Class SlackAdapter

Slack-specific adapter that implements all platform operations using the Slack Web API (@slack/web-api).

Features

Per-agent identity: each agent's name and avatar appear on their messages
Thread-based conversation context via conversations.replies
Progressive streaming updates via chat.postMessage / chat.update
Rich Block Kit formatting with agent headers, artifact cards, and metadata
Multi-word agent name matching (e.g., @Research Agent)
User email lookup via users.info for MJ user mapping
Bot mention stripping for clean agent input

Authentication

Requires a Bot User OAuth Token (xoxb-...) with these scopes:

chat:write — Post and update messages
chat:write.customize — Post with custom username and icon
channels:history / groups:history / im:history — Read thread history
users:read / users:read.email — Look up user email addresses
app_mentions:read — Receive

Mention

events

Hierarchy (View Summary)

BaseMessagingAdapter
- SlackAdapter

Constructors

constructor

new SlackAdapter(settings: MessagingAdapterSettings): SlackAdapter
Parameters
- settings: MessagingAdapterSettings
Returns SlackAdapter
Overrides BaseMessagingAdapter.constructor
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:65

Properties

`Protected`availableAgents

availableAgents: MJAIAgentEntityExtended[] = []

All active agents, loaded at init for multi-word name matching. Sorted longest-name-first.

`Protected`defaultAgent

defaultAgent: MJAIAgentEntityExtended | null = null

Default agent loaded from config DefaultAgentName.

`Protected`fallbackContextUser

fallbackContextUser: UserInfo | null = null

Fallback context user (service account) loaded from config email.

`Protected`settings

settings: MessagingAdapterSettings

Extension settings from mj.config.cjs.

Accessors

AvailableAgentNames

get AvailableAgentNames(): string[]
Get the list of available agent names, sorted longest-first. Useful for subclasses implementing multi-word agent name matching.

Returns string[]
Inherited from BaseMessagingAdapter.AvailableAgentNames
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:170

`Protected`PlatformName

get PlatformName(): string
Human-readable platform name (e.g., "Slack", "Teams") used in conversation names and log messages. Subclasses must return their platform identifier.

Returns string
Overrides BaseMessagingAdapter.PlatformName
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:63

Methods

`Protected`buildAgentIdentity

buildAgentIdentity(agent: MJAIAgentEntityExtended): AgentIdentity
Build an AgentIdentity from an agent entity. Only includes IconURL if it's a valid HTTPS URL.
Parameters
- agent: MJAIAgentEntityExtended
Returns AgentIdentity
Inherited from BaseMessagingAdapter.buildAgentIdentity
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:280

`Protected`fetchThreadHistory

fetchThreadHistory(
channelId: string,
threadId: string,
): Promise<IncomingMessage[]>
Fetch all messages in a Slack thread using conversations.replies.
Parameters
- channelId: string
- threadId: string
Returns Promise<IncomingMessage[]>
Overrides BaseMessagingAdapter.fetchThreadHistory
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:132

`Protected`formatResponse

formatResponse(
    result: ExecuteAgentResult | null,
    agent: MJAIAgentEntityExtended,
    responseText: string,
    metadata?: AgentResponseMetadata,
): Promise<FormattedResponse>
Format agent response as rich Slack Block Kit blocks.

When a full ExecuteAgentResult is available, builds a rich layout with agent header, artifact cards, action buttons, and metadata footer. Falls back to simple markdown→blocks conversion for plain text.
Parameters
- result: ExecuteAgentResult | null
- agent: MJAIAgentEntityExtended
- responseText: string
- Optionalmetadata: AgentResponseMetadata
Returns Promise<FormattedResponse>
Overrides BaseMessagingAdapter.formatResponse
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:238

`Protected`getBotUserId

getBotUserId(): string
Get the bot's own user ID on this platform (to identify bot messages in thread history).

Returns string
Overrides BaseMessagingAdapter.getBotUserId
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:105

HandleMessage

HandleMessage(message: IncomingMessage): Promise<void>
Main entry point: handle an incoming message from the platform.

