6634C0532925a3b844Bc454e4438f44e",
    "tokenId": "19633204485790857949828516737993423758628930235371629943999544859324645414627",
    "makerAmount": 5000000,
    "takerAmount": 10000000,
    "nonce": 0,
    "feeRateBps": 0,
    "side": 0,
    "signature": "0x6e3a3f2c2c2bb1ce3a14c4f5e4ad6f3c8b1ad9c44d4d5fa1c4cd5b6e74a4d4a36cc4ad9c44d4d5fa1c4cd5b6e74a4d4a36cc4ad9c44d4d5fa1c4cd5b6e74a4d41b",
    "signatureType": 2,
    "taker": "0x0000000000000000000000000000000000000000",
    "expiration": "0",
    "price": 0.75
  },
  "ownerId": 12345,
  "orderType": "GTC",
  "marketSlug": "biden-vs-trump-2024",
  "postOnly": true,
  "clientOrderId": "client-order-001",
  "onBehalfOf": 12345,
  "timestamp": 1735689600000,
  "recvWindow": 1500,
  "stpPolicy": "cancel_maker"
}
'

201

{
  "order": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "salt": "1778155025318314496",
    "maker": "<string>",
    "signer": "<string>",
    "tokenId": "<string>",
    "signatureType": 0,
    "signature": "<string>",
    "orderType": "GTC",
    "side": 0,
    "marketId": "<string>",
    "ownerId": 123,
    "createdAt": "2023-11-07T05:31:56Z",
    "market": {
      "id": 7348,
      "slug": "btc-up-or-down-1-hour",
      "title": "BTC Up or Down - Hourly",
      "status": "FUNDED",
      "yesPositionId": "11514974713064423461...",
      "noPositionId": "14525308260861904048...",
      "group": {
        "id": 42,
        "slug": "btc-price-markets",
        "title": "BTC Price Markets"
      }
    },
    "makerAmount": 5000000,
    "takerAmount": 10000000,
    "nonce": 0,
    "owner": {
      "id": 123,
      "account": "<string>",
      "client": "<string>",
      "tradeWalletOption": "eoa",
      "smartWallet": "<string>",
      "username": "<string>",
      "displayName": "<string>",
      "pfpUrl": "<string>",
      "socialUrl": "<string>",
      "rankName": "<string>",
      "points": 123,
      "referredUsersCount": 123,
      "isTop100": true,
      "leaderboardPosition": 123
    },
    "taker": "<string>",
    "expiration": "2023-11-07T05:31:56Z",
    "feeRateBps": 123,
    "price": 0.75
  },
  "execution": {
    "matched": true,
    "settlementStatus": "MINED",
    "feeRateBps": 25,
    "effectiveFeeBps": 26,
    "totalsRaw": {
      "contractsGross": "1000000",
      "contractsFee": "1000",
      "contractsNet": "999000",
      "usdGross": "500000",
      "usdFee": "500",
      "usdNet": "499500"
    },
    "reason": "settlement transaction reverted",
    "eligibleAt": "2026-06-08T10:15:30.000Z",
    "tradeEventId": "4aa706dd-6c57-4f3c-945a-99818dfd95f1",
    "txHash": "0xabc123",
    "clientOrderId": "client-order-001",
    "stpMakerCancels": [
      "4aa706dd-6c57-4f3c-945a-99818dfd95f1"
    ]
  },
  "makerMatches": [
    {
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "matchedSize": "1000000",
      "fillPrice": "0.55",
      "fillCost": "550000",
      "orderId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "order": {
        "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
        "maker": "<string>",
        "price": "0.55",
        "side": 0,
        "tokenId": "<string>",
        "owner": {
          "id": 123,
          "account": "<string>",
          "client": "<string>",
          "tradeWalletOption": "eoa",
          "smartWallet": "<string>",
          "username": "<string>",
          "displayName": "<string>",
          "pfpUrl": "<string>",
          "socialUrl": "<string>",
          "points": 0,
          "referredUsersCount": 0
        }
      }
    }
  ]
}

Before creating orders:

1. Fetch market data via Get Market Details to get venue and token IDs
2. Sign the order using EIP-712 with venue.exchange as verifyingContract
3. Ensure you have token approvals set up

Order creation can be temporarily restricted during maintenance. In post_only, only orders with postOnly: true are accepted. In cancel_only or disabled, new orders return 425 Too Early with a trading-mode code. Check Maintenance Mode before sending orders.

Authentication

Use a scoped API token with HMAC signing and the trading scope.

Signed order rules

For client-signed orders, signature and signatureType are both required. They must either both be present or both be omitted. Omission is accepted only for delegated server signing with an HMAC token carrying delegated_signing.

nonce is required and must be the numeric value 0. expiration may be omitted; omission is signed as zero. If supplied, it must represent zero, for example "0". Non-zero expiration is not supported.

