diff --git a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.test.ts b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.test.ts
index b5470628be0aa9d7ca31bae2fd31e62cf98f0a96..ff5e47f6d1bd89093bd190b08bdd07f312dd5a2e 100644
--- a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.test.ts
+++ b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.test.ts
@@ -12,6 +12,59 @@ import {
   make,
 } from "./BitbucketPullRequestProvider.ts";
 
+it.effect.each([
+  {
+    metadata: "source commit hash",
+    commit: { hash: "9f3a7c2d8b1e6f045a9c3d7e2b8f1a6c0d4e5f93" },
+    headSha: "9f3a7c2d8b1e6f045a9c3d7e2b8f1a6c0d4e5f93",
+  },
+  { metadata: "absent commit", commit: undefined, headSha: undefined },
+  { metadata: "null commit", commit: null, headSha: undefined },
+  { metadata: "absent hash", commit: {}, headSha: undefined },
+  { metadata: "null hash", commit: { hash: null }, headSha: undefined },
+])("reads change request details with $metadata", ({ commit, headSha }) =>
+  Effect.gen(function* () {
+    const pullRequest = Result.getOrThrow(
+      decodePullRequestJson(
+        JSON.stringify({
+          id: 897,
+          title: "Add trustabl-pipe",
+          state: "OPEN",
+          source: {
+            branch: { name: "feat/page" },
+            commit,
+            repository: { full_name: "fork/web" },
+          },
+          destination: { branch: { name: "master" }, commit: { hash: "base-commit" } },
+          created_on: "2026-06-16T05:04:32.258456+00:00",
+          updated_on: "2026-06-16T05:04:33.750542+00:00",
+          links: { html: { href: "https://bitbucket.org/acme/web/pull-requests/897" } },
+        }),
+      ),
+    );
+    const provider = yield* make.pipe(
+      Effect.provide(
+        Layer.mock(BitbucketPullRequestApi.BitbucketPullRequestApi)({
+          getPullRequest: () => Effect.succeed(pullRequest),
+          getDiffStat: () => Effect.succeed({ additions: 0, deletions: 0, changedFiles: 0 }),
+          getMergeability: () => Effect.succeed("unknown"),
+          listChecks: () => Effect.succeed([]),
+          getRepositoryPermission: () => Effect.succeed(true),
+        }),
+      ),
+    );
+    const detail = yield* provider.getChangeRequest({
+      cwd: "/repo",
+      repository: "acme/web",
+      host: "bitbucket.org",
+      number: 897,
+    });
+
+    expect(detail).toMatchObject({ number: 897, headBranch: "feat/page" });
+    expect(detail.headSha).toBe(headSha);
+  }),
+);
+
 for (const operation of [
   "getMergeability",
   "listChecks",
diff --git a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.ts b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.ts
index 3d26d5401602995b9e31c8a63fee3c501f3dfaa4..7f8794730be5aeb6f324ae9641247661d52bcd2e 100644
--- a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.ts
+++ b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.ts
@@ -98,6 +98,7 @@ function toChangeRequest(pullRequest: BitbucketPullRequest): ProviderChangeReque
     url: pullRequest.url,
     author: pullRequest.author,
     headBranch: pullRequest.headBranch,
+    ...(pullRequest.headSha ? { headSha: pullRequest.headSha } : {}),
     ...(pullRequest.headRepositoryNameWithOwner
       ? { headRepositoryNameWithOwner: pullRequest.headRepositoryNameWithOwner }
       : {}),
diff --git a/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.test.ts b/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.test.ts
index 356c5da96f333345ff4104a4217be496978f0357..00696287b7859d70e58fd79b17436b598ef54c40 100644
--- a/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.test.ts
+++ b/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.test.ts
@@ -24,8 +24,12 @@ function pullRequest(overrides: Record<string, unknown> = {}): Record<string, un
     created_on: "2026-06-16T05:04:32.258456+00:00",
     updated_on: "2026-06-16T05:04:33.750542+00:00",
     author: { display_name: "Bilal Hassan", nickname: "bilal", type: "user" },
-    source: { branch: { name: "feat/page" }, repository: { full_name: "fork/web" } },
-    destination: { branch: { name: "master" } },
+    source: {
+      branch: { name: "feat/page" },
+      commit: { hash: "9f3a7c2d8b1e6f045a9c3d7e2b8f1a6c0d4e5f93", type: "commit" },
+      repository: { full_name: "fork/web" },
+    },
+    destination: { branch: { name: "master" }, commit: { hash: "base-commit" } },
     links: { html: { href: "https://bitbucket.org/acme/web/pull-requests/897" } },
     ...overrides,
   };
@@ -52,6 +56,7 @@ describe("decodePullRequestPageJson", () => {
       url: "https://bitbucket.org/acme/web/pull-requests/897",
       author: { login: "bilal", name: "Bilal Hassan" },
       headBranch: "feat/page",
+      headSha: "9f3a7c2d8b1e6f045a9c3d7e2b8f1a6c0d4e5f93",
       headRepositoryNameWithOwner: "fork/web",
       baseBranch: "master",
       state: "open",
@@ -106,6 +111,27 @@ describe("decodePullRequestPageJson", () => {
 });
 
