synctv/synctv.example.yaml

# SyncTV Configuration Example
#
# Copy this file to synctv.yaml and modify as needed
#
# Configuration priority: defaults < config file < environment variables
#
# Secret-like settings also support sibling *_file keys in this config file.
# Relative *_file paths are resolved relative to the config file location.
#
# Environment variables use SYNCTV_ prefix with single underscore separator:
#   SYNCTV_SERVER_HOST=0.0.0.0
#   SYNCTV_DATABASE_URL=postgresql://...
#   SYNCTV_DATABASE_URL_FILE=/run/secrets/database_url
#   SYNCTV_OAUTH2_REDIRECT_SCHEME=https
#
# Secret-like settings support two file-based forms:
#   1. Config file sibling keys: jwt.secret_file, management.auth_token_file, ...
#   2. Env file variables: SYNCTV_JWT_SECRET_FILE, SYNCTV_MANAGEMENT_AUTH_TOKEN_FILE, ...

server:
  host: "0.0.0.0"
  port: 8080
  enable_reflection: false
  # Maximum gRPC message size in bytes (both incoming and outgoing).
  # Prevents OOM attacks from oversized messages. Default: 16MB (16777216 bytes).
  # Minimum: 1MB (1048576 bytes), Maximum: 1GB (1073741824 bytes).
  # Environment variable: SYNCTV_SERVER_GRPC_MAX_MESSAGE_SIZE_BYTES
  # grpc_max_message_size_bytes: 16777216
  # Trusted proxy IP addresses/CIDRs for X-Forwarded-For validation.
  # If empty, X-Forwarded-For headers are NOT trusted (socket address is used).
  # Example: ["10.0.0.0/8", "192.168.0.0/16"]
  trusted_proxies: []
  # CORS allowed origins for cross-origin requests from web frontends.
  #
  # You MUST set this to your frontend URL(s) or cross-origin
  # requests (fetch, WebSocket upgrades from browsers) will be rejected.
  #
  # Examples:
  #   cors_allowed_origins: ["https://app.example.com"]
  #   cors_allowed_origins: ["https://app.example.com", "https://admin.example.com"]
  #
  # Environment variable:
  #   SYNCTV_SERVER_CORS_ALLOWED_ORIGINS='["https://app.example.com"]'
  #
  # WARNING: An empty list in production means ALL cross-origin requests are denied.
  cors_allowed_origins: []
  # Shared secret for authenticating cluster gRPC calls between nodes.
  # REQUIRED when cluster.enabled is true — startup fails if this is empty in cluster mode.
  # This prevents unauthorized inter-node gRPC calls in multi-replica deployments.
  # Not required in standalone mode even when Redis is configured.
  # Generate a secret with: openssl rand -hex 32
  # Environment variable: SYNCTV_SERVER_CLUSTER_SECRET
  # Environment file variable: SYNCTV_SERVER_CLUSTER_SECRET_FILE
  # File-based secret: server.cluster_secret_file: "/run/secrets/cluster_secret"
  cluster_secret: ""
  # Advertise host for cluster node registration (address other nodes use to reach this instance).
  # Falls back to POD_IP env var, then system hostname if empty.
  # In Kubernetes, set via SYNCTV_SERVER_ADVERTISE_HOST or downward API (status.podIP).
  advertise_host: ""
  # Maximum time in seconds to wait for active connections to drain during shutdown.
  # Defaults to 30 seconds. Increase for deployments with many long-lived connections.
  shutdown_drain_timeout_seconds: 30

time:
  # Default IANA timezone used for human-readable time output and local datetime parsing.
  # Resolution priority:
  #   1. time.timezone
  #   2. SYNCTV_TIME_TIMEZONE
  #   3. TZ
  #   4. system timezone
  #   5. UTC
  #
  # Examples: "Asia/Shanghai", "UTC", "America/New_York"
  # Leave empty to use env/system detection.
  timezone: ""

