diff --git a/apps/server/src/git/GitManager.test.ts b/apps/server/src/git/GitManager.test.ts
index 643e1e7a0d5b..0c4fc4d34a53 100644
--- a/apps/server/src/git/GitManager.test.ts
+++ b/apps/server/src/git/GitManager.test.ts
@@ -4384,6 +4384,91 @@ it.layer(GitManagerTestLayer)("GitManager", (it) => {
     }),
   );
 
+  it.effect("prepares a worktree PR thread on a host that publishes no pull request head ref", () =>
+    Effect.gen(function* () {
+      const repoDir = yield* makeTempDir("t3code-git-manager-");
+      yield* initRepo(repoDir);
+      const remoteDir = yield* createBareRemote();
+      yield* runGit(repoDir, ["remote", "add", "origin", remoteDir]);
+      yield* runGit(repoDir, ["push", "-u", "origin", "main"]);
+      yield* runGit(repoDir, ["checkout", "-b", "feature/pr-no-pull-ref"]);
+      NodeFS.writeFileSync(NodePath.join(repoDir, "azure.txt"), "azure\n");
+      yield* runGit(repoDir, ["add", "azure.txt"]);
+      yield* runGit(repoDir, ["commit", "-m", "PR branch with no pull ref"]);
+      yield* runGit(repoDir, ["push", "origin", "feature/pr-no-pull-ref"]);
+      const headCommit = (yield* runGit(repoDir, ["rev-parse", "HEAD"])).stdout.trim();
+      yield* runGit(repoDir, ["checkout", "main"]);
+      yield* runGit(repoDir, ["branch", "-D", "feature/pr-no-pull-ref"]);
+
+      const { manager } = yield* makeManager({
+        ghScenario: {
+          pullRequest: {
+            number: 26855,
+            title: "PR with no pull ref",
+            url: "https://dev.azure.com/acme/project/_git/repo/pullrequest/26855",
+            baseRefName: "main",
+            headRefName: "feature/pr-no-pull-ref",
+            state: "open",
+            isCrossRepository: false,
+          },
+        },
+      });
+
+      const result = yield* preparePullRequestThread(manager, {
+        cwd: repoDir,
+        reference: "26855",
+        mode: "worktree",
+      });
+
+      expect(result.worktreePath).not.toBeNull();
+      expect(result.isOnPullRequestHead).toBe(true);
+      expect(
+        (yield* runGit(result.worktreePath as string, ["rev-parse", "HEAD"])).stdout.trim(),
+      ).toBe(headCommit);
+    }),
+  );
+
+  it.effect("fails closed when a fork pull request repository is unknown", () =>
+    Effect.gen(function* () {
+      const repoDir = yield* makeTempDir("t3code-git-manager-");
+      yield* initRepo(repoDir);
+      const remoteDir = yield* createBareRemote();
+      yield* runGit(repoDir, ["remote", "add", "origin", remoteDir]);
+      yield* runGit(repoDir, ["push", "-u", "origin", "main"]);
+      yield* runGit(repoDir, ["checkout", "-b", "feature/ambiguous-head"]);
+      NodeFS.writeFileSync(NodePath.join(repoDir, "unrelated.txt"), "unrelated\n");
+      yield* runGit(repoDir, ["add", "unrelated.txt"]);
+      yield* runGit(repoDir, ["commit", "-m", "Unrelated same-named branch"]);
+      yield* runGit(repoDir, ["push", "origin", "feature/ambiguous-head"]);
+      yield* runGit(repoDir, ["checkout", "main"]);
+      yield* runGit(repoDir, ["branch", "-D", "feature/ambiguous-head"]);
+
+      const { manager, ghCalls } = yield* makeManager({
+        ghScenario: {
+          pullRequest: {
+            number: 26856,
+            title: "PR with unknown head repository",
+            url: "https://github.com/pingdotgg/codething-mvp/pull/26856",
+            baseRefName: "main",
+            headRefName: "feature/ambiguous-head",
+            state: "open",
+            isCrossRepository: true,
+          },
+        },
+      });
+
+      const error = yield* preparePullRequestThread(manager, {
+        cwd: repoDir,
+        reference: "26856",
+        mode: "worktree",
+      }).pipe(Effect.flip);
+
+      expect(error._tag).toBe("GitPullRequestMaterializationError");
+      expect(ghCalls.some((call) => call.startsWith("repo view "))).toBe(false);
+      expect(ghCalls).not.toContain("pr checkout 26856 --force");
+    }),
+  );
+
   it.effect("preserves fork upstream tracking when preparing a worktree PR thread", () =>
     Effect.gen(function* () {
       const repoDir = yield* makeTempDir("t3code-git-manager-");
diff --git a/apps/server/src/git/GitManager.ts b/apps/server/src/git/GitManager.ts
index 2d8af0c9e8bb..d7e544206539 100644
--- a/apps/server/src/git/GitManager.ts
+++ b/apps/server/src/git/GitManager.ts
@@ -832,12 +832,27 @@ export const make = Effect.gen(function* () {
     ) {
       const repositoryNameWithOwner = resolveHeadRepositoryNameWithOwner(pullRequest) ?? "";
 
