diff --git a/mock_payloads/pull_request.labeled_two_labels.json b/mock_payloads/pull_request.labeled_two_labels_no_thread.json
similarity index 100%
rename from mock_payloads/pull_request.labeled_two_labels.json
rename to mock_payloads/pull_request.labeled_two_labels_no_thread.json
diff --git a/mock_payloads/pull_request.labeled_two_labels_with_thread.json b/mock_payloads/pull_request.labeled_two_labels_with_thread.json
new file mode 100644
index 00000000..5ac29a39
--- /dev/null
+++ b/mock_payloads/pull_request.labeled_two_labels_with_thread.json
@@ -0,0 +1,474 @@
+{
+  "action": "labeled",
+  "number": 4,
+  "pull_request": {
+    "url": "https://api.github.com/repos/xinyuluo/monorepo/pulls/4",
+    "id": 0,
+    "node_id": "00000000000000000000",
+    "html_url": "https://github.com/xinyuluo/monorepo/pull/4",
+    "diff_url": "https://github.com/xinyuluo/monorepo/pull/4.diff",
+    "patch_url": "https://github.com/xinyuluo/monorepo/pull/4.patch",
+    "issue_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/4",
+    "number": 4,
+    "state": "open",
+    "locked": false,
+    "title": "README update",
+    "user": {
+      "login": "xinyuluo",
+      "id": 0,
+      "node_id": "00000000000000000000",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
+      "gravatar_id": "",
+      "url": "https://api.github.com/users/xinyuluo",
+      "html_url": "https://github.com/xinyuluo",
+      "followers_url": "https://api.github.com/users/xinyuluo/followers",
+      "following_url": "https://api.github.com/users/xinyuluo/following{/other_user}",
+      "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+      "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+      "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+      "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+      "repos_url": "https://api.github.com/users/xinyuluo/repos",
+      "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+      "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+      "type": "User",
+      "site_admin": false
+    },
+    "body": "",
+    "created_at": "2020-05-21T05:55:56Z",
+    "updated_at": "2020-05-21T05:55:56Z",
+    "closed_at": null,
+    "merged_at": null,
+    "merge_commit_sha": null,
+    "assignee": null,
+    "assignees": [],
+    "requested_reviewers": [],
+    "requested_teams": [],
+    "labels": [
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+        "id": 0,
+        "node_id": "00000000000000000000",
+        "url": "https://api.github.com/repos/xinyuluo/monorepo/labels/a1",
+        "name": "a1",
+        "color": "c5def5",
+        "default": false,
+        "description": ""
+      },
+      {
+        "id": 0,
+        "node_id": "00000000000000000000",
+        "url": "https://api.github.com/repos/xinyuluo/monorepo/labels/backend",
+        "name": "backend",
+        "color": "c70ad8",
+        "default": false,
+        "description": ""
+      }
+    ],
+    "milestone": null,
+    "draft": false,
+    "commits_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls/4/commits",
+    "review_comments_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls/4/comments",
+    "review_comment_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls/comments{/number}",
+    "comments_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/4/comments",
+    "statuses_url": "https://api.github.com/repos/xinyuluo/monorepo/statuses/cd92b75d1adfc5d5810445e3e3c4b019d4f7e3c0",
+    "head": {
+      "label": "xinyuluo:readme_update",
+      "ref": "readme_update",
+      "sha": "cd92b75d1adfc5d5810445e3e3c4b019d4f7e3c0",
+      "user": {
+        "login": "xinyuluo",
+        "id": 0,
+        "node_id": "00000000000000000000",
+        "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
+        "gravatar_id": "",
+        "url": "https://api.github.com/users/xinyuluo",
+        "html_url": "https://github.com/xinyuluo",
+        "followers_url": "https://api.github.com/users/xinyuluo/followers",
+        "following_url": "https://api.github.com/users/xinyuluo/following{/other_user}",
