---
title: "Changes to Check if the connection with the given connectionId exists."
method: HEAD
path: "/api/hubs/{hub}/connections/{connectionId}"
---

# Changes to Check if the connection with the given connectionId exists.

`HEAD /api/hubs/{hub}/connections/{connectionId}`

> Every recorded change to this endpoint, newest first.

## Timeline

Changed in 3 of 10 revisions.

- **2026-07-13** (2021-05-01-preview) `3c12a9fc6305` — 1 info
- **2026-07-13** (2021-05-01-preview) `db70e5df6e15` — 1 breaking
- **2021-04-21** (2021-05-01-preview) `5c057b21a138` — 1 warning, 2 info

## Changes

- **2026-07-13** (2021-05-01-preview) `3c12a9fc6305` — 1 info
  - api operation id `WebPubSub_ConnectionExists` removed and replaced with `ConnectionExists`
- **2026-07-13** (2021-05-01-preview) `db70e5df6e15` — 1 breaking
  - the `query` request parameter `api-version` became required
- **2021-04-21** (2021-05-01-preview) `5c057b21a138` — 1 warning, 2 info
  - the optional response header `x-ms-error-code` removed for the status `default`
  - api operation id `ConnectionExists` removed and replaced with `WebPubSub_ConnectionExists`
  - the `query` request parameter `api-version` became optional

---

[Operation](https://skmtc.dev/azure/apis/webpubsub/docs/api/hubs/:hub/connections/:connectionId/head.md) · [API](https://skmtc.dev/azure/apis/webpubsub.md) · [Page](https://skmtc.dev/azure/apis/webpubsub/changes/api/hubs/:hub/connections/:connectionId/head)