-      if (repositoryNameWithOwner.length === 0) {
-        yield* gitCore.fetchPullRequestBranch({
-          cwd,
-          prNumber: pullRequest.number,
-          branch: localBranch,
-        });
+      if (repositoryNameWithOwner.length === 0 && pullRequest.isCrossRepository === false) {
+        yield* gitCore
+          .fetchPullRequestBranch({
+            cwd,
+            prNumber: pullRequest.number,
+            branch: localBranch,
+          })
+          .pipe(
+            // Azure DevOps publishes no pull-request head ref for same-repository PRs.
+            Effect.catch(() =>
+              Effect.gen(function* () {
+                const remoteName = yield* gitCore.resolvePrimaryRemoteName(cwd);
+                yield* gitCore.fetchRemoteBranch({
+                  cwd,
+                  remoteName,
+                  remoteBranch: pullRequest.headBranch,
+                  localBranch,
+                });
+              }),
+            ),
+          );
         return;
       }
 
@@ -876,8 +891,24 @@ export const make = Effect.gen(function* () {
     cwd: string,
     pullRequest: ResolvedPullRequest & PullRequestHeadRemoteInfo,
     localBranch = pullRequest.headBranch,
-  ) =>
-    materializePullRequestHeadBranchBase(cwd, pullRequest, localBranch).pipe(
+  ) => {
+    const headRepository = resolveHeadRepositoryNameWithOwner(pullRequest);
+    if (pullRequest.isCrossRepository === true && headRepository === null) {
+      return Effect.fail(
+        new GitPullRequestMaterializationError({
+          cwd,
+          pullRequestNumber: pullRequest.number,
+          headRepository,
+          headBranch: pullRequest.headBranch,
+          localBranch,
+          cause: new Error(
+            "Cross-repository pull request is missing its head repository identity.",
+          ),
+        }),
+      );
+    }
+
+    return materializePullRequestHeadBranchBase(cwd, pullRequest, localBranch).pipe(
       Effect.catch((primaryCause) =>
         gitCore
           .fetchPullRequestBranch({
@@ -904,6 +935,7 @@ export const make = Effect.gen(function* () {
           ),
       ),
     );
+  };
   const tempDir = process.env.TMPDIR ?? process.env.TEMP ?? process.env.TMP ?? "/tmp";
   const canonicalizeExistingPath = (value: string) =>
     fileSystem.realPath(value).pipe(Effect.orElseSucceed(() => value));
diff --git a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
index d893924b3f2a..68b22be370dd 100644
--- a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
+++ b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.test.ts
@@ -516,7 +516,7 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
     }),
   );
 
