Order IDs

Deterministic order IDs — no client order ID required; compute on the fly or use bulk-keychain

Order IDs on BULK are deterministic: they are derived from the signed transaction (action, account, nonce, and action index). You do not need to supply a client order ID. You can compute the order ID before or after sending the request, and use the official library to do it for you.

Why deterministic?

• No client order ID required - The exchange assigns a unique ID from the transaction contents.
• Know the ID before the node responds - Useful for optimistic UI and local tracking.
• Reproducible - Same action + account + nonce + index always yields the same order ID.

Computing order IDs

You can compute order IDs yourself from the protocol formula, or use bulk-keychain so you don’t have to implement the binary encoding.

Option 1: Use bulk-keychain (recommended)

The official signing library bulk-keychain can compute order IDs for you in Node.js, browser (WASM), Rust, and Python. Single-order and batch (group) transactions are supported.

Environment	Package	Install
Node.js	bulk-keychain	npm install bulk-keychain
Browser (Web)	bulk-keychain-wasm	npm install bulk-keychain-wasm
Python	bulk-keychain	pip install bulk-keychain
Rust	bulk-keychain	cargo add bulk-keychain

After signing, the returned object includes the order ID(s):

TypeScript (Node.js):

const signed = signer.sign(order);
console.log(signed.orderId);  // Pre-computed order ID

Python:

signed = signer.sign(order)
print(signed.get("order_id"))

Rust:

let signed = signer.sign(order.into(), None)?;
println!("Order ID: {:?}", signed.order_id);

For multi-order (grouped) transactions, enable batch order ID computation so you get an ID per order. See the bulk-keychain README for signGroup, prepareGroup, and batch order ID options.

You can also compute an order ID without signing (e.g. for display or lookup) using the library’s compute_order_id / computeOrderId helpers with order fields, nonce, and account.

Option 2: Compute from the protocol

Order IDs are the base58-encoded SHA-256 hash of:

order_id = bs58_encode(
  sha256(seqno_le_u32 + bincode_serialize(single_action) + account_pubkey_bytes + nonce_le_u64)
)

• seqno: Zero-based index of the order-producing action in the actions array (0 for a single-order tx).
• single_action: Canonical bincode of that one action (same encoding used for signing).
• For limit/market actions, px and sz use fixed-point: round(value * 1e8) as u64.

Implementing this requires the same canonical action encoding as the rest of the protocol; using bulk-keychain avoids that.

Summary

Need	Approach
Sign and send orders	Use bulk-keychain (Node, Web, Rust, Python).
Know order ID before response	Use bulk-keychain’s pre-computed order ID after signing (or after prepare, with external wallet).
Order ID without private key	Use bulk-keychain’s compute_order_id / computeOrderId with order + nonce + account.