Today, we are shipping a new system for webhooks for use with our suite of GraphQL APIs, which are under development as part of our larger beta plans. We’re not the first to use this design for webhooks, but it is somewhat uncommon, so I’ll take this opportunity to explain it to those who may be unfamiliar with it.
Let’s first establish, for contrast, how traditional webhooks work. Here’s an example of a webhook payload from GitHub:
Click to expand (large)
{
"action": "opened",
"number": 2,
"pull_request": {
"url": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2",
"id": 279147437,
"node_id": "MDExOlB1bGxSZXF1ZXN0Mjc5MTQ3NDM3",
"html_url": "https://github.com/Codertocat/Hello-World/pull/2",
"diff_url": "https://github.com/Codertocat/Hello-World/pull/2.diff",
"patch_url": "https://github.com/Codertocat/Hello-World/pull/2.patch",
"issue_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/2",
"number": 2,
"state": "open",
"locked": false,
"title": "Update the README with new information.",
"user": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"body": "This is a pretty simple change that we need to pull into master.",
"created_at": "2019-05-15T15:20:33Z",
"updated_at": "2019-05-15T15:20:33Z",
"closed_at": null,
"merged_at": null,
"merge_commit_sha": null,
"assignee": null,
"assignees": [],
"requested_reviewers": [],
"requested_teams": [],
"labels": [],
"milestone": null,
"commits_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2/commits",
"review_comments_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2/comments",
"review_comment_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls/comments{/number}",
"comments_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/2/comments",
"statuses_url": "https://api.github.com/repos/Codertocat/Hello-World/statuses/ec26c3e57ca3a959ca5aad62de7213c562f8c821",
"head": {
"label": "Codertocat:changes",
"ref": "changes",
"sha": "ec26c3e57ca3a959ca5aad62de7213c562f8c821",
"user": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"repo": {
"id": 186853002,
"node_id": "MDEwOlJlcG9zaXRvcnkxODY4NTMwMDI=",
"name": "Hello-World",
"full_name": "Codertocat/Hello-World",
"private": false,
"owner": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"html_url": "https://github.com/Codertocat/Hello-World",
"description": null,
"fork": false,
"url": "https://api.github.com/repos/Codertocat/Hello-World",
"forks_url": "https://api.github.com/repos/Codertocat/Hello-World/forks",
"keys_url": "https://api.github.com/repos/Codertocat/Hello-World/keys{/key_id}",
"collaborators_url": "https://api.github.com/repos/Codertocat/Hello-World/collaborators{/collaborator}",
"teams_url": "https://api.github.com/repos/Codertocat/Hello-World/teams",
"hooks_url": "https://api.github.com/repos/Codertocat/Hello-World/hooks",
"issue_events_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/events{/number}",
"events_url": "https://api.github.com/repos/Codertocat/Hello-World/events",
"assignees_url": "https://api.github.com/repos/Codertocat/Hello-World/assignees{/user}",
"branches_url": "https://api.github.com/repos/Codertocat/Hello-World/branches{/branch}",
"tags_url": "https://api.github.com/repos/Codertocat/Hello-World/tags",
"blobs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/blobs{/sha}",
"git_tags_url": "https://api.github.com/repos/Codertocat/Hello-World/git/tags{/sha}",
"git_refs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/refs{/sha}",
"trees_url": "https://api.github.com/repos/Codertocat/Hello-World/git/trees{/sha}",
"statuses_url": "https://api.github.com/repos/Codertocat/Hello-World/statuses/{sha}",
"languages_url": "https://api.github.com/repos/Codertocat/Hello-World/languages",
"stargazers_url": "https://api.github.com/repos/Codertocat/Hello-World/stargazers",
"contributors_url": "https://api.github.com/repos/Codertocat/Hello-World/contributors",
"subscribers_url": "https://api.github.com/repos/Codertocat/Hello-World/subscribers",
"subscription_url": "https://api.github.com/repos/Codertocat/Hello-World/subscription",
