diff --git a/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/.openspec.yaml b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/.openspec.yaml
new file mode 100644
index 0000000..4b8c565
--- /dev/null
+++ b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/.openspec.yaml
@@ -0,0 +1,2 @@
+schema: spec-driven
+created: 2026-04-21
diff --git a/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/proposal.md b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/proposal.md
new file mode 100644
index 0000000..67afd87
--- /dev/null
+++ b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/proposal.md
@@ -0,0 +1,25 @@
+## Why
+
+- When `codex-agent` keeps a sandbox after the first lane exits early, the next
+  agent only gets generic merge/cleanup hints and has to reconstruct the exact
+  takeover flow by hand.
+- Fresh OpenSpec change workspaces do not scaffold a copy-paste takeover note,
+  so usage-limit handoffs are inconsistent and easy to botch.
+
+## What Changes
+
+- Make `codex-agent` print a concrete takeover prompt with the existing branch,
+  sandbox path, OpenSpec artifact, and finish command whenever auto-finish does
+  not complete and the worktree stays alive.
+- Teach `init-change-workspace.sh` to scaffold structured `Handoff:` and
+  `Copy prompt:` lines, and resolve the cleanup command base branch from repo
+  metadata instead of hardcoding `dev`.
+- Add regression coverage for both the launcher handoff output and the scaffold
+  defaults.
+
+## Impact
+
+- Affects `scripts/codex-agent.sh`, `scripts/openspec/init-change-workspace.sh`,
+  and `test/install.test.js`.
+- Keeps the existing finish pipeline intact while making quota-hit/manual
+  takeovers copy-pasteable instead of reconstructive.
diff --git a/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/specs/improve-usage-limit-takeover-handoff/spec.md b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/specs/improve-usage-limit-takeover-handoff/spec.md
new file mode 100644
index 0000000..aaf4c90
--- /dev/null
+++ b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/specs/improve-usage-limit-takeover-handoff/spec.md
@@ -0,0 +1,32 @@
+## ADDED Requirements
+
+### Requirement: `codex-agent` SHALL emit a takeover prompt when a sandbox is kept
+`codex-agent` SHALL print a copy-paste takeover prompt whenever it leaves a
+branch/worktree alive for manual follow-up.
+
+#### Scenario: incomplete run keeps the sandbox alive
+- **GIVEN** `codex-agent` keeps the sandbox because auto-finish did not complete
+- **WHEN** it reports the kept worktree
+- **THEN** it SHALL print a takeover prompt that references the existing branch
+  and sandbox path
+- **AND** the prompt SHALL tell the next agent to continue from the current
+  state instead of creating a new sandbox
+- **AND** the prompt SHALL include the cleanup/finish command for
+  `agent-branch-finish.sh`.
+
+### Requirement: OpenSpec change scaffolds SHALL include structured takeover copy
+OpenSpec change workspaces SHALL scaffold a structured handoff line plus a
+copy-paste takeover prompt for usage-limit/manual handoffs.
+
+#### Scenario: standard change workspace scaffold
+- **WHEN** `scripts/openspec/init-change-workspace.sh` creates a non-minimal
+  change workspace
+- **THEN** `tasks.md` SHALL include a `Handoff:` line and a `Copy prompt:` line
+- **AND** the generated cleanup command SHALL resolve the branch base from repo
+  metadata when available.
+
+#### Scenario: minimal notes workspace scaffold
+- **WHEN** `scripts/openspec/init-change-workspace.sh` runs in minimal mode
+- **THEN** `notes.md` SHALL include the same `Handoff:` and `Copy prompt:` flow
+- **AND** the generated cleanup command SHALL resolve the branch base from repo
+  metadata when available.
diff --git a/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/tasks.md b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/tasks.md
new file mode 100644
index 0000000..9701d8b
--- /dev/null
+++ b/openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/tasks.md
@@ -0,0 +1,34 @@
+## Definition of Done
+
+This change is complete only when **all** of the following are true:
+
+- Every checkbox below is checked.
+- The agent branch reaches `MERGED` state on `origin` and the PR URL + state are recorded in the completion handoff.
+- If any step blocks (test failure, conflict, ambiguous result), append a `BLOCKED:` line under section 4 explaining the blocker and **STOP**. Do not tick remaining cleanup boxes; do not silently skip the cleanup pipeline.
+
+## Handoff
+
+- Handoff: change=`agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30`; branch=`agent/codex/improve-usage-limit-takeover-handoff-2026-04-21-23-30`; scope=`OpenSpec change docs, codex-agent takeover output, change scaffold defaults, install regressions`; action=`emit a copy-paste takeover prompt and keep usage-limit/manual rescue flow inside the existing sandbox`.
+- Copy prompt: Continue `agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30` on branch `agent/codex/improve-usage-limit-takeover-handoff-2026-04-21-23-30`. Work inside the existing sandbox, review `openspec/changes/agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30/tasks.md`, continue from the current state instead of creating a new sandbox, and when the work is done run `bash scripts/agent-branch-finish.sh --branch "agent/codex/improve-usage-limit-takeover-handoff-2026-04-21-23-30" --base main --via-pr --wait-for-merge --cleanup`.
+
+## 1. Specification
+
+- [x] 1.1 Finalize proposal scope and acceptance criteria for `agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30`.
+- [x] 1.2 Define normative requirements in `specs/improve-usage-limit-takeover-handoff/spec.md`.
+
+## 2. Implementation
+
+- [x] 2.1 Implement scoped behavior changes in `scripts/codex-agent.sh` and `scripts/openspec/init-change-workspace.sh`, then mirror the same changes into the managed templates.
+- [x] 2.2 Add/update focused regression coverage in `test/install.test.js` for the launcher takeover prompt and the scaffolded handoff/copy prompt defaults.
+
+## 3. Verification
+
+- [x] 3.1 Run targeted project verification commands. Result: `node --test --test-name-pattern "(codex-agent prints a takeover prompt when the sandbox is kept after an incomplete run|OpenSpec change workspace scaffold creates proposal/tasks/spec defaults|OpenSpec change workspace scaffold supports minimal T1 notes mode|critical runtime helper scripts stay in sync with templates)" test/install.test.js test/metadata.test.js` passed `4/4`; `bash -n scripts/codex-agent.sh scripts/openspec/init-change-workspace.sh templates/scripts/codex-agent.sh templates/scripts/openspec/init-change-workspace.sh` passed.
+- [x] 3.2 Run `openspec validate agent-codex-improve-usage-limit-takeover-handoff-2026-04-21-23-30 --type change --strict`. Result: passed.
+- [x] 3.3 Run `openspec validate --specs`. Result: `No items found to validate.`
+
+## 4. Cleanup (mandatory; run before claiming completion)
+
+- [ ] 4.1 Run the cleanup pipeline: `bash scripts/agent-branch-finish.sh --branch agent/codex/improve-usage-limit-takeover-handoff-2026-04-21-23-30 --base dev --via-pr --wait-for-merge --cleanup`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
+- [ ] 4.2 Record the PR URL and final merge state (`MERGED`) in the completion handoff.
+- [ ] 4.3 Confirm the sandbox worktree is gone (`git worktree list` no longer shows the agent path; `git branch -a` shows no surviving local/remote refs for the branch).
diff --git a/scripts/codex-agent.sh b/scripts/codex-agent.sh
index 8b509dd..1829d92 100755
--- a/scripts/codex-agent.sh
+++ b/scripts/codex-agent.sh
@@ -510,6 +510,31 @@ resolve_worktree_base_branch() {
   printf 'dev'
 }
 
