MessagePack API
Encode and decode MessagePack — the compact binary serialization format ("it's like JSON, but fast and small") used by Redis, Fluentd, many RPC systems and IoT protocols. The encode endpoint turns a JSON value into MessagePack bytes, automatically choosing the smallest representation for each integer, string, array and map; the decode endpoint parses MessagePack back into a JSON value. It implements the full spec — nil, booleans, every fixed and variable integer width, float32 and float64, str and bin, arrays and maps, and the ext family — and rejects trailing or truncated data rather than silently mangling it. Binary (bin) values and any non-UTF-8 string come back losslessly as a {"_bytes_hex":"…"} object, and ext values as {"_ext":{"type":N,"hex":"…"}}, so encode and decode round-trip exactly. Bytes are exchanged as both hex and base64 so they survive any transport. Everything is computed locally and deterministically, so it is instant and private. Ideal for debugging MessagePack payloads, bridging JSON and msgpack systems, RPC and cache tooling, IoT pipelines, and teaching the format. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is MessagePack specifically; for JSON, YAML, TOML or XML use those format APIs, for BitTorrent's Bencode use the Bencode API, and for base64, hex, URL or HTML encoding use a general encoding API.
api.oanor.com/msgpack-api