diff --git a/apps/server/src/git/GitManager.test.ts b/apps/server/src/git/GitManager.test.ts
index 3c1f225ca35f7..a7f64f925bef6 100644
--- a/apps/server/src/git/GitManager.test.ts
+++ b/apps/server/src/git/GitManager.test.ts
@@ -2565,6 +2565,46 @@ it.layer(layerGitManagerTest)("GitManager", (it) => {
     }),
   );
 
+  it.effect("keeps signature output out of recent commit subjects", () =>
+    Effect.gen(function* () {
+      const repoDir = yield* makeTempDir("t3code-git-manager-");
+      yield* initRepo(repoDir);
+      const signingKey = NodePath.join(yield* makeTempDir("t3code-git-signing-key-"), "key");
+      NodeChildProcess.execFileSync("ssh-keygen", [
+        "-q",
+        "-t",
+        "ed25519",
+        "-N",
+        "",
+        "-f",
+        signingKey,
+      ]);
+      yield* runGit(repoDir, ["config", "gpg.format", "ssh"]);
+      // A global signer such as 1Password's cannot use the fixture's generated key.
+      yield* runGit(repoDir, ["config", "gpg.ssh.program", "ssh-keygen"]);
+      yield* runGit(repoDir, ["config", "user.signingkey", `${signingKey}.pub`]);
+      yield* runGit(repoDir, ["config", "log.showSignature", "true"]);
+      yield* runGit(repoDir, ["commit", "--amend", "-S", "--no-edit"]);
+      NodeFS.writeFileSync(NodePath.join(repoDir, "README.md"), "hello again\n");
+      let commitInstructions: string | undefined;
+
+      const { manager } = yield* makeManager({
+        textGeneration: {
+          generateCommitMessage: (input) => {
+            commitInstructions = input.policy?.commitInstructions;
+            return Effect.succeed({ subject: "Update readme", body: "" });
+          },
+        },
+      });
+
+      yield* runStackedAction(manager, { cwd: repoDir, action: "commit" });
+
+      expect(commitInstructions).toMatch(
+        /Recent commit subjects from this repository:\nInitial commit$/,
+      );
+    }),
+  );
+
   it.effect("falls back when the dedicated source control writer is unavailable", () =>
     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 d1f48bfed3681..f8a64733736f0 100644
--- a/apps/server/src/git/GitManager.ts
+++ b/apps/server/src/git/GitManager.ts
@@ -791,7 +791,7 @@ export const make = Effect.gen(function* () {
       .execute({
         operation: "GitManager.readRecentCommitSubjects",
         cwd,
-        args: ["log", "-n", "20", "--no-merges", "--pretty=format:%s"],
+        args: ["log", "-n", "20", "--no-merges", "--no-show-signature", "--pretty=format:%s"],
       })
       .pipe(
         Effect.map((result) =>
diff --git a/apps/server/src/vcs/GitVcsDriverCore.test.ts b/apps/server/src/vcs/GitVcsDriverCore.test.ts
index 1c3e075d165c8..7c9e764f441b3 100644
--- a/apps/server/src/vcs/GitVcsDriverCore.test.ts
+++ b/apps/server/src/vcs/GitVcsDriverCore.test.ts
@@ -2849,20 +2849,38 @@ it.layer(layerTest)("GitVcsDriver core integration", (it) => {
       }),
     );
 
-    it.effect("reads range patches from source without textconv, color, or diff.relative", () =>
+    it.effect("reads raw range context regardless of Git display configuration", () =>
       Effect.gen(function* () {
         const cwd = yield* makeTmpDir();
         const { initialBranch } = yield* initRepoWithCommit(cwd);
         yield* git(cwd, ["config", "diff.probe.textconv", "touch textconv-ran; echo converted"]);
         yield* git(cwd, ["config", "color.ui", "always"]);
         yield* git(cwd, ["config", "diff.relative", "true"]);
+        yield* git(cwd, ["config", "log.decorate", "short"]);
         yield* git(cwd, ["checkout", "-b", "feature/range"]);
         yield* writeTextFile(cwd, ".gitattributes", "*.doc diff=probe\n");
         yield* writeTextFile(cwd, "notes.doc", "source line\n");
         yield* writeTextFile(cwd, "plain.txt", "plain line\n");
         yield* writeTextFile(cwd, "binary.dat", "binary\0data");
         yield* git(cwd, ["add", "."]);
-        yield* git(cwd, ["commit", "-m", "range files"]);
+        const signingKey = `${yield* makeTmpDir("git-vcs-driver-signing-key-")}/key`;
+        const spawner = yield* ChildProcessSpawner.ChildProcessSpawner;
+        const keygen = ChildProcess.make("ssh-keygen", [
+          "-q",
+          "-t",
+          "ed25519",
+          "-N",
+          "",
+          "-f",
+          signingKey,
+        ]);
+        assert.equal(Number(yield* spawner.exitCode(keygen)), 0);
+        yield* git(cwd, ["config", "gpg.format", "ssh"]);
+        // A global signer such as 1Password's cannot use the fixture's generated key.
+        yield* git(cwd, ["config", "gpg.ssh.program", "ssh-keygen"]);
+        yield* git(cwd, ["config", "user.signingkey", `${signingKey}.pub`]);
+        yield* git(cwd, ["config", "log.showSignature", "true"]);
+        yield* git(cwd, ["commit", "-S", "-m", "range files"]);
         const driver = yield* GitVcsDriver.GitVcsDriver;
         const fileSystem = yield* FileSystem.FileSystem;
         const projectCwd = `${cwd}/app`;
@@ -2870,6 +2888,7 @@ it.layer(layerTest)("GitVcsDriver core integration", (it) => {
 
         const context = yield* driver.readRangeContext(projectCwd, initialBranch);
 
+        assert.match(context.commitSummary.trim(), /^[a-f0-9]+ range files$/);
         assert.include(context.diffPatch, "+source line");
         assert.notInclude(context.diffPatch, "converted");
         assert.include(context.diffPatch, "+plain line");
diff --git a/apps/server/src/vcs/GitVcsDriverCore.ts b/apps/server/src/vcs/GitVcsDriverCore.ts
index 2736cbc6d4fcb..f8b59f389567b 100644
--- a/apps/server/src/vcs/GitVcsDriverCore.ts
+++ b/apps/server/src/vcs/GitVcsDriverCore.ts
@@ -2942,7 +2942,15 @@ export const makeGitVcsDriverCore = Effect.fn("makeGitVcsDriverCore")(function*
         runGitStdoutWithOptions(
           "GitVcsDriver.readRangeContext.log",
           cwd,
-          ["log", "--oneline", "--no-color", "--end-of-options", commitRange],
+          [
+            "log",
+            "--oneline",
+            "--no-color",
+            "--no-decorate",
+            "--no-show-signature",
+            "--end-of-options",
+            commitRange,
+          ],
           {
             maxOutputBytes: RANGE_COMMIT_SUMMARY_MAX_OUTPUT_BYTES,
             appendTruncationMarker: true,