NosCall is a free, open-source app for making audio and video calls over the Nostr protocol. It is aimed at people who want to talk to contacts directly without routing calls through a central company that controls accounts and user lists. If you already use Nostr for posts and messages, NosCall adds a voice and video layer to the same identity.
The app encrypts calls end to end and runs on several platforms, including Windows, macOS, Linux, Android and iOS. Its feature set covers the basics you would expect from a calling app, such as call history and contact management, plus several extras aimed at Nostr users, including NIP-05 identity support and an optional Tor layer for extra privacy.
What Is NosCall and Who Is It For?
NosCall sits in the growing group of apps built on Nostr, a protocol in which users hold their own cryptographic keys and send events through relays rather than a single server. Instead of signing up with a company and accepting its terms, you generate or import a key pair and use it across compatible applications.
The app suits three kinds of people. Privacy-minded users who want calls that are encrypted between participants will find the core design appealing. Nostr enthusiasts who already post and chat through the network can add voice and video without a new account. Developers and community builders can study an open codebase written in Dart and Flutter, which is a useful reference for cross-platform work.
How Nostr Identity Changes the Calling Experience
In most calling apps, your account is tied to a phone number or an email address held by the operator. With Nostr, your identity is a key you control. That changes how you find people and how you verify them.
NIP-05 identifiers help bridge the gap between a long, random-looking public key and a name you can remember. A contact published at a domain you trust can be found more easily, and you can check that a profile matches the identifier shown. If a key is lost or compromised, however, there is no password reset in the usual sense, so backing up your key is essential.
Practical Scenarios for Encrypted Calls
Consider a freelance designer who wants to review mockups with a client without sending files through a commercial platform. A short encrypted video call, followed by a voice note summarizing the decisions, keeps the conversation in one place.
A small open-source team spread across several countries might use the group features to keep their core members within reach, while using Tor when a participant is in a region with heavy monitoring. Journalists and activists are another group that often looks for calling tools with minimal metadata, although no single app removes every risk, and careful operational habits still matter more than any feature list.
Key features
Audio and Video Calls
End-to-End Encryption
Cross-Platform Support
Compatibility With Other Nostr Clients
Friend Grouping and Favorites
NIP-05 Identity Support
Tor Network Support
Push Notifications
Voice Messages and Call Recording
Pay to Call
Dark Mode and Custom Themes
Supported coins
NosCall is built around the Nostr network. Its documentation refers to Nostr as the underlying network, and identity is based on Nostr keys rather than a separate token or wallet system.
How to install NosCall on Windows
- 1
Get the Program
Download the Windows build or installer from the official project page or from the project's GitHub Releases page. The source code is public at the repository linked from the project, so you can also review the code before running it.
- 2
Verify the File
Before running the installer, compare its SHA-256 checksum with the value published by the developers, if one is provided on the release page. If the project offers a signature, verify it as well. A mismatch means the file should not be used.
- 3
Run the Installer
Open the downloaded file and follow the on-screen prompts. Windows may show a SmartScreen warning for software from smaller projects; confirm that the file came from the official source before choosing to continue.
-
Set Up Your Identity
On first launch, create a new Nostr key or import an existing one. Write down or securely store your key before you start making calls, because it is the only way to recover your identity on another device.
System requirements
- Windows with a current, supported version of the operating system
- Enough free disk space for the installed application
- A working internet connection for calls and relay communication
- A microphone and webcam for audio and video calls
How to use NosCall
Getting started with NosCall takes only a few minutes once the app is installed and your key is set up. The main steps are below, and they follow the same general pattern you would expect from a calling app.
- Open NosCall and sign in with your Nostr key.
- Add contacts by pasting their public key or NIP-05 identifier.
- Organize people into groups and mark frequent contacts as favorites.
- Choose audio or video when starting a call, and wait for the other person to accept.
- Use the call history to return to recent conversations.
- Send a voice message when a live call is not convenient.
- Turn on Tor support in the settings if you want the extra privacy layer.
- Adjust notification and appearance options to suit your routine.
Pros & cons
- Free and open-source, so the code can be reviewed by anyone
- End-to-end encrypted calls
- Built on an open protocol instead of a closed account system
- Works across desktop and mobile platforms
- Optional Tor support for an additional privacy layer
- NIP-05 identifiers make contacts easier to find
- Relies on Nostr relays, so call setup depends on network availability
- Identity recovery is your responsibility if you lose your key
- Smaller user base than mainstream calling apps, which can limit who you can reach
- Tor support may increase latency during calls
- Some features, such as pay-to-call, are niche
Is NosCall safe?
NosCall is open source, which lets security-minded users inspect the code. Download the app only from the official project page or the GitHub Releases page, not from third-party download sites. Check the SHA-256 checksum or signature when one is published, and treat any unexpected file as suspicious.
Never enter your private key or recovery phrase on a website that asks for it, and do not paste it into messages to other people. Anyone with your key can act as you on the network. Keep the app updated, and consider the security of your device as well, since encryption protects a call only as far as your endpoint is secure.
- Official source only. Download from github.com/sanah9/noscall. 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
Compared with other Nostr clients, NosCall is focused on real-time calls rather than posting or reading feeds. Amethyst and Gossip are primarily social clients, while NosCall adds voice and video on top of the same identity model.
Nostr Commander RS and NAK take a command-line approach, which suits technical users but does not offer calls at all. Vega is a desktop client for general Nostr use. If your main need is encrypted calling, NosCall is the most direct fit of the programs in this group; if you mainly want a full social client, one of the others may serve you better.
Specifications
- Price
- Free
- Type
- Open source
- License
- —
- Latest version
- v0.6.0-release
- Last update
- 16 Sept 2026
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/sanah9/noscall
Frequently asked questions
Yes, NosCall is free and open source. You can download the Windows build from the official project page or the GitHub Releases page. Some optional features, such as pay-to-call, let users charge others, but the app itself does not require payment to install or use.
NosCall is open source, which allows independent review of its code. Safety depends on downloading from the official source, checking the file's checksum or signature when provided, and protecting your private key. Never share your key with anyone or enter it on a third-party site.
You need a Nostr key pair, which the app can create for you on first launch. Your key serves as your identity, so there is no separate sign-up with a company. Back up the key securely, because losing it means losing access to that identity.
NIP-05 is a Nostr standard that links a public key to a readable identifier in the form [email protected]. It makes contacts easier to find and share. The identifier is verified against a file published by the domain owner, so it helps confirm that a profile is who it claims to be.
Yes, the app is designed to encrypt calls end to end, which means the content should not be readable by relays or other intermediaries. Metadata such as who is connected to whom can still be visible to some network operators, so the Tor option may be useful for additional privacy.
The app is available on several platforms, and your Nostr identity can be used across them. Check the current release notes for how multiple devices handle active calls and notifications, since behavior can vary between versions.
There is no password reset for a Nostr key. If you lose it and have no backup, you cannot recover that identity or its contacts. This is why storing the key securely before making calls is one of the most important steps when you first set up the app.
Verdict
NosCall is a worthwhile choice for Windows users who want encrypted audio and video calls on an open protocol and are comfortable managing their own keys. It is free, open source and works across desktop and mobile systems. Its trade-offs are a smaller network, reliance on Nostr relays and personal responsibility for key backup. It suits privacy-minded individuals, Nostr users and small groups more than people who need a large mainstream contact list.