-  it.effect("reads the conversation through the REST API, pinned to a version", () =>
+  it.effect("reads the authenticated conversation through the REST API, pinned to a version", () =>
     Effect.gen(function* () {
       mockedExecute.mockReturnValueOnce(
         Effect.succeed(
@@ -543,10 +543,18 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
       });
 
       assert.strictEqual(comments.length, 1);
-      expect(argsOfCall(0)).toContain("rest");
-      expect(argsOfCall(0)).toContain(
+      assert.deepStrictEqual(argsOfCall(0), [
+        "rest",
+        "--method",
+        "get",
+        "--url",
         "https://dev.azure.com/acme/platform/_apis/git/r/web/pullRequests/42/threads?api-version=7.1",
-      );
+        "--resource",
+        "499b84ac-1321-427f-aa17-267ca6975798",
+        "--only-show-errors",
+        "--output",
+        "json",
+      ]);
     }),
   );
 
diff --git a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.ts b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.ts
index fe87692e1cc3..8ed299215641 100644
--- a/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.ts
+++ b/apps/server/src/pullRequest/AzureDevOpsPullRequestCli.ts
@@ -111,6 +111,7 @@ export type AzureDevOpsPullRequestCliError =
 
 /** The version every REST call below is pinned to, so a new default cannot reshape a response. */
 const REST_API_VERSION = "7.1";
+const AZURE_DEVOPS_RESOURCE_ID = "499b84ac-1321-427f-aa17-267ca6975798";
 const PULL_REQUEST_LIST_MAX_OUTPUT_BYTES = 16 * 1024 * 1024;
 
 export class AzureDevOpsPullRequestCli extends Context.Service<
@@ -455,6 +456,8 @@ export const make = Effect.gen(function* () {
           "get",
           "--url",
           `${input.threadsUrl}?api-version=${REST_API_VERSION}`,
+          "--resource",
+          AZURE_DEVOPS_RESOURCE_ID,
         ],
       }).pipe(
         Effect.flatMap((result) => {
diff --git a/apps/server/src/pullRequest/azureDevOpsPullRequestJson.ts b/apps/server/src/pullRequest/azureDevOpsPullRequestJson.ts
index 55d9b544ab3d..38027b99523a 100644
--- a/apps/server/src/pullRequest/azureDevOpsPullRequestJson.ts
+++ b/apps/server/src/pullRequest/azureDevOpsPullRequestJson.ts
@@ -189,7 +189,7 @@ function toMergeability(value: string | null | undefined): PullRequestMergeabili
 
 /**
  * The REST collection a pull request's threads hang from. Built from what Azure returned rather
- * than from the local remote, whose shape differs between the modern, legacy and SSH forms.
+ * the local remote, whose shape differs between the modern, legacy and SSH forms.
  */
 function toThreadsUrl(raw: Schema.Schema.Type<typeof RawPullRequestSchema>): string | null {
   const base = azureDevOpsOrganizationBaseFromRestApiUrl(raw.url);
diff --git a/apps/server/src/sourceControl/AzureDevOpsCli.test.ts b/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
index f0cb52003029..12d05117f0dd 100644
--- a/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
+++ b/apps/server/src/sourceControl/AzureDevOpsCli.test.ts
@@ -129,6 +129,153 @@ describe("AzureDevOpsCli.layer", () => {
     }).pipe(Effect.provide(layer)),
   );
 