Amounts are integer raw units with 6 decimals. makerAmount must be at least 100 raw units. For GTC and FAK orders, price is required, must be between 0.01 and 0.99, and may have at most three decimal places. The collateral equation must be exact. price × contracts must be an integer raw-unit amount, without rounding.

Type	BUY amounts	SELL amounts	Price
GTC / FAK	makerAmount = price × contracts; takerAmount = contracts	makerAmount = contracts; takerAmount = price × contracts	Required
FOK	makerAmount = maximum collateral to spend; takerAmount = 1	makerAmount = shares to sell; takerAmount = 1	Must be omitted

postOnly is supported only for GTC orders.

Optional fields

Field	Type	Description
clientOrderId	string	Optional uniqueness and deduplication key. The submitted value may contain at most 128 characters; it is then trimmed and must not be blank. Reuse returns 409 Conflict; the API does not replay the earlier response.
onBehalfOf	number	Profile ID of the sub-account to place the order for. Requires a scoped API token with trading scope and a partner relationship with the target profile. The maker and signer in the order must match the sub-account’s wallet address.
postOnly	boolean	GTC orders only. When true, the order is rejected if it would immediately match. Guarantees the order rests on the book as a maker order. Default false.
timestamp	number	Optional client-stamped Unix time in milliseconds for receive-window checks. Top-level request field; not part of the signed order.
recvWindow	number	Optional maximum accepted order age in milliseconds, up to 10000. If omitted, the API default applies. Top-level request field; not part of the signed order.
stpPolicy	string	Self-trade prevention policy. Values: cancel_maker, cancel_taker, cancel_both. Default cancel_maker. Top-level request field; not part of the signed order.

Receive window

POST /orders supports optional receive-window controls for clients that want freshness checks on order submission. Send these fields at the top level of the request body, next to order, orderType, and marketSlug; never put them inside the EIP-712 signed order object.

{
  "order": {
    "...": "signed order fields"
  },
  "orderType": "GTC",
  "marketSlug": "btc-100k",
  "timestamp": 1779870000000,
  "recvWindow": 1500
}

Field	Description
timestamp	Client order creation time as Unix milliseconds. Send it with a nonzero effective recvWindow to enforce client-to-server freshness. If omitted while a window applies, the server uses its receive time.
recvWindow	Maximum accepted age, in milliseconds, between the effective timestamp and server receive time, up to 10000. If omitted, the API default applies. A timestamp alone has no freshness effect when the effective window is zero.

Keep trading hosts NTP-synced. If the timestamp is too far in the future or older than the receive window, the API returns 425 Too Early. Do not retry the same signed payload after a receive-window 425; build and sign a fresh order. If the 425 body has a trading-mode code, refresh maintenance status instead.

Self-trade prevention

POST /orders can reject or cancel orders that would match against your own resting order on the same token.

{
  "order": {
    "...": "signed order fields"
  },
  "orderType": "GTC",
  "marketSlug": "btc-100k",
  "stpPolicy": "cancel_taker"
}

Policy	Result
cancel_maker	Default. Cancel your conflicting resting order and continue with the incoming order.
cancel_taker	Reject the incoming order before it self-trades.
cancel_both	Cancel your conflicting resting order and reject the incoming order.

With cancel_maker, matching continues against the remaining non-self liquidity, and limit orders still never execute past their limit price.

Outcomes on the placement response:

• A rejected taker (cancel_taker / cancel_both) returns settlementStatus: "CANCELED" with reason: "STP_TAKER_REJECTED".
• A cancel_maker taker lists the cancelled resting order IDs in stpMakerCancels and keeps its normal status (UNMATCHED when nothing else fills it); no reason is set.

stpPolicy is a top-level request field. Do not include it inside the EIP-712 signed order object.

SDK support. Self-trade prevention is available in the TypeScript, Python, Rust, and Go SDKs. Pass the policy on order creation and read the outcome from the execution object on the response. See TypeScript, Python, Rust, and Go.

Where does ownerId come from? It is the id field returned by GET /profiles/me or GET /profiles/{address}. For partner sub-accounts, it is the profileId returned by POST /profiles/partner-accounts, or recovered with GET /profiles/partner-accounts.

ownerId must match the profile that owns the order (see Programmatic API — EOA flow):

• Partner EOA + signed order + onBehalfOf: set both onBehalfOf and ownerId to the sub-account’s profileId. order.maker and order.signer must match that sub-account’s wallet. A mismatched ownerId returns 400 with the message "Profile ID does not match the order owner".
• Delegated signing (unsigned order, delegated_signing scope, server wallet sub-account): send the target profile ID as both onBehalfOf and ownerId. The server normalizes ownerId to that target when it signs. Omit the client signature per Delegated signing below.
• Trading as yourself (no onBehalfOf): ownerId is your own profile id (the SDK often fills this after fetching your profile).
• Signer does not match - you should use embedded address for smart wallet: your profile is in smart-wallet trading mode, which self-signed API orders can’t satisfy. Switch to EOA mode. See Trading wallet mode.

