kvend

Kvend is a compact binary serialization format designed for transmitting sequences of key-value pairs in resource-constrained environments. It aims to minimize overhead by encoding each key-value pair as a compact, length-prefixed binary record within a continuous stream, enabling efficient parsing and incremental processing.

A kvend record consists of a length field for the key, the key bytes, a length field for the value, and the value bytes. Lengths are encoded as variable-length integers to reduce waste on small keys and values. Records are concatenated in a stream, so a receiver can parse entries sequentially without requiring a full frame boundary.

Variants and implementations exist in various projects. Some proposals describe a kvend-lite variant for very small keys/values and a kvend-extended variant that adds optional metadata, alignment hints, or compression indicators. The format is designed to be strictly a sequence of key-value pairs, with no inherent schema or type system.

Kvend is commonly contrasted with text-based formats like JSON, which are human readable but heavier to parse, and with general binary formats such as MessagePack or Protocol Buffers, which support richer data models. Kvend focuses on efficient streaming of simple key-value entries and is thus favored for low-latency telemetry, log shipping, inter-service event streams, and cache synchronization in microservice architectures.

Origin and status: Kvend emerged in open-source discussions in the early 2020s as a lightweight alternative for kv streaming. It has not become a widely standardized format, and implementations remain experimental or project-specific. As with most niche serialization schemes, adoption depends on ecosystem support and specific performance needs. See also: key-value store, binary serialization, varint, streaming protocol.