Midnight Activates Ledger 9: A New Era for Private DeFi

Midnight has completed a hard fork that upgraded its mainnet from Ledger 8 to Ledger 9. The release introduces direct calls between smart contracts, expands compatibility with existing blockchain infrastructure, and includes security and performance improvements.

Existing token balances and deployed smart contracts migrated automatically, according to Midnight. Mainnet cNIGHT holders do not need to take action to continue generating DUST, the resource used to cover transaction costs.

The network deployed Ledger 9 directly to mainnet, bypassing its usual Preprod deployment and observation period. Midnight described this as a controlled release path used when security fixes require additional protection for the network.

Smart Contracts Can Now Work Together

Ledger 9 allows one smart contract to call a function in another within the same transaction. The capability, known as composability, gives developers a way to connect reusable components when building applications.

Midnight offered an example involving three DeFi steps: approving a token, swapping it, and depositing it into a liquidity pool. With connected contracts, developers can combine those operations into a single user action.

Contracts can also identify which other contract called them and use that information to authorize specific operations. A vault could, for example, permit an approved lending contract to withdraw funds while restricting access from other contracts.

The release introduces public events and logs that contracts can publish when an action occurs. Wallets, explorers, and other applications can monitor those events and display the resulting information to users.

Midnight presents these capabilities as a foundation for more advanced private financial applications. A separate Private Composability milestone remains on its roadmap for the first quarter of 2027. Developers must still account for what their contracts disclose: Midnight’s documentation notes that a cross-contract call exposes the address of the called contract.

New Standards Expand Wallet and Custody Compatibility

Ledger 9 adds native support for ECDSA, a digital signature method used by Bitcoin and Ethereum, and Keccak-256, a cryptographic hash function used in the Ethereum ecosystem.

The ledger now accepts both Schnorr and ECDSA signatures for transaction authorization. According to Midnight, direct ECDSA support makes it easier for custody providers to connect their existing systems to the network.

The release also implements BIP-44, a standard that allows wallets to derive multiple addresses from a single seed. Midnight expects the addition to help wallet providers and institutional custodians integrate the network into existing infrastructure.

In the Compact programming language, the new cryptographic capabilities give developers tools for building connections with other blockchains. Midnight identifies private stablecoin transfers and cross-chain financial applications as potential uses. Each bridge, custody service, or token integration would still require its own implementation.

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What Changes for Developers and Token Holders

Previously deployed contracts carry over without modification and do not need to be recompiled or redeployed because of the migration. Application developers will need to update to Midnight.js 5, while contracts that have not yet been deployed must be compiled with a Compact toolchain targeting Ledger 9.

The release also updates infrastructure used to generate and verify zero-knowledge proofs. Its support for ZKIR v3, an intermediate format for cryptographic programs, enables newer signature formats. Ledger 9.1.0.0 release notes identify specific circuit types whose verification keys need to be regenerated.

Mainnet cNIGHT DUST registrations are replayed automatically. On the Preview and Preprod test networks, builders must register their test NIGHT, or tNIGHT, again to resume generating DUST.

Midnight’s engineering team is still completing documentation for some of the new capabilities. Further technical details, including operation code references and transaction format specifications, are planned for release in the coming weeks.