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Channels

note

The Agent Builder is part of the Mastra Enterprise Edition. Production deployments require a valid EE license. Contact sales for more information.

Channels let Builder-created agents reach users outside the Mastra server. Register a channel provider on Mastra.channels and the Builder exposes the channel as an integration option for every agent.

Slack is currently the only supported channel.

Quickstart
Direct link to Quickstart

Install the Slack provider:

npm install @mastra/slack

Register SlackProvider on Mastra.channels:

src/mastra/index.ts
import { Mastra } from '@mastra/core/mastra'
import { MastraEditor } from '@mastra/editor'
import { createBuilderAgent } from '@mastra/editor/ee'
import { SlackProvider } from '@mastra/slack'

export const mastra = new Mastra({
  storage,
  channels: {
    slack: new SlackProvider({
      refreshToken: process.env.SLACK_APP_CONFIG_REFRESH_TOKEN,
      baseUrl: process.env.SLACK_BASE_URL,
    }),
  },
  agents: { builderAgent: createBuilderAgent() },
  editor: new MastraEditor({
    builder: { enabled: true },
  }),
})

The Slack provider handles app creation, OAuth, slash commands, and message routing for every Builder-created agent that opts in.

Configuration
Direct link to Configuration

SlackProvider requires one environment variable and accepts one optional override:

  • SLACK_APP_CONFIG_REFRESH_TOKEN (required): the refresh token from your Slack app configuration tokens, available under Your App Configuration Tokens on api.slack.com/apps. The refresh token does not expire, but the access tokens it issues rotate every 12 hours and are auto-persisted to Mastra.storage.
  • baseUrl (optional): the public URL Slack should send events and OAuth callbacks to. Defaults to the running Mastra server's host and port (for example, http://localhost:4111 in local development). Pass baseUrl explicitly when the public URL differs from the server's resolved address — typically a tunnel for local development (cloudflared tunnel --url http://localhost:4111) or a deployed URL in production.

Storage requirement
Direct link to Storage requirement

SlackProvider requires a persistent storage backend on the Mastra instance. Without storage, rotated tokens and app installations are lost on restart.

  • Deploying — set a public baseUrl for production deployments.
  • Configuration — wire channel toggles into the Builder UI.
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