+        "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+        "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+        "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+        "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+        "repos_url": "https://api.github.com/users/xinyuluo/repos",
+        "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+        "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+        "type": "User",
+        "site_admin": false
+      },
+      "repo": {
+        "id": 0,
+        "node_id": "00000000000000000000",
+        "name": "monorepo",
+        "full_name": "xinyuluo/monorepo",
+        "private": true,
+        "owner": {
+          "login": "xinyuluo",
+          "id": 0,
+          "node_id": "00000000000000000000",
+          "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
+          "gravatar_id": "",
+          "url": "https://api.github.com/users/xinyuluo",
+          "html_url": "https://github.com/xinyuluo",
+          "followers_url": "https://api.github.com/users/xinyuluo/followers",
+          "following_url": "https://api.github.com/users/xinyuluo/following{/other_user}",
+          "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+          "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+          "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+          "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+          "repos_url": "https://api.github.com/users/xinyuluo/repos",
+          "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+          "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+          "type": "User",
+          "site_admin": false
+        },
+        "html_url": "https://github.com/xinyuluo/monorepo",
+        "description": "a test repository",
+        "fork": false,
+        "url": "https://api.github.com/repos/xinyuluo/monorepo",
+        "forks_url": "https://api.github.com/repos/xinyuluo/monorepo/forks",
+        "keys_url": "https://api.github.com/repos/xinyuluo/monorepo/keys{/key_id}",
+        "collaborators_url": "https://api.github.com/repos/xinyuluo/monorepo/collaborators{/collaborator}",
+        "teams_url": "https://api.github.com/repos/xinyuluo/monorepo/teams",
+        "hooks_url": "https://api.github.com/repos/xinyuluo/monorepo/hooks",
+        "issue_events_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/events{/number}",
+        "events_url": "https://api.github.com/repos/xinyuluo/monorepo/events",
+        "assignees_url": "https://api.github.com/repos/xinyuluo/monorepo/assignees{/user}",
+        "branches_url": "https://api.github.com/repos/xinyuluo/monorepo/branches{/branch}",
+        "tags_url": "https://api.github.com/repos/xinyuluo/monorepo/tags",
+        "blobs_url": "https://api.github.com/repos/xinyuluo/monorepo/git/blobs{/sha}",
+        "git_tags_url": "https://api.github.com/repos/xinyuluo/monorepo/git/tags{/sha}",
+        "git_refs_url": "https://api.github.com/repos/xinyuluo/monorepo/git/refs{/sha}",
+        "trees_url": "https://api.github.com/repos/xinyuluo/monorepo/git/trees{/sha}",
+        "statuses_url": "https://api.github.com/repos/xinyuluo/monorepo/statuses/{sha}",
+        "languages_url": "https://api.github.com/repos/xinyuluo/monorepo/languages",
+        "stargazers_url": "https://api.github.com/repos/xinyuluo/monorepo/stargazers",
+        "contributors_url": "https://api.github.com/repos/xinyuluo/monorepo/contributors",
+        "subscribers_url": "https://api.github.com/repos/xinyuluo/monorepo/subscribers",
+        "subscription_url": "https://api.github.com/repos/xinyuluo/monorepo/subscription",
+        "commits_url": "https://api.github.com/repos/xinyuluo/monorepo/commits{/sha}",
+        "git_commits_url": "https://api.github.com/repos/xinyuluo/monorepo/git/commits{/sha}",
+        "comments_url": "https://api.github.com/repos/xinyuluo/monorepo/comments{/number}",
+        "issue_comment_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/comments{/number}",
+        "contents_url": "https://api.github.com/repos/xinyuluo/monorepo/contents/{+path}",
