A promise before consensus finishes
Users often want feedback faster than a chain can finalize blocks. A preconfirmation supplies an earlier assurance, potentially from a sequencer, builder, or participating proposer. Its meaning depends on what is promised: inclusion in a future block, a particular order, or a particular execution result are different guarantees. Research on based preconfirmations explores commitments connected to Ethereum proposers and mechanisms for making broken commitments economically costly.
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An everyday comparison
Imagine a wallet immediately displaying that a swap is expected to execute. That message could be a best-effort RPC response, a sequencer receipt, or a signed commitment backed by collateral. These are not interchangeable. If another transaction changes the pool before execution, an inclusion promise alone does not guarantee the original quoted output. A useful interface identifies the assurance received and continues tracking the transaction until its actual settlement condition is reached.
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Questions that reveal the real guarantee
Ask who signs the commitment, whether users can verify it, what actions count as a breach, and how compensation is enforced. Some designs depend on an external adjudication path or on proving conflicting promises. Network faults and reorganizations also matter. An early confirmation can improve responsiveness while introducing a separate trust or economic assumption; it should not be displayed as irreversible settlement simply because the response arrived quickly or used a familiar validator's identity.
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The source notesEvidence & further reading2 sources
- Based preconfirmations Ethereum Research · Primary source · accessed 2026-09-21
- OP Stack transaction flow Optimism · Primary source · accessed 2026-09-21