Lightning BOLT 9 Feature-Bits Reference: Every Assigned Bit and Its Rules
Before two Lightning nodes will transact, they compare notes on what each can do — anchors, multi-part payments, splicing, blinded paths — through a compact vector of feature bits defined by BOLT 9. Get a bit wrong and the connection or payment simply fails. This reference lists every assigned feature bit with its name, the contexts it appears in, its dependencies, and the even/odd “optional vs required” rule that governs them. It rounds out our Lightning set beside the BOLTs index and the BOLT11 invoice reference.
Quick answer
Lightning nodes advertise their capabilities with a feature-bit vector, defined by BOLT 9. Bits come in even/odd pairs: the odd bit signals "I support this (optional)", the even bit signals "I require this (compulsory)" — the "it's ok to be odd" rule that lets a feature roll out softly before becoming mandatory. This reference lists all 24 assigned bits with their option_* name, purpose, the contexts they appear in (init, node_announcement, channel_announcement, BOLT11 invoice, channel_type, blinded path) and their dependencies. Five features so universal the spec marks them "ASSUMED" (implied, not advertised) are shown as such.
The rule that matters: if both bits of a pair are set, the feature is treated as REQUIRED. Unknown even bits fail the connection/payment (a peer cannot honor a requirement it does not understand); unknown odd bits are ignored. For an invoice, the "9"-context bits override node_announcement features. Free CSV/JSON under CC BY 4.0; as of 2026-07-26.
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| Bits | Name | Description | Contexts | Depends on |
|---|---|---|---|---|
| 0/1 | option_data_loss_protect | ASSUMED implied in all modern nodes | — | — |
| 4/5 | option_upfront_shutdown_script | Commits to a shutdown scriptpubkey when opening a channel | IN | — |
| 6/7 | gossip_queries | Peer has useful gossip to share | — | — |
| 8/9 | var_onion_optin | ASSUMED implied in all modern nodes | — | — |
| 10/11 | gossip_queries_ex | Gossip queries can include additional information | IN | — |
| 12/13 | option_static_remotekey | ASSUMED implied in all modern nodes | — | — |
| 14/15 | payment_secret | ASSUMED implied in all modern nodes | — | — |
| 16/17 | basic_mpp | Node can receive basic multi-part payments | IN9 | payment_secret |
| 18/19 | option_support_large_channel | Can create large channels | IN | — |
| 22/23 | option_anchors | Anchor commitment type with zero-fee HTLC transactions | INT | — |
| 24/25 | option_route_blinding | Node supports blinded paths | IN9 | — |
| 26/27 | option_shutdown_anysegwit | Future segwit versions allowed in shutdown | IN | — |
| 28/29 | option_dual_fund | Use v2 of channel open, enables dual funding | IN | — |
| 34/35 | option_quiesce | Support for the stfu (quiescence) message | IN | — |
| 36/37 | option_attribution_data | Can generate/relay attribution data in update_fail_htlc and update_fulfill_htlc | IN9 | — |
| 38/39 | option_onion_messages | Can forward onion messages | IN | — |
| 40/41 | zero_fee_commitments | Zero-fee commitment and HTLC transactions | IN | option_channel_type |
| 42/43 | option_provide_storage | Can store other nodes' encrypted backup data | IN | — |
| 44/45 | option_channel_type | ASSUMED implied in all modern nodes | — | — |
| 46/47 | option_scid_alias | Supply channel aliases for routing | INT | — |
| 48/49 | option_payment_metadata | Payment metadata in a tlv record | 9 | — |
| 50/51 | option_zeroconf | Understands zeroconf channel types | INT | option_scid_alias |
| 60/61 | option_simple_close | Simplified closing negotiation | IN | option_shutdown_anysegwit |
| 62/63 | option_splice | Allows replacing the funding transaction with a new one | IN | — |
Context legend
I Presented in the init message.N Presented in node_announcement messages.C Presented in the channel_announcement message.C- Presented in channel_announcement, but always odd (optional).C+ Presented in channel_announcement, but always even (required).9 Presented in BOLT11 invoices.B Presented in the allowed_features field of a blinded path.T Used in the channel_type field when opening channels.Source: the canonical BOLT 9 from lightning/bolts (09-features.md, fetched 2026-07-26). Pairs with the Lightning BOLTs reference and the BOLT11 invoice reference (where the "9"-context bits show up).
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Last reviewed July 26, 2026.