"commits_url": "https://api.github.com/repos/Codertocat/Hello-World/commits{/sha}",
"git_commits_url": "https://api.github.com/repos/Codertocat/Hello-World/git/commits{/sha}",
"comments_url": "https://api.github.com/repos/Codertocat/Hello-World/comments{/number}",
"issue_comment_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/comments{/number}",
"contents_url": "https://api.github.com/repos/Codertocat/Hello-World/contents/{+path}",
"compare_url": "https://api.github.com/repos/Codertocat/Hello-World/compare/{base}...{head}",
"merges_url": "https://api.github.com/repos/Codertocat/Hello-World/merges",
"archive_url": "https://api.github.com/repos/Codertocat/Hello-World/{archive_format}{/ref}",
"downloads_url": "https://api.github.com/repos/Codertocat/Hello-World/downloads",
"issues_url": "https://api.github.com/repos/Codertocat/Hello-World/issues{/number}",
"pulls_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls{/number}",
"milestones_url": "https://api.github.com/repos/Codertocat/Hello-World/milestones{/number}",
"notifications_url": "https://api.github.com/repos/Codertocat/Hello-World/notifications{?since,all,participating}",
"labels_url": "https://api.github.com/repos/Codertocat/Hello-World/labels{/name}",
"releases_url": "https://api.github.com/repos/Codertocat/Hello-World/releases{/id}",
"deployments_url": "https://api.github.com/repos/Codertocat/Hello-World/deployments",
"created_at": "2019-05-15T15:19:25Z",
"updated_at": "2019-05-15T15:19:27Z",
"pushed_at": "2019-05-15T15:20:32Z",
"git_url": "git://github.com/Codertocat/Hello-World.git",
"ssh_url": "git@github.com:Codertocat/Hello-World.git",
"clone_url": "https://github.com/Codertocat/Hello-World.git",
"svn_url": "https://github.com/Codertocat/Hello-World",
"homepage": null,
"size": 0,
"stargazers_count": 0,
"watchers_count": 0,
"language": null,
"has_issues": true,
"has_projects": true,
"has_downloads": true,
"has_wiki": true,
"has_pages": true,
"forks_count": 0,
"mirror_url": null,
"archived": false,
"disabled": false,
"open_issues_count": 2,
"license": null,
"forks": 0,
"open_issues": 2,
"watchers": 0,
"default_branch": "master",
"allow_squash_merge": true,
"allow_merge_commit": true,
"allow_rebase_merge": true,
"delete_branch_on_merge": false
}
},
"base": {
"label": "Codertocat:master",
"ref": "master",
"sha": "f95f852bd8fca8fcc58a9a2d6c842781e32a215e",
"user": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"repo": {
"id": 186853002,
"node_id": "MDEwOlJlcG9zaXRvcnkxODY4NTMwMDI=",
"name": "Hello-World",
"full_name": "Codertocat/Hello-World",
"private": false,
"owner": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"html_url": "https://github.com/Codertocat/Hello-World",
"description": null,
"fork": false,
"url": "https://api.github.com/repos/Codertocat/Hello-World",
"forks_url": "https://api.github.com/repos/Codertocat/Hello-World/forks",
"keys_url": "https://api.github.com/repos/Codertocat/Hello-World/keys{/key_id}",
"collaborators_url": "https://api.github.com/repos/Codertocat/Hello-World/collaborators{/collaborator}",
"teams_url": "https://api.github.com/repos/Codertocat/Hello-World/teams",
"hooks_url": "https://api.github.com/repos/Codertocat/Hello-World/hooks",
"issue_events_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/events{/number}",
"events_url": "https://api.github.com/repos/Codertocat/Hello-World/events",
"assignees_url": "https://api.github.com/repos/Codertocat/Hello-World/assignees{/user}",
"branches_url": "https://api.github.com/repos/Codertocat/Hello-World/branches{/branch}",
"tags_url": "https://api.github.com/repos/Codertocat/Hello-World/tags",
"blobs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/blobs{/sha}",
"git_tags_url": "https://api.github.com/repos/Codertocat/Hello-World/git/tags{/sha}",
"git_refs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/refs{/sha}",
"trees_url": "https://api.github.com/repos/Codertocat/Hello-World/git/trees{/sha}",
"statuses_url": "https://api.github.com/repos/Codertocat/Hello-World/statuses/{sha}",
