claude-dev-suite Lightning BOLTs
Quick refs: bolt-summary.md, feature-bits.md
The Lightning Network's specs live in github.com/lightning/bolts.
There are 11 numbered BOLTs plus several "BLIPs" (BOLT improvement
proposals) for in-progress extensions.
BOLT Index
| BOLT | Title |
|---|---|
| 1 | Base Protocol — wire format, init, ping, error |
| 2 | Peer Protocol — channel open/close/update |
| 3 | Bitcoin Transaction and Script Formats — funding, commitment, HTLC, anchor |
| 4 | Onion Routing Protocol — Sphinx packet, payment forwarding |
| 5 | Recommendations for On-chain Transaction Handling |
| 7 | P2P Node and Channel Discovery — gossip |
| 8 | Encrypted and Authenticated Transport — Noise XK handshake |
| 9 | Assigned Feature Flags — feature bit registry |
| 10 | DNS Bootstrap and Assisted Node Location (deprecated) |
| 11 | Invoice Protocol — BOLT11 |
| 12 | Flexible Protocol for Lightning Payments — BOLT12 offers |
Concepts spread across BOLTs
- Channels (BOLT 2/3): two-party state channel with on-chain funding output spent into a sequence of off-chain commitment txs.
- HTLCs (BOLT 2/3/4): hash-time-locked contracts route payments across multiple channels atomically.
- Onion routing (BOLT 4): Sphinx-style; each hop sees only the next hop, not source / destination.
- Gossip (BOLT 7): nodes announce themselves and channels; pathfinders use this graph.
- Wire encryption (BOLT 8): Noise_XK handshake; ChaCha20-Poly1305 per-message.
Versioning
Lightning's wire protocol is append-only with feature bits:
- Init message exchanges feature bits.
- New features negotiated, not breaking changes.
- Implementations must gracefully degrade for unknown bits.
Major recent additions
- Anchor outputs (BOLT-3 update, ~2020).
- Dual-funded channels (BOLT 2 v2, ~2022).
- Splicing (BOLT 2 splice, partial deployment 2024-2025).
- Taproot channels ("simple-taproot-chans", proposal/early deployment).
- BOLT12 (offers, blinded paths) — adopted by CLN; LND in progress.
- Async payments — partial deployment via "trampoline-light" and similar.
Implementations and feature support
| Feature | LND | CLN | LDK | Eclair |
|---|---|---|---|---|
| Static channels (legacy) | yes | yes | yes | yes |
| Anchor commitment | yes | yes | yes | yes |
| Dual-funded | partial | yes | partial | yes |
| MPP / AMP | yes | yes | yes | yes |
| Trampoline | partial | yes | yes | yes |
| BOLT12 offers | partial | yes | yes | yes |
| Taproot channels | partial | partial | partial | partial |
| Splicing | partial | yes | partial | yes |
(Status as of late 2025; check current docs for latest.)
Test vectors
Lightning has test vector files (bolt03-tx-test-vectors.json,
bolt04-onion-test-vectors.json, etc.) that all impls verify
against. Used as part of CI.
Reading order
For new implementers:
- BOLT 1 — message framing.
- BOLT 8 — encryption.
- BOLT 2 — channel state machine.
- BOLT 3 — funding, commitment, HTLC scripts.
- BOLT 4 — onion routing.
- BOLT 7 — gossip.
- BOLT 11 / 12 — invoices / offers.