Opt-in Full Replace-by-Fee Signaling

The five-minute read

One action, walked through

1. Open BIP 125 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: Many nodes today will not replace any transaction in their mempool with another transaction that spends the same inputs, making it difficult for spenders to adjust their previously-sent transactions to deal with unexpected confirmation delays or to perform other useful replacements.
3. Name the object that changes: RBF.
4. Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.

The argument, unpacked

What has to be true

• You are implementing BIP 125 at the status the text itself states: Deployed.
• The object that has to change is RBF. A neighbouring document with a similar name is not this one.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.

What happened after the paper

The source marks this deployed. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

• What does Opt-in Full Replace-by-Fee Signaling charge, reject, or redefine on the first touch versus a later one?
• Does a reverted subcall roll the change back?
• Can you point at the object in a client: RBF?

Terms

BIP 125

The public text titled Opt-in Full Replace-by-Fee Signaling.

Deployed

The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

An underpriced or ambiguous EVM rule is not a feature. It is a block that takes longer than the gas limit claimed, or a client that disagrees about the result.

What the design proposes

• Many nodes today will not replace any transaction in their mempool with another transaction that spends the same inputs, making it difficult for spenders to adjust their previously-sent transactions to deal with unexpected confirmation delays or to perform other useful replacements.
• The opt-in full Replace-by-Fee (opt-in full-RBF) signaling policy described here allows spenders to add a signal to a transaction indicating that they want to be able to replace that transaction in the future.
• In response to this signal, Nodes may allow transactions containing this signal to be replaced in their mempools.

How the mechanism is specified

• Taken from the specification, the next constraint is: The opt-in full Replace-by-Fee (opt-in full-RBF) signaling policy described here allows spenders to add a signal to a transaction indicating that they want to be able to replace that transaction in the future.
• Locate RBF in BIP 125 and apply it to one transaction or call.
• Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.

What this page does not treat as proven

• A gas or opcode change is not a throughput benchmark. It is a relative price and a validity rule.
• Constants in the text can be superseded by a later fork. Cite the EIP number and the fork you mean.
• The source marks this deployed. That is a statement about the text, not a promise that every wallet or node has shipped it.

Why a venture studio still reads it

Use BIP 125 when a pitch says 'Opt-in Full Replace-by-Fee Signaling' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.