# Public IDs are prefixed decimal IDs by default, for example usr_1 and room_1.
# Set sqids to enable prefixed sqids instead, for example usr_<sqid>.
# Environment variables:
#   SYNCTV_PUBLIC_IDS_SQIDS_ALPHABET
#   SYNCTV_PUBLIC_IDS_SQIDS_MIN_LENGTH
public_ids: {}
# public_ids:
#   sqids:
#     alphabet: null
#     min_length: 12

security:
  # AES-256-GCM key used to encrypt sensitive provider credentials.
  # Prefer file-based secrets so keys are not stored inline in config files.
  # Generate with: openssl rand -hex 32
  # Environment variables:
  #   SYNCTV_SECURITY_CREDENTIAL_ENCRYPTION_KEY
  #   SYNCTV_SECURITY_CREDENTIAL_ENCRYPTION_KEY_FILE
  # credential_encryption_key_file: "/run/secrets/credential_encryption_key"
  credential_encryption_key: ""

metrics:
  # Dedicated metrics listener. When enabled, /metrics is not served on the API port.
  enabled: false
  host: "0.0.0.0"
  port: 9090
  # tls:
  #   enabled: true
  #   # Static input files: relative cert/key paths stay relative to this config file.
  #   # They are NOT rebased through data_dir.
  #   cert_path: "./tls/metrics.crt"
  #   key_path: "./tls/metrics.key"
  auth:
    # Authentication mode for /metrics: bearer_token, basic, kubernetes
    mode: "bearer_token"
    bearer_token: ""
    # Environment variable: SYNCTV_METRICS_AUTH_BEARER_TOKEN_FILE
    # bearer_token_file: "/run/secrets/metrics_bearer_token"
    # basic_username: "metrics"
    # basic_password: ""
    # Environment variable: SYNCTV_METRICS_AUTH_BASIC_PASSWORD_FILE
    # basic_password_file: "/run/secrets/metrics_basic_password"

management:
  # Local-only management daemon transport used by the `synctv` CLI for remote lifecycle commands.
  # Unix-like platforms default to a Unix domain socket for daemon-style local access.
  # Switch transport to "tcp" when the CLI must connect over a TCP loopback endpoint.
  # TCP transport REQUIRES auth_token; startup fails if it is empty.
  # Unix transport also supports auth_token, but defaults to empty and may rely on
  # owner-only socket permissions instead.
  # Runtime-owned local paths use the top-level `data_dir` root shown below.
  # Leave unix_socket_path unset to use the platform default under data_dir/run/.
  # Environment variables:
  #   SYNCTV_DATA_DIR=/var/lib/synctv
  #   SYNCTV_MANAGEMENT_ENABLED=true
  #   SYNCTV_MANAGEMENT_TRANSPORT=unix
  #   SYNCTV_MANAGEMENT_UNIX_SOCKET_PATH=/path/to/synctv.sock
  #   SYNCTV_MANAGEMENT_PORT=50052
  #   SYNCTV_MANAGEMENT_AUTH_TOKEN=replace-with-a-random-secret
  #   SYNCTV_MANAGEMENT_AUTH_TOKEN_FILE=/run/secrets/management_auth_token
  enabled: true
  transport: "unix"
  port: 50052
  # Relative unix_socket_path values are resolved from data_dir.
  # unix_socket_path: "/absolute/path/to/synctv.sock"
  # auth_token: "replace-with-a-random-secret"
  # auth_token_file is a static config input. Relative paths stay relative to this config file.
  # auth_token_file: "/run/secrets/management_auth_token"
  # Reflection can be configured independently from the public API gRPC listener.
  enable_reflection: false

