diff --git a/.github/workflows/agent-mention-opencode-dispatch.yml b/.github/workflows/agent-mention-opencode-dispatch.yml
index 160b4723d..af8446286 100644
--- a/.github/workflows/agent-mention-opencode-dispatch.yml
+++ b/.github/workflows/agent-mention-opencode-dispatch.yml
@@ -1,7 +1,7 @@
 name: Agent Mention OpenCode Dispatch
 run-name: >-
-  Agent Mention OpenCode ${{ github.event.client_payload.target_repository }}#${{
-  github.event.client_payload.pr_number }} [cwl-agent-invocation:${{
+  Agent Mention OpenCode ${{ github.event.client_payload.claim.repository }}#${{
+  github.event.client_payload.claim.pr_number }} [cwl-agent-invocation:${{
   github.event.client_payload.agent_invocation_key }}]
 
 on:
@@ -26,40 +26,15 @@ jobs:
       contents: write
     env:
       GH_TOKEN: ${{ github.token }}
-      REQUESTED_AGENT: "opencode-agent"
-      PAYLOAD_AGENT: ${{ github.event.client_payload.requested_agent || '' }}
+      CLIENT_PAYLOAD_JSON: ${{ toJSON(github.event.client_payload) }}
+      PAYLOAD_SCHEMA: ${{ github.event.client_payload.schema || '' }}
       INVOCATION_KEY: ${{ github.event.client_payload.agent_invocation_key || '' }}
-      TARGET_REPOSITORY: ${{ github.event.client_payload.target_repository || '' }}
-      PR_NUMBER: ${{ github.event.client_payload.pr_number || '' }}
-      PR_HEAD_SHA: ${{ github.event.client_payload.pr_head_sha || '' }}
-      PR_BASE_SHA: ${{ github.event.client_payload.pr_base_sha || '' }}
-      BASE_BRANCH: ${{ github.event.client_payload.base_branch || '' }}
-      REQUESTED_BY: ${{ github.event.client_payload.requested_by || '' }}
-      SOURCE_COMMENT_ID: ${{ github.event.client_payload.source_comment_id || '' }}
-      TRIGGER_REVIEWS: ${{ github.event.client_payload.trigger_reviews }}
-      REVIEW_DISPATCH_LIMIT: ${{ github.event.client_payload.review_dispatch_limit || '' }}
-      ENABLE_AUTO_MERGE: ${{ github.event.client_payload.enable_auto_merge }}
-      UPDATE_BRANCHES: ${{ github.event.client_payload.update_branches }}
-      MERGE_MODE: ${{ github.event.client_payload.merge_mode || '' }}
     steps:
-      - name: Validate exact invocation payload
+      - name: Validate exact invocation payload and prepare scheduler request
         run: |
           set -euo pipefail
-          if [ "$PAYLOAD_AGENT" != "$REQUESTED_AGENT" ] ||
-            ! [[ "$INVOCATION_KEY" =~ ^[0-9a-f]{64}$ ]] ||
-            ! [[ "$TARGET_REPOSITORY" =~ ^ContextualWisdomLab/[A-Za-z0-9_.-]+$ ]] ||
-            ! [[ "$PR_NUMBER" =~ ^[1-9][0-9]*$ ]] ||
-            ! [[ "$PR_HEAD_SHA" =~ ^[0-9a-f]{40}$ ]] ||
-            ! [[ "$PR_BASE_SHA" =~ ^[0-9a-f]{40}$ ]] ||
-            ! [[ "$BASE_BRANCH" =~ ^[A-Za-z0-9._/-]+$ ]] ||
-            [[ "$BASE_BRANCH" == -* ]] ||
-            ! [[ "$SOURCE_COMMENT_ID" =~ ^[1-9][0-9]*$ ]] ||
-            [ "$TRIGGER_REVIEWS" != "true" ] ||
-            [ "$REVIEW_DISPATCH_LIMIT" != "1" ] ||
-            [ "$ENABLE_AUTO_MERGE" != "false" ] ||
-            [ "$UPDATE_BRANCHES" != "false" ] ||
-            [ "$MERGE_MODE" != "disabled" ] ||
-            ! [[ "$REQUESTED_BY" =~ ^[A-Za-z0-9-]+$ ]]; then
+          if [ "$PAYLOAD_SCHEMA" != "cwl.agent-invocation/v2" ] ||
+            ! [[ "$INVOCATION_KEY" =~ ^[0-9a-f]{64}$ ]]; then
             echo "::error::Rejected malformed or mismatched OpenCode agent invocation payload."