Orchestrates the full flow from message receipt to response delivery. Errors are caught and reported as user-facing error messages — this method never throws.
Parameters
- message: IncomingMessage
  Normalized incoming message from the platform adapter.
Returns Promise<void>
Inherited from BaseMessagingAdapter.HandleMessage
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:139

Initialize

Initialize(): Promise<void>
Initialize the adapter: resolve the fallback context user, load the default MJ agent (using the fallback user as contextUser), load all available agents, then run platform init. Must be called before handling any messages.

Returns Promise<void>
Throws
Error if the configured agent or fallback user cannot be found.
Inherited from BaseMessagingAdapter.Initialize
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:122

`Protected`lookupUserEmail

lookupUserEmail(platformUserId: string): Promise<string | null>
Look up a Slack user's email address via the Web API.

Requires the users:read.email scope on the bot token.
Parameters
- platformUserId: string
  Slack user ID (e.g., U0123456).
Returns Promise<string | null>
Email address, or null if not available.
Overrides BaseMessagingAdapter.lookupUserEmail
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:276

MapSlackEvent

MapSlackEvent(event: Record<string, unknown>): IncomingMessage
Convert a raw Slack event payload into a normalized IncomingMessage.

Called by SlackMessagingExtension when a webhook event is received. Uses multi-word agent name matching against the loaded agent list.
Parameters
- event: Record<string, unknown>
  Raw Slack event object from the Events API.
Returns IncomingMessage
Normalized incoming message.
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:79

`Protected`matchAgentMentions

matchAgentMentions(text: string): string[]
Match agent names mentioned in the message text against known agents.

Strips the bot's platform mention, then checks for known agent names preceded by @ (case-insensitive). Names are checked longest-first to avoid prefix collisions (e.g., "Research Agent" before "Research").
Parameters
- text: string
  The raw message text.
Returns string[]
Array of matched agent names.
Inherited from BaseMessagingAdapter.matchAgentMentions
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:299

`Protected`onInitialize

onInitialize(): Promise<void>
Fetch the bot's own user ID from the Slack API. This is needed to identify bot messages in thread history.

Returns Promise<void>
Overrides BaseMessagingAdapter.onInitialize
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:100

`Protected`resolveAgent

resolveAgent(
    message: IncomingMessage,
    contextUser: UserInfo,
    threadHistory?: IncomingMessage[],
): Promise<
    { agent: MJAIAgentEntityExtended; multiAgentNote: string
    | null },
>
Resolve which agent to use for this message.

Priority:
1. Explicit
Parameters
- message: IncomingMessage
- contextUser: UserInfo
- threadHistory: IncomingMessage[] = []
Returns Promise<{ agent: MJAIAgentEntityExtended; multiAgentNote: string | null }>
Mention
in the current message 2. Thread affinity — if this is a reply in a thread, use the same agent that was originally

Mentioned
in the thread's first message 3. Fall back to the default agent from config

If the mentioned agent is not found, responds with available agents.
Inherited from BaseMessagingAdapter.resolveAgent
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:483

`Protected`resolveContextUser

resolveContextUser(message: IncomingMessage): Promise<UserInfo>
Resolve the MJ user for the platform sender.

Flow:
1. If IncomingMessage has SenderEmail, look up in UserCache
2. If not, call lookupUserEmail() (platform API) then look up
3. Fall back to the configured service account
Parameters
- message: IncomingMessage
Returns Promise<UserInfo>
Inherited from BaseMessagingAdapter.resolveContextUser
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:447

`Protected`sendFinalMessage

sendFinalMessage(
originalMessage: IncomingMessage,
response: FormattedResponse,
): Promise<void>
Send the final formatted response. If a "Thinking..." message exists (no streaming occurred), update it in-place instead of posting a new message.
Parameters
- originalMessage: IncomingMessage
- response: FormattedResponse
Returns Promise<void>
Overrides BaseMessagingAdapter.sendFinalMessage
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:193

`Protected`sendOrUpdateStreamingMessage

sendOrUpdateStreamingMessage(
    originalMessage: IncomingMessage,
    currentContent: string,
    existingMessageId: string | null,
    agent?: MJAIAgentEntityExtended,
): Promise<string>
Post a new streaming message or update an existing one. Shows the agent's identity on new messages.
Parameters
- originalMessage: IncomingMessage
- currentContent: string
- existingMessageId: string | null
- Optionalagent: MJAIAgentEntityExtended
Returns Promise<string>
Overrides BaseMessagingAdapter.sendOrUpdateStreamingMessage
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:157

`Protected`shouldRespond

shouldRespond(message: IncomingMessage): boolean
Determine whether the bot should respond to this message.

