The transaction pipeline
Intent to confirmation in seven stages, the contract each stage owes the next, and the specific way each one fails when the network is busy.
Open the notePipeline: build, sign, send, confirm
One swap is the unit of work an engine is judged on. Everything upstream is planning and everything downstream is accounting, but the seconds between a route quote and a confirmed signature are where cost, landing rate and correctness are all decided at once.
These notes walk that path stage by stage. Each stage gets the same treatment: what it receives, what it must produce, what it is allowed to change, and the way it fails when the network is busy rather than when your code is wrong.
- Packet limit
- 1232 bytes for a serialised transaction
- Blockhash life
- About 150 blocks before expiry
- Fee shape
- Base signature fee plus optional priority fee
- Determinism
- Same intent and route should rebuild identically
3 notes in this section
What happens to a single swap between the moment a scheduler emits it and the moment a validator finalises it, stage by stage, with the failure mode of each stage.
Versioned transactions and lookup tables
Why the 1232-byte packet is the real constraint, how address lookup tables buy back account slots, and what a table costs you in setup, rent and coupling.
Open the noteCompute budget and priority
Compute unit limits and unit prices as two separate levers, how the product becomes a fee, and how to set both from simulation instead of superstition.
Open the noteWhy the pipeline is documented separately
Pipeline problems look like architecture problems from a distance. A run with a poor landing rate gets blamed on the scheduler when the real cause is a transaction that grew past the packet limit and started dropping accounts, or a compute unit limit set once and never re-simulated. Isolating the stages makes the difference visible, because each stage has a signature you can inspect and a failure that names itself.
Architecture Components and contracts The parts a volume engine is assembled from, the interface each one exposes to its neighbours, and what breaks when a boundary is drawn in the wrong place. Reliability Failure, retry, scale Retries that do not double-spend, backpressure that protects an endpoint instead of hammering it, metrics that expose the truth, and a growth path that does not break on the way up. Engine notes The full index Every note the desk has published, listed with the component it describes and the section it belongs to.