             exit 1
           fi
@@ -69,23 +44,85 @@ jobs:
           import hmac
           import json
           import os
+          from pathlib import Path
+          import re
+
+          envelope = json.loads(os.environ["CLIENT_PAYLOAD_JSON"])
+          envelope_keys = {"schema", "claim", "agent_invocation_key"}
+          claim_keys = {
+              "actor",
+              "agent",
+              "base_branch",
+              "base_sha",
+              "comment_id",
+              "enable_auto_merge",
+              "head_sha",
+              "merge_mode",
+              "pr_number",
+              "repository",
+              "review_dispatch_limit",
+              "trigger_reviews",
+              "update_branches",
+          }
+          if not isinstance(envelope, dict) or set(envelope) != envelope_keys:
+              raise SystemExit("invalid OpenCode invocation envelope")
+          claim = envelope["claim"]
+          if not isinstance(claim, dict):
+              raise SystemExit("OpenCode invocation claim must be an object")
+          if envelope["schema"] != "cwl.agent-invocation/v2":
+              raise SystemExit("unsupported OpenCode invocation schema")
+          if envelope["schema"] != os.environ["PAYLOAD_SCHEMA"]:
+              raise SystemExit("OpenCode invocation schema context mismatch")
+          if envelope["agent_invocation_key"] != os.environ["INVOCATION_KEY"]:
+              raise SystemExit("OpenCode invocation key context mismatch")
+          if set(claim) != claim_keys:
+              raise SystemExit("invalid OpenCode invocation claim fields")
+
+          text_fields = {
+              "actor",
+              "agent",
+              "base_branch",
+              "base_sha",
+              "head_sha",
+              "merge_mode",
+              "repository",
+              "review_dispatch_limit",
+          }
+          if any(not isinstance(claim[field], str) for field in text_fields):
+              raise SystemExit("OpenCode invocation claim has a non-string text field")
+          if type(claim["comment_id"]) is not int or claim["comment_id"] < 1:
+              raise SystemExit("OpenCode invocation claim has an invalid comment id")
+          if type(claim["pr_number"]) is not int or claim["pr_number"] < 1:
+              raise SystemExit("OpenCode invocation claim has an invalid pull request number")
+          for field in ("enable_auto_merge", "trigger_reviews", "update_branches"):
+              if type(claim[field]) is not bool:
+                  raise SystemExit(f"OpenCode invocation claim has an invalid {field} flag")
+          if not re.fullmatch(r"ContextualWisdomLab/[A-Za-z0-9_.-]+", claim["repository"]):
+              raise SystemExit("OpenCode invocation claim has an invalid repository")
+          if not re.fullmatch(r"[0-9a-f]{40}", claim["head_sha"]):
+              raise SystemExit("OpenCode invocation claim has an invalid head SHA")
+          if not re.fullmatch(r"[0-9a-f]{40}", claim["base_sha"]):
+              raise SystemExit("OpenCode invocation claim has an invalid base SHA")
+          if (
+              not re.fullmatch(r"[A-Za-z0-9._/-]+", claim["base_branch"])
+              or claim["base_branch"].startswith("-")
+          ):
+              raise SystemExit("OpenCode invocation claim has an invalid base branch")
+          if not re.fullmatch(r"[A-Za-z0-9-]+", claim["actor"]):
+              raise SystemExit("OpenCode invocation claim has an invalid actor")
+          expected_policy = {
+              "agent": "opencode-agent",
+              "enable_auto_merge": False,
+              "merge_mode": "disabled",
+              "review_dispatch_limit": "1",
+              "trigger_reviews": True,
+              "update_branches": False,
+          }