# `data_dir` is the shared root for runtime-owned local files.
# It affects relative:
#   - management.unix_socket_path
#   - logging.file_path
#   - livestream.hls_storage_path
#   - cache.proxy_slice_file_cache_dir
# It does NOT affect:
#   - *_file secret paths (they stay relative to this config file)
#   - metrics.tls.cert_path / metrics.tls.key_path
# CLI `--data-dir` and env `SYNCTV_DATA_DIR` override this value.
# data_dir: "/var/lib/synctv"

database:
  # Environment variables:
  #   SYNCTV_DATABASE_URL
  #   SYNCTV_DATABASE_URL_FILE
  # Split configuration is also supported:
  #   SYNCTV_DATABASE_HOST / PORT / USERNAME / PASSWORD / PASSWORD_FILE / NAME
  # `user` is accepted as a config-file alias for `username`;
  # SYNCTV_DATABASE_USER is accepted as an env alias for SYNCTV_DATABASE_USERNAME.
  url: "postgresql://synctv:synctv@localhost:5432/synctv"
  # url_file: "/run/secrets/database_url"
  # host: "localhost"
  # port: 5432
  # username: "synctv"
  # password_file: "/run/secrets/database_password"
  # name: "synctv"
  max_connections: 20
  min_connections: 5
  connect_timeout_seconds: 10
  idle_timeout_seconds: 600
  # Maximum lifetime of a connection in seconds before it is closed and replaced.
  # Defaults to 1800 (30 minutes).
  max_lifetime_seconds: 1800

# ============================================================================
# Redis Configuration
# ============================================================================
#
# Redis is OPTIONAL in standalone mode (cluster.enabled=false) and MANDATORY
# in cluster mode (cluster.enabled=true).
#
# When Redis is not configured (url is empty), all features still work using
# in-memory fallbacks:
#   - Token blacklist → in-memory cache (lost on restart)
#   - Rate limiting → in-memory counters (lost on restart)
#   - Brute-force protection → in-memory tracking (lost on restart)
#   - Username/user/room caches → in-memory only
#   - OAuth2 state → in-memory store
#   - Livestream registry → in-memory publisher tracking
#   - Migration locking → PostgreSQL advisory locks
#   - Leader election → single node is always the leader
#
# When Redis IS configured in standalone mode, it enhances features with
# persistence across restarts and shared state.
#
# Redis provides critical infrastructure for:
#   - Token blacklist (JWT revocation across replicas)
#   - Rate limiting
#   - Username cache
#   - Cache invalidation (Redis Streams with per-node consumer groups)
#   - Cluster coordination (pub/sub for room events, kicks, etc.)
#
# Deployment Modes:
#   - standalone: Single Redis instance (default, OK for development)
#   - sentinel: Redis Sentinel for high availability (recommended for production)
#   - cluster: Redis Cluster (not yet fully supported - requires refactoring)
#
# IMPORTANT: Standalone Redis is a single point of failure (SPOF). For production
# deployments, use sentinel mode with 3+ sentinel nodes monitoring a master-replica setup.

redis:
  # Leave empty to run without Redis in standalone mode.
  # Environment variables:
  #   SYNCTV_REDIS_URL
  #   SYNCTV_REDIS_URL_FILE
  # Split configuration also supports:
  #   SYNCTV_REDIS_HOST / PORT / USERNAME / PASSWORD / PASSWORD_FILE / DATABASE
  # `user` is accepted as a config-file alias for `username`;
  # SYNCTV_REDIS_USER is accepted as an env alias for SYNCTV_REDIS_USERNAME.
  url: "redis://localhost:6379"
  # url_file: "/run/secrets/redis_url"
  # host: "localhost"
  # port: 6379
  # username: ""
  # password_file: "/run/secrets/redis_password"
  # database: 0
  connect_timeout_seconds: 5
  key_prefix: "synctv:"

  # Deployment mode: standalone, sentinel, or cluster
  deployment_mode: "standalone"
  # --- Sentinel Mode Configuration (for high availability) ---
  # When deployment_mode is "sentinel", these fields are required:
  # sentinel_master_name: "mymaster"
  # sentinel_addresses:
  #   - "redis://sentinel1:26379"
  #   - "redis://sentinel2:26379"
  #   - "redis://sentinel3:26379"

