Draft sync

Draft sync is a long-running connector for one league's draft. It records every pick, whoever made it, and publishes them to Redis for the core pipeline's draft listener. It never writes to ESPN, except when it executes a pick the draft clicker delegates to it.

What starts it?

The core API creates a Kubernetes Job for each draft, live or practice. The Job runs node src/bots/draft_sync.js and stops when the draft finishes or it gives up. It is not a queue consumer.

Variable	Purpose
ESPN_LEAGUE_ID, ESPN_TEAM_ID, CURRENT_YEAR	Which draft to join.
DRAFT_MODE	mock tries to start a practice draft itself.
DRAFT_ROOM_URL	An already-open practice room URL. Takes priority over DRAFT_MODE. Use it for tests only.
DRAFT_HEALTH_INTERVAL_MS	Health heartbeat cadence. Default 10 000.
DRAFT_PICK_SILENCE_WARN_MS	Warn when no new pick arrives for this long. Default 180 000.
DRAFT_STALL_TERMINAL_CYCLES	Reconnect cycles with no picks before the log escalates to an error. Default 3.
DRAFT_COMMAND_POLL_INTERVAL_MS	How often it polls for delegated picks. Default 1 000.
DRAFT_COMMAND_CONFIRM_TIMEOUT_MS	How long it waits for ESPN to confirm a delegated pick. Default 5 000.

Why three ingest tiers?

The draft room allows one session per league, team and member. A second connection evicts the first, and the protocol has no replay.

Tier	Strength	Weakness
WebSocket	Fastest, exact ids	Misses every pick while evicted.
REST	Authoritative, has pick and round numbers	Returns zero picks during a practice draft.
DOM observer	Always shows the full board	Slower. Its selectors are unverified.

The pick ledger collapses overlapping observations into one publish plus later corrections. Source precedence is REST, then DOM, then init, then WebSocket. Identity is the player id, not the pick number.

What does it write to Redis?

Key or channel	Type	Content
draft_picks:{leagueId}:{seasonId}	Stream	Each pick as payload JSON.
draft:{leagueId}:{seasonId}:picks	Hash	Pick number to pick JSON. Rehydrated on restart.
draft_picks	Pub/sub	Each new or corrected pick.
draft:{leagueId}:health	String, 1 h TTL	Per-tier counters, last pick time, WebSocket state and the ownership lease.
draft:{leagueId}:connected	String, 60 s TTL	Liveness flag.
draft:{leagueId}:selecting	String	Whose turn it is and the clock, from SELECTING and CLOCK frames.
draft:{leagueId}:suggested	String	ESPN's own suggested pick from AUTOSUGGEST.
draft:{leagueId}:autodraft	String	Autodraft toggles.
draft_commands:{leagueId}	Stream	Read side: picks delegated by the clicker.
draft_commands:{leagueId}:results	Pub/sub	Write side: result of each delegated pick.

How does it recover?

Condition	Behavior
Socket closes	ESPN reconnects on its own. The sync restarts the browser only after 30 s with no open socket.
Reconnect cycle with no new picks	Retries with backoff (2 s doubling to 30 s), up to 10 attempts.
Draft finished	Exits 0. Silence alone is never treated as proof of completion.
Room confirmed gone	PermanentError, no retries.
Attempts exhausted	Exits 1 with an error.

REST also reconciles every 15 s. SIGTERM exits immediately so the core API can tear the Job down.

Related

• Draft clicker
• Mock draft helper
• Draft room protocol