"languages_url": "https://api.github.com/repos/Codertocat/Hello-World/languages",
"stargazers_url": "https://api.github.com/repos/Codertocat/Hello-World/stargazers",
"contributors_url": "https://api.github.com/repos/Codertocat/Hello-World/contributors",
"subscribers_url": "https://api.github.com/repos/Codertocat/Hello-World/subscribers",
"subscription_url": "https://api.github.com/repos/Codertocat/Hello-World/subscription",
"commits_url": "https://api.github.com/repos/Codertocat/Hello-World/commits{/sha}",
"git_commits_url": "https://api.github.com/repos/Codertocat/Hello-World/git/commits{/sha}",
"comments_url": "https://api.github.com/repos/Codertocat/Hello-World/comments{/number}",
"issue_comment_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/comments{/number}",
"contents_url": "https://api.github.com/repos/Codertocat/Hello-World/contents/{+path}",
"compare_url": "https://api.github.com/repos/Codertocat/Hello-World/compare/{base}...{head}",
"merges_url": "https://api.github.com/repos/Codertocat/Hello-World/merges",
"archive_url": "https://api.github.com/repos/Codertocat/Hello-World/{archive_format}{/ref}",
"downloads_url": "https://api.github.com/repos/Codertocat/Hello-World/downloads",
"issues_url": "https://api.github.com/repos/Codertocat/Hello-World/issues{/number}",
"pulls_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls{/number}",
"milestones_url": "https://api.github.com/repos/Codertocat/Hello-World/milestones{/number}",
"notifications_url": "https://api.github.com/repos/Codertocat/Hello-World/notifications{?since,all,participating}",
"labels_url": "https://api.github.com/repos/Codertocat/Hello-World/labels{/name}",
"releases_url": "https://api.github.com/repos/Codertocat/Hello-World/releases{/id}",
"deployments_url": "https://api.github.com/repos/Codertocat/Hello-World/deployments",
"created_at": "2019-05-15T15:19:25Z",
"updated_at": "2019-05-15T15:19:27Z",
"pushed_at": "2019-05-15T15:20:32Z",
"git_url": "git://github.com/Codertocat/Hello-World.git",
"ssh_url": "git@github.com:Codertocat/Hello-World.git",
"clone_url": "https://github.com/Codertocat/Hello-World.git",
"svn_url": "https://github.com/Codertocat/Hello-World",
"homepage": null,
"size": 0,
"stargazers_count": 0,
"watchers_count": 0,
"language": null,
"has_issues": true,
"has_projects": true,
"has_downloads": true,
"has_wiki": true,
"has_pages": true,
"forks_count": 0,
"mirror_url": null,
"archived": false,
"disabled": false,
"open_issues_count": 2,
"license": null,
"forks": 0,
"open_issues": 2,
"watchers": 0,
"default_branch": "master",
"allow_squash_merge": true,
"allow_merge_commit": true,
"allow_rebase_merge": true,
"delete_branch_on_merge": false
}
},
"_links": {
"self": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2"
},
"html": {
"href": "https://github.com/Codertocat/Hello-World/pull/2"
},
"issue": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/issues/2"
},
"comments": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/issues/2/comments"
},
"review_comments": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2/comments"
},
"review_comment": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/pulls/comments{/number}"
},
"commits": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/pulls/2/commits"
},
"statuses": {
"href": "https://api.github.com/repos/Codertocat/Hello-World/statuses/ec26c3e57ca3a959ca5aad62de7213c562f8c821"
}
},
"author_association": "OWNER",
"draft": false,
"merged": false,
"mergeable": null,
"rebaseable": null,
"mergeable_state": "unknown",
"merged_by": null,
"comments": 0,
"review_comments": 0,
"maintainer_can_modify": false,
"commits": 1,
"additions": 1,
"deletions": 1,
"changed_files": 1
},
"repository": {
"id": 186853002,
"node_id": "MDEwOlJlcG9zaXRvcnkxODY4NTMwMDI=",
"name": "Hello-World",
"full_name": "Codertocat/Hello-World",
"private": false,
"owner": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
},
"html_url": "https://github.com/Codertocat/Hello-World",
"description": null,
"fork": false,
"url": "https://api.github.com/repos/Codertocat/Hello-World",
