Skip to main content
£0.00 0

Basket

No products in the basket.

ASIC mining articles and advice

Bitcoin Core psbtbumpfee RPC: Offline RBF Fee Guide

Bitcoin Core 0.21 psbtbumpfee guide covering wallet and mempool prerequisites, sat/vB fees, change handling, replacement policy, PSBT review and signing.

Bitcoin Core psbtbumpfee RPC guide cover

This guide explains Bitcoin Core psbtbumpfee RPC in plain English. It shows what the command does, what its result means and what it cannot prove.

TL;DR

  • What it is: Bitcoin Core 0.21 psbtbumpfee constructs a replacement for an opt-in Replace-by-Fee wallet transaction and returns a PSBT rather than signing or broadcasting it. It keeps every original input, may reduce or create change and can add inputs when necessary.
  • Why it matters: psbtbumpfee separates fee replacement construction from signing, which is useful for controlled custody. That safety exists only when operators verify the new fee, every output, any added input and the replacement state before authorisation.
  • Current position: Require a second reviewer and explicit rollback or expiry, and pause payments, signing or network-dependent services until post-change evidence is complete.

Bitcoin Core psbtbumpfee RPC in simple English

Bitcoin Core psbtbumpfee RPC: The txid must identify an opt-in-RBF transaction in the selected wallet. Core fails when the wallet or mempool already contains a transaction spending an output of the original, so reconcile replacement state first.

Simple example

A miner is checking Bitcoin Core psbtbumpfee RPC. Compare recipient scripts and amounts, input set, fee, vsize, locktime, sequences and change ownership. In 0.21 fee_rate is satoshis per virtual byte, replacing the pre-0.21 BTC-per-kilobyte unit.

Key terms in plain English

BIP:
Bitcoin Improvement Proposal: a document describing a proposed rule, standard or process. Its status must be checked separately.
Bitcoin Core:
Widely used software that validates Bitcoin and can provide wallet, network and operator tools.
RPC:
A command that software sends to a node to request information or a local action.
Mempool:
A node’s changing local collection of valid, unconfirmed transactions.
PSBT:
A portable format for passing an unsigned or partly signed Bitcoin transaction between tools and signers.

Eligibility

The txid must identify an opt-in-RBF transaction in the selected wallet. Core fails when the wallet or mempool already contains a transaction spending an output of the original, so reconcile replacement state first.

Fee units

In 0.21 fee_rate is satoshis per virtual byte, replacing the pre-0.21 BTC-per-kilobyte unit. Pin the RPC version and reject ambiguous configuration during mixed-version migrations.

Estimator or explicit rate

Without fee_rate the wallet uses estimatesmartfee, optionally with a block confirmation target and economical or conservative mode. An explicit rate must satisfy replacement and incremental relay requirements.

Bitcoin Core psbtbumpfee RPC technical diagram
Estimator or explicit rate: the fields, validation boundary and operational evidence that implementations need to agree.

Replacement construction

All original inputs remain. Core can reduce change, add inputs or create a new change output. Compare recipient scripts and amounts, input set, fee, vsize, locktime, sequences and change ownership.

Replaceable option

The default leaves the replacement BIP 125 replaceable. Setting false raises qualifying sequence numbers, but unconfirmed replaceable ancestors can still make practical replacement possible.

PSBT result

The response includes base64 PSBT, original fee, new fee and an errors array. It is a proposal, not evidence of signatures, broadcast, mempool acceptance or confirmation.

Signing workflow

Decode and analyse on a trusted node, show the fee delta and recipient invariants to approvers, sign using isolated devices, finalise, test mempool acceptance and broadcast once under idempotent controls. Build a revision-pinned evidence pack on an isolated node, wallet or protocol harness. Record source commit, binary hash, network, chain identity, configuration and dependencies.

Frequently asked questions

What is the main point of Bitcoin Core psbtbumpfee RPC?

Bitcoin Core psbtbumpfee RPC: The txid must identify an opt-in-RBF transaction in the selected wallet.

For Bitcoin Core psbtbumpfee RPC, what should a beginner know about eligibility?

The txid must identify an opt-in-RBF transaction in the selected wallet.

For Bitcoin Core psbtbumpfee RPC, what should a beginner know about fee units?

In 0.21 fee_rate is satoshis per virtual byte, replacing the pre-0.21 BTC-per-kilobyte unit.

For Bitcoin Core psbtbumpfee RPC, what should a beginner know about estimator or explicit rate?

Without fee_rate the wallet uses estimatesmartfee, optionally with a block confirmation target and economical or conservative mode.

Conclusion

psbtbumpfee separates fee replacement construction from signing, which is useful for controlled custody. That safety exists only when operators verify the new fee, every output, any added input and the replacement state before authorisation.

Primary sources

Check the current specification status and the documentation for the exact implementation you operate before moving production funds or changing a mining node.

ASIC MINER PICKS

Recommended ASIC Mining Hardware

Compare three of our highest ranked ASIC miners currently available, with live product details and pricing.
Browse all ASIC miners
MORE MINING ADVICE

More ASIC Mining Articles

Read practical advice about choosing hardware, calculating electricity costs, setting up miners, hosting and maintenance.
MINER COMMUNITY

Join the ASIC Mining Discussion

Ask a question or share what has worked for you. Your experience may help another miner make a better decision.

Members can read and join the discussion

Log in to read comments from other miners. Create a free account if you would like to ask a question or share your experience.

Log in to read comments Register to join the discussion

Membership helps us protect the discussion from spam and keep answers useful.

ASIC MINING SUPPORT

Need Help Choosing an ASIC Miner?

Tell us what you want to mine, your electricity cost and where the machine will run. We can help you compare hardware, power requirements, hosting and repairs.
Contact our mining team
Browse ASIC miners