+  it.effect("reads a pull request whose optional fields Azure answered with null", () =>
+    Effect.gen(function* () {
+      mockRun.mockReturnValueOnce(
+        Effect.succeed(
+          processOutput(
+            // @effect-diagnostics-next-line preferSchemaOverJson:off
+            JSON.stringify({
+              pullRequestId: 26855,
+              title: "Braze iam_click event",
+              url: "https://dev.azure.com/acme/411da70a/_apis/git/repositories/2697671b/pullRequests/26855",
+              repository: {
+                name: "repo",
+                webUrl: null,
+                project: { name: "project" },
+              },
+              sourceRefName: "refs/heads/feature/iam-click",
+              targetRefName: "refs/heads/main",
+              status: "active",
+              creationDate: "2026-01-02T00:00:00.000Z",
+              closedDate: null,
+              _links: null,
+            }),
+          ),
+        ),
+      );
+
+      const az = yield* AzureDevOpsCli.AzureDevOpsCli;
+      const result = yield* az.getPullRequest({ cwd: "/repo", reference: "26855" });
+
+      assert.strictEqual(result.number, 26855);
+      assert.strictEqual(result.headRefName, "feature/iam-click");
+      assert.strictEqual(
+        result.url,
+        "https://dev.azure.com/acme/project/_git/repo/pullrequest/26855",
+      );
+    }).pipe(Effect.provide(layer)),
+  );
+
+  it.effect("keeps listed pull requests whose optional fields Azure answered with null", () =>
+    Effect.gen(function* () {
+      mockRun.mockReturnValueOnce(
+        Effect.succeed(
+          processOutput(
+            // @effect-diagnostics-next-line preferSchemaOverJson:off
+            JSON.stringify([
+              {
+                pullRequestId: 7,
+                title: "Merged work",
+                url: "https://dev.azure.com/acme/411da70a/_apis/git/repositories/2697671b/pullRequests/7",
+                repository: { name: "repo", webUrl: null, project: { name: "project" } },
+                sourceRefName: "refs/heads/feature/merged",
+                targetRefName: "refs/heads/main",
+                status: "completed",
+                closedDate: "2026-01-03T00:00:00.000Z",
+                _links: null,
+              },
+            ]),
+          ),
+        ),
+      );
+
+      const az = yield* AzureDevOpsCli.AzureDevOpsCli;
+      const result = yield* az.listPullRequests({
+        cwd: "/repo",
+        headSelector: "origin:feature/merged",
+        state: "merged",
+        limit: 10,
+      });
+
+      assert.strictEqual(result.length, 1);
+      assert.strictEqual(result[0]?.number, 7);
+    }).pipe(Effect.provide(layer)),
+  );
+
+  it.effect("preserves the source repository for pull requests from Azure forks", () =>
+    Effect.gen(function* () {
+      mockRun.mockReturnValueOnce(
+        Effect.succeed(
+          processOutput(
+            // @effect-diagnostics-next-line preferSchemaOverJson:off
+            JSON.stringify({
+              pullRequestId: 8,
+              title: "Forked work",
+              url: "https://dev.azure.com/acme/project/_apis/git/repositories/repo/pullRequests/8",
+              repository: { name: "repo", project: { name: "project" } },
+              forkSource: {
+                name: "refs/heads/feature/forked",
+                repository: { name: "repo-fork", project: { name: "contributor-project" } },
+              },
+              sourceRefName: "refs/heads/feature/forked",
+              targetRefName: "refs/heads/main",
+              status: "active",
+            }),
+          ),
+        ),
+      );
+
+      const az = yield* AzureDevOpsCli.AzureDevOpsCli;
+      const result = yield* az.getPullRequest({ cwd: "/repo", reference: "8" });
+
+      assert.deepStrictEqual(
+        {
+          isCrossRepository: result.isCrossRepository,
+          headRepositoryNameWithOwner: result.headRepositoryNameWithOwner,
+          headRepositoryOwnerLogin: result.headRepositoryOwnerLogin,
+        },
+        {
+          isCrossRepository: true,
+          headRepositoryNameWithOwner: "contributor-project/repo-fork",
+          headRepositoryOwnerLogin: "contributor-project",
+        },
+      );
+    }).pipe(Effect.provide(layer)),
+  );
+
+  it.effect("does not expose an ambiguous Azure fork repository without its project", () =>
+    Effect.gen(function* () {
+      mockRun.mockReturnValueOnce(
+        Effect.succeed(
+          processOutput(
+            // @effect-diagnostics-next-line preferSchemaOverJson:off
+            JSON.stringify({
+              pullRequestId: 9,
+              title: "Forked work with incomplete identity",
+              url: "https://dev.azure.com/acme/project/_apis/git/repositories/repo/pullRequests/9",
+              repository: { name: "repo", project: { name: "project" } },
+              forkSource: {
+                name: "refs/heads/feature/forked",
+                repository: { name: "repo" },
+              },
+              sourceRefName: "refs/heads/feature/forked",
+              targetRefName: "refs/heads/main",
+              status: "active",
+            }),
+          ),
+        ),
+      );
+
+      const az = yield* AzureDevOpsCli.AzureDevOpsCli;
+      const result = yield* az.getPullRequest({ cwd: "/repo", reference: "9" });
+
+      assert.strictEqual(result.isCrossRepository, true);
+      assert.strictEqual(result.headRepositoryNameWithOwner, null);
+      assert.strictEqual(result.headRepositoryOwnerLogin, null);
+    }).pipe(Effect.provide(layer)),
+  );
+
   it.effect("lists pull requests with Azure status and source branch arguments", () =>
     Effect.gen(function* () {
       mockRun.mockReturnValueOnce(
@@ -210,7 +357,7 @@ describe("AzureDevOpsCli.layer", () => {
       const az = yield* AzureDevOpsCli.AzureDevOpsCli;
       const result = yield* az.getRepositoryCloneUrls({
         cwd: "/repo",
-        repository: "repo",
+        repository: "project/repo",
       });
 
