@molecule/api-channel-slack

Auto-generated, AI-first package reference for the molecule.dev ecosystem. It is written to be read by coding agents as much as by people, and is generated from this package's source — edit src/index.ts JSDoc, not this file.

Slack channel bond for molecule.dev.

Implements the {@link ChannelProvider} interface from @molecule/api-channel on top of @slack/web-api. Used by apps that post into Slack channels (notifications, AI bot replies, helpdesk announcements) and consume inbound Slack events (message events, app_mention, slash commands) via signed webhooks.

Quick Start

import { setProvider } from '@molecule/api-channel'
import { createProvider } from '@molecule/api-channel-slack'

setProvider(
  'slack',
  createProvider({
    botToken: process.env.SLACK_BOT_TOKEN,
    signingSecret: process.env.SLACK_SIGNING_SECRET,
  }),
)

Type

provider

Installation

npm install @molecule/api-channel-slack @molecule/api-channel @molecule/api-secrets @slack/web-api

API

Interfaces

ProcessEnv

Environment variables consumed by the Slack channel provider.

interface ProcessEnv {
  /**
   * Bot user OAuth token (xoxb-…). Required for outbound `sendMessage`.
   */
  SLACK_BOT_TOKEN: string

  /**
   * Slack app signing secret. Required for `verifyWebhookSignature`.
   */
  SLACK_SIGNING_SECRET: string
}

SlackBlock

Minimal shape of a Slack Block Kit block as used by this provider. Slack's full block schema is large; we only constrain the fields we emit (section and actions) and treat the rest as opaque pass-through.

interface SlackBlock {
  type: string
  text?: { type: string; text: string }
  elements?: Array<{
    type: string
    text?: { type: string; text: string }
    value?: string
    action_id?: string
  }>
}

SlackChannelConfig

Configuration for the Slack channel provider.

Tokens default to environment variables when not supplied so deployment pipelines that already inject SLACK_BOT_TOKEN / SLACK_SIGNING_SECRET keep working without extra wiring.

interface SlackChannelConfig {
  /**
   * Bot user OAuth token used for `chat.postMessage` and other Web API
   * calls. Defaults to `process.env.SLACK_BOT_TOKEN`.
   */
  botToken?: string

  /**
   * Slack app signing secret used to verify the HMAC of inbound webhook
   * requests. Defaults to `process.env.SLACK_SIGNING_SECRET`.
   */
  signingSecret?: string

  /**
   * Maximum allowed clock skew (in seconds) between the request timestamp
   * and the verifier when validating `x-slack-signature`. Defaults to 300
   * seconds (5 minutes), matching Slack's documented replay window.
   */
  signatureToleranceSeconds?: number

  /**
   * Optional pre-built `WebClient`-shaped object. Tests inject a minimal
   * mock here; production code should leave this unset and let the
   * provider construct its own client from {@link botToken}.
   */
  webClient?: SlackWebClientLike
}

SlackChatPostMessageArgs

Subset of chat.postMessage arguments consumed by this provider.

interface SlackChatPostMessageArgs {
  channel: string
  text?: string
  blocks?: SlackBlock[]
  thread_ts?: string
  attachments?: SlackOutboundAttachment[]
}

SlackChatPostMessageResponse

Subset of chat.postMessage response fields consumed by this provider.

interface SlackChatPostMessageResponse {
  ok: boolean
  ts?: string
  channel?: string
  error?: string
}

SlackOutboundAttachment

Slack-flavoured outbound attachment (legacy attachments API). Used as a pass-through for callers that already speak Slack's attachment shape.

interface SlackOutboundAttachment {
  fallback?: string
  text?: string
  title?: string
  title_link?: string
  image_url?: string
  thumb_url?: string
  color?: string
}

SlackWebClientLike

The narrow surface of @slack/web-api's WebClient that this provider actually uses. Defining it explicitly keeps tests free of the full SDK type tree and documents the integration contract.

interface SlackWebClientLike {
  chat: {
    postMessage(args: SlackChatPostMessageArgs): Promise<SlackChatPostMessageResponse>
  }
}

Functions

createProvider(config)

Creates a Slack-backed {@link ChannelProvider}.

Tokens are sourced from the supplied {@link SlackChannelConfig} or, as a fallback, the documented environment variables. Methods that require a particular secret throw a generic error if the secret is missing — the missing token name is surfaced, but never its value.

function createProvider(config?: SlackChannelConfig): ChannelProvider

• config — Provider configuration. All fields are optional; env vars cover the production wiring path.

Returns: A ChannelProvider ready to be bonded under name 'slack'.

Constants

channelSlackSecretDefinitions

Secret definitions required by the Slack channel bond.

const channelSlackSecretDefinitions: SecretDefinition[]

provider

Default Slack channel provider — pre-bound to env vars at import time.

Convenience export for apps that want to bond('channel', 'slack', provider) without explicit configuration. Configuration via env vars still applies.

const provider: ChannelProvider

Core Interface

Implements @molecule/api-channel interface.

Injection Notes

Requirements

Peer dependencies:

• @molecule/api-channel ^1.0.1
• @molecule/api-secrets ^1.0.1

Environment Variables

• SLACK_BOT_TOKEN (required) — Slack bot token
  • Setup: Create a Slack app, add bot scopes under OAuth & Permissions, install to your workspace, and copy the Bot User OAuth Token.
  • Get it here: https://api.slack.com/apps
  • Example: xoxb-...
• SLACK_SIGNING_SECRET (required) — Slack signing secret
  • Setup: Your Slack app → Basic Information → App Credentials → Signing Secret.
  • Get it here: https://api.slack.com/apps

Runtime Dependencies

• @molecule/api-channel
• @molecule/api-secrets
• @slack/web-api

Tokens are deliberately scrubbed from any error this provider raises; upstream stack traces that contain a token are still possible if a higher layer re-throws without going through this bond.

E2E Tests

Integration checklist — drive the real UI (live preview, no mocks), adapt each item to this app's actual screens/flows, and check every box off one by one. A box you can't check is an integration bug to fix — not a skip:

• Each channel-notifying flow the app defines (a Slack/Discord alert on a new order, a status-change message) actually produces a message. The sandbox CAPTURES channel messages instead of sending — read them with the read_activity tool (filter type 'channel'); never mock the flow or modify production code to expose the message.
• The captured message targets the configured channel/provider name and carries the app's real content (readable text, no undefined placeholders, no secrets).
• A failed send (unbonded or misconfigured provider) is visible in logs/UI — never silently swallowed.