+        "compare_url": "https://api.github.com/repos/xinyuluo/monorepo/compare/{base}...{head}",
+        "merges_url": "https://api.github.com/repos/xinyuluo/monorepo/merges",
+        "archive_url": "https://api.github.com/repos/xinyuluo/monorepo/{archive_format}{/ref}",
+        "downloads_url": "https://api.github.com/repos/xinyuluo/monorepo/downloads",
+        "issues_url": "https://api.github.com/repos/xinyuluo/monorepo/issues{/number}",
+        "pulls_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls{/number}",
+        "milestones_url": "https://api.github.com/repos/xinyuluo/monorepo/milestones{/number}",
+        "notifications_url": "https://api.github.com/repos/xinyuluo/monorepo/notifications{?since,all,participating}",
+        "labels_url": "https://api.github.com/repos/xinyuluo/monorepo/labels{/name}",
+        "releases_url": "https://api.github.com/repos/xinyuluo/monorepo/releases{/id}",
+        "deployments_url": "https://api.github.com/repos/xinyuluo/monorepo/deployments",
+        "created_at": "2020-05-21T03:03:30Z",
+        "updated_at": "2020-05-21T03:36:41Z",
+        "pushed_at": "2020-05-21T05:53:34Z",
+        "git_url": "git://github.com/xinyuluo/monorepo.git",
+        "ssh_url": "git@github.com:xinyuluo/monorepo.git",
+        "clone_url": "https://github.com/xinyuluo/monorepo.git",
+        "svn_url": "https://github.com/xinyuluo/monorepo",
+        "homepage": "",
+        "size": 0,
+        "stargazers_count": 0,
+        "watchers_count": 0,
+        "language": "OCaml",
+        "has_issues": true,
+        "has_projects": true,
+        "has_downloads": true,
+        "has_wiki": true,
+        "has_pages": false,
+        "forks_count": 0,
+        "mirror_url": null,
+        "archived": false,
+        "disabled": false,
+        "open_issues_count": 0,
+        "license": null,
+        "forks": 0,
+        "open_issues": 0,
+        "watchers": 0,
+        "default_branch": "master"
+      }
+    },
+    "base": {
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+      "ref": "master",
+      "sha": "074c4e4f15fccb905ed008993cae54830aa4fd83",
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+        "node_id": "00000000000000000000",
+        "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
+        "gravatar_id": "",
+        "url": "https://api.github.com/users/xinyuluo",
+        "html_url": "https://github.com/xinyuluo",
+        "followers_url": "https://api.github.com/users/xinyuluo/followers",
+        "following_url": "https://api.github.com/users/xinyuluo/following{/other_user}",
+        "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+        "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+        "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+        "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+        "repos_url": "https://api.github.com/users/xinyuluo/repos",
+        "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+        "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+        "type": "User",
+        "site_admin": false
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+      "repo": {
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+        "node_id": "00000000000000000000",
+        "name": "monorepo",
+        "full_name": "xinyuluo/monorepo",
+        "private": true,
+        "owner": {
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+          "node_id": "00000000000000000000",
+          "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
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+          "url": "https://api.github.com/users/xinyuluo",
+          "html_url": "https://github.com/xinyuluo",
+          "followers_url": "https://api.github.com/users/xinyuluo/followers",
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+          "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+          "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+          "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+          "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+          "repos_url": "https://api.github.com/users/xinyuluo/repos",
