Choose a spec

Every feed on DoubleZero Edge publishes a wire format defined in edge-feed-spec. Specs are maintained in that repository, not by individual builders, so a subscriber can decode any feed that uses a given spec with the same decoder, and every feed can be checked against the same standard.

Supported specs

Spec	Contents	Spec ID
Top-of-Book & Trades	Best bid and offer, and trades	top-of-book@v3
Midpoint	One derived price per instrument, such as the mid or VWAP	midpoint@v3
Market-by-Price	Full-depth order book aggregated by price level	market-by-price@v3
Market-by-Order	Every resting order in the book	market-by-order@v3
Order-Intent	Order, cancel, and modify submissions observed before the venue confirms them	order-intent@v3
Perp Stats	Funding and other per-perpetual values the venue publishes	perp-stats@v3

Every spec also uses the Reference Data supplement, which sends instrument definitions on a separate UDP port so that a subscriber who joins late can still decode the feed. Each message identifies its venue by a Source ID from the Source ID Registry. If your venue is not listed, open a pull request to add it.

A feed publishes one spec. To publish two specs for the same venue, deploy two feeds, each with its own bond.

Spec ID

The --spec-id flag on doublezero feed create takes the form <spec>@v<major>. The major version matches the Schema Version byte in every datagram header, which is the part of the version a subscriber's decoder depends on. Minor and patch releases only add fields and message types that existing decoders ignore, so the spec ID does not change when they are released. See VERSIONING.md for the full policy.

Check your feed

dz-conformance checks a feed against its spec, either live on the multicast group or from a packet capture. It exits with 0 on a pass, 1 on a violation, and 2 on an error, so it can run in CI. It supports Top-of-Book, Midpoint, Market-by-Price, and Market-by-Order. Order-Intent and Perp Stats are not supported yet.

Check a packet capture:

./dz-conformance --feed tob --pcap capture.pcapng \
  --mktdata-port 7001 --refdata-port 7002

Check the live feed from a subscribing host:

./dz-conformance --feed tob --group <multicast_ip> \
  --mktdata-port 7001 --refdata-port 7002 --interface doublezero1

The dz-conformance README covers building the tool, every flag, and the full list of rules.

Reference designs for publishers are in edge-multicast-ref.

Service level

A service level is the update cadence, completeness, and availability the builder commits to, and any public feed it can be compared against.

Planned

A standard format for the service level, a way to record it on the feed, and a way for subscribers to read it are planned. A feed does not need one to start publishing.