dex-api-server is a single-process daemon that serves a pkg/lx.OrderBook over REST and WebSocket. It is the simplest deployment shape of the LX matching engine and is what most local-dev workflows reach for first.

Topology

There is exactly one operating mode: standalone.

Aspect	Behavior
Orderbook	In-process `pkg/lx.OrderBook`. No replication.
Consensus	None. The daemon "mines" orders by calling `AddOrder` synchronously.
Persistence	None — the book is rebuilt from scratch on every start.
Auth	None (CORS open). Do not expose this binary to the public internet.

Multi-node consensus deployments use a different binary, cmd/dag-network (build tag zmqtest), which wires pkg/consensus.LuxDAGOrderBook and broadcasts vertices over ZeroMQ. That code path has its own multi-node test in pkg/consensus/multinode_test.go.

Standalone start

dex-api-server -port 8080

Endpoints:

Method	Path	Purpose
GET	`/`	HTML index (debug)
GET	`/api/orderbook`	Snapshot of bids / asks
GET	`/api/trades`	Recent trades
GET	`/api/stats`	Market stats
POST	`/api/order`	Place a limit or market order
GET (Upgrade)	`/ws`	WebSocket for live updates

Why no built-in single-node consensus mode

Adding a Quasar / LuxDAG self-loop here would be redundant: the orderbook inside dex-api-server already finalises orders synchronously inside OrderBook.AddOrder, so a single-validator consensus loop on top would only add latency without altering semantics. The consensus engine (pkg/consensus) is meaningful when there are real peers to vote with — hence cmd/dag-network for that case and dex-api-server for the local dev / single-process case.

If a future use-case requires a single binary that does both, the right refactor is to extract a Daemon struct with a --peers flag where len(peers) == 0 selects the in-process orderbook and len(peers) > 0 selects the consensus-bound one. That work is not in this commit — it would require defining clean interfaces between the two orderbook implementations and is a separate change.

Smoke test

go test -tags=integration ./cmd/dex-api-server/... -count=1 -timeout 60s

standalone_test.go builds the daemon, starts it on a free port, places a limit order via /api/order, and confirms the orderbook is queryable. It exercises the HTTP plumbing end-to-end.