Slack bot hosting: Socket Mode or HTTP in production?

Choose Slack bot hosting by receiver type. A Socket Mode app needs one process that keeps an outbound WebSocket open and reconnects after interruptions. An HTTP app needs a stable HTTPS URL, signature verification, and a handler that acknowledges each request before doing slow work.

Slack recommends Socket Mode for local development, apps behind a firewall, and cases where a public endpoint is unavailable. Its production guidance favors HTTP request URLs when possible because long-lived WebSockets can disconnect and are harder to scale. That distinction should drive the hosting decision.

Pick the receiver before the provider

What the common hosting options actually provide

Do not buy a continuous worker for an HTTP-only app just because the code was first tested with Socket Mode. Do not put a Socket Mode process on a host that suspends idle services. A WebSocket waiting for an event can look idle even though it is doing its job.

The two tokens in Socket Mode are not interchangeable

A Bolt Socket Mode app normally needs a bot token that starts with xoxb and an app-level token that starts with xapp. The app-level token needs the connections:write scope so the SDK can request a temporary WebSocket URL. Keep both in environment variables.

import { App } from '@slack/bolt';

const app = new App({
  token: process.env.SLACK_BOT_TOKEN,
  appToken: process.env.SLACK_APP_TOKEN,
  socketMode: true,
});

await app.start();

A process that prints a connected message but receives no events may still have the wrong subscriptions, scopes, or installed app version. Hosting can keep the socket alive, but it cannot grant a missing Slack permission.

Production checks that catch the quiet failures

• Confirm the app is installed in the workspace after the latest scope change.
• Subscribe only to the events the code handles, and invite the bot to channels where membership is required.
• Log startup, reconnects, Slack API errors, and handler failures without printing either token.
• Acknowledge events and interactions before calling a model, generating a file, or waiting on another API.
• Put durable jobs and user state in a database or queue outside the container.
• Test a cold start, one reconnect, one bad token, and a real event from Slack before ending the migration.

Move the app without creating two consumers

Deploy the new copy with its tokens withheld, verify that dependencies install, then stop the old process. Add the tokens to the new host and watch one successful connection. For HTTP mode, move the Slack request URL only after the new endpoint answers its health check and verifies signatures.

Spocket runs Node 22 and Python 3.11 apps as continuous processes and gives HTTP apps an HTTPS URL. The Solo plan is $3 per month for one 512MB app. It is a direct fit for a small internal Slack app, but a platform with automatic replicas, a managed queue, or public Marketplace distribution needs a different architecture. Use /run/slack for the hosting path and /documentation/domains-and-webhooks for an HTTP receiver.