       assert.deepStrictEqual(result, {
@@ -218,6 +365,25 @@ describe("AzureDevOpsCli.layer", () => {
         url: "https://dev.azure.com/acme/project/_git/repo",
         sshUrl: "git@ssh.dev.azure.com:v3/acme/project/repo",
       });
+      expect(mockRun).toHaveBeenCalledWith({
+        operation: "AzureDevOpsCli.execute",
+        command: "az",
+        args: [
+          "repos",
+          "show",
+          "--detect",
+          "true",
+          "--repository",
+          "repo",
+          "--project",
+          "project",
+          "--only-show-errors",
+          "--output",
+          "json",
+        ],
+        cwd: "/repo",
+        timeoutMs: 30_000,
+      });
     }).pipe(Effect.provide(layer)),
   );
 
diff --git a/apps/server/src/sourceControl/AzureDevOpsCli.ts b/apps/server/src/sourceControl/AzureDevOpsCli.ts
index f05f4a7588c4..a91cfc466e67 100644
--- a/apps/server/src/sourceControl/AzureDevOpsCli.ts
+++ b/apps/server/src/sourceControl/AzureDevOpsCli.ts
@@ -461,10 +461,19 @@ export const make = Effect.gen(function* () {
           ),
         ),
       ),
-    getRepositoryCloneUrls: (input) =>
-      executeJson({
+    getRepositoryCloneUrls: (input) => {
+      const repository = parseRepositorySpecifier(input.repository);
+      return executeJson({
         cwd: input.cwd,
-        args: ["repos", "show", "--detect", "true", "--repository", input.repository],
+        args: [
+          "repos",
+          "show",
+          "--detect",
+          "true",
+          "--repository",
+          repository.name,
+          ...(repository.project ? ["--project", repository.project] : []),
+        ],
       }).pipe(
         Effect.map((result) => result.stdout.trim()),
         Effect.flatMap((raw) =>
@@ -476,7 +485,8 @@ export const make = Effect.gen(function* () {
           ),
         ),
         Effect.map(normalizeRepositoryCloneUrls),
-      ),
+      );
+    },
     createRepository: (input) => {
       const repository = parseRepositorySpecifier(input.repository);
       // Azure Repos access is governed by project/organization permissions.
diff --git a/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.test.ts b/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.test.ts
index cacdd1a3cd97..8d1a1405274d 100644
--- a/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.test.ts
+++ b/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.test.ts
@@ -24,6 +24,9 @@ it.effect("maps Azure DevOps PR summaries into provider-neutral change requests"
           headRefName: "feature/source-control",
           state: "open",
           updatedAt: Option.none(),
+          isCrossRepository: false,
+          headRepositoryNameWithOwner: null,
+          headRepositoryOwnerLogin: null,
         }),
     });
 