+          if any(claim[field] != value for field, value in expected_policy.items()):
+              raise SystemExit("OpenCode invocation claim violates review-only policy")
 
           canonical = json.dumps(
-              {
-                  "actor": os.environ["REQUESTED_BY"],
-                  "agent": os.environ["REQUESTED_AGENT"],
-                  "base_branch": os.environ["BASE_BRANCH"],
-                  "base_sha": os.environ["PR_BASE_SHA"],
-                  "comment_id": int(os.environ["SOURCE_COMMENT_ID"]),
-                  "enable_auto_merge": os.environ["ENABLE_AUTO_MERGE"] == "true",
-                  "head_sha": os.environ["PR_HEAD_SHA"],
-                  "merge_mode": os.environ["MERGE_MODE"],
-                  "pr_number": int(os.environ["PR_NUMBER"]),
-                  "repository": os.environ["TARGET_REPOSITORY"],
-                  "review_dispatch_limit": os.environ["REVIEW_DISPATCH_LIMIT"],
-                  "trigger_reviews": os.environ["TRIGGER_REVIEWS"] == "true",
-                  "update_branches": os.environ["UPDATE_BRANCHES"] == "true",
-              },
+              claim,
               ensure_ascii=True,
               separators=(",", ":"),
               sort_keys=True,
@@ -93,6 +130,41 @@ jobs:
           expected = hashlib.sha256(canonical).hexdigest()
           if not hmac.compare_digest(expected, os.environ["INVOCATION_KEY"]):
               raise SystemExit("invocation key does not match canonical payload")
+
+          scheduler_request = {
+              "event_type": "merge-scheduler-agent-review-v2",
+              "client_payload": envelope,
+          }
+          encoded_request = json.dumps(
+              scheduler_request,
+              ensure_ascii=True,
+              separators=(",", ":"),
+              sort_keys=True,
+          ).encode("utf-8")
+          if len(envelope) > 10 or len(encoded_request) > 65_535:
+              raise SystemExit("scheduler repository dispatch exceeds GitHub limits")
+
+          request_path = Path(os.environ["RUNNER_TEMP"]) / "agent-review-scheduler-request.json"
+          request_path.write_bytes(encoded_request)
+          exports = {
+              "BASE_BRANCH": claim["base_branch"],
+              "ENABLE_AUTO_MERGE": str(claim["enable_auto_merge"]).lower(),
+              "MERGE_MODE": claim["merge_mode"],
+              "PR_BASE_SHA": claim["base_sha"],
+              "PR_HEAD_SHA": claim["head_sha"],
+              "PR_NUMBER": str(claim["pr_number"]),
+              "REQUESTED_AGENT": claim["agent"],
+              "REQUESTED_BY": claim["actor"],
+              "REVIEW_DISPATCH_LIMIT": claim["review_dispatch_limit"],
+              "SCHEDULER_REQUEST_FILE": str(request_path),
+              "SOURCE_COMMENT_ID": str(claim["comment_id"]),
+              "TARGET_REPOSITORY": claim["repository"],
+              "TRIGGER_REVIEWS": str(claim["trigger_reviews"]).lower(),
+              "UPDATE_BRANCHES": str(claim["update_branches"]).lower(),
+          }
+          with Path(os.environ["GITHUB_ENV"]).open("a", encoding="utf-8") as handle:
+              for name, value in exports.items():
+                  handle.write(f"{name}={value}\n")
           PYTHON
 
       - name: Inspect exact-name Actions artifact ledger
@@ -189,33 +261,6 @@ jobs:
         if: steps.ledger.outputs.claim == 'true'
         run: |
           set -euo pipefail
-          jq -n \
-            --arg target_repository "$TARGET_REPOSITORY" \
-            --argjson pr_number "$PR_NUMBER" \
-            --arg pr_head_sha "$PR_HEAD_SHA" \
-            --arg pr_base_sha "$PR_BASE_SHA" \
-            --arg base_branch "$BASE_BRANCH" \
-            --arg requested_agent "$REQUESTED_AGENT" \
-            --arg agent_invocation_key "$INVOCATION_KEY" \