 describe("decodePullRequestJson", () => {
+  it("preserves the source commit hash as the head SHA", () => {
+    const decoded = expectSuccess(decodePullRequestJson(JSON.stringify(pullRequest())));
+
+    expect(decoded).toMatchObject({ headSha: "9f3a7c2d8b1e6f045a9c3d7e2b8f1a6c0d4e5f93" });
+  });
+
+  it.each([
+    { metadata: "absent commit", commit: undefined },
+    { metadata: "null commit", commit: null },
+    { metadata: "absent hash", commit: {} },
+    { metadata: "null hash", commit: { hash: null } },
+  ])("reads detail and list payloads with $metadata", ({ commit }) => {
+    const raw = pullRequest({ source: { branch: { name: "feat/page" }, commit } });
+    const detail = expectSuccess(decodePullRequestJson(JSON.stringify(raw)));
+    const list = expectSuccess(decodePullRequestPageJson(page([raw])));
+
+    expect(detail).toMatchObject({ number: 897, headBranch: "feat/page", headSha: null });
+    expect(list.items).toHaveLength(1);
+    expect(list.items[0]).toMatchObject({ number: 897, headBranch: "feat/page", headSha: null });
+  });
+
   it("reads reviewers as review requests", () => {
     const decoded = expectSuccess(
       decodePullRequestJson(
diff --git a/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.ts b/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.ts
index 8f0b520ca089b64d6851b8c1bd8e159964ac48b1..9337e888c840968df6b5a425cfe0cf17e8f42f9e 100644
--- a/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.ts
+++ b/packages/source-control-bitbucket/src/server/bitbucketPullRequestJson.ts
@@ -52,6 +52,9 @@ const RawUserSchema = Schema.Struct({
  */
 const RawBranchSchema = Schema.Struct({
   branch: Schema.Struct({ name: TrimmedNonEmptyString }),
+  commit: Schema.optional(
+    Schema.NullOr(Schema.Struct({ hash: Schema.optional(Schema.NullOr(Schema.String)) })),
+  ),
   repository: Schema.optional(Schema.NullOr(Schema.Struct({ full_name: TrimmedNonEmptyString }))),
 });
 
@@ -178,6 +181,7 @@ export interface BitbucketPullRequest {
   readonly url: string;
   readonly author: PullRequestActor | null;
   readonly headBranch: string;
+  readonly headSha: string | null;
   readonly headRepositoryNameWithOwner: string | null;
   readonly baseBranch: string;
   readonly state: PullRequestState;
@@ -293,6 +297,7 @@ function toPullRequest(raw: Schema.Schema.Type<typeof RawPullRequestSchema>): Bi
     url: raw.links.html.href,
     author: toActor(raw.author),
     headBranch: raw.source.branch.name,
+    headSha: trimmed(raw.source.commit?.hash),
     headRepositoryNameWithOwner: raw.source.repository?.full_name ?? null,
     baseBranch: raw.destination.branch.name,
     state: toState(raw),