delegateed

Alpha software: use at your own risk.

delegateed renews Arkade VTXOs and boards bitcoin while their owner is offline. A wallet registers a delegation on its address; every spend is co-signed by the emulator only if it satisfies the template's covenant.

The default templates in templates/ (renew, board for non-interactive boarding, and the VHTLC claim stream claim) are registered at startup.

Run

make regtest-up   # nigiri, arkd, emulator, postgres
make run          # UI on http://localhost:7081/
make test         # unit tests
make test-e2e     # end-to-end tests on the regtest stack
make regtest-down

In production use ghcr.io/arkade-os/delegatee with the variables below. Port 7080 is the public API (service.proto), 7081 the admin API and UI: keep it private. Back up the cosigner and encryption keys.

Configuration

Variable		Default
DELEGATEE_ARK_URL	arkd gRPC address	required
DELEGATEE_EMULATOR_URL	emulator gRPC address	required
DELEGATEE_ELECTRUM_URL	Electrum server, tcp://host:port or ssl://host:port	required
DELEGATEE_DATABASE_URL	postgres DSN	required
DELEGATEE_COSIGNER_KEY	private key cosigning arkd's vtxo trees, 32 bytes hex	required
DELEGATEE_ADMIN_AUTH	file or disabled	required
DELEGATEE_ADMIN_USERS_FILE	user:bcrypt lines	with file
DELEGATEE_ENCRYPTION_KEY	ECIES key for template secrets, hex; a secret is sealed to the key and the id of its template	unset
DELEGATEE_DEFAULT_TEMPLATES	register the default templates at startup	true
DELEGATEE_MIN_DELEGATION_EXPIRY	minimum lead of a delegation's expiry	24h
DELEGATEE_EXPIRY_INTERVAL	how often delegations past their expiry are marked	1m
DELEGATEE_OFFCHAIN_CONCURRENCY	offchain attempts in flight at once	8
DELEGATEE_ATTEMPT_TIMEOUT	building and signing an offchain attempt, before arkd is called	1m
DELEGATEE_RETRY_DELAY	before the coins of a failed attempt are tried again	1m
DELEGATEE_INTENTS_PER_BATCH	intents arkd takes per batch: at most that many are kept registered	128
DELEGATEE_INTENT_TIMEOUT	an intent no batch selected by then is deleted from arkd and queued again	5m
DELEGATEE_BAN_DURATION	how long the coins of an intent a batch failed on keep out of the queue	5m
DELEGATEE_LANDING_WINDOW	after a restart, how long an attempt whose forfeits may have reached arkd waits to see its coins spent before it is failed	5m
DELEGATEE_RESERVE	latest a coin enters a batch, before its vtxo expires	15m
DELEGATEE_TEMPLATE_MAX_FAILURES	consecutive failed attempts that disable a template	10
DELEGATEE_LOOP_STALL	how long the loop may stay silent past a due time before /healthz reports it	2m
DELEGATEE_PUBLIC_RATE_LIMIT	requests per second per client address on the public port, loopback exempt; 0 disables	5
DELEGATEE_MAX_DELEGATIONS	active delegations cap	50000
DELEGATEE_MAX_STREAM_CHILDREN	active spawned delegations cap, apart from MAX_DELEGATIONS	10000
DELEGATEE_PRUNE_AFTER	how long after expiry a delegation a stream spawned is deleted	720h
DELEGATEE_LOG_LEVEL	logrus level	4

The delegations a stream spawns count only toward MAX_STREAM_CHILDREN, the others toward MAX_DELEGATIONS.

Renewals are grouped. A coin's deadline is the later of its due time and its expiry minus RESERVE. The earliest deadline forces a group, which carries every renewal due by then, so they share one batch; the entries of a group are registered one batch before it. A group over INTENTS_PER_BATCH splits into consecutive batches ending at its time, the earliest deadlines first. A boarding coin is registered at once. The reserve must be at least twice INTENT_TIMEOUT: one intent that times out and a retry. The admin GET /v1/admin/status shows the queue, what is registered, the coins forecast to miss their deadline and the batches the plan expects.

A template whose attempts arkd, the emulator or the template itself refuse TEMPLATE_MAX_FAILURES times in a row is disabled; a succeeded attempt resets the count. Onchain templates are not served.

Other limits and intervals are in internal/config/config.go.

Streams

A template with a trigger is not registered by clients: the operator registers it as a stream (admin RegisterStream, ListStreams, CancelStream; a default with a trigger starts by itself when an encryption key is configured, and stays cancelled once the operator cancels it). The daemon reads arkd's transaction stream and, for every transaction whose extension holds the trigger's packet, captures the trigger's variables, checks the template locks the output, and spawns a delegation of the template that expires after expires_after_seconds. When several delegations share a script, the coins go to the one a stream spawned, otherwise to the oldest.