zat#

zig primitives for AT Protocol.

install#

zig fetch --save https://tangled.org/zzstoatzz.io/zat/archive/main

then in build.zig:

const zat = b.dependency("zat", .{}).module("zat");
exe.root_module.addImport("zat", zat);

what's here#

string primitives#

parsing and validation for atproto string identifiers:

• Tid - timestamp identifiers (base32-sortable)
• Did - decentralized identifiers
• Handle - domain-based handles
• Nsid - namespaced identifiers (lexicon types)
• Rkey - record keys
• AtUri - at:// URIs

const zat = @import("zat");

if (zat.AtUri.parse(uri_string)) |uri| {
    const authority = uri.authority();
    const collection = uri.collection();
    const rkey = uri.rkey();
}

did resolution#

resolve did:plc and did:web identifiers to their documents:

var resolver = zat.DidResolver.init(allocator);
defer resolver.deinit();

const did = zat.Did.parse("did:plc:z72i7hdynmk6r22z27h6tvur").?;
var doc = try resolver.resolve(did);
defer doc.deinit();

const handle = doc.handle();           // "jay.bsky.social"
const pds = doc.pdsEndpoint();         // "https://..."
const key = doc.signingKey();          // verification method

xrpc client#

call AT Protocol endpoints:

var client = zat.XrpcClient.init(allocator, "https://bsky.social");
defer client.deinit();

const nsid = zat.Nsid.parse("app.bsky.actor.getProfile").?;
var response = try client.query(nsid, params);
defer response.deinit();

if (response.ok()) {
    var json = try response.json();
    defer json.deinit();
    // use json.value
}

json helpers#

navigate nested json without verbose if-chains:

// instead of 6 nested if-checks:
const uri = zat.json.getString(value, "embed.external.uri");
const items = zat.json.getArray(value, "posts");
const count = zat.json.getInt(value, "meta.count");

specs#

validation follows atproto.com/specs.