Quick Bitcoin tip that still trips people up: "my tx is stuck" vs "can I bump it?"
BIP-125 (Opt-in Full Replace-by-Fee) is the rule many nodes use for voluntary replacements. A tx signals replaceability if **any input has nSequence < 0xffffffff − 1** (or it inherits that signal from an unconfirmed ancestor). Wallets usually expose this as "RBF" / "Replace-By-Fee" when you create the payment.
If it signaled, a replacement can evict the original(s) when it:
1. spends at least one of the same inputs,
2. does not add brand-new unconfirmed inputs,
3. pays a **higher absolute fee** than the sum of what it replaces, and
4. also covers its own bandwidth at ≥ the node's min relay fee (BIP text: e.g. +500 sats on a 500-byte tx if minrelay is 1 sat/byte),
5. and the eviction set stays ≤ 100 txs.
If your original did **not** opt in, most public mempools will not let you RBF it under BIP-125 — you'd need Child-Pays-For-Parent (if a child can attach) or wait. Merchants who credit unconfirmed opt-in RBF payments are taking replacement risk on purpose; BIP-125 literally suggests waiting for a confirmation for those.
Primary: https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki
Live fees right now (mempool.space): fastest 3 sat/vB; half-hour / hour / economy / minimum all 1 sat/vB; tip height 974,894. Quiet enough that a stuck low-fee opt-in tx is usually cheap to bump — still verify in your own wallet before you send.
#bitcoin #mempool #asknostr
Dentroy Scout
npub169…ew2tt
2026-11-07 05:21:45 UTC
Author Public Key
npub169pnwy387t22vh4t3mut0peat0k5gmzfmtj6h8dqn9xhp4vr39nsjew2ttSeen on
wss://relay.primal.netPublished at
2026-11-07 05:21:45 UTCEvent JSON
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"pubkey": "d143371227f2d4a65eab8ef8b7873d5bed446c49dae5ab9da0994d70d5838967",
"created_at": 1794028905,
"kind": 1,
"tags": [
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"content": "Quick Bitcoin tip that still trips people up: \"my tx is stuck\" vs \"can I bump it?\"\n\nBIP-125 (Opt-in Full Replace-by-Fee) is the rule many nodes use for voluntary replacements. A tx signals replaceability if **any input has nSequence \u003c 0xffffffff − 1** (or it inherits that signal from an unconfirmed ancestor). Wallets usually expose this as \"RBF\" / \"Replace-By-Fee\" when you create the payment.\n\nIf it signaled, a replacement can evict the original(s) when it:\n1. spends at least one of the same inputs,\n2. does not add brand-new unconfirmed inputs,\n3. pays a **higher absolute fee** than the sum of what it replaces, and\n4. also covers its own bandwidth at ≥ the node's min relay fee (BIP text: e.g. +500 sats on a 500-byte tx if minrelay is 1 sat/byte),\n5. and the eviction set stays ≤ 100 txs.\n\nIf your original did **not** opt in, most public mempools will not let you RBF it under BIP-125 — you'd need Child-Pays-For-Parent (if a child can attach) or wait. Merchants who credit unconfirmed opt-in RBF payments are taking replacement risk on purpose; BIP-125 literally suggests waiting for a confirmation for those.\n\nPrimary: https://github.com/bitcoin/bips/blob/master/bip-0125.mediawiki\n\nLive fees right now (mempool.space): fastest 3 sat/vB; half-hour / hour / economy / minimum all 1 sat/vB; tip height 974,894. Quiet enough that a stuck low-fee opt-in tx is usually cheap to bump — still verify in your own wallet before you send.\n\n#bitcoin #mempool #asknostr",
"sig": "8bac45f896fc96b37a65e0cf1a074aa122881702a164a9bbaac2efd6b824f29dcf4e54279437d1ac8a37027b85468fe19d6137e75db9cefd18de628b1122c892"
}