Configuration Reference

# Project
# Defaults to "Blnk Server" when not set.
BLNK_PROJECT_NAME=Blnk Server

# Server
# Port defaults to 5001. SSL and secure mode are off by default.
BLNK_SERVER_SECURE=false
BLNK_SERVER_SECRET_KEY=
BLNK_SERVER_PORT=5001
BLNK_SERVER_MAX_REQUEST_BODY_SIZE_MB=5
BLNK_SERVER_MAX_UPLOAD_SIZE_MB=256
BLNK_METRICS_BEARER_TOKEN=

# Database
# DNS is required for Blnk to start successfully. Docker default shown below.
# CONNECTION_MAX_LIFETIME and CONNECTION_MAX_IDLE_TIME are integer seconds.
BLNK_DATA_SOURCE_DNS=postgres://postgres:password@postgres:5432/blnk?sslmode=disable
BLNK_DATABASE_MAX_OPEN_CONNS=50
BLNK_DATABASE_MAX_IDLE_CONNS=25
BLNK_DATABASE_CONN_MAX_LIFETIME=30m
BLNK_DATABASE_CONN_MAX_IDLE_TIME=5m

# Redis
# DNS is required for Blnk to start successfully. Docker default shown below.
BLNK_REDIS_DNS=redis:6379
BLNK_REDIS_SKIP_TLS_VERIFY=false

# Typesense
# Docker default shown for the Typesense endpoint. The API key defaults to "blnk-api-key".
BLNK_TYPESENSE_DNS=http://typesense:8108
BLNK_TYPESENSE_KEY=blnk-api-key

# Transactions
# LOCK_DURATION and LOCK_WAIT_TIMEOUT are integer seconds.
BLNK_TRANSACTION_BATCH_SIZE=1000
BLNK_TRANSACTION_MAX_QUEUE_SIZE=1000
BLNK_TRANSACTION_MAX_WORKERS=10
BLNK_TRANSACTION_LOCK_DURATION=30m
BLNK_TRANSACTION_LOCK_WAIT_TIMEOUT=3s
BLNK_TRANSACTION_INDEX_QUEUE_PREFIX=transactions
BLNK_TRANSACTION_ENABLE_COALESCING=true
BLNK_TRANSACTION_ENABLE_QUEUED_CHECKS=false
BLNK_TRANSACTION_DISABLE_BATCH_REFERENCE_CHECK=false

# Queue
BLNK_QUEUE_TRANSACTION=new:transaction
BLNK_QUEUE_WEBHOOK=new:webhook
BLNK_QUEUE_INDEX=new:index
BLNK_QUEUE_INFLIGHT_EXPIRY=new:inflight-expiry
BLNK_QUEUE_INFLIGHT_COMMIT=new:inflight-commit
BLNK_QUEUE_NUMBER_OF_QUEUES=20
BLNK_QUEUE_INSUFFICIENT_FUND_RETRIES=false
BLNK_QUEUE_MAX_RETRY_ATTEMPTS=5
BLNK_QUEUE_MONITORING_PORT=5004
BLNK_QUEUE_WEBHOOK_CONCURRENCY=20

# Hot-lane and worker tuning
# HOT_PAIR_TTL is integer seconds.
BLNK_QUEUE_ENABLE_HOT_LANE=false
BLNK_QUEUE_HOT_QUEUE_NAME=hot_transactions
BLNK_QUEUE_HOT_QUEUE_CONCURRENCY=1
BLNK_QUEUE_HOT_PAIR_TTL=300
BLNK_QUEUE_HOT_PAIR_LOCK_CONTENTION_THRESHOLD=3
BLNK_QUEUE_REJECT_LOCK_CONTENTION_IMMEDIATELY=false
BLNK_QUEUE_TRANSACTION_WORKER_CONCURRENCY=4

# Rate limiting
# These are the runtime defaults used when rate limiting is not configured. Values are integer seconds.
BLNK_RATE_LIMIT_RPS=5000000
BLNK_RATE_LIMIT_BURST=10000000
BLNK_RATE_LIMIT_CLEANUP_INTERVAL_SEC=10800

# Reconciliation
# Retry delay uses Go duration format.
BLNK_RECONCILIATION_DEFAULT_STRATEGY=one_to_one
BLNK_RECONCILIATION_PROGRESS_INTERVAL=100
BLNK_RECONCILIATION_MAX_RETRIES=3
BLNK_RECONCILIATION_RETRY_DELAY=5s

# Notifications
# Leave these blank until you are ready to send Slack alerts or webhooks.
BLNK_SLACK_WEBHOOK_URL=
BLNK_WEBHOOK_URL=
BLNK_WEBHOOK_HEADERS={}

# Observability
BLNK_ENABLE_TELEMETRY=false
BLNK_ENABLE_OBSERVABILITY=false
# Blnk Cloud DSN for managed monitoring export. Format: https://<write-key>@<host>/<project-id>
BLNK_CLOUD_DSN=
# Self-hosted OTLP HTTP export (works when observability is enabled)
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=
OTEL_EXPORTER_OTLP_METRICS_ENDPOINT=

# Tokenization
BLNK_TOKENIZATION_SECRET=

# Backups
BLNK_BACKUP_DIR=
BLNK_AWS_ACCESS_KEY_ID=
BLNK_AWS_SECRET_ACCESS_KEY=
BLNK_S3_ENDPOINT=
BLNK_S3_BUCKET_NAME=
BLNK_S3_REGION=