+print_takeover_prompt() {
+  local wt="$1"
+  local branch="$2"
+  local base_branch change_slug change_artifact finish_cmd
+
+  base_branch="$(resolve_worktree_base_branch "$wt")"
+  if [[ -z "$base_branch" ]]; then
+    base_branch="dev"
+  fi
+
+  change_slug="$(resolve_openspec_change_slug "$branch")"
+  change_artifact="openspec/changes/${change_slug}/tasks.md"
+  if [[ ! -f "${wt}/${change_artifact}" ]]; then
+    change_artifact="openspec/changes/${change_slug}/notes.md"
+  fi
+  if [[ ! -f "${wt}/${change_artifact}" ]]; then
+    change_artifact="openspec/changes/${change_slug}/"
+  fi
+
+  finish_cmd="bash scripts/agent-branch-finish.sh --branch \"${branch}\" --base ${base_branch} --via-pr --wait-for-merge --cleanup"
+
+  echo "[codex-agent] Takeover sandbox: ${wt}"
+  echo "[codex-agent] Takeover prompt: Continue \`${change_slug}\` on branch \`${branch}\`. Work inside \`${wt}\`, review \`${change_artifact}\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`${finish_cmd}\`."
+}
+
 sync_worktree_with_base() {
   local wt="$1"
   if ! has_origin_remote; then
@@ -952,6 +977,7 @@ else
     if [[ "$auto_finish_completed" -eq 1 ]]; then
       echo "[codex-agent] Branch kept intentionally. Cleanup on demand: gx cleanup --branch \"${worktree_branch}\""
     else
+      print_takeover_prompt "$worktree_path" "$worktree_branch"
       echo "[codex-agent] If finished, merge with: bash scripts/agent-branch-finish.sh --branch \"${worktree_branch}\" --base dev --via-pr --wait-for-merge"
       echo "[codex-agent] Cleanup on demand: gx cleanup --branch \"${worktree_branch}\""
     fi
diff --git a/scripts/openspec/init-change-workspace.sh b/scripts/openspec/init-change-workspace.sh
index 07f26c7..6f0930d 100755
--- a/scripts/openspec/init-change-workspace.sh
+++ b/scripts/openspec/init-change-workspace.sh
@@ -21,9 +21,27 @@ if [[ "$CAPABILITY_SLUG" =~ [^a-z0-9-] ]]; then
   exit 1
 fi
 
