1. Deployer actions now support
registerAndAssociateNamedOutcomeFromTemplate which allows deployers to add additional named outcomes to a question after creation. The initial balances of the new named outcome match the outstanding fallback balances. See hyperliquid.gitbook.io/hyperliquid-docs/for-developers/api/hip-4-deployer-actions for details.2. Template instantiations now require
deployerFeeScale for questions and standalone outcomes. Similar to HIP-3, this is a multiplier on the base fee that deployers can configure to collect, bounded between 0 and 10. See hyperliquid.gitbook.io/hyperliquid-docs/trading/fees for more details on outcome fees.3.
shortString type hint has been added, which appears in templated side names so that interfaces can make useful assumptions about the respective fields.4. Settlement details are now pruned from the L1 state. Applications depending on node API servers or read precompiles could separately index settlement details if needed in perpetuity.
5. Additional templates have been added to testnet. Template IDs are suffixed with an index. All but the largest index in each series are considered deprecated templates.
On the next network upgrade, validator-deployed outcome markets will have fees enabled in preparation for point 2 above. The average outcome trading fee will be half that of non-outcome spot trading. See hyperliquid.gitbook.io/hyperliquid-docs/trading/fees for more details.
The mainnet launch of HIP-4 will have conservative specs as a staged rollout. Initially, each deployer will be limited to 100 concurrent outcomes, with 500 outcome deployments per day. Once the tech is stabilized, deployer limits are expected to increase quickly to 1k concurrent outcomes and 5k deployments per day. Based on feedback, a design for further limit increases will be implemented.