Polar

Polar 4.0.0

One-click Bitcoin Lightning networks for local app development & testing

  • By jamaljsr
  • Open Source
  • Updated Dec 29, 2025
Download for Windows

About Polar

One-click Bitcoin Lightning networks for local app development & testing

What's new in 4.0.0

This release introduces two new major features into Polar.
1. Adds a new Model Context Protocol (MCP) server into Polar which allows AI assistants (Claude Code, Codex, Cursor, etc) to perform automated actions within Polar. They now have the ability to create networks, open channels, make payments, mint assets, and many more via 48 MCP tools. You can describe complex network scenarios in plain English and and let the AI set them up. Learn more about the MCP capabilities and how to configure it in the README for @lightningpolar/mcp NPM package. ▶️ View the demo video
2. Adds the ability to simulate realistic Lightning payments between the nodes. You can create activity rules by specifying a source, destination, amount, and time interval. Each activity will automate sending payments across the network while the simulation is running. This feature was made possible by integrating sim-ln into Polar.
Features
- Add sim-ln integration to simulate realistic Lightning payments by @Abdulkbk in #1159
- Retain custom block count input for "Manually Mine Blocks" by @Jem256 in #1300
- Add Model Context Protocol (MCP) server for AI assistant integration by @jamaljsr in #1328
Bug Fixes
- Fixed Core Lightning gRPC API not being accessible to host by @Abdulkbk in #1238
- Use correct ports for litd gRPC and REST endpoints by @jcbrand in #1315
- Add arm64 release builds for all platforms by @jamaljsr in #1349
Node Updates
- Add support for LND v0.19.2-beta by @jamaljsr in #1248
- Add support for LND v0.19.3-beta by @jamaljsr in #1325
- Add support for LND v0.20.0-beta by @jamaljsr in #1325
- Add support for Core Lightning v25.09.3 by @jamaljsr in #1325
- Add support for Core Lightning v25.12 by @jamaljsr in #1345
- Add support for Eclair v0.13.1 by @jamaljsr in #1326
- Add support for Taproot Assets v0.6.1-alpha by @jamaljsr in #1248
- Add support for Terminal (litd) v0.15.1-alpha by @jamaljsr in #1248
- Add support for Terminal (litd) v0.15.3-alpha by @jamaljsr in #1325
- Add support for Terminal (litd) v0.16.0-alpha by @jamaljsr in #1330
- Add support for Bitcoin Core v30.0 by @jamaljsr in #1326
New Contributors
- @jcbrand made their first contribution in #1315
Full Changelog: v3.3.0...v4.0.0

Full release notes »

Technical details

Publisherjamaljsr
Version4.0.0
Release date2025-12-29
LicenseMIT
Installer typenullsoft
Architecturex64, arm64
Package IDjamaljsr.Polar

Install Polar from the command line

Install with Windows Package Manager
winget install --id=jamaljsr.Polar -e
Update to the latest version
winget upgrade --id=jamaljsr.Polar -e
Uninstall
winget uninstall --id=jamaljsr.Polar -e
Silent install with the offline installer
"polar-win-x64-v4.0.0.exe" /S

bitcoindockerelectronlightningreact

Polar version history

  • 3.3.0
  • 3.2.0
  • 3.1.0
  • 3.0.0
  • 2.2.0
  • 2.1.0
  • 2.0.0
  • 1.4.0
  • 1.3.0

Frequently asked questions

Is Polar free?

Yes. Polar is free and open-source software released under the MIT license.

What is the latest version of Polar?

The latest version is 4.0.0, released on Dec 29, 2025.

Is it safe to download Polar?

The download button links to the official installer published on github.com, the same file Windows Package Manager installs. You can verify the downloaded file by comparing its SHA-256 checksum with 73cbfe0b90a7da161c7718e79f51fd368ad7a887a2d5dfd575e92dac782af056.

Which Windows versions does Polar support?

Polar runs on Windows and is available for 64-bit (x64), ARM64 systems.

How do I install Polar silently?

Run the offline installer with "polar-win-x64-v4.0.0.exe" /S, or install it with Windows Package Manager: winget install --id=jamaljsr.Polar -e --silent.

How do I uninstall Polar?

Open Settings › Apps › Installed apps, find Polar and select Uninstall. From the command line, run winget uninstall --id=jamaljsr.Polar -e.

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