@@ -42,10 +45,47 @@ it.effect("maps Azure DevOps PR summaries into provider-neutral change requests"
       state: "open",
       updatedAt: Option.none(),
       isCrossRepository: false,
+      headRepositoryNameWithOwner: null,
+      headRepositoryOwnerLogin: null,
     });
   }),
 );
 
+it.effect("preserves Azure fork repository metadata for pull request checkout", () =>
+  Effect.gen(function* () {
+    const provider = yield* makeProvider({
+      getPullRequest: () =>
+        Effect.succeed({
+          number: 43,
+          title: "Forked change",
+          url: "https://dev.azure.com/acme/project/_git/repo/pullrequest/43",
+          baseRefName: "main",
+          headRefName: "feature/forked",
+          state: "open",
+          updatedAt: Option.none(),
+          isCrossRepository: true,
+          headRepositoryNameWithOwner: "contributor-project/repo-fork",
+          headRepositoryOwnerLogin: "contributor-project",
+        }),
+    });
+
+    const changeRequest = yield* provider.getChangeRequest({ cwd: "/repo", reference: "43" });
+
+    assert.deepStrictEqual(
+      {
+        isCrossRepository: changeRequest.isCrossRepository,
+        headRepositoryNameWithOwner: changeRequest.headRepositoryNameWithOwner,
+        headRepositoryOwnerLogin: changeRequest.headRepositoryOwnerLogin,
+      },
+      {
+        isCrossRepository: true,
+        headRepositoryNameWithOwner: "contributor-project/repo-fork",
+        headRepositoryOwnerLogin: "contributor-project",
+      },
+    );
+  }),
+);
+
 it.effect("adds change-request context while retaining Azure CLI causes", () =>
   Effect.gen(function* () {
     const cause = new AzureDevOpsCli.AzureDevOpsCommandFailedError({
diff --git a/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.ts b/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.ts
index 8a840c524eba..e86fed2f6c20 100644
--- a/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.ts
+++ b/apps/server/src/sourceControl/AzureDevOpsSourceControlProvider.ts
@@ -63,6 +63,9 @@ function toChangeRequest(summary: {
   readonly state: "open" | "closed" | "merged";
   readonly isDraft?: boolean;
   readonly updatedAt: ChangeRequest["updatedAt"];
+  readonly isCrossRepository: boolean;
+  readonly headRepositoryNameWithOwner: string | null;
+  readonly headRepositoryOwnerLogin: string | null;
 }): ChangeRequest {
   return {
     provider: "azure-devops",
@@ -74,7 +77,9 @@ function toChangeRequest(summary: {
     state: summary.state,
     ...(summary.isDraft === true ? { isDraft: true } : {}),
     updatedAt: summary.updatedAt,
-    isCrossRepository: false,
+    isCrossRepository: summary.isCrossRepository,
+    headRepositoryNameWithOwner: summary.headRepositoryNameWithOwner,
+    headRepositoryOwnerLogin: summary.headRepositoryOwnerLogin,
   };
 }
 
diff --git a/apps/server/src/sourceControl/azureDevOpsPullRequests.ts b/apps/server/src/sourceControl/azureDevOpsPullRequests.ts
index 8ac682399e1d..2b52884dccf6 100644
--- a/apps/server/src/sourceControl/azureDevOpsPullRequests.ts
+++ b/apps/server/src/sourceControl/azureDevOpsPullRequests.ts
@@ -16,22 +16,47 @@ export interface NormalizedAzureDevOpsPullRequestRecord {
   readonly state: "open" | "closed" | "merged";
   readonly isDraft?: boolean;
   readonly updatedAt: Option.Option<DateTime.Utc>;
+  readonly isCrossRepository: boolean;
+  readonly headRepositoryNameWithOwner: string | null;
+  readonly headRepositoryOwnerLogin: string | null;
 }
 
