Capabilities and rate limits

Generic channel code should inspect channel.capabilities before using an optional operation, and pace outbound calls when the adapter has no built-in rate limiting. See Channel core for the full utility map.

Advertise capabilities

channel.capabilities is optional; generic code should inspect it before presenting a feature or calling an optional operation:

if (channel.capabilities?.typing === true) {
  await channel.showTyping?.(address)
}

if (channel.capabilities?.reactions === true && channel.react !== undefined) {
  await channel.react(sentMessage, '👍')
}

if (channel.capabilities?.delete === true && channel.delete !== undefined) {
  await channel.delete(sentMessage)
}

if (channel.capabilities?.messageEdits === true && channel.edit !== undefined) {
  await channel.edit(sentMessage, { text: 'Dashboard snapshot (updated)' })
}

if (channel.capabilities?.reactionRemovals === true && channel.unreact !== undefined) {
  await channel.unreact(sentMessage, '👀')
}

capabilities.actions is the only required flag; outboundAttachments lists accepted attachment kinds ('image', 'audio', 'video', 'file'), and replies, typing, reactions, reactionRemovals, delete, and messageEdits gate the optional operations (replies gates replyToMessageId support). The standard adapters advertise their exact support; a custom text-only adapter may omit capabilities entirely.

Pace outbound calls

Wrap any adapter with createRateLimitedChannel() to serialize outbound calls (send, edit, delete, typing, reactions, and reaction removals) with a minimum spacing between them:

import { createRateLimitedChannel } from '@anvia/channel'

const paced = createRateLimitedChannel({ channel, minimumIntervalMs: 1_000 })

minimumIntervalMs must be a positive integer (TypeError otherwise). A failed call never blocks later ones — the chain survives failures. Inbound behavior (start, stop, loadAttachment, splitMessage) and the advertised capabilities pass straight through unpaced. Discord and Slack SDK clients already rate-limit internally, so the wrapper is most useful for raw-REST adapters such as Telegram, or for application code that fans out many proactive messages.

Continue with

• Send channel messages — the outbound path these operations pace.
• Build a custom adapter — advertise the right capabilities for your platform.