# zat

> zat is a zig library of AT Protocol building blocks: parsing and validation
> for atproto identifiers, DID and handle resolution, DAG-CBOR / CAR / MST repo
> primitives, commit signing and verification, XRPC, JWT and OAuth, and
> firehose / jetstream streaming. It targets zig 0.16+.

## Project contracts

- [Homepage](https://zat.dev)
- [Examples](https://zat.dev/docs/examples/index.md)
- [Roadmap](https://zat.dev/docs/roadmap.md)
- [Changelog](https://zat.dev/docs/changelog.md)
- [Source repository](https://tangled.org/zat.dev/zat)
- [AT Protocol specs](https://atproto.com/specs)

## Built with zat

- [zds](https://tangled.org/zat.dev/zds) — an AT Protocol personal data server, built on zat.
- [zlay](https://tangled.org/zat.dev/zlay) — an AT Protocol relay, built on zat: subscribes to every PDS on the network, verifies commit signatures, and serves the merged event stream.

## Install

- Run `zig fetch --save https://tangled.org/zat.dev/zat/archive/main`, then add
  the `zat` module in your `build.zig`.

## Agent guidance

- The public API is whatever `src/root.zig` exports; everything under
  `src/internal/` is implementation. Import symbols through the `zat` module.
- Runnable, compile-checked recipes live in `examples/` — each is a
  `zig build example-<name>` step. Start there for real usage patterns.
- Identifier types (`AtUri`, `Did`, `Handle`, `Nsid`, `Rkey`, `Tid`) parse to
  `?T` and borrow their input: validate at the boundary, keep the input alive.
- Network APIs take an explicit `std.Io` handle (zig 0.16).
- For Zig language semantics, reach for zigman: https://nate.tngl.io/zigman/

## Source docs

- `README.md` documents the overview and per-area snippets (the site homepage).
- `examples/` holds the runnable recipes, each a paired `.zig` and `.md`.
- `docs/roadmap.md` documents the architecture and what is next.
- `CHANGELOG.md` documents the per-version history.