Numeric conventions

Which convention each line uses

The three prefixes differ by one segment, the precision differs by 100×, and even the enum spelling differs. Every endpoint page carries this marker in its endpoint bar so you can always tell which line you are on.

The five conventions

Where it fails silently

1. Reading an E4 price as E6 is off by 100× and never errors。 `priceE4: 5200` is 0.52 USD; read as E6 it becomes 0.0052. Both are valid integers and no layer will catch it. The only signal is the field-name suffix and which line you are on.
2. On both PX lines the values are strings, not numbers。 E6 values exceed 2^53, so serialising them as JSON numbers loses precision; both PX lines emit decimal strings instead. After `JSON.parse`, using them directly in arithmetic concatenates strings rather than adding numbers.
3. Prices must be an integer multiple of the market tick。 `tickE4` comes from the market detail. A price that is not a multiple is rejected with a 400 on a single place; in a batch only **that entry** fails while the rest are still accepted.
4. Health can be null, and null is not zero。 With no debt `healthBps` is null, because health is undefined without debt. Treating that null as 0 turns the healthiest account into the most distressed one.
5. Do the arithmetic in integers or a fixed-point library, never floats。 The whole pipeline is integer arithmetic and floating point is display-only. `0.1 + 0.2 !== 0.3` becomes a cent that reconciliation can never close.

Related

Fee rates in ppm and the tiered limits are on Limits & fees; runtime behaviour of matching and settlement is on Runtime behaviour.