---
title: "Slack API Node Socket Mode v3.1.0 pins WebSocket connections to HTTP/1.1: 2026-09-30 | Harbyn"
description: "Slack API Node Socket Mode v3.1.0 pins WebSocket connections to HTTP/1.1, announced Sep 30, 2026."
canonical: "https://harbyn.com/changes/slack/2026-09-30-release-node-sdk-updates"
last-updated: 2026-10-17
---

# Slack API Node Socket Mode v3.1.0 pins WebSocket connections to HTTP/1.1

Markdown version of <https://harbyn.com/changes/slack/2026-09-30-release-node-sdk-updates>.

Behavior change - Slack API. low severity. In effect.

The default dispatcher in Node SDK Socket Mode v3.1.0 now pins the WebSocket connection to HTTP/1.1, because undici@^8 offers HTTP/2 by default. Apps with a custom ProxyAgent dispatcher should pass requestTls: { allowH2: false } to do the same.

## Facts

| Fact | Value |
| --- | --- |
| Vendor | [Slack API](https://harbyn.com/vendors/slack.md) |
| Kind | Behavior change |
| Severity | low |
| Status | In effect |
| Announced | Sep 30, 2026 |
| Added to Harbyn | Oct 17, 2026 |
| Lead time | No dated deadline |
| Vendor page | <https://docs.slack.dev/changelog/2026/09/30/node-sdk> |
| Review | Reviewed by a person, extracted by a model |

## Find it in your code

```sh
npx harbyn scan
```

This change names no identifier the scanner can match line by line, so the scan tells you whether your repository uses Slack API, from its packages and API hosts. Nothing leaves your machine.

## Sources

Where this event comes from: the page we read, when we read it, and the hash of that snapshot.

- <https://docs.slack.dev/changelog/rss.xml> (changelog, fetched 2026-10-17 13:00 UTC, sha256 `7824e0f0c73625fc993f67026c392d0e18ce350ac292d79ab831d030b5ac5b82`)

## Related changes

### More from Slack API

- [Password-free sign-in is the default for new Slack sandboxes](https://harbyn.com/changes/slack/2026-10-22-release-slack-cli-v4-11-0.md) (Behavior change, announced Oct 22, 2026)
- [Restricted-scopes installation error explains how to resolve the issue](https://harbyn.com/changes/slack/2026-10-22-release-slack-cli-v4-11-0-4.md) (Behavior change, announced Oct 22, 2026)

### Changes at other vendors

- [Amazon Selling Partner API: ORDER\_CHANGE notifications add PreFulfillmentStatusChange for Amazon Autos](https://harbyn.com/changes/amazon-sp-api/2026-10-14-sp-api-updates-new-listings-items-api-ivp-values-in-eu5-jp-and-ca-stores-oct-3.md) (effective Oct 28, 2026)
- [BigCommerce: 301 redirects will apply only to storefront channels](https://harbyn.com/changes/bigcommerce/2026-10-07-301-redirects-now-apply-to-storefront-channels-only.md) (effective Nov 10, 2026)
- [GitHub: Secret scanning audit log business field changes to enterprise slug](https://harbyn.com/changes/github/2026-10-20-updates-to-github-secret-scanning-7.md) (effective Nov 12, 2026)
- [Jira / Atlassian Cloud: New IP address ranges in use from January 1, 2027](https://harbyn.com/changes/atlassian-jira/2026-10-16-atlassian-cloud-adds-new-ip-address-ranges.md) (effective Jan 1, 2027)

[All upcoming deadlines](https://harbyn.com/deadlines.md)