Andarist · Jun 24, 2026 · Jun 26, 2026
diff --git a/.changeset/lucky-repos-jump.md b/.changeset/lucky-repos-jump.md
@@ -0,0 +1,5 @@
+---
+"@changesets/changelog-github": patch
+---
+
+Use `GITHUB_REPOSITORY` as the default repo when no `repo` option is configured
diff --git a/docs/config-file-options.md b/docs/config-file-options.md
@@ -162,6 +162,8 @@ You would specify our github changelog generator with:
 }
 ```
 
+When running in GitHub Actions, `repo` is optional because it defaults to the `GITHUB_REPOSITORY` environment variable.
+
 If you want to disable thank you messages, add `"disableThanks": true` to the options.
 
 For more details on these functions and information on how to write your own see [changelog-functions](./modifying-changelog-format.md)

diff --git a/packages/changelog-github/src/index.test.ts b/packages/changelog-github/src/index.test.ts
@@ -1,8 +1,14 @@
 import { parseChangesetFile as parse } from "@changesets/parse";
-import { describe, expect, it, test, vi } from "vitest";
+import type { ModCompWithPackage } from "@changesets/types";
+import { afterEach, describe, expect, it, test, vi } from "vitest";
 import changelogFunctions from "./index.ts";
 
 const getReleaseLine = changelogFunctions.getReleaseLine;
+const getDependencyReleaseLine = changelogFunctions.getDependencyReleaseLine;
+
+afterEach(() => {
+  vi.unstubAllEnvs();
+});
 
 vi.mock(
   "@changesets/get-github-info",
@@ -99,6 +105,59 @@ const data = {
   repo: "emotion-js/emotion",
 };
 
+it("uses GITHUB_REPOSITORY when repo option is absent", async () => {
+  vi.stubEnv("GITHUB_REPOSITORY", data.repo);
+  const [changeset, releaseType] = getChangeset("", data.commit);
+
+  expect(await getReleaseLine(changeset, releaseType, null)).toEqual(
+    `\n\n- [#1613](https://github.com/emotion-js/emotion/pull/1613) [\`a085003\`](https://github.com/emotion-js/emotion/commit/a085003) Thanks [@Andarist](https://github.com/Andarist)! - something\n`,
+  );
+});
+
+it("uses explicit repo option before GITHUB_REPOSITORY", async () => {
+  vi.stubEnv("GITHUB_REPOSITORY", "other/repo");
+
+  expect(await getReleaseLine(...getChangeset("", data.commit))).toEqual(
+    `\n\n- [#1613](https://github.com/emotion-js/emotion/pull/1613) [\`a085003\`](https://github.com/emotion-js/emotion/commit/a085003) Thanks [@Andarist](https://github.com/Andarist)! - something\n`,
+  );
+});
+
+it("uses GITHUB_REPOSITORY for dependency release lines", async () => {
+  vi.stubEnv("GITHUB_REPOSITORY", data.repo);
+
+  const changeset = {
+    ...parse(
+      `---
+  pkg: "minor"
+  ---
+
+  something
+  `,
+    ),
+    id: "some-id",
+    commit: data.commit,
+  };
+
+  const dependency: ModCompWithPackage = {
+    name: "pkg",
+    type: "patch",
+    oldVersion: "0.0.1",
+    newVersion: "1.0.0",
+    changesets: [],
+    dir: "/repo/pkg",
+    packageJson: {
+      name: "pkg",
+      version: "0.0.1",
+    },
+  };
+
+  expect(await getDependencyReleaseLine([changeset], [dependency], null))
+    .toMatchInlineSnapshot(`
+    "- Updated dependencies [[\`a085003\`](https://github.com/emotion-js/emotion/commit/a085003)]:
+      - pkg@1.0.0"
+  `);
+});
+
 describe.each([data.commit, "wrongcommit", undefined])(
   "with commit from changeset of %s",
   (commitFromChangeset) => {

diff --git a/packages/changelog-github/src/index.ts b/packages/changelog-github/src/index.ts
@@ -39,7 +39,29 @@ async function readEnv() {
     process.env.GITHUB_SERVER_URL ||
     (await readEnvFileCached()).GITHUB_SERVER_URL ||
     "https://github.com";
-  return { GITHUB_SERVER_URL };
+  const GITHUB_REPOSITORY =
+    process.env.GITHUB_REPOSITORY ||
+    (await readEnvFileCached()).GITHUB_REPOSITORY;
+
+  return { GITHUB_SERVER_URL, GITHUB_REPOSITORY };
+}
+
+async function getRepo(options: null | Record<string, unknown>) {
+  let repo: string | undefined;
+  if (options && "repo" in options) {
+    repo =
+      typeof options.repo === "string" && options.repo
+        ? options.repo
+        : undefined;
+  } else {
+    repo = (await readEnv()).GITHUB_REPOSITORY;
+  }
+  if (!repo) {
+    throw new Error(
+      'Please provide a repo to this changelog generator like this:\n"changelog": ["@changesets/changelog-github", { "repo": "org/repo" }]\nor set the GITHUB_REPOSITORY environment variable.',
+    );
+  }
+  return repo;
 }
 
 const changelogFunctions: ChangelogFunctions = {
@@ -48,12 +70,7 @@ const changelogFunctions: ChangelogFunctions = {
     dependenciesUpdated,
     options,
   ) => {
-    const repo = options?.repo;
-    if (!repo || typeof repo !== "string") {
-      throw new Error(
-        'Please provide a repo to this changelog generator like this:\n"changelog": ["@changesets/changelog-github", { "repo": "org/repo" }]',
-      );
-    }
+    const repo = await getRepo(options);
     if (dependenciesUpdated.length === 0) return "";
 
     const changesetLink = `- Updated dependencies [${(
@@ -76,12 +93,7 @@ const changelogFunctions: ChangelogFunctions = {
     return [changesetLink, ...updatedDepenenciesList].join("\n");