+          "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+          "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+          "type": "User",
+          "site_admin": false
+        },
+        "html_url": "https://github.com/xinyuluo/monorepo",
+        "description": "a test repository",
+        "fork": false,
+        "url": "https://api.github.com/repos/xinyuluo/monorepo",
+        "forks_url": "https://api.github.com/repos/xinyuluo/monorepo/forks",
+        "keys_url": "https://api.github.com/repos/xinyuluo/monorepo/keys{/key_id}",
+        "collaborators_url": "https://api.github.com/repos/xinyuluo/monorepo/collaborators{/collaborator}",
+        "teams_url": "https://api.github.com/repos/xinyuluo/monorepo/teams",
+        "hooks_url": "https://api.github.com/repos/xinyuluo/monorepo/hooks",
+        "issue_events_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/events{/number}",
+        "events_url": "https://api.github.com/repos/xinyuluo/monorepo/events",
+        "assignees_url": "https://api.github.com/repos/xinyuluo/monorepo/assignees{/user}",
+        "branches_url": "https://api.github.com/repos/xinyuluo/monorepo/branches{/branch}",
+        "tags_url": "https://api.github.com/repos/xinyuluo/monorepo/tags",
+        "blobs_url": "https://api.github.com/repos/xinyuluo/monorepo/git/blobs{/sha}",
+        "git_tags_url": "https://api.github.com/repos/xinyuluo/monorepo/git/tags{/sha}",
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+        "languages_url": "https://api.github.com/repos/xinyuluo/monorepo/languages",
+        "stargazers_url": "https://api.github.com/repos/xinyuluo/monorepo/stargazers",
+        "contributors_url": "https://api.github.com/repos/xinyuluo/monorepo/contributors",
+        "subscribers_url": "https://api.github.com/repos/xinyuluo/monorepo/subscribers",
+        "subscription_url": "https://api.github.com/repos/xinyuluo/monorepo/subscription",
+        "commits_url": "https://api.github.com/repos/xinyuluo/monorepo/commits{/sha}",
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+        "comments_url": "https://api.github.com/repos/xinyuluo/monorepo/comments{/number}",
+        "issue_comment_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/comments{/number}",
+        "contents_url": "https://api.github.com/repos/xinyuluo/monorepo/contents/{+path}",
+        "compare_url": "https://api.github.com/repos/xinyuluo/monorepo/compare/{base}...{head}",
+        "merges_url": "https://api.github.com/repos/xinyuluo/monorepo/merges",
+        "archive_url": "https://api.github.com/repos/xinyuluo/monorepo/{archive_format}{/ref}",
+        "downloads_url": "https://api.github.com/repos/xinyuluo/monorepo/downloads",
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+        "pulls_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls{/number}",
+        "milestones_url": "https://api.github.com/repos/xinyuluo/monorepo/milestones{/number}",
+        "notifications_url": "https://api.github.com/repos/xinyuluo/monorepo/notifications{?since,all,participating}",
+        "labels_url": "https://api.github.com/repos/xinyuluo/monorepo/labels{/name}",
+        "releases_url": "https://api.github.com/repos/xinyuluo/monorepo/releases{/id}",
+        "deployments_url": "https://api.github.com/repos/xinyuluo/monorepo/deployments",
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+        "updated_at": "2020-05-21T03:36:41Z",
+        "pushed_at": "2020-05-21T05:53:34Z",
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+        "ssh_url": "git@github.com:xinyuluo/monorepo.git",
+        "clone_url": "https://github.com/xinyuluo/monorepo.git",
+        "svn_url": "https://github.com/xinyuluo/monorepo",
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+        "language": "OCaml",
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+    "name": "backend",
+    "color": "c70ad8",
+    "default": false,
+    "description": ""
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+    "name": "monorepo",
+    "full_name": "xinyuluo/monorepo",
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+    },