"forks_url": "https://api.github.com/repos/Codertocat/Hello-World/forks",
"keys_url": "https://api.github.com/repos/Codertocat/Hello-World/keys{/key_id}",
"collaborators_url": "https://api.github.com/repos/Codertocat/Hello-World/collaborators{/collaborator}",
"teams_url": "https://api.github.com/repos/Codertocat/Hello-World/teams",
"hooks_url": "https://api.github.com/repos/Codertocat/Hello-World/hooks",
"issue_events_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/events{/number}",
"events_url": "https://api.github.com/repos/Codertocat/Hello-World/events",
"assignees_url": "https://api.github.com/repos/Codertocat/Hello-World/assignees{/user}",
"branches_url": "https://api.github.com/repos/Codertocat/Hello-World/branches{/branch}",
"tags_url": "https://api.github.com/repos/Codertocat/Hello-World/tags",
"blobs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/blobs{/sha}",
"git_tags_url": "https://api.github.com/repos/Codertocat/Hello-World/git/tags{/sha}",
"git_refs_url": "https://api.github.com/repos/Codertocat/Hello-World/git/refs{/sha}",
"trees_url": "https://api.github.com/repos/Codertocat/Hello-World/git/trees{/sha}",
"statuses_url": "https://api.github.com/repos/Codertocat/Hello-World/statuses/{sha}",
"languages_url": "https://api.github.com/repos/Codertocat/Hello-World/languages",
"stargazers_url": "https://api.github.com/repos/Codertocat/Hello-World/stargazers",
"contributors_url": "https://api.github.com/repos/Codertocat/Hello-World/contributors",
"subscribers_url": "https://api.github.com/repos/Codertocat/Hello-World/subscribers",
"subscription_url": "https://api.github.com/repos/Codertocat/Hello-World/subscription",
"commits_url": "https://api.github.com/repos/Codertocat/Hello-World/commits{/sha}",
"git_commits_url": "https://api.github.com/repos/Codertocat/Hello-World/git/commits{/sha}",
"comments_url": "https://api.github.com/repos/Codertocat/Hello-World/comments{/number}",
"issue_comment_url": "https://api.github.com/repos/Codertocat/Hello-World/issues/comments{/number}",
"contents_url": "https://api.github.com/repos/Codertocat/Hello-World/contents/{+path}",
"compare_url": "https://api.github.com/repos/Codertocat/Hello-World/compare/{base}...{head}",
"merges_url": "https://api.github.com/repos/Codertocat/Hello-World/merges",
"archive_url": "https://api.github.com/repos/Codertocat/Hello-World/{archive_format}{/ref}",
"downloads_url": "https://api.github.com/repos/Codertocat/Hello-World/downloads",
"issues_url": "https://api.github.com/repos/Codertocat/Hello-World/issues{/number}",
"pulls_url": "https://api.github.com/repos/Codertocat/Hello-World/pulls{/number}",
"milestones_url": "https://api.github.com/repos/Codertocat/Hello-World/milestones{/number}",
"notifications_url": "https://api.github.com/repos/Codertocat/Hello-World/notifications{?since,all,participating}",
"labels_url": "https://api.github.com/repos/Codertocat/Hello-World/labels{/name}",
"releases_url": "https://api.github.com/repos/Codertocat/Hello-World/releases{/id}",
"deployments_url": "https://api.github.com/repos/Codertocat/Hello-World/deployments",
"created_at": "2019-05-15T15:19:25Z",
"updated_at": "2019-05-15T15:19:27Z",
"pushed_at": "2019-05-15T15:20:32Z",
"git_url": "git://github.com/Codertocat/Hello-World.git",
"ssh_url": "git@github.com:Codertocat/Hello-World.git",
"clone_url": "https://github.com/Codertocat/Hello-World.git",
"svn_url": "https://github.com/Codertocat/Hello-World",
"homepage": null,
"size": 0,
"stargazers_count": 0,
"watchers_count": 0,
"language": null,
"has_issues": true,
"has_projects": true,
"has_downloads": true,
"has_wiki": true,
"has_pages": true,
"forks_count": 0,
"mirror_url": null,
"archived": false,
"disabled": false,
"open_issues_count": 2,
"license": null,
"forks": 0,
"open_issues": 2,
"watchers": 0,
"default_branch": "master"
},
"sender": {
"login": "Codertocat",
"id": 21031067,
"node_id": "MDQ6VXNlcjIxMDMxMDY3",
"avatar_url": "https://avatars1.githubusercontent.com/u/21031067?v=4",
"gravatar_id": "",