   },
   getReleaseLine: async (changeset, type, options) => {
-    const repo = options?.repo;
-    if (!repo || typeof repo !== "string") {
-      throw new Error(
-        'Please provide a repo to this changelog generator like this:\n"changelog": ["@changesets/changelog-github", { "repo": "org/repo" }]',
-      );
-    }
+    const repo = await getRepo(options);
 
     const { GITHUB_SERVER_URL } = await readEnv();
 
@@ -133,7 +145,7 @@ const changelogFunctions: ChangelogFunctions = {
       links.user = info?.author?.markdownLink;
     }
 
-    const users = options.disableThanks
+    const users = options?.disableThanks
       ? null
       : usersFromSummary.length
         ? usersFromSummary

diff --git a/packages/get-github-info/src/get-commit-info.test.ts b/packages/get-github-info/src/get-commit-info.test.ts
@@ -437,57 +437,55 @@ test("gets the author of the associated pull request if it exists rather than th
 
 test("uses custom GITHUB_GRAPHQL_URL when set", async () => {
   let githubQuery = "";
-  const originalGraphqlUrl = process.env.GITHUB_GRAPHQL_URL;
-  process.env.GITHUB_GRAPHQL_URL = "https://custom.github.com/api/graphql";
+  vi.stubEnv("GITHUB_GRAPHQL_URL", "https://custom.github.com/api/graphql");
 
-  try {
-    nock("https://custom.github.com", {
-      reqheaders: {
-        Authorization: `Token ${process.env.GITHUB_TOKEN}`,
-      },
+  nock("https://custom.github.com", {
+    reqheaders: {
+      Authorization: `Token ${process.env.GITHUB_TOKEN}`,
+    },
+  })
+    .post("/api/graphql", ({ query }) => {
+      githubQuery = query;
+      return true;
     })
-      .post("/api/graphql", ({ query }) => {
-        githubQuery = query;
-        return true;
-      })
-      .reply(
-        200,
-        JSON.stringify({
-          data: {
-            repo__0: {
-              commit__a085003: {
-                commitUrl:
-                  "https://custom.github.com/emotion-js/emotion/commit/a085003d4c8ca284c116668d7217fb747802ed85",
-                associatedPullRequests: {
-                  nodes: [
-                    {
-                      number: 1613,
-                      url: "https://custom.github.com/emotion-js/emotion/pull/1613",
-                      mergedAt: "2019-11-07T06:43:58Z",
-                      author: {
-                        login: "Andarist",
-                        url: "https://custom.github.com/Andarist",
-                      },
+    .reply(
+      200,
+      JSON.stringify({
+        data: {
+          repo__0: {
+            commit__a085003: {
+              commitUrl:
+                "https://custom.github.com/emotion-js/emotion/commit/a085003d4c8ca284c116668d7217fb747802ed85",
+              associatedPullRequests: {
+                nodes: [
+                  {
+                    number: 1613,
+                    url: "https://custom.github.com/emotion-js/emotion/pull/1613",
+                    mergedAt: "2019-11-07T06:43:58Z",
+                    author: {
+                      login: "Andarist",
+                      url: "https://custom.github.com/Andarist",
                     },
-                  ],
-                },
-                author: {
-                  user: {
-                    login: "Andarist",
-                    url: "https://custom.github.com/Andarist",
                   },
+                ],
+              },
+              author: {
+                user: {
+                  login: "Andarist",
+                  url: "https://custom.github.com/Andarist",
                 },
               },
             },
           },
-        }),
-      );
+        },
+      }),
+    );
 
-    const result = await getCommitInfo({
-      commit: "a085003",
-      repo: "emotion-js/emotion",
-    });
-    expect(result).toMatchInlineSnapshot(`
+  const result = await getCommitInfo({
+    commit: "a085003",
+    repo: "emotion-js/emotion",
+  });
+  expect(result).toMatchInlineSnapshot(`
       {
         "author": {
           "login": "Andarist",
@@ -506,7 +504,7 @@ test("uses custom GITHUB_GRAPHQL_URL when set", async () => {
         },
       }
     `);
-    expect(githubQuery).toMatchInlineSnapshot(`
+  expect(githubQuery).toMatchInlineSnapshot(`
       "query {
         repo__0: repository(
           owner: "emotion-js",
@@ -541,7 +539,4 @@ test("uses custom GITHUB_GRAPHQL_URL when set", async () => {
       }
       "
     `);
-  } finally {
-    process.env.GITHUB_GRAPHQL_URL = originalGraphqlUrl;
-  }
 });
-Original file line number
+Diff line change
@@ Expand Up / @@ -162,6 +162,8 @@ You would specify our github changelog generator with: @@
     }
     ```
+    When running in GitHub Actions, `repo` is optional because it defaults to the `GITHUB_REPOSITORY` environment variable.
     If you want to disable thank you messages, add `"disableThanks": true` to the options.
     For more details on these functions and information on how to write your own see [changelog-functions](./modifying-changelog-format.md)
@@ Expand Down @@