  # --- Cluster Mode Configuration (experimental) ---
  # Cluster mode is not yet fully supported and will fail at startup.
  # Future implementation will require switching from ConnectionManager to ClusterConnection.
  # cluster_nodes:
  #   - "redis://node1:6379"
  #   - "redis://node2:6379"
  #   - "redis://node3:6379"

jwt:
  # REQUIRED in production. Generate with: openssl rand -base64 32
  # Minimum 32 characters with high entropy (at least 16 unique characters).
  # Environment variables:
  #   SYNCTV_JWT_SECRET
  #   SYNCTV_JWT_SECRET_FILE
  secret: ""
  # secret_file is a static config input. Relative paths stay relative to this config file,
  # not data_dir.
  # secret_file: "/run/secrets/jwt_secret"
  access_token_duration_hours: 1
  refresh_token_duration_days: 30
  # Duration for guest (anonymous) access tokens
  guest_token_duration_hours: 4
  # Clock skew leeway for token validation (seconds)
  clock_skew_leeway_secs: 60

logging:
  level: "info"
  format: "pretty"
  # Relative file_path values are treated as runtime-owned output and resolved from data_dir.
  # file_path: "/var/log/synctv/app.log"

cache:
  # Enable persisted proxy slice files on local/shared storage.
  proxy_slice_file_backend_enabled: false
  # Relative proxy_slice_file_cache_dir values are resolved from data_dir.
  # Leave empty to use the built-in default under data_dir/cache/proxy-slice when enabled.
  # proxy_slice_file_cache_dir: "cache/proxy-slice"

livestream:
  rtmp_port: 1935
  gop_cache_size: 2
  stream_timeout_seconds: 300
  # How often to check for idle streams (seconds)
  cleanup_check_interval_seconds: 60
  # Max retries for pull stream connections
  pull_max_retries: 10
  # Initial backoff for pull retries (milliseconds)
  pull_initial_backoff_ms: 1000
  # Max backoff for pull retries (milliseconds)
  pull_max_backoff_ms: 30000
  # Max FLV tag size to accept in bytes (prevents OOM). Default: 10MB
  max_flv_tag_size_bytes: 10485760
  # Maximum memory (in megabytes) for the GOP cache across all GOPs per stream.
  # When exceeded, the oldest GOP is evicted even if gop_cache_size hasn't
  # been reached. Default: 100 MB. Set to 0 to use the built-in default (50 MB).
  gop_cache_max_memory_mb: 100
  # Relative hls_storage_path values are resolved from data_dir.
  # This is runtime-owned storage, unlike *_file secrets or metrics TLS files.
  # hls_storage_path: "livestream/hls"

  # ============================================================================
  # Email Configuration (SMTP)
  # ============================================================================
  #
  # Configure SMTP to enable email features (verification, notifications).
  # Leave smtp_host empty to disable email functionality.

email:
  smtp_host: ""
  smtp_port: 587
  smtp_username: ""
  # Environment variables:
  #   SYNCTV_EMAIL_SMTP_PASSWORD
  #   SYNCTV_EMAIL_SMTP_PASSWORD_FILE
  smtp_password: ""
  # smtp_password_file is a static config input. Relative paths stay relative to this config file.
  # smtp_password_file: "/run/secrets/smtp_password"
  from_email: ""
  from_name: "SyncTV"
  use_tls: true

# ============================================================================
# Password Complexity Requirements
# ============================================================================
#
# Controls password strength validation for user account passwords.
# These settings do NOT apply to room passwords (which have simpler requirements).

password_complexity:
  # Minimum password length
  min_length: 8
  # Require at least one uppercase letter
  require_uppercase: true
  # Require at least one lowercase letter
  require_lowercase: true
  # Require at least one digit
  require_digit: true
  # Require at least one special character (e.g., !@#$%^&*)
  require_special: false
  # Maximum consecutive repeated characters allowed (prevents "aaaaaa").
  # Set to 0 to disable this check.
  max_repeated_chars: 3

