Weekly SIP Call #164 – Call Recap | Fri, 27 Feb 2026

SIP Weekly SIP call
1

Date: Fri, February 27, 2026, at 10:30 AM Eastern Time

Hosted by: HeroGamer; PeaceLoveMusic

Guests: Brice (core dev), Francesco (core dev), Elena

Duration: ~1 hr 10 mins

Recording: https://x.com/i/broadcasts/1RKZzjzLLYaKB?s=20 starting 1:59:20 ~ 3:06:33 or watch on DeOrganized Youtube

1. Agenda Overview

  • 3 Key SIP Proposals Overview

  • at-block Proposal (Complete Removal)

  • Improved Post Conditions (SIP-040)

  • Clarity 5 Bug Fixes and Improvements (SIP-039)

  • ZeroAuthority SIP Community Page Updates

  • Technical and Social Infrastructure Progress

2. Key Meeting Highlights

3 Key SIP Proposals Overview

  • Three main proposals on the table for community feedback

  • All bundled together for single community vote ~ March

  • Timeline: hoping for quick implementation after feedback period in March

  • Core developers seeking community input before activation to avoid post-implementation issues

1) at-block Proposal (Complete Removal)

  • Current Blockchain State:

    • Current blockchain state: 1 TB storage, growing 2.7 GB per day

    • 95% of this data comes exactly from the past marked information that we we have to keep for this use case (at-block)

    • Usage statistics from the past 1 year:

      • 120 total contracts called at-block functions

      • they were called by 8 addresses

  • Latest Proposal: completely remove at-block functionality

    • Eliminates several bugs and code complexity

    • Enables pruned nodes (lighter Stacks blockchain copies)

    • Alternative methods exist for all known use cases

  • Jude N. (core dev) added in the stream chat that: “All the “pruning” does is remove the extra tries in the MARF, which has the effect of rendering at-block’ inoperable for the blocks those tries represent.”

  • Trade-offs and Safeguards:

    • Contracts using at-block need migration time before activation

    • Full archival nodes still available for those who want complete history

    • Can recreate full unpruned node from pruned nodes if needed (confirmed by Francesco)

  • Pruned nodes will enable:

    • Easier node operation for average users

    • Better decentralization through lower barriers to entry

  • Ecosystem advantage for service providers and partners integrations and business development - Elena added

2) Improved Post Conditions (SIP-040)

  • Transaction Security:

    • Introduces “originator mode” for wallet asset protection.

    • Protects transaction initiator’s wallet assets (deny mode) while allowing other parties flexibility (allow mode)

  • Adds new NFT condition: “may send” option:

    • Previously: NFT either sent or not sent

    • After upgrade: transaction can succeed whether or not specific NFT gets sent

  • Completely opt-in, non-controversial upgrade

3) Clarity 5 Bug Fixes and Improvements (SIP-039)

Multiple technical fixes and improvements bundled together:

  1. SECP256R1 verify function fix

    • Removes double-hash issue preventing web authentication compatibility

    • Enables passkey onboarding and wallet abstraction improvements

  2. Consensus buffer empty input handling

    • Returns ‘none’ instead of runtime error for empty buffers

  3. At-Block time-travel bug fixes

    • Burn block height, STX balance, and STX account functions now return correct historical values

  4. Increased stack depth limit

    • Doubled from 64 to 128 nested contract calls

    • Addresses DeFi contract complexity requirements while staying within memory limits

  5. Rejectable transactions implementation

    • Failed transactions now can be included in blocks

    • Prevents account nonce blocking issues

    • Miners get paid for processing work (currently they do the compute for this, but not get paid through collecting the gas fee)

    • Improves overall user experience

ZeroAuthority SIP Community Page Updates

  • SIP Tracker Improvements:

    • New “Get Started” section for governance newcomers

    • AI integration for SIP understanding and implementation help

    • GitHub integration with forum conversations

    • Making governance more accessible to non-GitHub native users

Technical and Social Infrastructure Progress

  • Significant technical advancement over past 2 years:

    • Moved from 10-minute block times to faster processing

    • Nakamoto upgrade completed

    • sBTC implementation

    • Improved user experience with reduced transaction stuck issues

  • Social progress

    • Weekly SIP calls gaining traction with increased forum engagement

    • Active discussion and marketing to the community - increasing awareness and engagement

    • Core developers actively participating in community discussions

:link: Resources & References

“at-block” change

Improved post-conditions

Clarity 5 and Epoch 3.4

:megaphone: Call To Action

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