Delegated signing

Partners place orders for a managed sub-account by setting body onBehalfOf to its profile ID. A client-signed order requires trading; the target must belong to the authenticated partner.

With both trading and delegated_signing, partners may instead omit both signature and signatureType. The request must still include the target profile ID as both onBehalfOf and ownerId. The server signs using a Privy server wallet linked to that profile, replaces maker and signer with that wallet address, and normalizes ownerId to the target. See Authentication.

Execution response

The response includes an execution object with settlement details:

Field	Type	Description
matched	boolean	Whether the order was matched immediately
settlementStatus	string	UNMATCHED, MATCHED, MINED, CONFIRMED, RETRYING, FAILED, DELAYED, or CANCELED
reason	string	Free-form terminal detail. For example, STP_TAKER_REJECTED accompanies an STP-cancelled taker; settlement or recovery failures can return other text with FAILED.
eligibleAt	string	ISO-8601 time the order is released to the matching engine. Present only when settlementStatus is DELAYED (taker delay).
tradeEventId	string	Trade event ID (present when matched)
txHash	string	On-chain transaction hash (present when mined)
stpMakerCancels	string[]	Resting order IDs cancelled by self-trade prevention (present when cancel_maker / cancel_both cancelled one or more of your resting orders)
feeRateBps	number	Fee rate in basis points
effectiveFeeBps	number	Effective fee rate after rebates
totalsRaw	object	Raw execution totals (contractsGross, contractsFee, contractsNet, usdGross, usdFee, usdNet)

DELAYED (taker delay). Some markets apply a short hold to marketable (taker) orders before the matching engine fills them. On such a market, a marketable order’s response returns immediately with settlementStatus: "DELAYED", matched: false, zero totalsRaw, and an eligibleAt timestamp. It does not block until the trade is mined. Track the outcome over subscribe_order_events (provisional MATCHED → terminal MINED / FAILED), correlating by clientOrderId / tradeEventId. postOnly orders are never delayed.

Errors

Status	Meaning
400	Structural validation, invalid signature/owner/token/amounts, insufficient balance or allowance, unavailable/resolved/expired market, delegated-signing failure, or matching-engine rejection. Validation failures use a message array; business failures usually use a string. Missing markets and profiles are normalized to 400 on this endpoint.
401	Authentication failed.
403	The HMAC token lacks trading, or onBehalfOf is not an authorized partner target.
409	clientOrderId or the signed order hash already exists or is being processed.
425	Receive-window rejection or a maintenance trading mode that blocks creation. Receive-window bodies contain a message; maintenance bodies contain a trading-mode code.
500	Unexpected order-creation failure.

Authorizations

lmts-api-key · string · header · required

Scoped API token with HMAC-SHA256 signing. Requires three headers: lmts-api-key (token ID), lmts-timestamp (ISO-8601), lmts-signature (Base64-encoded HMAC). See Authentication docs for details.

Body

application/json

Order creation data including signature and order parameters

order · object · required

Order details including signature and amounts

Option 1

Option 2

Show child attributes

ownerId · integer · required

Required profile ID of the order owner. For delegated signing, send the target profile ID as both ownerId and onBehalfOf.

Example:

12345

orderType · enum<string> · required

Order type (GTC=Good Till Cancelled, FAK=Fill And Kill, FOK=Fill Or Kill)

Available options: FAK, FOK, GTC

Example:

"GTC"

marketSlug · string · required

Market identifier slug

Example:

"biden-vs-trump-2024"

postOnly · boolean

Reject the order if it would match immediately. Supported only for GTC orders.

Example:

true

clientOrderId · string

Optional owner-scoped uniqueness and deduplication key. The submitted value is limited to 128 characters, then trimmed; blank values are rejected. Reuse returns 409 rather than replaying an earlier response.

Maximum string length: 128

Example:

"client-order-001"

onBehalfOf · integer

Managed profile ID for partner placement. Requires trading and a partner relationship; unsigned delegated placement also requires delegated_signing.

Required range: x >= 1

Example:

12345

timestamp · integer

Optional client-stamped order creation time, Unix ms epoch. Top-level request field; not part of the EIP-712 signed order payload.

Required range: x >= 0

Example:

1735689600000

recvWindow · integer

Optional maximum accepted order age in milliseconds. Valid range: 1 to 10000. If omitted, the server applies a 2000 ms default receive window. Top-level request field; not part of the EIP-712 signed order payload.

Required range: 1 <= x <= 10000

Example:

1500

stpPolicy · enum<string>

Self-trade prevention policy. If omitted, defaults to cancel_maker. Top-level request field; not part of the EIP-712 signed order payload.

Available options: cancel_both, cancel_maker, cancel_taker

Example:

"cancel_maker"

Response

201

application/json

Order accepted. It may be resting, delayed, matched, settled, canceled by STP, or accepted with a settlement failure reported in execution.

order · object · required

Order details including slim market and owner

Show child attributes

execution · object · required

Execution and settlement summary

Show child attributes

makerMatches · object[]

Maker matches if order was matched immediately

Show child attributes