POST/order

Post a new order

Creates a new order in the order book

Base URL: https://clob.polymarket.com
Auth: L2 API credentials (key, secret, passphrase)POLY_API_KEY, POLY_ADDRESS, POLY_SIGNATURE, POLY_PASSPHRASE, POLY_TIMESTAMP
Rate limit: 5,000 req / 10s (500 per second)sustained 120,000 req / 10 min
Limit applies to: POST /order

Things to know

Trading endpoints carry two Cloudflare limits: a burst of 5,000 req / 10s and a sustained 120,000 req / 10 min. Separate per-signer token buckets, sized by 30-day volume, apply on top.

Request body

Field	Type	Required	Description
order	object	yes	Order payload submitted to the CLOB API. In CLOB V2, `expiration` remains in the POST /order wire body for GTD/order-expiry handling, but it is not part of the EIP-712 signed order struct.
owner	string	yes	UUID of the API key owner
orderType	string	no	Time in force
deferExec	boolean	no	Whether to defer execution
postOnly	boolean	no	Whether the order must rest on the book and not match immediately. Only supported for GTC and GTD orders.

Example

curl -X POST "https://clob.polymarket.com/order" \
  -H "Content-Type: application/json" \
  -H "POLY_API_KEY: $POLY_API_KEY" \
  -H "POLY_ADDRESS: $POLY_ADDRESS" \
  -H "POLY_SIGNATURE: $POLY_SIGNATURE" \
  -H "POLY_PASSPHRASE: $POLY_PASSPHRASE" \
  -H "POLY_TIMESTAMP: $POLY_TIMESTAMP" \
  -d '{
  "order": {},
  "owner": "<owner>"
}'

L2 requests are signed with HMAC-SHA256 using your API secret, and the timestamp is part of the signature, so keep the machine's clock accurate. A missing credential or a stale signature both come back as Unauthorized/Invalid api key. The Python SDK signs for you.

Response fields

Field	Type	Description
success	boolean	Whether the order was successfully processed
orderID	string	Unique identifier for the order (order hash)
status	string	Status of the order after processing
makingAmount	string	Amount the maker is providing in fixed-math with 6 decimals
takingAmount	string	Amount the taker is providing in fixed-math with 6 decimals
transactionsHashes	string[]	Array of transaction hashes (present when status is 'matched')
tradeIDs	string[]	Array of trade IDs (present when status is 'matched')
errorMsg	string	Error message (empty on success)

Responses

Status	Meaning
200	Order successfully processed
400	Bad request - Invalid order payload or validation error
401	Unauthorized - Invalid API key or authentication failed
500	Internal server error
503	Service unavailable - Trading disabled or cancel-only mode

Errors this endpoint returns

Related endpoints

DELETE /order CLOB API
POST /orders CLOB API
DELETE /orders CLOB API

Polymarket's API serves current state only, so it cannot show what a market's book looked like after it resolved. PolyTest records Up/Down markets while they run and keeps the snapshots. Try it free, or read the full rate limit reference.

From Polymarket's published OpenAPI spec and rate-limit tables, synced 2026-10-04.