+resolve_base_branch() {
+  local branch="$1"
+  local base_branch=""
+
+  if [[ -n "$branch" ]] && [[ "$branch" != "agent/<your-name>/<branch-slug>" ]]; then
+    base_branch="$(git config --get "branch.${branch}.guardexBase" || true)"
+  fi
+  if [[ -z "$base_branch" ]]; then
+    base_branch="$(git config --get multiagent.baseBranch || true)"
+  fi
+  if [[ -z "$base_branch" ]]; then
+    base_branch="dev"
+  fi
+
+  printf '%s' "$base_branch"
+}
+
 CHANGE_DIR="openspec/changes/${CHANGE_SLUG}"
 SPEC_DIR="${CHANGE_DIR}/specs/${CAPABILITY_SLUG}"
 TODAY="$(date -u +%Y-%m-%d)"
+BASE_BRANCH="$(resolve_base_branch "$AGENT_BRANCH")"
 
 MINIMAL_RAW="${GUARDEX_OPENSPEC_MINIMAL:-0}"
 case "$(printf '%s' "$MINIMAL_RAW" | tr '[:upper:]' '[:lower:]')" in
@@ -53,9 +71,14 @@ Branch: \`${AGENT_BRANCH}\`
 
 Describe the change in a sentence or two. Commit message is the spec of record.
 
+## Handoff
+
+- Handoff: change=\`${CHANGE_SLUG}\`; branch=\`${AGENT_BRANCH}\`; scope=\`TODO\`; action=\`continue this sandbox or finish cleanup after a usage-limit/manual takeover\`.
+- Copy prompt: Continue \`${CHANGE_SLUG}\` on branch \`${AGENT_BRANCH}\`. Work inside the existing sandbox, review \`openspec/changes/${CHANGE_SLUG}/notes.md\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`.
+
 ## Cleanup
 
-- [ ] Run: \`bash scripts/agent-branch-finish.sh --branch ${AGENT_BRANCH} --base dev --via-pr --wait-for-merge --cleanup\`
+- [ ] Run: \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`
 - [ ] Record PR URL + \`MERGED\` state in the completion handoff.
 - [ ] Confirm sandbox worktree is gone (\`git worktree list\`, \`git branch -a\`).
 NOTESEOF
@@ -91,6 +114,11 @@ This change is complete only when **all** of the following are true:
 - The agent branch reaches \`MERGED\` state on \`origin\` and the PR URL + state are recorded in the completion handoff.
 - If any step blocks (test failure, conflict, ambiguous result), append a \`BLOCKED:\` line under section 4 explaining the blocker and **STOP**. Do not tick remaining cleanup boxes; do not silently skip the cleanup pipeline.
 