-            --arg requested_by "$REQUESTED_BY" \
-            --argjson source_comment_id "$SOURCE_COMMENT_ID" \
-            '{
-              event_type: "merge-scheduler",
-              client_payload: {
-                target_repository: $target_repository,
-                pr_number: $pr_number,
-                pr_head_sha: $pr_head_sha,
-                pr_base_sha: $pr_base_sha,
-                base_branch: $base_branch,
-                trigger_reviews: true,
-                review_dispatch_limit: "1",
-                enable_auto_merge: false,
-                update_branches: false,
-                merge_mode: "disabled",
-                requested_agent: $requested_agent,
-                agent_invocation_key: $agent_invocation_key,
-                requested_by: $requested_by,
-                source_comment_id: $source_comment_id
-              }
-            }' \
-            | gh api "repos/${GITHUB_REPOSITORY}/dispatches" -X POST --input -
+          gh api "repos/${GITHUB_REPOSITORY}/dispatches" \
+            -X POST \
+            --input "$SCHEDULER_REQUEST_FILE"
diff --git a/.github/workflows/agent-mention-router-quality-ci.yml b/.github/workflows/agent-mention-router-quality-ci.yml
index f69cdce10..7492b7671 100644
--- a/.github/workflows/agent-mention-router-quality-ci.yml
+++ b/.github/workflows/agent-mention-router-quality-ci.yml
@@ -8,11 +8,21 @@ on:
       - ".github/workflows/agent-mention-router-quality-ci.yml"
       - ".github/workflows/agent-mention-noema-dispatch.yml"
       - ".github/workflows/agent-mention-opencode-dispatch.yml"
+      - ".github/workflows/opencode-review-dispatch.yml"
+      - ".github/workflows/pr-review-merge-scheduler.yml"
+      - ".github/workflows/strix.yml"
       - "docs/automation/review-agent-comment-invocation.md"
       - "scripts/ci/agent_mention_router.py"
       - "scripts/ci/agent_mention_sweep.py"
+      - "scripts/ci/pr_review_fix_scheduler.py"
+      - "scripts/ci/pr_review_merge_scheduler.py"
+      - "scripts/ci/test_strix_quick_gate.sh"
       - "tests/test_agent_mention_*.py"
+      - "tests/test_opencode_agent_contract.py"
+      - "tests/test_opencode_workflow_shell_syntax.py"
+      - "tests/test_pr_review_merge_scheduler.py"
       - "tests/test_pr_review_fix_scheduler_coverage.py"
+      - "tests/test_required_workflow_queue_contract.py"
       - "requirements-opencode-review-ci-hashes.txt"
   push:
     branches: [main]
@@ -21,11 +31,21 @@ on:
       - ".github/workflows/agent-mention-router-quality-ci.yml"
       - ".github/workflows/agent-mention-noema-dispatch.yml"
       - ".github/workflows/agent-mention-opencode-dispatch.yml"
+      - ".github/workflows/opencode-review-dispatch.yml"
+      - ".github/workflows/pr-review-merge-scheduler.yml"
+      - ".github/workflows/strix.yml"
       - "docs/automation/review-agent-comment-invocation.md"
       - "scripts/ci/agent_mention_router.py"
       - "scripts/ci/agent_mention_sweep.py"
+      - "scripts/ci/pr_review_fix_scheduler.py"
+      - "scripts/ci/pr_review_merge_scheduler.py"
+      - "scripts/ci/test_strix_quick_gate.sh"
       - "tests/test_agent_mention_*.py"
+      - "tests/test_opencode_agent_contract.py"
+      - "tests/test_opencode_workflow_shell_syntax.py"
+      - "tests/test_pr_review_merge_scheduler.py"
       - "tests/test_pr_review_fix_scheduler_coverage.py"
+      - "tests/test_required_workflow_queue_contract.py"
       - "requirements-opencode-review-ci-hashes.txt"
 
 concurrency:
@@ -99,6 +119,8 @@ jobs:
           include =
               scripts/ci/agent_mention_router.py
               scripts/ci/agent_mention_sweep.py
+              scripts/ci/pr_review_fix_scheduler.py
+              scripts/ci/pr_review_merge_scheduler.py
           [report]
           fail_under = 100
