Question about 2026-03-10 REST API breaking changes: Deprecate support for the beta media type

[carlcsaposs-canonical]

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Hi!

Regarding the recent announcement about the 2026-03-10 version of the REST API, could you clarify what this section of the breaking changes means?

Deprecate support for the beta media type This media type was officially deprecated in 2014. However, there are still remnants of its use that modify response payloads. The following response properties are deprecated as a result:

• emails response as a flat array of strings instead of email objects
• pull_request response property with null default values
• user response property, replaced by owner
• master_branch response property, replaced by default_branch

Affected endpoints
[...]
GET /repos/{owner}/{repo}/pulls/{pull_number}
[...]

(from https://docs.github.com/en/rest/about-the-rest-api/breaking-changes?apiVersion=2026-03-10#version-2026-03-10)

I expected that the user field would be replaced with the owner field, but it appears to be the same:
2022-11-28

$ curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2022-11-28" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 | jq .user
{
  "login": "marceloneppel",
  "id": 26063517,
  "node_id": "MDQ6VXNlcjI2MDYzNTE3",
  "avatar_url": "https://v-avatars-githubusercontent-com.adclosenn.dev/u/26063517?v=4",
  "gravatar_id": "",
  "url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel",
  "html_url": "https://github.com/marceloneppel",
  "followers_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/followers",
  "following_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/following{/other_user}",
  "gists_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/gists{/gist_id}",
  "starred_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/starred{/owner}{/repo}",
  "subscriptions_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/subscriptions",
  "organizations_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/orgs",
  "repos_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/repos",
  "events_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/events{/privacy}",
  "received_events_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/received_events",
  "type": "User",
  "user_view_type": "public",
  "site_admin": false
}
$ curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2022-11-28" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 | jq .owner
null

2026-03-10

$ curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2026-03-10" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 | jq .user
{
  "login": "marceloneppel",
  "id": 26063517,
  "node_id": "MDQ6VXNlcjI2MDYzNTE3",
  "avatar_url": "https://v-avatars-githubusercontent-com.adclosenn.dev/u/26063517?v=4",
  "gravatar_id": "",
  "url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel",
  "html_url": "https://github.com/marceloneppel",
  "followers_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/followers",
  "following_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/following{/other_user}",
  "gists_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/gists{/gist_id}",
  "starred_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/starred{/owner}{/repo}",
  "subscriptions_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/subscriptions",
  "organizations_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/orgs",
  "repos_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/repos",
  "events_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/events{/privacy}",
  "received_events_url": "https://v-api-github-com.adclosenn.dev/users/marceloneppel/received_events",
  "type": "User",
  "user_view_type": "public",
  "site_admin": false
}
$ curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2026-03-10" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 | jq .owner
null

I'm struggling to understand what that section of the documentation is saying/what the breaking change is

[easwar16]

Hey @carlcsaposs-canonical,

This section of the breaking-changes documentation is easy to misinterpret because it does not mean that the user field in the pull request response is being replaced with owner.

What the note is referring to is the removal of behavior that only occurred when clients used the old beta media type (for example application/vnd.github.beta+json). That media type altered some response payloads compared to the standard API format.

Key points:

1. The change only affects the deprecated beta media type

   • The beta media type modified certain response structures.
   • GitHub is removing the remaining code paths that changed payloads when that media type was used.

2. The user → owner note does not apply to pull request authors

   • In the standard API responses, a pull request still has a user field that represents the PR author.
   • This field is not being removed or replaced.

3. The owner replacement refers to specific legacy payload variations

   • Some older beta responses used user for objects where the canonical field is now owner (for example in repository-related objects).
   • Those legacy aliases are what are being removed.

4. Why your test shows no difference
   Your requests use:

   Accept: application/vnd.github+json
   

   which is the current default media type, not the deprecated beta one. Because of that, both API versions return the same structure, which is expected.

So in practice:

• If you are using application/vnd.github+json (or the default API behavior), nothing changes for the pull request user field.
• The breaking change only impacts clients that were still relying on the deprecated beta media type behavior.

That’s why your responses look identical across the two API versions.

[carlcsaposs-canonical]

Thank you @easwar16!

only affects [...] application/vnd.github.beta+json

That's exactly what I was missing

---

$ curl -s -L -H "Accept: application/vnd.github.beta+json" -H "X-GitHub-Api-Version: 2022-11-28" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 > a
$ curl -s -L -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2022-11-28" https://v-api-github-com.adclosenn.dev/repos/canonical/postgresql-operator/pulls/1 > b
$ diff a b
223,224c223
<       "default_branch": "main",
<       "master_branch": "main"
---
>       "default_branch": "main"