Spectacles Gateway

The Spectacles gateway acts as a standalone process between your Discord bot application and the Discord gateway, allowing your bot to focus entirely on application logic. This has numerous benefits:

1. Seamless upgrades. If you configure the Spectacles Gateway to use one of the supported message broker protocols, you can restart your bot and not lose any messages from the Discord Gateway.
2. Load scalability. With the Spectacles Gateway responsible for all of the Discord logic, you can scale your bot to handle high-load situations without worrying about restarting shards and sessions.
3. Feature scalability. Since Discord messages get sent into a message broker, you can consume them from more than just your bot application. Making a dashboard is trivial since you can run a web application independently of your bot application and receive the exact same data.

Getting Started

The recommended usage is through Docker, but pre-built binaries are also available in Github Actions or you can compile it yourself using the latest Go compiler. Note that C build tools must be available on your machine.

Example

This example uses Docker to launch the most basic form of gateway with only the MESSAGE_CREATE event being output to STDOUT.

$ docker run --rm -it
	-e DISCORD_TOKEN="your token"
	-e DISCORD_EVENTS=MESSAGE_CREATE
	-e DISCORD_INTENTS=GUILD,GUILD_MESSAGES
	spectacles/gateway

Usage

Usage of gateway:
  -config string
        location of the gateway config file (default "gateway.toml")
  -loglevel string
        log level for the client (default "info")

The gateway can be configured using either a config file or environment variables. Environment variables take precedence over their corresponding entry in the config file.

Config file

token = "" # Discord token
events = [] # array of gateway event names to publish

# https://discord.com/developers/docs/topics/gateway#gateway-intents
intents = [] # array of gateway intents to send when identifying

# everything below is optional

[shards]
count = 2
ids = [0, 1]

[broker]
type = "redis" # can also use "amqp"
group = "gateway"
message_timeout = "2m" # this is the default value: https://golang.org/pkg/time/#ParseDuration

# exposes Prometheus-compatible statistics
[prometheus]
address = ":8080"
endpoint = "/metrics"

[shard_store]
type = "redis" # if left empty, shard info is stored locally
prefix = "gateway" # string to prefix shard-store keys

[presence]
# https://discord.com/developers/docs/topics/gateway#update-status

[redis]
url = "localhost:6379"
pool_size = 5 # size of Redis connection pool

# required for AMQP broker type
[amqp]
url = "amqp://localhost"

Example presence:

[presence]
status = "online"

[presence.game]
name = "test"
type = 0

Environment variables

Each of the below environment variables corresponds exactly to the config file above.

• DISCORD_TOKEN
• DISCORD_EVENTS: comma-separated list of gateway events

Optional:

• DISCORD_INTENTS: comma-separated list of gateway intents
• DISCORD_RAW_INTENTS: bitfield containing raw intent flags
• DISCORD_SHARD_COUNT
• DISCORD_SHARD_IDS: comma-separated list of shard IDs
• BROKER_TYPE
• BROKER_GROUP
• BROKER_MESSAGE_TIMEOUT
• PROMETHEUS_ADDRESS
• PROMETHEUS_ENDPOINT
• SHARD_STORE_TYPE
• SHARD_STORE_PREFIX
• DISCORD_PRESENCE: JSON-formatted presence object

External connections:

• AMQP_URL
• REDIS_URL
• REDIS_POOL_SIZE

How It Works

The Spectacles Gateway handles all of the Discord logic and simply forwards events to the specified message broker. Your application is completely unaware of the existence of shards and just focuses on handling incoming messages.

By default, the Spectacles Gateway sends and receives data through standard input and output. For optimal use, you should use one of the available message broker protocols (Redis or AMQP) to send output to an external message broker (we recommend Redis). Your application can then consume messages from the message broker.

Logs are output to STDERR and can be used to inspect the state of the gateway at any point. The Spectacles Gateway also offers integration with Prometheus to enable detailed stats collection.

If you configure a shard storage solution (currently only Redis), shard information will be stored there and used if/when the Spectacles Gateway restarts. If the Gateway restarts quickly enough, it will be able to resume sessions without re-identifying to Discord. If you do not configure shard storage, the gateway will just store the info in local memory.

Goals

• Multiple output destinations
  • STDIO
  • AMQP
  • Redis
• Sharding
  • Internal
  • External
  • Auto (fully managed)
• Distributable binary builds
  • Linux
  • Windows
• Multithreading
• Zero-alloc message handling
• Discord compression (ZSTD)
• Automatic restarting
• Failover
• Session resuming
  • Local
  • Redis