# Thoughts on the upcoming activation of succinctness

**URL:** <https://talk.neptune.cash/t/thoughts-on-the-upcoming-activation-of-succinctness/421>\
**Category:** General\
**Created:** [October 30, 2026, 12:18pm UTC](https://talk.neptune.cash/t/thoughts-on-the-upcoming-activation-of-succinctness/421 "2026-10-30T12:18:31Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sword-smith](https://talk.neptune.cash/user_avatar/talk.neptune.cash/sword-smith/32/20_2.png) [@sword-smith](https://talk.neptune.cash/u/sword-smith)\
**Post date:** [October 30, 2026, 12:18pm UTC](https://talk.neptune.cash/t/thoughts-on-the-upcoming-activation-of-succinctness/421/1 "2026-10-30T12:18:31Z")

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This post is to explain some design decisions about our activation of succinctness, the epsilon soft fork.

As many of you know, [the PR](https://github.com/Neptune-Crypto/neptune-core) has been opened, with a plan of activation at block height 61,000. Regularly users don’t have to upgrade before that that but miners and exchanges _must_, or they risk being forked off on the wrong chain.

The PR is currently undergoing review and will be merged any day now.

- Activation through a softfork is a defensive strategy: All existing block rules stay in force. That means that the thoroughly vetted consensus rules stay in place. The softfork only _adds_ more rules for what it means for a block to be valid. Stated differently: If there were holes in the new logic, the old logic would still guarantee the soundness of the blockchain.
- Softfork epsilon leaves a gap in archival vs. succinct block verification: the so-called chunk dictionaries are not verified the same way in the VM as on the host machine. This does not affect the no-double spending guarantee. That works in both models. The reason for leaving this gap is the in-VM cost of the check, which would make block proof production too expensive. This gap will be closed soon.
- During this development it was discovered that the per-block input limit was less than we anticipated, in the hundreds, not in the thousands where we want it to be. This, combined with the above-mentioned gap, means that the epsilon softfork will be followed up by a hardfork that removed the chunk dictionaries from the blocks. That future hardfork will serve three purposes: increase input throughput per block by at least a factor 10, remove the archival/succinctness gap in block validation, and change the transaction logic to allow for inputs in the coinbase transaction, a feature a smart contract developer has requested.