+## Handoff
+
+- Handoff: change=\`${CHANGE_SLUG}\`; branch=\`${AGENT_BRANCH}\`; scope=\`TODO\`; action=\`continue this sandbox or finish cleanup after a usage-limit/manual takeover\`.
+- Copy prompt: Continue \`${CHANGE_SLUG}\` on branch \`${AGENT_BRANCH}\`. Work inside the existing sandbox, review \`openspec/changes/${CHANGE_SLUG}/tasks.md\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`.
+
 ## 1. Specification
 
 - [ ] 1.1 Finalize proposal scope and acceptance criteria for \`${CHANGE_SLUG}\`.
@@ -109,7 +137,7 @@ This change is complete only when **all** of the following are true:
 
 ## 4. Cleanup (mandatory; run before claiming completion)
 
-- [ ] 4.1 Run the cleanup pipeline: \`bash scripts/agent-branch-finish.sh --branch ${AGENT_BRANCH} --base dev --via-pr --wait-for-merge --cleanup\`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
+- [ ] 4.1 Run the cleanup pipeline: \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
 - [ ] 4.2 Record the PR URL and final merge state (\`MERGED\`) in the completion handoff.
 - [ ] 4.3 Confirm the sandbox worktree is gone (\`git worktree list\` no longer shows the agent path; \`git branch -a\` shows no surviving local/remote refs for the branch).
 TASKSEOF
diff --git a/templates/scripts/codex-agent.sh b/templates/scripts/codex-agent.sh
index 8b509dd..1829d92 100755
--- a/templates/scripts/codex-agent.sh
+++ b/templates/scripts/codex-agent.sh
@@ -510,6 +510,31 @@ resolve_worktree_base_branch() {
   printf 'dev'
 }
 
+print_takeover_prompt() {
+  local wt="$1"
+  local branch="$2"
+  local base_branch change_slug change_artifact finish_cmd
+
+  base_branch="$(resolve_worktree_base_branch "$wt")"
+  if [[ -z "$base_branch" ]]; then
+    base_branch="dev"
+  fi
+
+  change_slug="$(resolve_openspec_change_slug "$branch")"
+  change_artifact="openspec/changes/${change_slug}/tasks.md"
+  if [[ ! -f "${wt}/${change_artifact}" ]]; then
+    change_artifact="openspec/changes/${change_slug}/notes.md"
+  fi
+  if [[ ! -f "${wt}/${change_artifact}" ]]; then
+    change_artifact="openspec/changes/${change_slug}/"
+  fi
+
+  finish_cmd="bash scripts/agent-branch-finish.sh --branch \"${branch}\" --base ${base_branch} --via-pr --wait-for-merge --cleanup"
+
+  echo "[codex-agent] Takeover sandbox: ${wt}"
+  echo "[codex-agent] Takeover prompt: Continue \`${change_slug}\` on branch \`${branch}\`. Work inside \`${wt}\`, review \`${change_artifact}\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`${finish_cmd}\`."
+}
+
 sync_worktree_with_base() {
   local wt="$1"
   if ! has_origin_remote; then
@@ -952,6 +977,7 @@ else
     if [[ "$auto_finish_completed" -eq 1 ]]; then
       echo "[codex-agent] Branch kept intentionally. Cleanup on demand: gx cleanup --branch \"${worktree_branch}\""
     else
+      print_takeover_prompt "$worktree_path" "$worktree_branch"
       echo "[codex-agent] If finished, merge with: bash scripts/agent-branch-finish.sh --branch \"${worktree_branch}\" --base dev --via-pr --wait-for-merge"
       echo "[codex-agent] Cleanup on demand: gx cleanup --branch \"${worktree_branch}\""
     fi
diff --git a/templates/scripts/openspec/init-change-workspace.sh b/templates/scripts/openspec/init-change-workspace.sh
index 07f26c7..6f0930d 100755
--- a/templates/scripts/openspec/init-change-workspace.sh
+++ b/templates/scripts/openspec/init-change-workspace.sh
@@ -21,9 +21,27 @@ if [[ "$CAPABILITY_SLUG" =~ [^a-z0-9-] ]]; then
   exit 1
 fi
 
+resolve_base_branch() {
+  local branch="$1"
+  local base_branch=""
+
+  if [[ -n "$branch" ]] && [[ "$branch" != "agent/<your-name>/<branch-slug>" ]]; then
+    base_branch="$(git config --get "branch.${branch}.guardexBase" || true)"
+  fi
+  if [[ -z "$base_branch" ]]; then
+    base_branch="$(git config --get multiagent.baseBranch || true)"
+  fi
+  if [[ -z "$base_branch" ]]; then
+    base_branch="dev"
+  fi
+
+  printf '%s' "$base_branch"
+}
+
 CHANGE_DIR="openspec/changes/${CHANGE_SLUG}"
 SPEC_DIR="${CHANGE_DIR}/specs/${CAPABILITY_SLUG}"
 TODAY="$(date -u +%Y-%m-%d)"
+BASE_BRANCH="$(resolve_base_branch "$AGENT_BRANCH")"
 
 MINIMAL_RAW="${GUARDEX_OPENSPEC_MINIMAL:-0}"
 case "$(printf '%s' "$MINIMAL_RAW" | tr '[:upper:]' '[:lower:]')" in
@@ -53,9 +71,14 @@ Branch: \`${AGENT_BRANCH}\`
 
 Describe the change in a sentence or two. Commit message is the spec of record.
 