+    "html_url": "https://github.com/xinyuluo/monorepo",
+    "description": "a test repository",
+    "fork": false,
+    "url": "https://api.github.com/repos/xinyuluo/monorepo",
+    "forks_url": "https://api.github.com/repos/xinyuluo/monorepo/forks",
+    "keys_url": "https://api.github.com/repos/xinyuluo/monorepo/keys{/key_id}",
+    "collaborators_url": "https://api.github.com/repos/xinyuluo/monorepo/collaborators{/collaborator}",
+    "teams_url": "https://api.github.com/repos/xinyuluo/monorepo/teams",
+    "hooks_url": "https://api.github.com/repos/xinyuluo/monorepo/hooks",
+    "issue_events_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/events{/number}",
+    "events_url": "https://api.github.com/repos/xinyuluo/monorepo/events",
+    "assignees_url": "https://api.github.com/repos/xinyuluo/monorepo/assignees{/user}",
+    "branches_url": "https://api.github.com/repos/xinyuluo/monorepo/branches{/branch}",
+    "tags_url": "https://api.github.com/repos/xinyuluo/monorepo/tags",
+    "blobs_url": "https://api.github.com/repos/xinyuluo/monorepo/git/blobs{/sha}",
+    "git_tags_url": "https://api.github.com/repos/xinyuluo/monorepo/git/tags{/sha}",
+    "git_refs_url": "https://api.github.com/repos/xinyuluo/monorepo/git/refs{/sha}",
+    "trees_url": "https://api.github.com/repos/xinyuluo/monorepo/git/trees{/sha}",
+    "statuses_url": "https://api.github.com/repos/xinyuluo/monorepo/statuses/{sha}",
+    "languages_url": "https://api.github.com/repos/xinyuluo/monorepo/languages",
+    "stargazers_url": "https://api.github.com/repos/xinyuluo/monorepo/stargazers",
+    "contributors_url": "https://api.github.com/repos/xinyuluo/monorepo/contributors",
+    "subscribers_url": "https://api.github.com/repos/xinyuluo/monorepo/subscribers",
+    "subscription_url": "https://api.github.com/repos/xinyuluo/monorepo/subscription",
+    "commits_url": "https://api.github.com/repos/xinyuluo/monorepo/commits{/sha}",
+    "git_commits_url": "https://api.github.com/repos/xinyuluo/monorepo/git/commits{/sha}",
+    "comments_url": "https://api.github.com/repos/xinyuluo/monorepo/comments{/number}",
+    "issue_comment_url": "https://api.github.com/repos/xinyuluo/monorepo/issues/comments{/number}",
+    "contents_url": "https://api.github.com/repos/xinyuluo/monorepo/contents/{+path}",
+    "compare_url": "https://api.github.com/repos/xinyuluo/monorepo/compare/{base}...{head}",
+    "merges_url": "https://api.github.com/repos/xinyuluo/monorepo/merges",
+    "archive_url": "https://api.github.com/repos/xinyuluo/monorepo/{archive_format}{/ref}",
+    "downloads_url": "https://api.github.com/repos/xinyuluo/monorepo/downloads",
+    "issues_url": "https://api.github.com/repos/xinyuluo/monorepo/issues{/number}",
+    "pulls_url": "https://api.github.com/repos/xinyuluo/monorepo/pulls{/number}",
+    "milestones_url": "https://api.github.com/repos/xinyuluo/monorepo/milestones{/number}",
+    "notifications_url": "https://api.github.com/repos/xinyuluo/monorepo/notifications{?since,all,participating}",
+    "labels_url": "https://api.github.com/repos/xinyuluo/monorepo/labels{/name}",
+    "releases_url": "https://api.github.com/repos/xinyuluo/monorepo/releases{/id}",
+    "deployments_url": "https://api.github.com/repos/xinyuluo/monorepo/deployments",
+    "created_at": "2020-05-21T03:03:30Z",
+    "updated_at": "2020-05-21T03:36:41Z",
+    "pushed_at": "2020-05-21T05:53:34Z",
+    "git_url": "git://github.com/xinyuluo/monorepo.git",
+    "ssh_url": "git@github.com:xinyuluo/monorepo.git",
+    "clone_url": "https://github.com/xinyuluo/monorepo.git",
+    "svn_url": "https://github.com/xinyuluo/monorepo",
+    "homepage": "",
+    "size": 0,
+    "stargazers_count": 0,
+    "watchers_count": 0,
+    "language": "OCaml",
+    "has_issues": true,
+    "has_projects": true,
+    "has_downloads": true,
+    "has_wiki": true,
+    "has_pages": false,
+    "forks_count": 0,
+    "mirror_url": null,
+    "archived": false,
+    "disabled": false,
+    "open_issues_count": 0,
+    "license": null,
+    "forks": 0,
+    "open_issues": 0,
+    "watchers": 0,
+    "default_branch": "master"