           show_missing = True
@@ -109,6 +131,8 @@ jobs:
           python -m coverage report --fail-under=100
           python -m interrogate --fail-under=100 \
             scripts/ci/agent_mention_router.py \
-            scripts/ci/agent_mention_sweep.py
+            scripts/ci/agent_mention_sweep.py \
+            scripts/ci/pr_review_fix_scheduler.py \
+            scripts/ci/pr_review_merge_scheduler.py
           python -m compileall -q scripts/ci tests
           git diff --check "$CHANGE_DIFF_RANGE"
diff --git a/.github/workflows/pr-review-merge-scheduler.yml b/.github/workflows/pr-review-merge-scheduler.yml
index 8e1157060..0520a555b 100644
--- a/.github/workflows/pr-review-merge-scheduler.yml
+++ b/.github/workflows/pr-review-merge-scheduler.yml
@@ -84,7 +84,7 @@ on:
     # within ~15 minutes instead of sitting idle for up to an hour.
     - cron: "*/15 * * * *"
   repository_dispatch:
-    types: [merge-scheduler]
+    types: [merge-scheduler, merge-scheduler-agent-review-v2]
 
 concurrency:
   group: >-
@@ -95,8 +95,10 @@ concurrency:
     github.event_name == 'workflow_call' && inputs.pr_number != '' && format('pr-{0}', inputs.pr_number) ||
     github.event_name == 'workflow_call' && inputs.base_branch != '' && format('call-{0}', inputs.base_branch) ||
     github.event_name == 'schedule' && format('schedule-{0}', github.event.schedule) ||
-    github.event_name == 'repository_dispatch' && github.event.client_payload.target_repository != '' && github.event.client_payload.pr_number != '' && format('target-{0}-pr-{1}', github.event.client_payload.target_repository, github.event.client_payload.pr_number) ||
-    github.event_name == 'repository_dispatch' && github.event.client_payload.pr_number != '' && format('pr-{0}', github.event.client_payload.pr_number) ||
+    github.event_name == 'repository_dispatch' && github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.agent_invocation_key != '' && format('agent-review-{0}', github.event.client_payload.agent_invocation_key) ||
+    github.event_name == 'repository_dispatch' && github.event.action == 'merge-scheduler-agent-review-v2' && github.run_id ||
+    github.event_name == 'repository_dispatch' && github.event.action != 'merge-scheduler-agent-review-v2' && github.event.client_payload.target_repository != '' && github.event.client_payload.pr_number != '' && format('target-{0}-pr-{1}', github.event.client_payload.target_repository, github.event.client_payload.pr_number) ||
+    github.event_name == 'repository_dispatch' && github.event.action != 'merge-scheduler-agent-review-v2' && github.event.client_payload.pr_number != '' && format('pr-{0}', github.event.client_payload.pr_number) ||
     github.event_name == 'repository_dispatch' && github.run_id ||
     github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request_target' || github.event_name == 'pull_request_review' || github.event_name == 'repository_dispatch' }}
@@ -150,17 +152,17 @@ jobs:
     env:
       FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: true
       GH_TOKEN: ${{ github.token }}
-      DEFAULT_BRANCH: ${{ github.event.client_payload.base_branch || inputs.base_branch || github.event.repository.default_branch }}
+      DEFAULT_BRANCH: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.base_branch || github.event.client_payload.base_branch || inputs.base_branch || github.event.repository.default_branch }}
       DRY_RUN: ${{ github.event.client_payload.dry_run == true || inputs.dry_run == true }}
       MAX_PRS: ${{ github.event.client_payload.max_prs || inputs.max_prs || '100' }}
       PROJECT_FLOW_INPUT: ${{ github.event.client_payload.project_flow || inputs.project_flow || vars.PROJECT_FLOW || '' }}