+## Handoff
+
+- Handoff: change=\`${CHANGE_SLUG}\`; branch=\`${AGENT_BRANCH}\`; scope=\`TODO\`; action=\`continue this sandbox or finish cleanup after a usage-limit/manual takeover\`.
+- Copy prompt: Continue \`${CHANGE_SLUG}\` on branch \`${AGENT_BRANCH}\`. Work inside the existing sandbox, review \`openspec/changes/${CHANGE_SLUG}/notes.md\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`.
+
 ## Cleanup
 
-- [ ] Run: \`bash scripts/agent-branch-finish.sh --branch ${AGENT_BRANCH} --base dev --via-pr --wait-for-merge --cleanup\`
+- [ ] Run: \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`
 - [ ] Record PR URL + \`MERGED\` state in the completion handoff.
 - [ ] Confirm sandbox worktree is gone (\`git worktree list\`, \`git branch -a\`).
 NOTESEOF
@@ -91,6 +114,11 @@ This change is complete only when **all** of the following are true:
 - The agent branch reaches \`MERGED\` state on \`origin\` and the PR URL + state are recorded in the completion handoff.
 - If any step blocks (test failure, conflict, ambiguous result), append a \`BLOCKED:\` line under section 4 explaining the blocker and **STOP**. Do not tick remaining cleanup boxes; do not silently skip the cleanup pipeline.
 
+## Handoff
+
+- Handoff: change=\`${CHANGE_SLUG}\`; branch=\`${AGENT_BRANCH}\`; scope=\`TODO\`; action=\`continue this sandbox or finish cleanup after a usage-limit/manual takeover\`.
+- Copy prompt: Continue \`${CHANGE_SLUG}\` on branch \`${AGENT_BRANCH}\`. Work inside the existing sandbox, review \`openspec/changes/${CHANGE_SLUG}/tasks.md\`, continue from the current state instead of creating a new sandbox, and when the work is done run \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`.
+
 ## 1. Specification
 
 - [ ] 1.1 Finalize proposal scope and acceptance criteria for \`${CHANGE_SLUG}\`.
@@ -109,7 +137,7 @@ This change is complete only when **all** of the following are true:
 
 ## 4. Cleanup (mandatory; run before claiming completion)
 
-- [ ] 4.1 Run the cleanup pipeline: \`bash scripts/agent-branch-finish.sh --branch ${AGENT_BRANCH} --base dev --via-pr --wait-for-merge --cleanup\`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
+- [ ] 4.1 Run the cleanup pipeline: \`bash scripts/agent-branch-finish.sh --branch "${AGENT_BRANCH}" --base ${BASE_BRANCH} --via-pr --wait-for-merge --cleanup\`. This handles commit -> push -> PR create -> merge wait -> worktree prune in one invocation.
 - [ ] 4.2 Record the PR URL and final merge state (\`MERGED\`) in the completion handoff.
 - [ ] 4.3 Confirm the sandbox worktree is gone (\`git worktree list\` no longer shows the agent path; \`git branch -a\` shows no surviving local/remote refs for the branch).
 TASKSEOF
diff --git a/test/install.test.js b/test/install.test.js
index 89c7c5f..65cd18f 100644
--- a/test/install.test.js
+++ b/test/install.test.js
@@ -3498,6 +3498,63 @@ exit 1
   assert.match(launchedArgs, /--model gpt-5\.4-mini/);
 });
 