"url": "https://api.github.com/users/Codertocat",
"html_url": "https://github.com/Codertocat",
"followers_url": "https://api.github.com/users/Codertocat/followers",
"following_url": "https://api.github.com/users/Codertocat/following{/other_user}",
"gists_url": "https://api.github.com/users/Codertocat/gists{/gist_id}",
"starred_url": "https://api.github.com/users/Codertocat/starred{/owner}{/repo}",
"subscriptions_url": "https://api.github.com/users/Codertocat/subscriptions",
"organizations_url": "https://api.github.com/users/Codertocat/orgs",
"repos_url": "https://api.github.com/users/Codertocat/repos",
"events_url": "https://api.github.com/users/Codertocat/events{/privacy}",
"received_events_url": "https://api.github.com/users/Codertocat/received_events",
"type": "User",
"site_admin": false
}
}
SourceHut offers a similar approach with our legacy API. The problem here is information overload. This payload contains a lot of information, almost none of which you actually need, and may omit information you do want. One of our services, dispatch.sr.ht, uses this particular GitHub payload to configure build submissions for projects who want to use GitHub for git hosting and builds.sr.ht for CI. When we receive this webhook, we need to make several follow-up API requests to collect the necessary information for build submission.
With the new GraphQL design, the user submits not only the URL and events they want to receive, but also a GraphQL query which will be executed to customize the request payload that will be sent to them. In this custom payload, you are able to collect not only information about the event which occured, but also any other information you would find in a typical GraphQL request. So, to accomplish similar functionality for submitting a build manifest on a git push, we can configure a webhook with the following query:
query {
# Collect details about the event which triggered the webhook
webhook {
uuid
date
profile { username }
... on GitPushEvent {
refs {
old { sha }
new {
sha
author { name, email }
message
}
}
}
}
# Collect build manifests
repository(id: 1234) {
# Case 1: several manifests under .builds/*.yml
multiple: path(path:".builds") {
object {
... on Tree {
entries {
results {
name
object { ... on TextBlob { text } }
}
}
}
}
}
# Case 2: one manifest at .build.yml
single: path(path:".build.yml") {
object {
... on TextBlob { text }
}
}
}
}
This is executed on the server before sending the webhook to our URL, and collects all of the information we need, and none of the information we don’t. We are then able to act on this webhook without any additional API requests. The payload we ultimately receive looks something like this:
{
"data": {
"webhook": {
"uuid":
"date":
"profile": {
"username": "sircmpwn"
},
"refs": [
"old": {
"sha": "81e98daa8341b1b5319645fecc81c7ba051c04d6"
},
"new": {
"sha": "64aff2197e08a687fca5779057bd0ac3341fea8f",
"author": {
"name": "Drew DeVault",
"email": "sir@cmpwn.com"
},
"message": "This is a commit message"
}
]
},
"repository": {
"multiple": {
"object": {
"entries": {
"results": [
{
"name": "alpine.yml",
"object": {
"text": "image: alpine/3.14\nrepositories: ..."
}
},
{
"name": "archlinux.yml",
"object": {
"text": "image: archlinux\nrepositories: ..."
}
},
{
"name": "debian.yml",
"object": {
"text": "image: debian/sid\nrepositories: ..."
}
}
]
}
}
},
"single": null
}
}
}
We only have the information we need, and nothing we don’t, and we can fetch arbitrary information from the entire system to build our webhook payload without making any further API requests. Nice!
The GraphQL schema has been expanded with tools for managing webhooks, such as browsing past deliveries. There is also a resolver which generates a sample webhook event, which you can use for testing your GraphQL query. We’ll be rolling this out for meta.sr.ht’s API first, and expanding it to support more services in the future. You can learn more in our documentation:
Swing by our IRC channel (irc://) or fire off an email to sr.ht-discuss if you have questions or feedback!