Newsletters: add 397 (2026-03-20)

_posts/en/newsletters/2026-03-20-newsletter.md

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+---
+title: 'Bitcoin Optech Newsletter #397'
+permalink: /en/newsletters/2026/03/20/
+name: 2026-03-20-newsletter
+slug: 2026-03-20-newsletter
+type: newsletter
+layout: newsletter
+lang: en
+---
+This week's newsletter includes our regular sections describing changes
+to services and client software, announcing new releases and release
+candidates, and summarizing recent changes to popular Bitcoin
+infrastructure software.
+
+## News
+
+*No significant news this week was found in any of our [sources][].*
+
+## Changes to services and client software
+
+*In this monthly feature, we highlight interesting updates to Bitcoin
+wallets and services.*
+
+- **Cake Wallet adds Lightning support:**
+  Cake Wallet [announced][cake ln post] Lightning Network support using the
+  Breez SDK and a [Spark][topic statechains] integration, including Lightning
+  addresses.
+
+- **Sparrow 2.4.0 and 2.4.2 released:**
+  Sparrow [2.4.0][sparrow 2.4.0] adds [BIP375][] [PSBT][topic psbt] fields for
+  [silent payment][topic silent payments] hardware wallet support and adds a
+  [Codex32][topic codex32] importer. Sparrow [2.4.2][sparrow 2.4.2] adds [v3
+  transaction][topic v3 transaction relay] support.
+
+- **Blockstream Jade adds Lightning via Liquid:**
+  Blockstream [announced][jade ln blog] that Jade hardware wallet (via Green app
+  5.2.0) can now interact with Lightning using [submarine swaps][topic submarine
+  swaps] that convert Lightning payments to [Liquid][topic sidechains] Bitcoin
+  (L-BTC), keeping keys offline.
+
+- **Lightning Labs releases agent tools:**
+  Lightning Labs [released][ll agent tools] an open-source toolkit enabling AI
+  agents to operate on Lightning without human intervention or API keys using
+  the [L402 protocol][blip 26].
+
+- **Tether launches MiningOS:**
+  Tether [launched][tether mos] MiningOS, an open-source operating system for
+  managing Bitcoin mining operations. The Apache 2.0 licensed software is
+  hardware-agnostic with a modular, P2P architecture.
+
+- **FIBRE network relaunched:**
+  Localhost Research [announced][fibre blog] the relaunch of FIBRE (Fast
+  Internet Bitcoin Relay Engine), previously shut down in 2017.
+  The reboot includes a Bitcoin Core v30 rebase and monitoring suite,
+  with six public nodes deployed globally. FIBRE complements [compact block
+  relay][topic compact block relay] for low-latency block propagation.
+
+- **TUI for Bitcoin Core released:**
+  [Bitcoin-tui][btctui tweet], a terminal interface for Bitcoin Core, connects
+  via JSON-RPC to display blockchain and network data, featuring mempool
+  monitoring, transaction search and broadcasting, and peer management.
+
+## Releases and release candidates
+
+_New releases and release candidates for popular Bitcoin infrastructure
+projects.  Please consider upgrading to new releases or helping to test
+release candidates._
+
+FIXME:Gustavojfe
+
+## Notable code and documentation changes
+
+_Notable recent changes in [Bitcoin Core][bitcoin core repo], [Core
+Lightning][core lightning repo], [Eclair][eclair repo], [LDK][ldk repo],
+[LND][lnd repo], [libsecp256k1][libsecp256k1 repo], [Hardware Wallet
+Interface (HWI)][hwi repo], [Rust Bitcoin][rust bitcoin repo], [BTCPay
+Server][btcpay server repo], [BDK][bdk repo], [Bitcoin Improvement
+Proposals (BIPs)][bips repo], [Lightning BOLTs][bolts repo],
+[Lightning BLIPs][blips repo], [Bitcoin Inquisition][bitcoin inquisition
+repo], and [BINANAs][binana repo]._
+
+FIXME:Gustavojfe
+
+{% include snippets/recap-ad.md when="2026-03-24 16:30" %}
+{% include references.md %}
+{% include linkers/issues.md v=2 issues="" %}
+[sources]: /en/internal/sources/
+[cake ln post]: https://blog.cakewallet.com/our-lightning-journey/
+[sparrow 2.4.0]: https://github.com/sparrowwallet/sparrow/releases/tag/2.4.0
+[sparrow 2.4.2]: https://github.com/sparrowwallet/sparrow/releases/tag/2.4.2
+[jade ln blog]: https://blog.blockstream.com/jade-lightning-payments-are-here/
+[ll agent tools]: https://github.com/lightninglabs/lightning-agent-tools
+[blip 26]: https://github.com/lightning/blips/pull/26
+[x402 blog]: https://blog.cloudflare.com/x402/
+[tether mos]: https://mos.tether.io/
+[fibre blog]: https://lclhost.org/blog/fibre-resurrected/
+[btctui tweet]: https://x.com/_jan__b/status/2031741548098896272