Responds to:
- Direct messages (DMs)
- Explicit
Parameters
- message: IncomingMessage
Returns boolean
Mentions
(app_mention events)
- Thread replies (any reply in a thread the bot is participating in)
Thread replies are included because the bot only has threads it started (via slash commands or
Mention
responses), so a reply in such a thread is implicitly directed at the bot.

Subclasses can override for platform-specific logic.
Inherited from BaseMessagingAdapter.shouldRespond
- Defined in packages/MessagingAdapters/src/base/BaseMessagingAdapter.ts:435

`Protected`showTypingIndicator

showTypingIndicator(
message: IncomingMessage,
agent?: MJAIAgentEntityExtended,
): Promise<void>
Post a "Thinking..." message as the typing indicator. Shows the agent's identity if available. This message gets replaced in-place by the first streaming update.
Parameters
- message: IncomingMessage
- Optionalagent: MJAIAgentEntityExtended
Returns Promise<void>
Overrides BaseMessagingAdapter.showTypingIndicator
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:114

`Protected`stripBotMention

stripBotMention(text: string): string
Strip the bot's
Parameters
- text: string
Returns string
Mention
from the message text. Slack

Mentions
use the format <@U0123456>.
Overrides BaseMessagingAdapter.stripBotMention
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:264

`Protected`updateFinalMessage

updateFinalMessage(
    originalMessage: IncomingMessage,
    messageId: string,
    response: FormattedResponse,
): Promise<void>
Update the streaming progress message with the final formatted response.
Parameters
- originalMessage: IncomingMessage
- messageId: string
- response: FormattedResponse
Returns Promise<void>
Overrides BaseMessagingAdapter.updateFinalMessage
- Defined in packages/MessagingAdapters/src/slack/SlackAdapter.ts:218

Class SlackAdapter

Features

Authentication

Mention

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns SlackAdapter

Properties

ProtectedavailableAgents

ProtecteddefaultAgent

ProtectedfallbackContextUser

Protectedsettings

Accessors

AvailableAgentNames

Returns string[]

ProtectedPlatformName

Returns string

Methods

ProtectedbuildAgentIdentity

Parameters

Returns AgentIdentity

ProtectedfetchThreadHistory

Parameters

Returns Promise<IncomingMessage[]>

ProtectedformatResponse

Parameters

Returns Promise<FormattedResponse>

ProtectedgetBotUserId

Returns string

HandleMessage

Parameters

Returns Promise<void>

Initialize

Returns Promise<void>

Throws

ProtectedlookupUserEmail

Parameters

Returns Promise<string | null>

MapSlackEvent

Parameters

Returns IncomingMessage

ProtectedmatchAgentMentions

Parameters

Returns string[]

ProtectedonInitialize

Returns Promise<void>

ProtectedresolveAgent

Parameters

Returns Promise<{ agent: MJAIAgentEntityExtended; multiAgentNote: string | null }>

Mention

Mentioned

ProtectedresolveContextUser

Parameters

Returns Promise<UserInfo>

ProtectedsendFinalMessage

Parameters

Returns Promise<void>

ProtectedsendOrUpdateStreamingMessage

Parameters

Returns Promise<string>

ProtectedshouldRespond

Parameters

Returns boolean

Mentions

Mention

ProtectedshowTypingIndicator

Parameters

Returns Promise<void>

ProtectedstripBotMention

Parameters

Returns string

Mention

Mentions

`Protected`availableAgents

`Protected`defaultAgent

`Protected`fallbackContextUser

`Protected`settings

`Protected`PlatformName

`Protected`buildAgentIdentity

`Protected`fetchThreadHistory

`Protected`formatResponse

`Protected`getBotUserId

`Protected`lookupUserEmail

`Protected`matchAgentMentions

`Protected`onInitialize

`Protected`resolveAgent

`Protected`resolveContextUser

`Protected`sendFinalMessage

`Protected`sendOrUpdateStreamingMessage

`Protected`shouldRespond

`Protected`showTypingIndicator

`Protected`stripBotMention

`Protected`updateFinalMessage