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TERM_DEF // UPGRADES_BIPS / BIP_159_NODE_NETWORK_LIMITED_SERVICE_BIT
BIP 159 (NODE_NETWORK_LIMITED
SERVICE BIT)
node-network-limited-service-bit/">BIP 159 (NODE_NETWORK_LIMITED Service Bit). Service bit advertising a pruned node's limited block availability.

This page sits in the Upgrades & BIPs section — The proposal process and the major upgrades that shaped Bitcoin. Read on for what it is, why it exists, how it works under the hood, and what to watch out for.
WHAT_BIP_159_NODE_NETWORK_LIMITED_SERVICE_BIT_IS
BIP 159 (NODE_NETWORK_LIMITED Service Bit) — at a glance
UPGRADES
BIP 159 — "NODE_NETWORK_LIMITED Service Bit" is a proposal in the Networking family, first published in 2018 with status final. Service bit advertising a pruned node's limited block availability. Its technical mechanism: NODE_NETWORK_LIMITED service bit indicating only last ~288 blocks served. lets pruned nodes still contribute to the network for IBD-tail clients
Why it exists
DESIGN
BIP 159 (NODE_NETWORK_LIMITED Service Bit) exists to solve a specific problem: support pruned full nodes serving recent blocks to peers. Without a written, numbered spec, every wallet and node implementer would interpret the requirement differently — and Bitcoin's value depends on every implementation agreeing exactly. BIP-159 is the single source of truth for this concern, so any new client built today can match the behaviour of every client built since 2018.
HOW_IT_WORKS
Mechanism
HOW IT WORKS
Mechanically, BIP-159 nODE_NETWORK_LIMITED service bit indicating only last ~288 blocks served. Adoption today: lets pruned nodes still contribute to the network for IBD-tail clients.
1. Author drafts BIP-159 against the BIP-2 template — abstract, motivation, specification, rationale. 2. The text + a reference implementation are posted on the bitcoin-dev list and as a PR to bitcoin/bips. 3. Reviewers tear it apart: ambiguities, security concerns, edge cases, interaction with prior BIPs. 4. Once stable, the BIP editor merges it; it gets a number (BIP-159) and the status "draft" or "proposed". 5. Implementations land in Bitcoin Core / wallets / other clients. For consensus changes: activation parameters chosen. 6. After deployment + adoption, BIP-159 is promoted to "final"; deprecated proposals get "replaced" or "withdrawn".
WORKED_EXAMPLE
BIP-159 — quick reference card
EXAMPLE
BIP number : 159 Title : NODE_NETWORK_LIMITED Service Bit Area : Networking First published: 2018 Status : final Fork class : no Motivation : support pruned full nodes serving recent blocks to peers. Mechanism : NODE_NETWORK_LIMITED service bit indicating only last ~288 blocks served. Where it shows up : lets pruned nodes still contribute to the network for IBD-tail clients. Read the spec : https://github.com/bitcoin/bips/blob/master/bip-0159.mediawiki
KEY_PROPERTIES
OPT-IN
No authority can force a BIP on anyone. Adoption depends entirely on whether the change is genuinely useful.
NUMBERED
Stable numeric reference — BIP-159 means the same thing across every wallet, miner, and node that has read this spec.
NON-CONSENSUS
BIP-159 is not a consensus rule — clients can implement it without coordinating with the network at large.
DEPLOYED
Implementations of BIP-159 are in production. The behaviour is observable on mainnet today.
COMMON_PITFALLS
Things that catch people out
PITFALLS
  • Don't confuse "draft" / "proposed" / "final" status — read the BIP header before relying on it in production.
  • The BIP number is just an editorial counter — it doesn't imply correctness or stability. Always cross-reference with the latest bitcoin/bips repo.
RELATED_CONCEPTS
Other terms from Upgrades & BIPs — click any to read its page:
Segregated Witness (SegWit, BIP 141) Taproot (BIP 341) Tapscript (BIP 342) Schnorr (BIP 340) BIP Process Soft Fork Activation MASF (Miner-Activated Soft Fork) UASF (User-Activated Soft Fork)
TERMINOLOGY_INDEX
TERMINOLOGY
BIP 159 (NODE_NETWORK_LIMITED Service Bit)
Service bit advertising a pruned node's limited block availability.
Segregated Witness (SegWit, BIP 141)
The 2017 upgrade separating witness-data/">witness data, fixing tx malleability, and introducing weight units.
Taproot (BIP 341)
The 2021 upgrade introducing key-aggregable schnorr-signatures/">Schnorr signatures and Merkleized script trees.
Tapscript (BIP 342)
Script-language updates accompanying Taproot — new opcodes, removed limits.
Schnorr (BIP 340)
The Schnorr signature spec adopted by Taproot.
BIP Process
The community workflow for proposing, discussing, and tracking changes to Bitcoin.
Soft Fork Activation
The mechanism (versionbits, MASF, UASF, Speedy Trial) by which soft forks turn on.
MASF (Miner-Activated Soft Fork)
Activation triggered by miner signaling in block versions.