Stacks 4.0.0 Network Upgrade (Hard Fork) - Clarity 6 & Bitcoin Staking
Project: Stacks
Ticker: STX
Upgrade Type: Hard fork
Mandatory: Yes
Summary
Stacks is undergoing a mandatory network upgrade with the release of stacks-core 4.0.0. This is a consensus-breaking hard fork that activates a new protocol epoch (Epoch 4.0) introducing Clarity 6 and Bitcoin Stacking as described in SIP-044 and SIP-45, respectively. All node and signer operators must upgrade before the activation height. After activation, nodes running 4.0.0 and nodes running 3.4.x will diverge.
Activation details
Governance
This upgrade is in process of completing the community Governance process all SIPs follow, including open vote. The vote has already crossed the threshold for approval, so the proposal is expected to be ratified.
Impact on deposits and withdrawals
This upgrade does not change the deposit or withdrawal logic for STX.
Impact on tokenomics and supply
Major supply mechanics are unchanged, however the block reward (emissions) will reset to the baseline 1,000 STX it had operated at before April 2026.
Actions required from operators
This release is recommended for all Stacks node and signer operators and is required to remain on consensus after the activation height.
References
Note: The Stacks Foundation recently migrated to stacks.foundation. You can access this post via stacks.org/release-4-0 if you still have stacks.org listed as your official domain of record for STX.
Ticker: STX
Upgrade Type: Hard fork
Mandatory: Yes
Summary
Stacks is undergoing a mandatory network upgrade with the release of stacks-core 4.0.0. This is a consensus-breaking hard fork that activates a new protocol epoch (Epoch 4.0) introducing Clarity 6 and Bitcoin Stacking as described in SIP-044 and SIP-45, respectively. All node and signer operators must upgrade before the activation height. After activation, nodes running 4.0.0 and nodes running 3.4.x will diverge.
Activation details
- Estimated date: Wednesday, July 29, 2026
- Estimated time: 03:00 UTC
- Activation trigger: Bitcoin block height 960,230
Governance
This upgrade is in process of completing the community Governance process all SIPs follow, including open vote. The vote has already crossed the threshold for approval, so the proposal is expected to be ratified.
Impact on deposits and withdrawals
This upgrade does not change the deposit or withdrawal logic for STX.
Impact on tokenomics and supply
Major supply mechanics are unchanged, however the block reward (emissions) will reset to the baseline 1,000 STX it had operated at before April 2026.
Actions required from operators
This release is recommended for all Stacks node and signer operators and is required to remain on consensus after the activation height.
- Operators must upgrade to stacks-core 4.0.0 before Bitcoin block 960,230. The 4.0.0 release is compatible with existing chainstate directories.
- Operators running their own Stacks Blockchain API should also note the corresponding API release (v9). This is a major version bump, so upgrading requires an Event Replay; skipping it will require wiping the API's chainstate and Postgres database and re-syncing from scratch. See the Hiro documentation.
References
- Official release (stacks-core 4.0.0): https://github.com/stacks-network/stacks-core/releases/tag/4.0.0
- Block explorer: https://explorer.hiro.so/?chain=mainnet
- Official Twitter/X: https://x.com/Stacks
Note: The Stacks Foundation recently migrated to stacks.foundation. You can access this post via stacks.org/release-4-0 if you still have stacks.org listed as your official domain of record for STX.