diff --git a/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/proposal.md b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/proposal.md
new file mode 100644
index 0000000..09e4e41
--- /dev/null
+++ b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/proposal.md
@@ -0,0 +1,17 @@
+## Why
+
+- `scripts/agent-branch-finish.sh` currently treats `git branch -d <agent-branch>` as a hard cleanup failure even after the merge already succeeded.
+- In the observed false-negative, `gh pr merge --delete-branch` reported that local branch deletion failed because of an active worktree, but by the time Guardex continued its own cleanup the local branch ref was already gone.
+- That leaves the merge outcome correct but still exits non-zero, which forces needless manual bookkeeping follow-ups.
+
+## What Changes
+
+- Make finish cleanup tolerate an already-missing local source branch during the post-merge branch-delete step.
+- Keep the existing warning for the GitHub CLI local-delete error, but continue cleanup when the branch ref has already disappeared.
+- Add a focused finish regression for the race where the local branch is gone by the time Guardex reaches its own cleanup.
+
+## Impact
+
+- Affects only the post-merge cleanup path in `agent-branch-finish.sh`.
+- Keeps true branch-delete failures fatal, but downgrades the already-deleted case to an informational cleanup warning.
+- Reduces false-negative finish exits while preserving merge, remote-delete, and worktree-prune behavior.
diff --git a/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/specs/workflow-guardrails/spec.md b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/specs/workflow-guardrails/spec.md
new file mode 100644
index 0000000..0a46cf1
--- /dev/null
+++ b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/specs/workflow-guardrails/spec.md
@@ -0,0 +1,21 @@
+## ADDED Requirements
+
+### Requirement: finish cleanup tolerates an already-missing local source branch after merge
+The `gx branch finish` cleanup flow SHALL treat the local source-branch delete step as successful when the branch ref is already absent by the time post-merge cleanup runs.
+
+#### Scenario: GitHub merge reports a local-branch delete problem but the branch is already gone during Guardex cleanup
+- **GIVEN** `scripts/agent-branch-finish.sh` merges an `agent/*` branch through the PR flow
+- **AND** the GitHub CLI reports a local branch delete problem during `gh pr merge --delete-branch`
+- **AND** the local `refs/heads/<agent-branch>` ref is already missing by the time Guardex reaches its own cleanup branch-delete step
+- **WHEN** Guardex continues cleanup
+- **THEN** the finish command SHALL keep going without failing
+- **AND** it SHALL emit an informational warning that the local branch was already deleted
+- **AND** it SHALL still continue remote-branch cleanup and worktree pruning
+
+#### Scenario: real local branch delete failures still fail finish cleanup
+- **GIVEN** `scripts/agent-branch-finish.sh` reaches the local source-branch delete step
+- **AND** the local `refs/heads/<agent-branch>` ref still exists
+- **AND** `git branch -d <agent-branch>` fails for a reason other than the branch already being absent
+- **WHEN** Guardex handles cleanup
+- **THEN** the finish command SHALL still fail
+- **AND** it SHALL preserve the underlying git error output
diff --git a/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/tasks.md b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/tasks.md
new file mode 100644
index 0000000..5b5f87f
--- /dev/null
+++ b/openspec/changes/agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43/tasks.md
@@ -0,0 +1,23 @@
+## 1. Specification
+
+- [x] 1.1 Finalize proposal scope and acceptance criteria for `agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43`.
+- [x] 1.2 Define normative requirements in `specs/workflow-guardrails/spec.md`.
+
+## 2. Implementation
+
+- [x] 2.1 Update `scripts/agent-branch-finish.sh` so post-merge cleanup tolerates an already-missing local source branch.
+- [x] 2.2 Mirror the same finish cleanup change into `templates/scripts/agent-branch-finish.sh`.
+- [x] 2.3 Add a focused regression in `test/finish.test.js` for the local-branch-already-deleted race.
+
+## 3. Verification
+
+- [x] 3.1 Run focused finish verification (`node --test test/finish.test.js`, `node --check bin/multiagent-safety.js`).
+- [x] 3.2 Run parity verification (`node --test test/metadata.test.js`).
+- [x] 3.3 Run `openspec validate agent-codex-tolerate-already-deleted-local-branch-in-2026-04-22-20-43 --type change --strict`.
+- [x] 3.4 Run `openspec validate --specs`.
+
+## 4. Completion
+
+- [ ] 4.1 Finish the agent branch via PR merge + cleanup (`gx finish --via-pr --wait-for-merge --cleanup` or `bash scripts/agent-branch-finish.sh --branch <agent-branch> --base <base-branch> --via-pr --wait-for-merge --cleanup`).
+- [ ] 4.2 Record PR URL + final `MERGED` state in the completion handoff.
+- [ ] 4.3 Confirm sandbox cleanup (`git worktree list`, `git branch -a`) or capture a `BLOCKED:` handoff if merge/cleanup is pending.
diff --git a/scripts/agent-branch-finish.sh b/scripts/agent-branch-finish.sh
index 6c47249..3e7e149 100755
--- a/scripts/agent-branch-finish.sh
+++ b/scripts/agent-branch-finish.sh
@@ -409,6 +409,33 @@ is_remote_branch_missing_error() {
   return 1
 }
 
