Change Service (Group 9)
The live denomination-management surface for making change, reserving serial numbers, breaking value, and joining value.
Overview
Group 9 handles denomination conversion workflows. The audited live surface includes both the older break/join building blocks and the top-level make_change command.
Live commands
| Code | Name | Primary role |
|---|---|---|
| 90 | make_change | High-level denomination conversion request. |
| 91 | get_available_change_sns | Reserve or discover serial numbers needed for change operations. |
| 92 | break | Split larger value into smaller denominations. |
| 93 | join | Combine smaller value into a larger denomination. |
90 — make_change
make_change is the orchestration-oriented entry point for denomination conversion. Use it when the client wants change without manually driving every lower-level step.
| Request body element | Size | Developer note |
|---|---|---|
| Coin to break | 21 bytes | The input coin record supplied to the RAIDA. |
| Starting serial number | 4 bytes | Big-endian start point for generated change SNs. |
| PAN set | 160 bytes | Ten 16-byte PAN values used for the resulting coins. |
The total documented body size in the live implementation is 203 bytes.
91 — get_available_change_sns
get_available_change_sns returns or reserves serial numbers needed for follow-up break or join flows. Treat it as the inventory/discovery step for controlled denomination changes.
92 — break
break consumes a higher denomination and returns smaller denominations. It is the explicit low-level operation when the client wants direct control over the conversion flow.
93 — join
join is live in the current audited dispatch table. Use it to combine lower denominations into a larger denomination when the resulting value is exactly representable.
Frontend guidance
Do not treat join as dormant. It belongs in the active developer surface together with make_change, get_available_change_sns, and break.