BIP 148 — Mandatory activation of segwit deployment

BIP 148 (Mandatory activation of segwit deployment) specified a user-activated soft fork (UASF): from 2017-08-01, enforcing nodes would reject blocks that did not signal for SegWit, creating economic pressure for activation. In the event, miner signaling locked SegWit in via the version-bits pathway (coordinated through a separate miner-activated deployment) shortly before the flag day. Repository status: Deployed.

Debate relevance: The canonical case study in 'users vs miners' governance debates and in arguments over whether economic nodes can compel activation. Its causal role in SegWit's lock-in is itself a debated historical question. Common misstatements: "BIP 148 activated SegWit" stated as settled fact — SegWit locked in through version-bits signaling; how much the UASF threat drove that signaling is genuinely contested. Also confusing BIP 148 (UASF) with the miner-coordinated deployment that preceded the flag day.