strata_server

strata_server combines mist (HTTP/WebSocket), beryl (channels and presence), shelf (persistence), and lattice CRDT primitives into the Strata server runtime.

Target: Erlang only.

Running it

just server

or, from the package, gleam run. Configuration comes from environment variables; see Operations.

Public surface

• StrataConfig — token, port, WebSocket path, storage directory, static and admin directories, rate limits, and admin broadcast interval.
• default_config() — reads the environment and fills in development defaults.
• run(config) — starts the HTTP server, channels, and storage, and blocks.

StrataConfig

Field	Default	Purpose
token	dev-strata-token	Shared WebSocket and admin secret
port	8000	HTTP listen port
websocket_path	/socket/websocket	WebSocket upgrade path
storage_dir	data	DETS data directory
static_dir	None	Optional application asset directory
admin_dir	Some("priv/admin")	Optional admin SPA directory
admin_status_interval_ms	2000	Admin update interval
rate_limit_messages_per_second	20	Sustained limit for each socket
rate_limit_messages_burst	20	Burst capacity
allowed_origins	[]	Exact origins; empty permits all

default_config reads the documented environment variables. It does not read environment variables for port, websocket_path, or admin_status_interval_ms. Change those fields before you call run.

run stops with an assertion failure if storage, supervision, or the HTTP listener cannot start. It does not return a startup error.

Internals worth knowing

• strata_server/auth — ?token= extraction and constant-time verification on upgrade.
• strata_server/document_channel — one beryl channel per doc:<id> topic; merges deltas, handles serialized create/delete, and broadcasts to other sockets.
• strata_server/admin_channel — the read-only admin:status channel.
• strata_server/store: in-memory documents, deletion parent links, and tombstones, with a single shelf checkpoint for documents and parents. See Composing Documents.

The store flushes to DETS every five seconds. See Durability and Recovery.

Source: packages/strata_server.