Optimistic Stream Entry

An Optimistic Stream Entry is a PoH Entry for the current slot, produced and validated within the BBM pipeline and emitted before the validator publishes the corresponding entries as part of the produced slot.

The entry follows standard Solana PoH Entry semantics and structure, but is exposed prior to validator-level dissemination.

Structure

Each Optimistic Stream Entry contains:

Slot Context

  • slot The slot number this entry belongs to.

PoH Data

  • num_hashes The number of PoH hash iterations (ticks) since the previous entry.

  • hash The PoH hash at the time the entry was produced.

Transactions

  • transactions[] A list of transactions included in the entry. The list may be empty for tick-only entries.

All transactions included in an Optimistic Stream Entry:

  • are fully validated

  • are executable against the BBM local state view at emission time

  • are ordered according to the actual execution order used by BBM

Execution semantics

  • Entries are emitted strictly in PoH order

  • Transaction ordering within an entry matches BBM execution order

  • Entries represent concrete execution results, not proposed or speculative transactions

Optimistic properties

An Optimistic Stream Entry:

  • has not yet been published by the validator

  • may be replaced by a different PoH Entry for the same slot if the validator does not disseminate the entry produced by BBM

  • may be dropped due to fork selection, in the same manner as canonical entries

Optimistic Stream Entries therefore represent a pre-publication view of slot contents rather than a finalized or network-visible state.

Canonical entry comparison

A Canonical Entry is a PoH Entry that:

  • has been published by the validator as part of the produced slot

  • is visible to the network as part of the current slot contents

Canonical Entries:

  • are not replaced by alternative entries for the same slot

  • may still be dropped if the cluster selects a different fork

Intended usage

Optimistic Stream Entries are intended for:

  • low-latency consumers

  • HFT and arbitrage systems

  • pre-publication execution reactions

  • construction of optimistic ledger views prior to validator publication

Consumer requirements

Consumers of the Optimistic Entry Stream must:

  • process entries sequentially

  • support replacement of entries within the same slot

  • handle fork-related rollbacks

  • treat all entries as non-final until slot progression confirms publication

Summary

An Optimistic Stream Entry is a PoH Entry of the current slot, validated and ordered by BBM, emitted prior to validator publication, and therefore subject to replacement within the slot.

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