# ============================================================================
# Connection Limits
# ============================================================================
#
# Controls concurrent WebSocket/streaming connection limits.

connection_limits:
  # Maximum concurrent connections per user
  max_per_user: 5
  # Maximum concurrent connections per room
  max_per_room: 200
  # Maximum total concurrent connections
  max_total: 10000
  # Idle timeout in seconds (disconnect if no activity)
  idle_timeout_seconds: 300
  # Maximum connection duration in seconds (24 hours)
  max_duration_seconds: 86400
  # Global per-connection WebSocket message rate limit (messages per second).
  # Prevents abuse from flooding the server with rapid messages.
  ws_message_rate_limit_per_second: 50

# ============================================================================
# Messaging Rate Limits
# ============================================================================
#
# Domain-level chat and danmaku limits enforced by the shared messaging logic.

messaging_rate_limits:
  # Maximum chat messages per sliding window.
  chat_per_second: 10
  # Maximum danmaku messages per sliding window.
  danmaku_per_second: 3
  # Sliding-window size in seconds.
  window_seconds: 1

# ============================================================================
# Bootstrap Configuration
# ============================================================================
#
# Initial setup options for first startup.
# IMPORTANT: Change root_password in production!

bootstrap:
  # Whether to create root user on first startup
  create_root_user: true
  root_username: "root"
  # REQUIRED for production: set a strong password (>= 12 chars, must contain
  # uppercase, lowercase, and digits). Do NOT use any default value in production.
  # Set via SYNCTV_BOOTSTRAP_ROOT_PASSWORD env var.
  # Or file-based env: SYNCTV_BOOTSTRAP_ROOT_PASSWORD_FILE
  # root_password: ""
  # root_password_file: "/run/secrets/bootstrap_root_password"

  # ============================================================================
  # Cluster Configuration
  # ============================================================================
  #
  # Controls multi-node cluster mode and internal channel buffer sizes.
  #
  # When enabled=true, Redis is MANDATORY and cluster_secret must be set.
  # When enabled=false (default), this is a standalone single-node deployment
  # and Redis is optional.

cluster:
  # Enable cluster mode for multi-node deployments.
  # When true, Redis is required and cluster_secret must be set.
  # When false (default), runs as a standalone single-node instance.
  # Environment variable: SYNCTV_CLUSTER_ENABLED
  enabled: false
  # Capacity for high-priority critical event channel (KickPublisher, KickUser, etc.)
  # Critical events are never dropped; senders block when full.
  critical_channel_capacity: 1000
  # Capacity for normal-priority Redis publish channel.
  # Normal events are dropped with a warning when full.
  publish_channel_capacity: 10000
  # Discovery mode: "redis" (default) or "k8s_dns" (requires HEADLESS_SERVICE_NAME
  # and POD_NAMESPACE env vars).
  #
  # IMPORTANT: "k8s_dns" mode still requires Redis for health monitoring, load
  # balancing, and cluster pub/sub. DNS only supplements peer discovery by detecting
  # new pods faster. Without Redis, k8s_dns provides DNS resolution only -- no
  # NodeRegistry, HealthMonitor, or LoadBalancer will be created.
  discovery_mode: "redis"

  # --- Static Discovery Configuration ---
  # When discovery_mode is "static", list peers explicitly.
  # Each peer is a single shared API address. The same port serves gRPC over h2
  # and REST over h1.
  # If a peer omits its port, SyncTV probes it on server.port.
  #
  # peers:
  #   - "node2.example.com:8080"
  #   - "node3.example.com"

  # Leader election mode for singleton operations.
  # - "redis": Use Redis-based distributed locks (default, works everywhere)
  # - "k8s_lease": Use Kubernetes coordination.k8s.io/v1 Lease resource
  #   (requires POD_NAME and POD_NAMESPACE env vars, RBAC permissions)
  leader_election_mode: "redis"

