Slack

OpenMatter provides one Slack Work Integration with several deployment shapes. Signed HTTP and Socket Mode both submit the same portable native input to the same Integration.

To see the Integration, Agent Driver, ContextProjection, Session, Reaction, and Effect composed together, start with the built-in Claude Tag orchestration.

Supported input

Input	WorkEvent	Activation
app_mention	slack.message.mentioned	Explicit mention
Direct message	slack.message.received	Direct
Channel message	slack.message.received	Observation
Slash command	slack.command.invoked	Isolated command
Block action	slack.action.invoked	Interaction
Modal submission	slack.form.submitted	Structured form
Unknown event	slack.event.received	Observation

Authority-scoped credentials

import { makeCredentialResolver } from "@openmatter/credentials";
import { makeSlackIntegration } from "@openmatter/integration-slack";

const credentials = makeCredentialResolver(({ authority }) =>
  credentialVault.slack(authority),
);

const slack = makeSlackIntegration({ credentials });

Slack Connect uses the authorized installation as authority, which may differ from the workspace that originated a shared-channel message. Organization-wide installations keep contextTeamId separate from Enterprise credential authority.

Operations

The manifest enumerates posting, thread reply, ephemeral reply, reactions, update/delete/schedule, modal and App Home lifecycle, and portable text-file upload. Arbitrary Web API calls are intentionally not exposed as one unbounded operation.

HTTP and Socket Mode

Signed HTTP endpoints can feed a durable Queue. Local Socket Mode needs no public webhook URL; DurableInbox persists the native envelope before acknowledgement. Both paths preserve the same WorkEvent and Reaction semantics.

External-select suggestions and modal field-error response_action payloads have a three-second synchronous contract. They stay in the immediate host handler instead of pretending to be durable Agent work.