-      PULL_REQUEST_NUMBER: ${{ github.event.pull_request.number || github.event.workflow_run.pull_requests[0].number || github.event.client_payload.pr_number || inputs.pr_number || '' }}
-      TRIGGER_REVIEWS: ${{ github.event_name == 'schedule' || github.event_name == 'workflow_run' || github.event_name == 'push' || github.event_name == 'pull_request_target' || (github.event_name == 'repository_dispatch' && github.event.client_payload.trigger_reviews != false) || inputs.trigger_reviews == true }}
-      REVIEW_DISPATCH_LIMIT_INPUT: ${{ github.event.client_payload.review_dispatch_limit || inputs.review_dispatch_limit || vars.REVIEW_DISPATCH_LIMIT || '1' }}
+      PULL_REQUEST_NUMBER: ${{ github.event.pull_request.number || github.event.workflow_run.pull_requests[0].number || github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.pr_number || github.event.client_payload.pr_number || inputs.pr_number || '' }}
+      TRIGGER_REVIEWS: ${{ github.event_name == 'schedule' || github.event_name == 'workflow_run' || github.event_name == 'push' || github.event_name == 'pull_request_target' || (github.event_name == 'repository_dispatch' && github.event.action == 'merge-scheduler-agent-review-v2') || (github.event_name == 'repository_dispatch' && github.event.action != 'merge-scheduler-agent-review-v2' && github.event.client_payload.trigger_reviews != false) || inputs.trigger_reviews == true }}
+      REVIEW_DISPATCH_LIMIT_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && '1' || github.event.client_payload.review_dispatch_limit || inputs.review_dispatch_limit || vars.REVIEW_DISPATCH_LIMIT || '1' }}
       BRANCH_UPDATE_LIMIT_INPUT: ${{ github.event.client_payload.branch_update_limit || inputs.branch_update_limit || vars.BRANCH_UPDATE_LIMIT || '1' }}
-      ENABLE_AUTO_MERGE: ${{ github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'pull_request_target' || github.event_name == 'workflow_run' || (github.event_name == 'repository_dispatch' && github.event.client_payload.enable_auto_merge != false) || inputs.enable_auto_merge == true }}
-      MERGE_MODE: ${{ github.event.client_payload.merge_mode || inputs.merge_mode || vars.PR_MERGE_MODE || 'direct_or_auto' }}
-      UPDATE_BRANCHES: ${{ github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'pull_request_target' || github.event_name == 'workflow_run' || (github.event_name == 'repository_dispatch' && github.event.client_payload.update_branches != false) || inputs.update_branches == true }}
+      ENABLE_AUTO_MERGE: ${{ github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'pull_request_target' || github.event_name == 'workflow_run' || (github.event_name == 'repository_dispatch' && github.event.action != 'merge-scheduler-agent-review-v2' && github.event.client_payload.enable_auto_merge != false) || inputs.enable_auto_merge == true }}
+      MERGE_MODE: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && 'disabled' || github.event.client_payload.merge_mode || inputs.merge_mode || vars.PR_MERGE_MODE || 'direct_or_auto' }}
+      UPDATE_BRANCHES: ${{ github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'pull_request_target' || github.event_name == 'workflow_run' || (github.event_name == 'repository_dispatch' && github.event.action != 'merge-scheduler-agent-review-v2' && github.event.client_payload.update_branches != false) || inputs.update_branches == true }}
       STALE_OPENCODE_MINUTES: ${{ github.event.client_payload.stale_opencode_minutes || inputs.stale_opencode_minutes || vars.STALE_OPENCODE_MINUTES || '90' }}
     steps:
       - name: Exchange OpenCode app token for scheduler mutations
@@ -233,13 +235,124 @@ jobs:
         id: targeted_dispatch
         env:
           GH_TOKEN: ${{ secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token || github.token }}
-          TARGET_REPOSITORY_INPUT: ${{ github.event.client_payload.target_repository || '' }}