+  },
+  "sender": {
+    "login": "xinyuluo",
+    "id": 0,
+    "node_id": "00000000000000000000",
+    "avatar_url": "https://avatars0.githubusercontent.com/u/000000?v=4",
+    "gravatar_id": "",
+    "url": "https://api.github.com/users/xinyuluo",
+    "html_url": "https://github.com/xinyuluo",
+    "followers_url": "https://api.github.com/users/xinyuluo/followers",
+    "following_url": "https://api.github.com/users/xinyuluo/following{/other_user}",
+    "gists_url": "https://api.github.com/users/xinyuluo/gists{/gist_id}",
+    "starred_url": "https://api.github.com/users/xinyuluo/starred{/owner}{/repo}",
+    "subscriptions_url": "https://api.github.com/users/xinyuluo/subscriptions",
+    "organizations_url": "https://api.github.com/users/xinyuluo/orgs",
+    "repos_url": "https://api.github.com/users/xinyuluo/repos",
+    "events_url": "https://api.github.com/users/xinyuluo/events{/privacy}",
+    "received_events_url": "https://api.github.com/users/xinyuluo/received_events",
+    "type": "User",
+    "site_admin": false
+  }
+}
diff --git a/mock_payloads/pull_request_review_comment.created.json b/mock_payloads/pull_request_review_comment.created.json
index acb36d36..9485836c 100644
--- a/mock_payloads/pull_request_review_comment.created.json
+++ b/mock_payloads/pull_request_review_comment.created.json
@@ -94,15 +94,9 @@
     "merged_at": null,
     "merge_commit_sha": "3ca0f58f17dc9ac354a3b1b89f289ac16806e860",
     "assignee": null,
-    "assignees": [
-
-    ],
-    "requested_reviewers": [
-
-    ],
-    "requested_teams": [
-
-    ],
+    "assignees": [],
+    "requested_reviewers": [],
+    "requested_teams": [],
     "labels": [
       {
         "id": 0,
diff --git a/mock_states/pull_request.labeled_two_labels_with_thread.json b/mock_states/pull_request.labeled_two_labels_with_thread.json
new file mode 100644
index 00000000..977c919e
--- /dev/null
+++ b/mock_states/pull_request.labeled_two_labels_with_thread.json
@@ -0,0 +1,18 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/xinyuluo/monorepo/pull/4": [
+      {
+        "channel": "a1-bot",
+        "ts": "1728399554.482879",
+        "cid": "Ca1bot"
+      },
+      {
+        "channel": "backend",
+        "ts": "1728399554.444444",
+        "cid": "Cbackend"
+      }
+    ]
+  }
+}
diff --git a/mock_states/pull_request_review.approved.json b/mock_states/pull_request_review.approved.json
new file mode 100644
index 00000000..279065b8
--- /dev/null
+++ b/mock_states/pull_request_review.approved.json
@@ -0,0 +1,13 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/Khady/monorepo/pull/6": [
+      {
+        "channel": "default",
+        "ts": "1728399554.482879",
+        "cid": "Cdefault"
+      }
+    ]
+  }
+}
diff --git a/mock_states/pull_request_review.commented.json b/mock_states/pull_request_review.commented.json
new file mode 100644
index 00000000..513a8cf1
--- /dev/null
+++ b/mock_states/pull_request_review.commented.json
@@ -0,0 +1,13 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/xinyuluo/monorepo/pull/3": [
+      {
+        "channel": "frontend-bot",
+        "ts": "1728399554.482879",
+        "cid": "Cfebot"
+      }
+    ]
+  }
+}
diff --git a/mock_states/pull_request_review.request_changes.json b/mock_states/pull_request_review.request_changes.json
new file mode 100644
index 00000000..279065b8
--- /dev/null
+++ b/mock_states/pull_request_review.request_changes.json
@@ -0,0 +1,13 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/Khady/monorepo/pull/6": [
+      {
+        "channel": "default",
+        "ts": "1728399554.482879",
+        "cid": "Cdefault"
+      }
+    ]
+  }
+}
diff --git a/mock_states/pull_request_review.submitted_comment.json b/mock_states/pull_request_review.submitted_comment.json
new file mode 100644
index 00000000..513a8cf1
--- /dev/null
+++ b/mock_states/pull_request_review.submitted_comment.json
@@ -0,0 +1,13 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/xinyuluo/monorepo/pull/3": [
+      {
+        "channel": "frontend-bot",
+        "ts": "1728399554.482879",
+        "cid": "Cfebot"
+      }
+    ]
+  }
+}