+local_branch_exists() {
+  local branch="$1"
+  git -C "$repo_root" show-ref --verify --quiet "refs/heads/${branch}"
+}
+
+delete_local_branch_for_cleanup() {
+  local branch="$1"
+  local delete_output=""
+
+  if ! local_branch_exists "$branch"; then
+    echo "[agent-branch-finish] Local branch '${branch}' was already deleted; continuing cleanup." >&2
+    return 0
+  fi
+
+  if delete_output="$(git -C "$repo_root" branch -d "$branch" 2>&1)"; then
+    return 0
+  fi
+
+  if ! local_branch_exists "$branch"; then
+    echo "[agent-branch-finish] Local branch '${branch}' was already deleted; continuing cleanup." >&2
+    return 0
+  fi
+
+  echo "$delete_output" >&2
+  return 1
+}
+
 read_pr_state() {
   local state_line
   state_line="$("$GH_BIN" pr view "$SOURCE_BRANCH" --json state,mergedAt,url --jq '[.state, (.mergedAt // ""), (.url // "")] | join("\u001f")' 2>/dev/null || true)"
@@ -607,7 +634,9 @@ if [[ "$CLEANUP_AFTER_MERGE" -eq 1 ]]; then
     git -C "$repo_root" worktree remove "$source_worktree" --force >/dev/null 2>&1 || true
   fi
 
-  git -C "$repo_root" branch -d "$SOURCE_BRANCH"
+  if ! delete_local_branch_for_cleanup "$SOURCE_BRANCH"; then
+    exit 1
+  fi
 
   if [[ "$PUSH_ENABLED" -eq 1 && "$DELETE_REMOTE_BRANCH" -eq 1 ]]; then
     if git -C "$repo_root" ls-remote --exit-code --heads origin "$SOURCE_BRANCH" >/dev/null 2>&1; then
diff --git a/templates/scripts/agent-branch-finish.sh b/templates/scripts/agent-branch-finish.sh
index 6c47249..3e7e149 100755
--- a/templates/scripts/agent-branch-finish.sh
+++ b/templates/scripts/agent-branch-finish.sh
@@ -409,6 +409,33 @@ is_remote_branch_missing_error() {
   return 1
 }
 
+local_branch_exists() {
+  local branch="$1"
+  git -C "$repo_root" show-ref --verify --quiet "refs/heads/${branch}"
+}
+
+delete_local_branch_for_cleanup() {
+  local branch="$1"
+  local delete_output=""
+
+  if ! local_branch_exists "$branch"; then
+    echo "[agent-branch-finish] Local branch '${branch}' was already deleted; continuing cleanup." >&2
+    return 0
+  fi
+
+  if delete_output="$(git -C "$repo_root" branch -d "$branch" 2>&1)"; then
+    return 0
+  fi
+
+  if ! local_branch_exists "$branch"; then
+    echo "[agent-branch-finish] Local branch '${branch}' was already deleted; continuing cleanup." >&2
+    return 0
+  fi
+
+  echo "$delete_output" >&2
+  return 1
+}
+
 read_pr_state() {
   local state_line
   state_line="$("$GH_BIN" pr view "$SOURCE_BRANCH" --json state,mergedAt,url --jq '[.state, (.mergedAt // ""), (.url // "")] | join("\u001f")' 2>/dev/null || true)"
@@ -607,7 +634,9 @@ if [[ "$CLEANUP_AFTER_MERGE" -eq 1 ]]; then
     git -C "$repo_root" worktree remove "$source_worktree" --force >/dev/null 2>&1 || true
   fi
 
-  git -C "$repo_root" branch -d "$SOURCE_BRANCH"
+  if ! delete_local_branch_for_cleanup "$SOURCE_BRANCH"; then
+    exit 1
+  fi
 
   if [[ "$PUSH_ENABLED" -eq 1 && "$DELETE_REMOTE_BRANCH" -eq 1 ]]; then
     if git -C "$repo_root" ls-remote --exit-code --heads origin "$SOURCE_BRANCH" >/dev/null 2>&1; then
diff --git a/test/finish.test.js b/test/finish.test.js
index 9160e21..a03eaf5 100644
--- a/test/finish.test.js
+++ b/test/finish.test.js
@@ -383,6 +383,89 @@ fi
   assert.equal(result.stdout.trim(), '', 'agent branch should be absent on origin');
 });
 
