07 — PIPs · PIP-0004
Composable liquidity, still reserved
Keep the settlement `route` field empty until a later PIP specifies who may fill it.
- Number
- PIP-0004
- Status
- backlog
- Type
- Core
- Author
- PATH
- Date
- 2026-09-09
- Source
- On the register
Why this exists
route is on every settlement receipt. In this version the value is null. PIP-0005 defines the only shape the field may take.
This PIP records the refusal to fill route in v0.1, and the conditions under which a later PIP may.
Rule, for now
Implementations MUST accept route and MUST leave it empty. A non-empty route in v0.1 is a non-conformity. PATH does not run a rail, and a network that puts its own corridor into route is inventing a PATH Liquidity that was not specified.
When a later PIP may fill it
Only when all of these are true:
- The field has a single canonical meaning across networks.
- A receipt with a route and a receipt without one remain verifiable as the same kind of object.
- Filling it does not require PATH to admit members or to hold balances.
PIP-0005 writes the canonical shape (legs, providers, eta_seconds). Condition 1 is met. Conditions 2 and 3 are unchanged: a receipt with a route and a receipt without one stay the same object, and filling it still must not require PATH to admit members or hold balances.
Until a later PIP names who may write a non-null route, implementations MUST emit null. PATH LIQUIDITY stays reserved.