diff --git a/mock_states/pull_request_review_comment.created.json b/mock_states/pull_request_review_comment.created.json
new file mode 100644
index 00000000..977c919e
--- /dev/null
+++ b/mock_states/pull_request_review_comment.created.json
@@ -0,0 +1,18 @@
+{
+  "pipeline_statuses": {},
+  "pipeline_commits": {},
+  "slack_threads": {
+    "https://github.com/xinyuluo/monorepo/pull/4": [
+      {
+        "channel": "a1-bot",
+        "ts": "1728399554.482879",
+        "cid": "Ca1bot"
+      },
+      {
+        "channel": "backend",
+        "ts": "1728399554.444444",
+        "cid": "Cbackend"
+      }
+    ]
+  }
+}
diff --git a/mock_states/status.commit1-02-failed.json b/mock_states/status.commit1-02-failed.json
index 48e41154..fe673357 100644
--- a/mock_states/status.commit1-02-failed.json
+++ b/mock_states/status.commit1-02-failed.json
@@ -21,5 +21,6 @@
       "s1": ["7e0a933e9c71b4ca107680ca958ca1888d5e479b"],
       "s2": []
     }
-  }
+  },
+  "slack_threads": {}
 }
diff --git a/mock_states/status.state_hide_success_test.json b/mock_states/status.state_hide_success_test.json
index f53e0857..b141aa26 100644
--- a/mock_states/status.state_hide_success_test.json
+++ b/mock_states/status.state_hide_success_test.json
@@ -21,5 +21,6 @@
       }
     }
   },
-  "pipeline_commits": {}
+  "pipeline_commits": {},
+  "slack_threads": {}
 }
diff --git a/mock_states/status.state_hide_success_test_disallowed_pipeline.json b/mock_states/status.state_hide_success_test_disallowed_pipeline.json
index 3438bf7e..41fbb975 100644
--- a/mock_states/status.state_hide_success_test_disallowed_pipeline.json
+++ b/mock_states/status.state_hide_success_test_disallowed_pipeline.json
@@ -16,5 +16,6 @@
       }
     }
   },
-  "pipeline_commits": {}
+  "pipeline_commits": {},
+  "slack_threads": {}
 }
diff --git a/test/slack_payloads.expected b/test/slack_payloads.expected
index ec1c7cbe..5a3cf175 100644
--- a/test/slack_payloads.expected
+++ b/test/slack_payloads.expected
@@ -230,7 +230,7 @@ will notify #backend
       "fallback": null,
       "mrkdwn_in": [ "text" ],
       "color": "#ccc",
-      "text": "Labels: backend"
+      "text": "*Labels*: _backend_"
     }
   ],
   "unfurl_links": false
@@ -286,17 +286,19 @@ will notify #default
   "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> Pull request #2 <https://github.com/xinyuluo/monorepo/pull/2|Update README.md> merged by *xinyuluo*",
   "unfurl_links": false
 }
-===== file ../mock_payloads/pull_request.labeled_two_labels.json =====
+===== file ../mock_payloads/pull_request.labeled_two_labels_no_thread.json =====
+===== file ../mock_payloads/pull_request.labeled_two_labels_with_thread.json =====
 will notify #a1-bot
 {
   "channel": "a1-bot",
+  "thread_ts": "1728399554.482879",
   "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> Pull request #4 <https://github.com/xinyuluo/monorepo/pull/4|README update> labeled by *xinyuluo*",
   "attachments": [
     {
       "fallback": null,
       "mrkdwn_in": [ "text" ],
       "color": "#ccc",
-      "text": "Labels: a1, backend"
+      "text": "*Labels*: _a1_, _backend_"
     }
   ],
   "unfurl_links": false
@@ -304,13 +306,14 @@ will notify #a1-bot
 will notify #backend
 {
   "channel": "backend",
+  "thread_ts": "1728399554.444444",
   "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> Pull request #4 <https://github.com/xinyuluo/monorepo/pull/4|README update> labeled by *xinyuluo*",
   "attachments": [
     {
       "fallback": null,
       "mrkdwn_in": [ "text" ],
       "color": "#ccc",
-      "text": "Labels: a1, backend"
+      "text": "*Labels*: _a1_, _backend_"
     }
   ],
   "unfurl_links": false
@@ -325,7 +328,7 @@ will notify #frontend-bot
       "fallback": null,
       "mrkdwn_in": [ "text" ],
       "color": "#ccc",
-      "text": ""
+      "text": "*Labels*: _enhancement_"
     }
   ],
   "unfurl_links": false
@@ -351,6 +354,21 @@ will notify #default
 {
   "channel": "default",
   "text": "<https://github.com/Khady/monorepo|[Khady/monorepo]> *Khady* <https://github.com/Khady/monorepo/pull/6#pullrequestreview-0|approved> #6 <https://github.com/Khady/monorepo/pull/6|create pr_review_test.md>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "*Comment*: approve review"
