v0.6.1: Principled Opposition to SegWit

We're pleased to announce c-lightning 0.6.1, named by co-maintainer ZmnSCPxj.

Highlights for c-lightning users

• Less stuck payments: Liveness ping test before locking up funds with peers.
• Better routing: now considers size of channels.
• Fewer spurious closes: fee estimate improvements, and new feerates command
• Several annoying bugs fixed.

Highlights for the network

• Gossipd now less spammy with channel_update.
• option_data_loss_protect to protect peers against being out-of-date.
• Payment errors now refer to the correct channel.

Internal Improvements

• Simplified client flow; after init message exchange by connectd, each is isolated in its own daemon.
• JSON parameter handling vastly simplfied.
• Python testing framework now uses proper fixtures, and split into separate files.
• Many other cleanups and clarifications.
• We keepachangelog.com!

The details can be found in the CHANGELOG:
https://github.com/ElementsProject/lightning/blob/v0.6.1/CHANGELOG.md

Contributions

We're grateful for all the bug reports and suggestions and your patience as we sometimes struggled to address them: please keep them coming!

Since 0.6 we've had 517 commits from 31 different authors, 15 of whom were first-time c-lightning contributors:

Bertrand Marlier
Cryptcoin Junkey
Fabian Raetz
Hiroki Gondo
Jonathan Zernik
Jordan Baczuk
Ronald Mannak
Simon Vrouwe
Stephanie Stroka
gallizoltan
lisa neigut
lucash-dev
mikhaelsantos
tock203
wintercooled

Cheers,
Rusty, Christian and ZmnSCPxj.

v0.6

While there are far too many new features in the 0.6 release to list, the following are the most interesting and impactful:

• Lightweight nodes: Previous releases required a full bitcoind node
  running alongside c-lightning, to provide access to the Bitcoin network. This
  release still requires the bitcoin-cli utility to be present, but it can
  now talk to remote nodes as well, including some lightweight nodes such as
  spruned. This makes it possible to run a c-lightning node on
  Raspberry Pis as well as other low-powered devices.
• The gossip protocol has been updated to use a more lightweight bandwidth
  mechanism that asks for specific information, rather than exchanging full
  network views as the previous release did. This is particularly important for
  low-powered and mobile devices that would otherwise spend a lot of bandwidth
  and energy downloading and verifying information they already have.
• API stability: The c-lightning JSON-RPC interface and supporting
  libraries have been redesigned in order to minimize changes in future
  releases. This API stability should make it easy for other projects to build
  on top of c-lightning because we will support this version of the API for the
  foreseeable future, maintaining backward compatibility, should we introduce
  any changes.
• Wallet and sync: c-lightning now includes a full-fledged wallet that
  manages both on-chain and off-chain funds. There is no more raw transaction
  handling! All funds are automatically tracked and returned to the internal
  wallet as soon as possible, with no user interaction required. In addition
  the blockchain tracking now maintains an internal view of the blockchain,
  ending long blockchain rescans.
• TOR support: c-lightning now supports connecting to nodes over the TOR
  network, auto-registering as a hidden service, and accepting incoming
  connections over TOR.
• The payment logic has undergone a major overhaul to support automatic
  retries for routing failures, randomization of route selection, and better
  feedback about the current state of a payment.
• And as always: performance, performance, performance.

v0.6rc2

Hope to release Monday...