Amaru Opens Mainnet Block Forging for Cardano’s Rust Node

PRAGMA has announced Amaru v10.11.20261105, a beta release designed to enable block forging on Cardano mainnet using its Rust-based node implementation. The update removes the previous restriction limiting block production to test networks and introduces functionality intended to let stake pool operators produce blocks without relying on the reference Haskell node.

The release advances Amaru’s Minimum Viable Block Producer milestone, extending its existing capabilities beyond blockchain synchronization, validation, and relay operations.

Amaru Expands Block Production to Cardano Mainnet

Maintained by PRAGMA, Amaru is an independent implementation of the Cardano node written in Rust. It implements networking, ledger validation, and consensus functionality separately from the reference Haskell software, providing an alternative codebase for operating within the Cardano network.

Before this update, Amaru could already function as a mainnet relay, synchronize through Mithril snapshots, validate incoming blocks, and follow the blockchain’s current state. Its block production capabilities, however, remained limited to test environments. The new release removes that restriction and adds transaction selection from the mempool, where pending transactions are held before inclusion in blocks.

Transactions are considered in arrival order, with those exceeding permitted block size or execution limits skipped during construction. The update also introduces CIP-0203 software identification, allowing blocks to carry information about the node implementation responsible for producing them.

Software tagging is enabled by default. Operators can disable it through the --software-tag-off option or the AMARU_SOFTWARE_TAG_OFF=true environment variable, while the new amaru dev software-tag command provides tools for inspecting and decoding the identifiers.

Ledger Corrections and Operational Improvements for Stake Pool Operators

Beyond block production, the release includes corrections intended to improve consistency with Cardano’s reference implementation. These address calculations used to determine block producer eligibility, including rounding edge cases, alongside discrepancies in transaction validation involving collateral returns, witnesses, governance operations, and failed Plutus script execution.

Monitoring capabilities have also been expanded. Additional connection metrics support tools such as gLiveView, while Key Evolving Signature (KES) metrics have been aligned with those exposed by the Haskell node. These changes provide operators with more consistent information when monitoring node connectivity and block production infrastructure.

According to the release documentation, Amaru requires an x86_64 or aarch64 processor with at least two cores running at 2 GHz, a minimum of 2 GiB of RAM, and between 20 and 300 GiB of storage. The amount of storage depends on the blockchain history synchronized by the operator.

Amaru does not automatically retrieve the entire chain history during initial bootstrapping. Additional history can be synchronized separately through amaru mithril sync. The default port for incoming peer connections is 3001 rather than 3000, with configuration options available for operators.

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Mainnet Deployment and Software Identification

Intersect’s Hard Fork Working Group identified November 5 as the target date for Amaru to begin producing blocks on Cardano mainnet. PRAGMA’s release documentation describes the functionality needed for that milestone, although the release information does not itself identify a specific mainnet block successfully produced by Amaru.

The beta software is described as available for Linux on x86_64 and aarch64 architectures, macOS on aarch64, and Windows. A Docker image is also specified under ghcr.io/pragma-org/amaru:v10.11.20261105.

The change concerns stake pool infrastructure rather than how ADA holders interact with the network. Wallet functionality, delegation, and staking participation remain unchanged regardless of which node implementation a pool operates.

CIP-0203 provides a mechanism for identifying the software used to produce individual blocks. When Amaru-generated blocks carrying those identifiers appear on Cardano mainnet, their origin can be distinguished from blocks produced by the reference Haskell implementation.