Errors and limits

Nord rejects an action with a value from the Error enum. This page lists the errors you are most likely to hit and the limits that cause them.

A rejected action still returns HTTP 200. The response is a Receipt whose kind is err and carries the Error value, so always decode the receipt (see Signed actions). The full enum is in the schema the exchange serves at GET /schema.proto.

Limits

Limit	Value	Error
Open orders per account	100	TOO_MANY_OPEN_ORDERS
Trading accounts per user (wallet)	8	TOO_MANY_USER_ACCOUNTS
Position size per market	$5,000,000 notional	POSITION_SIZE_LIMIT
Encoded action size	1648 bytes, plus a 64-byte signature	ENCODED_ACTION_TOO_LARGE
Action timestamp	Within 2 minutes of server time	TIMESTAMP_OUT_OF_THRESHOLD
Open sessions per user	200	None; the oldest session is evicted
Session duration	1 year	None; a longer expiry is capped to 1 year
External withdrawal fee	1 USDC	—

Rate limits

HTTP requests are rate-limited per client IP address, in two separate buckets:

Bucket	Requests
Actions	POST /action
Default	Every other HTTP request

Each bucket has its own requests-per-second rate and burst allowance, so heavy polling of REST endpoints doesn't consume your action budget. Requests over the limit are rejected. Back off and retry, and prefer WebSocket streams over polling.

Common errors

Error	Meaning	What to do
TIMESTAMP_OUT_OF_THRESHOLD	The action's currentTimestamp is more than 2 minutes from server time.	Fetch GET /timestamp before signing; don't use the local clock.
TOO_MANY_OPEN_ORDERS	The account already has 100 open orders.	Cancel resting orders, or spread orders across subaccounts.
POSITION_SIZE_LIMIT	The order would take the position past the position size limit.	Reduce the order size.
POST_ONLY_MUST_NOT_FILL_ANY_OPPOSITE_ORDERS	A post-only order would have crossed the book.	Reprice the order away from the opposite side.
MARKET_FROZEN	The market is frozen and isn't accepting this action.	Wait for the market to resume.
ENCODED_ACTION_TOO_LARGE	The encoded action exceeds 1648 bytes.	Split large atomic actions into smaller ones.
TRIGGER_WOULD_FIRE_IMMEDIATELY	The trigger price is already reached at placement.	Set a trigger price on the far side of the current price.
TOO_MANY_USER_ACCOUNTS	The wallet already owns 8 trading accounts.	Reuse an existing account.

Next steps

• Signed actions: build, sign, and submit actions.
• REST API: read state and server time.
• Changelog: protobuf and API changes by release.