What is Transit? Transit is a format and a set of libraries for conveying values between applications written in different languages. It is layered on top of JSON and MessagePack, so you get their tooling and speed, but with a much richer type system and built-in payload compression. Think of it as "JSON that round-trips real types": Ground types from the host format: maps, arrays, strings, numbers, booleans, null Extension types JSON lacks: keywords :foo, symbols, instants (timestamps), UUIDs, URIs, big integers/decimals, characters, byte arrays, sets, and lists Built-in compression (caching): repeated map keys, keywords, symbols, and tags are written once and then referenced by a short ^N code, so verbose, key-heavy payloads shrink dramatically Extensible via tagged values: ship your own types over the wire with a tag plus a representation, and decode them with a custom handler — no...