Exchange Native Sequence ID
An exchange native sequence ID is the identifier assigned by an exchange to order book, trade, or market data messages so clients can track their original ordering.
An exchange native sequence ID is a sequence value assigned by the source exchange rather than by a normalized downstream data provider. Exchanges often attach these identifiers to order book updates, trades, quotes, or other market data events so recipients can process messages in the same order intended by the venue.
Sequence IDs are especially important for order book maintenance. If a client receives incremental updates, the exchange native sequence ID may indicate whether each update follows the previous one correctly. A missing or unexpected value can signal a sequence gap, requiring the client to request a fresh snapshot or replay the book from a known-good point.
Different exchanges use different sequence formats. Some use strictly increasing integers, while others use update IDs, event IDs, timestamps, or channel-specific identifiers. Because of these differences, an exchange native sequence ID should be interpreted according to the rules of the source venue.
Why It Matters
Exchange native sequence IDs help preserve the original ordering and integrity of market data.
They matter because market data systems often need to:
- Detect missing incremental order book updates
- Identify duplicate or out-of-order messages
- Reconstruct an order book from a snapshot and update stream
- Compare normalized data with the exchange source feed
- Audit historical market data behavior
Without reliable sequence tracking, a local order book may appear valid while actually missing one or more updates.
What is an exchange native sequence ID used for?
An exchange native sequence ID is used to track the order of messages as provided by the exchange.
For example, when processing an order book feed, a client may compare the current update's sequence ID with the previous update's sequence ID. If the sequence does not advance as expected, the client may treat the local book state as unreliable and reload it from a current order book snapshot.
How is an exchange native sequence ID different from a normalized sequence number?
An exchange native sequence ID comes from the exchange itself, while a normalized sequence number is assigned by a data provider after processing the source feed.
A normalized sequence number can make cross-exchange processing easier, but the exchange native sequence ID is useful when you need to audit or reconcile behavior against the original exchange feed.
Can exchange native sequence IDs be compared across exchanges?
No. Exchange native sequence IDs should generally not be compared across exchanges.
Each exchange defines its own sequencing rules, reset behavior, channel structure, and message identifiers. A sequence ID from one venue does not carry the same meaning as a sequence ID from another venue.
Real-World Example
Suppose a client receives order book updates from an exchange with sequence IDs 10500, 10501, and 10503. The missing value 10502 indicates a possible sequence gap.
At that point, the client should not assume the locally reconstructed order book is complete. It may need to request a seed snapshot, replay updates from a known sequence, or restart the order book reconstruction process.
Exchange Native Sequence ID and CoinAPI Market Data API
CoinAPI Market Data API helps developers consume normalized and historical market data across many exchanges.
When source venues provide native sequencing information, these identifiers can help users understand exchange-specific ordering, validate replay workflows, and detect potential gaps in order book processing. This is especially useful for systems that reconstruct books, audit historical data, or compare normalized events with exchange-native behavior.