  # How far back (in seconds) to replay Redis Stream events when a new node
  # first connects to the cluster.  Replaying recent history prevents events
  # published just before this node subscribed from being silently missed.
  # Increase in clusters with high event rates; decrease to shorten startup
  # replay time.  Default: 300 (5 minutes).
  catchup_window_secs: 300
  # Maximum number of entries per Redis Stream (approximate, uses MAXLEN ~).
  # Controls how many events are retained in each per-room stream for catch-up
  # after reconnection. In high-throughput scenarios, increase this to avoid
  # trimming events that disconnected nodes still need to catch up on.
  # Default: 10000
  # Environment variable: SYNCTV_CLUSTER_STREAM_MAX_LENGTH
  stream_max_length: 10000

# ============================================================================
# Media Providers Configuration
# ============================================================================
#
# Stores media provider configurations (Alist, Emby, Jellyfin, Bilibili, etc.)

media_providers:
  # Provider configurations as a dynamic JSON/YAML value.
  # Secret-like provider fields also support sibling *_file keys, for example
  # token_file / api_key_file / password_file / access_token_file.
  # Example:
  # providers:
  #   alist:
  #     base_url: "https://alist.example.com"
  #     token: "your_token"
  #     # token_file: "/run/secrets/alist_token"
  #   emby:
  #     base_url: "https://emby.example.com"
  #     api_key: "your_api_key"
  #     # api_key_file: "/run/secrets/emby_api_key"
  providers: {}

# ============================================================================
# OAuth2/OIDC Configuration
# ============================================================================
#
# Providers are configured as a YAML string that is parsed separately
# to support dynamic provider-specific fields.
#
# Supported Providers:
#   - github:  GitHub OAuth2
#   - google:  Google OAuth2
#   - oidc:    Generic OIDC provider with .well-known discovery
#              Supports issuer, auth_url, token_url, userinfo_url fields
#   - qq, gitee, feishu, wechat: Chinese OAuth2 Providers (not yet implemented)
#   - Any OIDC-compliant provider (Casdoor, Keycloak, Authelia, etc.)
#     requires 'type: oidc' field
#
# Common fields (all providers):
#   client_id: OAuth2 client ID
#   client_secret: OAuth2 client secret
#   client_secret_file: Path to a file containing the client secret
#   redirect_url: (required) frontend/client callback URI
#
# Provider-specific fields:
#   logto:
#     endpoint: Logto server URL (e.g., "https://logto.example.com")
#   oidc:
#     issuer: Issuer URL for .well-known discovery
#     auth_url: (optional) Custom authorization endpoint
#     token_url: (optional) Custom token endpoint
#     userinfo_url: (optional) Custom userinfo endpoint
#
# Multiple Provider Instances:
#   Use different instance names (e.g., logto1, logto2) and add 'type' field
#   to specify the provider type.
#
# Callback URLs must point to your frontend or native client, because SyncTV
# uses a frontend-driven OAuth2 flow:
#   1. Provider redirects to your frontend/client callback URI with code+state
#   2. Frontend/client calls POST /api/oauth2/<instance_name>/exchange
# Examples:
#   https://app.example.com/oauth2/callback
#   synctv://oauth2/callback
#
# Security Notes:
#   - OAuth2 tokens are only used temporarily during login and then discarded
#   - Only provider-user mappings are stored (for future logins)
#   - Always use HTTPS in production for OAuth2 callbacks