+test('agent-branch-finish cleanup tolerates an already-deleted local branch after gh delete warning', () => {
+  const repoDir = initRepo();
+  seedCommit(repoDir);
+  attachOriginRemote(repoDir);
+
+  let result = runNode(['setup', '--target', repoDir, '--no-global-install'], repoDir);
+  assert.equal(result.status, 0, result.stderr || result.stdout);
+  result = runCmd('git', ['add', '.'], repoDir);
+  assert.equal(result.status, 0, result.stderr);
+  result = runCmd('git', ['commit', '-m', 'apply gx setup'], repoDir, {
+    ALLOW_COMMIT_ON_PROTECTED_BRANCH: '1',
+  });
+  assert.equal(result.status, 0, result.stderr);
+  result = runCmd('git', ['push', 'origin', 'dev'], repoDir);
+  assert.equal(result.status, 0, result.stderr);
+
+  const agentWorktreePath = path.join(repoDir, '.omx', 'agent-worktrees', 'agent__local-delete-race');
+  result = runCmd(
+    'git',
+    ['worktree', 'add', '-b', 'agent/test-pr-local-delete-race', agentWorktreePath, 'dev'],
+    repoDir,
+  );
+  assert.equal(result.status, 0, result.stderr || result.stdout);
+
+  fs.writeFileSync(path.join(agentWorktreePath, 'local-delete-race.txt'), 'cleanup race\n', 'utf8');
+  result = runCmd('git', ['add', 'local-delete-race.txt'], agentWorktreePath);
+  assert.equal(result.status, 0, result.stderr);
+  result = runCmd('git', ['commit', '--no-verify', '-m', 'local delete race change'], agentWorktreePath);
+  assert.equal(result.status, 0, result.stderr || result.stdout);
+
+  const { fakePath: fakeGhPath } = createFakeGhScript(`
+if [[ "$1" == "pr" && "$2" == "create" ]]; then
+  exit 0
+fi
+if [[ "$1" == "pr" && "$2" == "view" ]]; then
+  if [[ " $* " == *" --json url "* ]]; then
+    echo "https://example.test/pr/local-delete-race"
+    exit 0
+  fi
+  echo "unexpected gh pr view args: $*" >&2
+  exit 1
+fi
+if [[ "$1" == "pr" && "$2" == "merge" ]]; then
+  git_bin="$(command -v git)"
+  "$git_bin" -C "${'${GUARDEX_TEST_AGENT_WORKTREE}'}" checkout --detach >/dev/null 2>&1 || true
+  "$git_bin" -C "${'${GUARDEX_TEST_REPO_DIR}'}" branch -D "$3" >/dev/null 2>&1 || true
+  echo "failed to delete local branch $3: error: cannot delete branch '$3' used by worktree at '${'${GUARDEX_TEST_AGENT_WORKTREE}'}'" >&2
+  echo "/usr/bin/git: exit status 1" >&2
+  exit 1
+fi
+echo "unexpected gh args: $*" >&2
+exit 1
+`);
+
+  const finish = runBranchFinish(
+    ['--branch', 'agent/test-pr-local-delete-race', '--base', 'dev', '--mode', 'pr', '--cleanup'],
+    repoDir,
+    {
+      GUARDEX_GH_BIN: fakeGhPath,
+      GUARDEX_TEST_REPO_DIR: repoDir,
+      GUARDEX_TEST_AGENT_WORKTREE: agentWorktreePath,
+    },
+  );
+  assert.equal(finish.status, 0, finish.stderr || finish.stdout);
+  assert.match(
+    finish.stderr,
+    /PR merged but gh could not delete the local branch \(active worktree\); continuing local cleanup\./,
+  );
+  assert.match(
+    finish.stderr,
+    /Local branch 'agent\/test-pr-local-delete-race' was already deleted; continuing cleanup\./,
+  );
+  assert.match(
+    finish.stdout,
+    /Merged 'agent\/test-pr-local-delete-race' into 'dev' via pr flow and cleaned source branch\/worktree\./,
+  );
+
+  result = runCmd('git', ['show-ref', '--verify', '--quiet', 'refs/heads/agent/test-pr-local-delete-race'], repoDir);
+  assert.notEqual(result.status, 0, 'agent branch should stay deleted locally');
+  result = runCmd('git', ['ls-remote', '--heads', 'origin', 'agent/test-pr-local-delete-race'], repoDir);
+  assert.equal(result.stdout.trim(), '', 'agent branch should be deleted on origin');
+});
+
 
 test('agent-branch-finish cleanup succeeds from active agent worktree when base branch is checked out elsewhere', () => {
   const repoDir = initRepo();
diff --git a/test/metadata.test.js b/test/metadata.test.js
index 0ddc5e3..dcf634f 100644
--- a/test/metadata.test.js
+++ b/test/metadata.test.js
@@ -126,6 +126,7 @@ test('frontend mirror workflow skips cleanly when the mirror PAT is missing', ()
 test('critical runtime helper scripts and active-agents sources stay in sync with templates', () => {
   const pairs = [
     ['templates/scripts/agent-branch-start.sh', 'scripts/agent-branch-start.sh'],
+    ['templates/scripts/agent-branch-finish.sh', 'scripts/agent-branch-finish.sh'],
     ['templates/scripts/codex-agent.sh', 'scripts/codex-agent.sh'],
     ['templates/scripts/openspec/init-plan-workspace.sh', 'scripts/openspec/init-plan-workspace.sh'],
     ['templates/scripts/openspec/init-change-workspace.sh', 'scripts/openspec/init-change-workspace.sh'],