Fiber Dev Log 2026-07-23

[chenyukang]

Updates

The v0.9 release entered its final hardening phase over the past two weeks. As of July 23, 2026, the latest pre-release is v0.9.0-rc7, with the remaining work focused on completing the final v0.9 milestone before release (90% complete).

Recent development focused on Cross-Chain Hub (CCH) payment safety, operator-facing diagnostics, authorization reliability, release packaging, and further cleanup of gossip and channel-state edge cases.

On the product and developer experience side, fiber-pay v0.3.0 introduced multi-asset FiberNodeButton workflows and a live preview example. Meanwhile, a new CCH guide demonstrated how to pay a Bitcoin Lightning invoice with CKB UDT over Fiber.

Ongoing Integration testing also uncovered several CCH concurrency and recovery issues, leading to active work on recoverable receive-btc creation, invoice tracker coalescing, LND payment recovery after restart, and safer final TLC expiry defaults.

Features

fiber-pay v0.3.0 and multi-asset payment UI

• fiber-pay v0.3.0 expanded multi-asset FiberNodeButton workflows, added a live preview example, updated landing-page materials, and carried forward UDT-flow hardening from the v0.2.8 cycle.
  • fiber-pay v0.3.0 release
  • feat(react): support multi-asset FiberNodeButton workflows
  • chore(examples): add FiberNodeButton live preview
  • fix(react): harden UDT payment flows

CCH developer demo and onboarding material

We published a guide demonstrating how to pay a Bitcoin Lightning invoice with CKB UDT on Fiber. This demo complements the node-side CCH reliability work currently undergoing review.

• Paying a Bitcoin Lightning invoice with CKB UDT on Fiber

Improvements & Fixes

CCH payment safety and lifecycle handling

Several improvements strengthened the CCH payment lifecycle and reduced failure scenarios.

• Added a dry-run Fiber payment preflight before creating an externally payable LND hold invoice: Preflight CCH Fiber payments before creating LND invoices
• Prevented permanent LND send errors from entering retry loops: fix(cch): stop retrying permanent LND send errors
• Kept TLC expiry randomness inside the configured hard budget: Fix payment TLC expiry limit random delta

Authorization and operator stability

Intermittent Biscuit authorization failures were addressed by increasing RPC authorizer's execution-time limit. Datalog run-limit failures now surface through RPC responses and structured logs, making authorization issues easier to diagnose.

• Fix intermittent Biscuit authorization failures

Release packaging and test infrastructure

Release-readiness work covered Windows CRT packaging, RootActor test-helper support, and a focused dependency refresh. The dependency set now includes Tentacle 0.7.6, tentacle-multiaddr 0.3.7, Tokio, regex, serde_with, async-trait, and related Rust ecosystem crates.

• Fix Windows release CRT dependency
• test: add start_for_test method for RootActor
• chore(deps): bump tentacle from 0.7.5 to 0.7.6
• chore(deps): bump tentacle-multiaddr from 0.3.6 to 0.3.7
• Merged Fiber PRs, July 10-23

In Pipeline

v0.9 finalization

Final release preparation is underway as the team completes the remaining v0.9 milestone items.

CCH recovery, invoice tracking, and payment diagnostics

The CCH queue under review centers on recoverable receive-btc creation, duplicate invoice tracker coalescing, LND payment recovery after restart, reported receive amounts, incoming invoice cleanup, default final TLC expiry, and release-safe payment diagnostics.

• fix(cch): make receive_btc creation recoverable
• Coalesce duplicate CCH LND invoice trackers
• fix: recover CCH LND payments after restart
• Add release-safe payment diagnostics RPC
• CCH receive_btc RPC timeouts still create LND invoices and CCH orders

Channel recovery and force-close settlement

Two approved PRs target reconnect and settlement gaps:

• Improved ChannelReady replay after reconnect: fix: handle ChannelReady replay on reconnect,
• Reconciled on-chain TLC settlement and discovered preimages back into channel, payment, invoice, and CCH state: feat: handle on-chain TLC settlement for force-closed channels

Gossip, message admission, and channel-announcement hardening

Gossip and message-admission hardening is actively moving under review. Upcoming merges will bound inbound message processing, rotate stalled active-sync peers, ban no-progress active sync, clean up gossip peer outbound state, ban repeated invalid channel messages, and reject spent funding cells in channel announcements.

• fix: bound inbound Fiber peer message processing
• fix: rotate stalled active gossip sync peers
• Ban peers after repeated invalid channel messages
• Ignore spent funding cells in channel gossip messages

Liquidity management prototype

The liquidity-management design remains in prototype phase. Inspired by LND Loop, the team is defining milestones for Fiber-specific manual loop-out and loop-in flows before moving the prototype into production.

• Design: Fiber liquidity management milestones