+test('codex-agent prints a takeover prompt when the sandbox is kept after an incomplete run', () => {
+  const repoDir = initRepo();
+  seedCommit(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.stdout);
+
+  const fakeCodexBin = fs.mkdtempSync(path.join(os.tmpdir(), 'guardex-fake-codex-takeover-'));
+  const fakeCodexPath = path.join(fakeCodexBin, 'codex');
+  fs.writeFileSync(
+    fakeCodexPath,
+    '#!/usr/bin/env bash\n' +
+      'pwd > "${GUARDEX_TEST_CODEX_CWD}"\n' +
+      'echo "partial" > codex-partial.txt\n' +
+      'exit 42\n',
+    'utf8',
+  );
+  fs.chmodSync(fakeCodexPath, 0o755);
+
+  const cwdMarker = path.join(repoDir, '.codex-agent-cwd-takeover');
+  const launch = runCmd(
+    'bash',
+    ['scripts/codex-agent.sh', 'usage-limit-task', 'planner', 'dev'],
+    repoDir,
+    {
+      PATH: `${fakeCodexBin}:${process.env.PATH}`,
+      GUARDEX_TEST_CODEX_CWD: cwdMarker,
+    },
+  );
+  assert.equal(launch.status, 42, launch.stderr || launch.stdout);
+
+  const combinedOutput = `${launch.stdout}\n${launch.stderr}`;
+  const launchedBranch = extractCreatedBranch(launch.stdout);
+  const changeSlug = launchedBranch.replace(/\//g, '-');
+  assert.match(combinedOutput, /\[codex-agent\] Sandbox worktree kept:/);
+  assert.match(combinedOutput, new RegExp(`\\[codex-agent\\] Takeover sandbox: ${escapeRegexLiteral(fs.readFileSync(cwdMarker, 'utf8').trim())}`));
+  assert.match(
+    combinedOutput,
+    new RegExp(`\\[codex-agent\\] Takeover prompt: Continue \`${escapeRegexLiteral(changeSlug)}\` on branch \`${escapeRegexLiteral(launchedBranch)}\``),
+  );
+  assert.match(combinedOutput, /continue from the current state instead of creating a new sandbox/);
+  assert.match(
+    combinedOutput,
+    new RegExp(`openspec/changes/${escapeRegexLiteral(changeSlug)}/tasks\\.md`),
+  );
+  assert.match(
+    combinedOutput,
+    new RegExp(`agent-branch-finish\\.sh --branch "${escapeRegexLiteral(launchedBranch)}" --base dev --via-pr --wait-for-merge --cleanup`),
+  );
+});
+
 test('codex-agent keeps the sandbox when base branch advances without a mergeable remote context', () => {
   const repoDir = initRepo();
   seedCommit(repoDir);
@@ -4176,6 +4233,9 @@ test('OpenSpec change workspace scaffold creates proposal/tasks/spec defaults',
   const tasksContent = fs.readFileSync(path.join(changeDir, 'tasks.md'), 'utf8');
   assert.match(tasksContent, /## Definition of Done/);
   assert.match(tasksContent, /append a `BLOCKED:` line under section 4/);
+  assert.match(tasksContent, /## Handoff/);
+  assert.match(tasksContent, /Handoff: change=`change-workspace-smoke`/);
+  assert.match(tasksContent, /Copy prompt: Continue `change-workspace-smoke` on branch `agent\/<your-name>\/<branch-slug>`/);
   assert.match(tasksContent, /## 4\. Cleanup \(mandatory; run before claiming completion\)/);
   assert.match(tasksContent, /Run the cleanup pipeline:/);
   assert.match(tasksContent, /Record the PR URL and final merge state \(`MERGED`\)/);
@@ -4187,6 +4247,8 @@ test('OpenSpec change workspace scaffold supports minimal T1 notes mode', () =>
 
   const setupResult = runNode(['setup', '--target', repoDir, '--no-global-install'], repoDir);
   assert.equal(setupResult.status, 0, setupResult.stderr || setupResult.stdout);
+  let result = runCmd('git', ['config', 'multiagent.baseBranch', 'main'], repoDir);
+  assert.equal(result.status, 0, result.stderr || result.stdout);
 
   const changeSlug = 'change-workspace-minimal';
   const capabilitySlug = 'runtime-migration';
@@ -4209,6 +4271,10 @@ test('OpenSpec change workspace scaffold supports minimal T1 notes mode', () =>
   assert.match(notesContent, /minimal \/ T1/);
   assert.match(notesContent, new RegExp(agentBranch.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')));
   assert.match(notesContent, /Commit message is the spec of record/);
+  assert.match(notesContent, /## Handoff/);
+  assert.match(notesContent, /Handoff: change=`change-workspace-minimal`/);
+  assert.match(notesContent, /Copy prompt: Continue `change-workspace-minimal` on branch `agent\/codex\/minimal-change`/);
+  assert.match(notesContent, /--base main --via-pr --wait-for-merge --cleanup/);
   assert.match(notesContent, /Record PR URL \+ `MERGED` state/);
 });