Nostr is a decentralized communication protocol that allows users to send messages without reliance on a single corporation or government.

The protocol defines a simple client‑server architecture that can be implemented by any software.

According to the public specification, notes are transmitted using a cryptographic key pair that verifies authorship.

Clients can connect to many servers, and servers can relay notes to many clients, creating a many‑to‑many network.

Each user holds a secret key; messages carry a digital signature that proves authorship without a central authority.

Relay operators decide which notes to accept and store, so content moderation is handled at the server level.

Users may choose which relays to query, allowing them to filter content based on their own criteria.

The design permits hundreds of relays and clients to operate simultaneously, distributing load across the network.

Running a relay requires minimal resources, making it inexpensive for individuals or organizations to host one.

Search can be performed by indexing notes that have been observed, or by storing notes locally for offline searching.

Nostr does not depend on Bitcoin, though it uses similar cryptographic principles; tipping features are optional and not required for use.

Development of the protocol continues, and broader adoption will depend on user‑friendly clients and active relay operation.