This release implements the 3.2 Stacks consensus rules which activates at Bitcoin block 907,740. For more details see SIP-031.

This is a required upgrade

• Activation is estimated for July 29th, 2025 around 1800 UTC, or Bitcoin block 907,740.
• Upgrading after Bitcoin block 907,740 will require a genesis sync.

This release is compatible with chainstate directories from 3.x.x.x.x.

The version of stacks-signer compatible with this release is 3.2.0.0.0.0, available at: https://github.com/stacks-network/stacks-core/releases/tag/signer-3.2.0.0.0.0.

Added

• Added the clarity-serialization crate: A lightweight crate for serializing and deserializing Clarity values. This crate decouples core data types from the Clarity VM, making it easier to build off-chain tooling, and other applications that interact with Clarity data. It includes support for wasm32-unknown-unknown targets via the wasm-web and wasm-deterministic features.
• Added /v3/contracts/fast-call-read/:principal/:contract_name/:func_name api endpoint. It allows to run read-only calls faster by disabling the cost and memory trackers. This endpoint requires authentication.
• SIP-031 consensus rules, activating in epoch 3.2 at block 907_740

Changed

• The HTTP Date header in responses now strictly follows RFC7231.
• When a previous block commit is unable to be RBFed, the miner will now just wait for it to be confirmed instead of submitting a new block commit which breaks the miner's UTXO chain.
• When mining, only log new block proposal responses, not duplicates.

Fixed

• Fixed tenure downloader logic on reward cycle boundaries (#6234).
• Do not send events to event observers for stale StackerDB chunks.