Coop is a simple, fast Nostr client for secure messaging, designed for people who want to chat without depending on one company's servers. It is free and open source under the GPL-3.0 license, and it runs on Windows, macOS and Linux. This page covers Coop for Windows, including how to install it with Scoop or the .exe installer, what it does well, and where it may fall short.
Coop is still an early-stage project. The current release is 0.3.0, and the code was last updated on December 31, 2025, so development is recent. A version below 1.0 usually means interfaces and behavior can change between releases. Readers who want a focused desktop Nostr client will find it a practical option, while those who need a broad feature set may prefer a more mature tool.
What Is Nostr and Why Does It Matter for Messaging?
Nostr is an open protocol for sending messages and posts across a network of independent servers called relays. Instead of one company holding all user accounts, each user holds a cryptographic key pair. The public key acts as an identifier that others can use to find and contact you.
This design has practical effects. If one relay goes offline or changes its policies, you can usually publish to or read from other relays. Clients such as Coop are the apps you actually use to read and write, while the protocol itself stays the same across them.
For anyone interested in private communication, the appeal is control. You decide which relays to use and which keys to protect.
Who Coop Is For
Coop suits readers who already use Nostr or want a straightforward desktop entry point to it. A typical example is someone who wants a Windows app for direct conversations without opening a browser tab or installing a large suite of tools.
Privacy-minded users may also find it useful. Because the client is open source under GPL-3.0, anyone can read the code, check how it works, or contribute fixes. That openness matters more for messaging software than for many other categories, since people trust it with personal conversations.
Developers and technically curious users can treat Coop as a reference for how a Rust desktop client handles a decentralized protocol. Reading the source on GitHub is a concrete way to learn how such apps are built.
How Decentralized Messaging Differs From Traditional Chat Apps
Traditional messengers tie your account to a provider's servers. If the provider changes its terms, shuts down a service or suspends your account, your access and contact list can be affected. Decentralized messaging spreads that dependency across many independent servers and keeps identity in the user's hands.
The trade-off is responsibility. With Nostr, losing your private key can mean losing control of your identity, and there is no support desk to reset it. Backing up keys carefully is part of using the system well.
Speed and delivery also depend more on relay choice than on a single provider's infrastructure. Understanding this helps set realistic expectations when you first switch from a conventional chat app.
Key features
Clean, simple interface
Fast and reliable performance
Secure messaging focus
Same client on three platforms
Supported coins
Coop's documentation names Nostr as its network. It is a messaging client rather than a wallet, so its focus is on the Nostr protocol and its relays, not on tracking or holding cryptocurrency coins.
How to install Coop on Windows
PS> scoop install coop- 1
Option 1: Install with Scoop
If you already use Scoop, the Windows command-line package manager, open PowerShell and run scoop install coop. Scoop handles the download and placement of the program, which makes updates and removal easier to manage from the command line.
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Option 2: Run the Windows installer
Download the Windows package from the official website or the GitHub Releases page. Verify the file as described in the safety section, then run the .exe installer and follow the on-screen instructions. Choose the Windows option if you are asked which operating system you are installing for.
How to use Coop
Coop works like most Nostr clients: you bring your own identity and choose where your messages travel. The steps below give a general sequence for a first session.
- Launch Coop from the Start menu or the command line after installation.
- Sign in with an existing Nostr key, or create a new identity if you are starting fresh.
- Store your private key in a password manager or other offline backup before you rely on the account.
- Connect to the relays you want to use, keeping in mind that messages reach the people who share those relays.
- Add the public keys of contacts you want to message, using the identifiers they share with you.
- Open a conversation and send a test message to confirm that delivery works with your contact.
- Review your settings periodically, especially relay choices, as your needs change.
Pros & cons
- Free and open source under the GPL-3.0 license
- Simple, focused interface aimed at conversations
- Built in Rust, which suits efficient desktop software
- Available on Windows, macOS and Linux
- Can be installed on Windows with Scoop from the command line
- Aimed at secure messaging on an open, decentralized protocol
- Version 0.3.0 is pre-1.0, so features and behavior may change
- Message delivery depends on the relays you choose
- Losing a private key means losing access to the identity
- Narrower feature set than established messaging apps
- Smaller user community than mainstream chat platforms
Is Coop safe?
Coop is open source and does not require a seed phrase, but it does handle your Nostr keys, which control your identity. Download the Windows package only from the official website or the project's GitHub Releases page. Compare the SHA-256 checksum or verify the signature before running the installer, and keep antivirus protection active during installation.
Never enter your private key or any backup phrase on a third-party website or in a message from someone claiming to be support. The last code update was on December 31, 2025, which is recent, so the project is not deprecated. Check the official website for the latest version before installing.
- Official source only. Download from github.com/lumehq/coop. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
Coop shares the Nostr focus with several other entries in this catalog, but its emphasis is a simple, general-purpose messaging client. Gossip is also a desktop client written in Rust, so it is the closest technical neighbor, and readers who compare the two will find similar foundations with different interface choices. Vega describes itself as a cross-platform desktop client, which makes it a natural comparison if you want a similar Windows-friendly experience.
If you prefer a terminal workflow, NAK and Nostr Commander RS are command-line tools, not chat windows. They suit scripting or power users rather than everyday conversations. Amethyst is a Nostr client that many people explore first when they want a broader social feed alongside messages.
Specifications
- Price
- Free
- Type
- Open source
- License
- GPL-3.0
- Latest version
- 0.3.0
- Last update
- 31 Dec 2025
- Windows support
- Yes (available via Scoop)
- Source code
- github.com/lumehq/coop
- Install command
- scoop install coop
Frequently asked questions
Coop is a free, open source Nostr client focused on secure messaging. It is designed for people who want direct conversations on a decentralized network instead of a single company's platform. It is available for Windows, macOS and Linux.
Yes, Coop is free. It is released under the GPL-3.0 open source license, which means the code is publicly available and can be reviewed, modified and redistributed under the license terms.
If you use Scoop, run scoop install coop in PowerShell. Otherwise, download the Windows package from the official website or GitHub Releases, then run the .exe installer and follow the on-screen steps. Verify the file before running it.
Coop is open source, which allows public review of its code. Safety still depends on where you get the installer and how you manage your keys. Use only the official download sources, check the checksum, and never share your private key with anyone.
The project lists Windows, macOS and Linux as supported platforms. Each platform has its own package, so download the version that matches your operating system from the official source. The experience should be similar across systems.
Coop works on the Nostr network. Nostr is an open protocol that relies on relays to pass messages between users, so the relays you select influence how and when your messages are delivered.
Nostr is an open protocol for decentralized communication. Users are identified by cryptographic keys, and messages move through independent relay servers rather than one central service. Apps like Coop provide the interface for using the protocol.
The latest version listed for Coop is 0.3.0, and the code was last updated on December 31, 2025. Check the official website or GitHub Releases page for the newest release before installing.
Verdict
Coop is a good fit for people who want a simple, free Nostr messaging client on Windows. It suits users who already understand Nostr keys and relays, and who prefer a focused app over a large feature suite. Its pre-1.0 version and recent development mean it may change quickly, so it is worth following updates. Users who need a mature, broad-featured chat platform may want to look at other options first.