curl -X GET 'https://api.github.com/orgs/example-org/actions/hosted-runners/images/custom/10' \
  -H "Authorization: Bearer $GITHUB_TOKEN" \
  -H 'Accept: application/vnd.github+json' \
  -H 'X-GitHub-Api-Version: 2026-03-10'

# GET /orgs/{org}/actions/hosted-runners/images/custom/{image_definition_id} (GitHub API)
Base URL: https://api.github.com
Auth: Authorization; GitHub token; required.
Last verified: 2026-10-20

> Get a custom image definition for GitHub Actions Hosted Runners

## Critical Gotchas
* GitHub recommends an `Accept: application/vnd.github+json` header and an explicit `X-GitHub-Api-Version` header.
* Fine-grained tokens only authorize repositories and permissions selected when the token is created.

## cURL
curl -X GET 'https://api.github.com/orgs/example-org/actions/hosted-runners/images/custom/10' \
  -H "Authorization: Bearer $GITHUB_TOKEN" \
  -H 'Accept: application/vnd.github+json' \
  -H 'X-GitHub-Api-Version: 2026-03-10'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| org | path | string | Yes | The organization name. The name is not case sensitive. |
| image_definition_id | path | integer | Yes | Image definition ID of custom image |

## Response example
{"id":1,"platform":"linux-x64"}

---
Need an API key? Get one at https://github.com/settings/tokens

GET

GET /orgs/{org}/actions/hosted-runners/images/custom/{image_definition_id} — GitHub API

GitHub token (required); https://api.github.com

GitHub API

Get a custom image definition for GitHub Actions Hosted Runners

Base URL: https://api.github.com
Auth: Authorization: Bearer <GITHUB_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

Agents: curl -H "Accept: text/markdown" this URL
→ 192 tokens · Vary: Accept

Critical gotchas

GitHub recommends an Accept: application/vnd.github+json header and an explicit X-GitHub-Api-Version header.

Fine-grained tokens only authorize repositories and permissions selected when the token is created.

cURL

curl -X GET 'https://api.github.com/orgs/example-org/actions/hosted-runners/images/custom/10' \  -H "Authorization: Bearer $GITHUB_TOKEN" \  -H 'Accept: application/vnd.github+json' \  -H 'X-GitHub-Api-Version: 2026-03-10'

Parameters

Name	In	Type	Required	Description
org	path	string	Yes	The organization name. The name is not case sensitive.
image_definition_id	path	integer	Yes	Image definition ID of custom image

Response 200 OK

{
  "id": 1,
  "platform": "linux-x64",
  "total_versions_size": 200,
  "name": "CustomImage",
  "source": "custom",
  "versions_count": 4,
  "latest_version": "1.3.0",
  "state": "Ready"
}

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