+    }
+  ],
+  "unfurl_links": false
+}
+will notify #default
+{
+  "channel": "default",
+  "thread_ts": "1728399554.482879",
+  "text": "<https://github.com/Khady/monorepo|[Khady/monorepo]> *Khady* <https://github.com/Khady/monorepo/pull/6#pullrequestreview-0|approved> #6 <https://github.com/Khady/monorepo/pull/6|create pr_review_test.md>",
   "attachments": [
     {
       "fallback": null,
@@ -365,7 +383,22 @@ will notify #default
 will notify #frontend-bot
 {
   "channel": "frontend-bot",
-  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|commented on> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|reviewed> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "*Comment*: submit a PR review"
+    }
+  ],
+  "unfurl_links": false
+}
+will notify #frontend-bot
+{
+  "channel": "frontend-bot",
+  "thread_ts": "1728399554.482879",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|reviewed> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
   "attachments": [
     {
       "fallback": null,
@@ -383,6 +416,21 @@ will notify #default
 {
   "channel": "default",
   "text": "<https://github.com/Khady/monorepo|[Khady/monorepo]> *Khady* <https://github.com/Khady/monorepo/pull/6#pullrequestreview-0|requested changes on> #6 <https://github.com/Khady/monorepo/pull/6|create pr_review_test.md>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "*Comment*: request changes review"
+    }
+  ],
+  "unfurl_links": false
+}
+will notify #default
+{
+  "channel": "default",
+  "thread_ts": "1728399554.482879",
+  "text": "<https://github.com/Khady/monorepo|[Khady/monorepo]> *Khady* <https://github.com/Khady/monorepo/pull/6#pullrequestreview-0|requested changes on> #6 <https://github.com/Khady/monorepo/pull/6|create pr_review_test.md>",
   "attachments": [
     {
       "fallback": null,
@@ -397,7 +445,22 @@ will notify #default
 will notify #frontend-bot
 {
   "channel": "frontend-bot",
-  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|commented on> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|reviewed> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "*Comment*: This is a great PR, thank you!"
+    }
+  ],
+  "unfurl_links": false
+}
+will notify #frontend-bot
+{
+  "channel": "frontend-bot",
+  "thread_ts": "1728399554.482879",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* <https://github.com/xinyuluo/monorepo/pull/3#pullrequestreview-0|reviewed> #3 <https://github.com/xinyuluo/monorepo/pull/3|Update README.md>",
   "attachments": [
     {
       "fallback": null,
@@ -411,6 +474,38 @@ will notify #frontend-bot
 ===== file ../mock_payloads/pull_request_review.submitted_no_comment.json =====
 ===== file ../mock_payloads/pull_request_review.submitted_null_body.json =====
 ===== file ../mock_payloads/pull_request_review_comment.created.json =====
+will notify #a1-bot
+{
+  "channel": "a1-bot",
+  "thread_ts": "1728399554.482879",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* commented on #4 <https://github.com/xinyuluo/monorepo/pull/4|README update>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "PR review comment example",
+      "footer": "Commented in file <https://github.com/xinyuluo/monorepo/pull/4#discussion_r0|README.md>"
+    }
+  ],
+  "unfurl_links": false
+}
+will notify #backend
+{
+  "channel": "backend",
+  "thread_ts": "1728399554.444444",
+  "text": "<https://github.com/xinyuluo/monorepo|[xinyuluo/monorepo]> *xinyuluo* commented on #4 <https://github.com/xinyuluo/monorepo/pull/4|README update>",
+  "attachments": [
+    {
+      "fallback": null,
+      "mrkdwn_in": [ "text" ],
+      "color": "#ccc",
+      "text": "PR review comment example",
+      "footer": "Commented in file <https://github.com/xinyuluo/monorepo/pull/4#discussion_r0|README.md>"
+    }
+  ],
+  "unfurl_links": false
+}
 ===== file ../mock_payloads/pull_request_review_comment.deleted.json =====
 ===== file ../mock_payloads/pull_request_review_comment.edited.json =====
 ===== file ../mock_payloads/push.branch_filter_default.json =====