 const AzureDevOpsPullRequestSchema = Schema.Struct({
   pullRequestId: PositiveInt,
   title: TrimmedNonEmptyString,
-  url: Schema.optional(Schema.String),
+  url: Schema.optional(Schema.NullOr(Schema.String)),
   repository: Schema.optional(
-    Schema.Struct({
-      name: Schema.optional(Schema.String),
-      webUrl: Schema.optional(Schema.String),
-      project: Schema.optional(
-        Schema.Struct({
-          name: Schema.optional(Schema.String),
-        }),
-      ),
-    }),
+    Schema.NullOr(
+      Schema.Struct({
+        name: Schema.optional(Schema.NullOr(Schema.String)),
+        webUrl: Schema.optional(Schema.NullOr(Schema.String)),
+        project: Schema.optional(
+          Schema.NullOr(
+            Schema.Struct({
+              name: Schema.optional(Schema.NullOr(Schema.String)),
+            }),
+          ),
+        ),
+      }),
+    ),
+  ),
+  forkSource: Schema.optional(
+    Schema.NullOr(
+      Schema.Struct({
+        repository: Schema.optional(
+          Schema.NullOr(
+            Schema.Struct({
+              name: Schema.optional(Schema.NullOr(Schema.String)),
+              project: Schema.optional(
+                Schema.NullOr(
+                  Schema.Struct({ name: Schema.optional(Schema.NullOr(Schema.String)) }),
+                ),
+              ),
+            }),
+          ),
+        ),
+      }),
+    ),
   ),
   sourceRefName: TrimmedNonEmptyString,
   targetRefName: TrimmedNonEmptyString,
@@ -40,13 +65,17 @@ const AzureDevOpsPullRequestSchema = Schema.Struct({
   creationDate: Schema.optional(Schema.OptionFromNullOr(Schema.DateTimeUtcFromString)),
   closedDate: Schema.optional(Schema.OptionFromNullOr(Schema.DateTimeUtcFromString)),
   _links: Schema.optional(
-    Schema.Struct({
-      web: Schema.optional(
-        Schema.Struct({
-          href: Schema.String,
-        }),
-      ),
-    }),
+    Schema.NullOr(
+      Schema.Struct({
+        web: Schema.optional(
+          Schema.NullOr(
+            Schema.Struct({
+              href: Schema.optional(Schema.NullOr(Schema.String)),
+            }),
+          ),
+        ),
+      }),
+    ),
   ),
 });
 
@@ -163,6 +192,8 @@ function normalizeAzureDevOpsPullRequestUrl(
 function normalizeAzureDevOpsPullRequestRecord(
   raw: Schema.Schema.Type<typeof AzureDevOpsPullRequestSchema>,
 ): NormalizedAzureDevOpsPullRequestRecord {
+  const forkRepositoryName = trimOptionalString(raw.forkSource?.repository?.name);
+  const forkProjectName = trimOptionalString(raw.forkSource?.repository?.project?.name);
   return {
     number: raw.pullRequestId,
     title: raw.title,
@@ -174,6 +205,12 @@ function normalizeAzureDevOpsPullRequestRecord(
     updatedAt: (raw.closedDate ?? Option.none()).pipe(
       Option.orElse(() => raw.creationDate ?? Option.none()),
     ),
+    isCrossRepository: raw.forkSource != null,
+    headRepositoryNameWithOwner:
+      forkRepositoryName === null || forkProjectName === null
+        ? null
+        : `${forkProjectName}/${forkRepositoryName}`,
+    headRepositoryOwnerLogin: forkProjectName,
   };
 }