oauth2:
  # URL scheme for OAuth2 redirect URLs ("http" or "https").
  # When behind a reverse proxy terminating TLS, set to "https".
  redirect_scheme: "http"
  # Example configuration (uncomment and modify):
  # providers: |
  #   # Standard OAuth2 Providers
  #   github:
  #     client_id: "your_github_client_id"
  #     client_secret: "your_github_client_secret"
  #     # client_secret_file: "/run/secrets/github_client_secret"
  #     redirect_url: "https://app.example.com/oauth2/callback"
  #
  #   google:
  #     client_id: "your_google_client_id"
  #     client_secret: "your_google_client_secret"
  #     # client_secret_file: "/run/secrets/google_client_secret"
  #     redirect_url: "https://app.example.com/oauth2/callback"
  #
  #   # Multiple instances of same provider (requires 'type' field)
  #   logto1:
  #     type: logto
  #     client_id: "logto1_client_id"
  #     client_secret: "logto1_client_secret"
  #     # client_secret_file: "/run/secrets/logto1_client_secret"
  #     endpoint: "https://logto1.example.com"
  #     redirect_url: "https://app.example.com/oauth2/callback"
  #
  #   logto2:
  #     type: logto
  #     client_id: "logto2_client_id"
  #     client_secret: "logto2_client_secret"
  #     # client_secret_file: "/run/secrets/logto2_client_secret"
  #     endpoint: "https://logto2.example.com"
  #     redirect_url: "https://app.example.com/oauth2/callback"
  #
  #   # Generic OIDC provider
  #   custom_oidc:
  #     type: oidc
  #     client_id: "custom_client_id"
  #     redirect_url: "https://app.example.com/oauth2/callback"
  #     client_secret: "custom_client_secret"
  #     # client_secret_file: "/run/secrets/custom_oidc_client_secret"
  #     issuer: "https://custom.oidc.provider.com"
  providers: ""

# Environment Variables for OAuth2:
#   Format: SYNCTV_OAUTH2_<FIELD>
#   Examples:
#     SYNCTV_OAUTH2_REDIRECT_SCHEME=https

# ============================================================================
# WebRTC Configuration
# ============================================================================
#
# WebRTC supports 2 operation modes:
#   - signaling_only: Pure signaling relay without ICE bootstrap
#   - peer_to_peer:   P2P with built-in STUN plus optional external ICE servers

webrtc:
  mode: "peer_to_peer"

  # --- Built-in STUN Server ---
  enable_builtin_stun: true
  stun_port: 3478
  stun_host: "0.0.0.0"
  # External address for STUN reflexive candidates. In K8s/NAT, set to
  # the pod IP or service IP (e.g., via SYNCTV_WEBRTC_STUN_EXTERNAL_ADDR).
  # If empty, falls back to advertise_host:stun_port.
  # stun_external_addr: ""
  # --- External ICE Servers ---
  # Configured dynamically via the settings API (no restart required):
  #   "webrtc.external_ice_servers" - JSON array of ICE server objects, e.g.:
  #       [{"urls":["stun:stun.l.google.com:19302"]},{"urls":["turn:turn.example.com:3478"],"username":"user","credential":"pass"}]

  # ============================================================================
  # Dynamic ICE Servers Configuration
  # ============================================================================
  #
  # External ICE servers are managed via the settings API at runtime.
  #
  # Setting key: "webrtc.external_ice_servers"
  # Value: JSON array of ICE server objects
  #   Default:
  #   [{"urls":["stun:stun.l.google.com:19302"]},{"urls":["stun:stun1.l.google.com:19302"]}]
  #
  # Changes take effect immediately without restarting the server.

  # ============================================================================
  # Buffer Size Tuning
  # ============================================================================
  #
  # Controls internal channel buffer sizes. Larger values provide more resilience
  # during traffic spikes but use more memory. Defaults match the current
  # built-in runtime values.
  #
  # Additional buffer sizes are configured in their respective sections:
  #   - cluster.critical_channel_capacity (default: 1000)
  #   - cluster.publish_channel_capacity (default: 10000)
  #   - livestream.stream_hub_event_channel_capacity (default: 4096)

buffer_sizes:
  # Per-connection WebSocket outbound message queue.
  # When full, new messages are dropped (backpressure for slow clients).
  websocket_outbound: 256
  # Audit log event buffer. Events are batched and flushed to the database.
  # When full, new audit events are dropped with a warning.
  audit_buffer: 10000