-          TARGET_PR_NUMBER: ${{ github.event.client_payload.pr_number || '' }}
-          TARGET_BASE_BRANCH_INPUT: ${{ github.event.client_payload.base_branch || '' }}
+          DISPATCH_CLIENT_PAYLOAD_JSON: ${{ toJSON(github.event.client_payload) }}
+          GITHUB_EVENT_ACTION: ${{ github.event.action || '' }}
+          TARGET_REPOSITORY_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.repository || github.event.client_payload.target_repository || '' }}
+          TARGET_PR_NUMBER: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.pr_number || github.event.client_payload.pr_number || '' }}
+          TARGET_BASE_BRANCH_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.base_branch || github.event.client_payload.base_branch || '' }}
+          TARGET_EXPECTED_BASE_BRANCH_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.base_branch || '' }}
+          TARGET_HEAD_SHA_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.head_sha || '' }}
+          TARGET_BASE_SHA_INPUT: ${{ github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.base_sha || '' }}
           ALLOWED_TARGET_REPOSITORIES: ${{ vars.OPENCODE_REPOSITORY_DISPATCH_TARGETS }}
         run: |
           set -euo pipefail
 
+          EXPECTED_SCHEMA="cwl.agent-invocation/v2"
+          export EXPECTED_SCHEMA
+          python3 - <<'PYTHON'
+          import hashlib
+          import hmac
+          import json
+          import os
+          import re
+
+          envelope = json.loads(os.environ["DISPATCH_CLIENT_PAYLOAD_JSON"] or "null")
+          if envelope is None:
+              envelope = {}
+          if not isinstance(envelope, dict):
+              raise SystemExit("repository dispatch client_payload must be an object")
+          is_agent_review = (
+              os.environ["GITHUB_EVENT_ACTION"] == "merge-scheduler-agent-review-v2"
+          )
+          if not is_agent_review:
+              if "schema" in envelope or "claim" in envelope:
+                  raise SystemExit(
+                      "versioned scheduler payload cannot use the legacy merge-scheduler event"
+                  )
+              raise SystemExit(0)
+
+          envelope_keys = {"schema", "claim", "agent_invocation_key"}
+          claim_keys = {
+              "actor",
+              "agent",
+              "base_branch",
+              "base_sha",
+              "comment_id",
+              "enable_auto_merge",
+              "head_sha",
+              "merge_mode",
+              "pr_number",
+              "repository",
+              "review_dispatch_limit",
+              "trigger_reviews",
+              "update_branches",
+          }
+          if set(envelope) != envelope_keys:
+              raise SystemExit("invalid agent-review scheduler envelope fields")
+          if envelope["schema"] != os.environ["EXPECTED_SCHEMA"]:
+              raise SystemExit("unsupported agent-review scheduler schema")
+          invocation_key = envelope["agent_invocation_key"]
+          if not isinstance(invocation_key, str) or not re.fullmatch(
+              r"[0-9a-f]{64}", invocation_key
+          ):
+              raise SystemExit("invalid agent-review scheduler invocation key")
+          claim = envelope["claim"]
+          if not isinstance(claim, dict) or set(claim) != claim_keys:
+              raise SystemExit("invalid agent-review scheduler claim fields")
+
+          text_fields = {
+              "actor",
+              "agent",
+              "base_branch",
+              "base_sha",
+              "head_sha",
+              "merge_mode",
+              "repository",
+              "review_dispatch_limit",
+          }
+          if any(not isinstance(claim[field], str) for field in text_fields):
+              raise SystemExit("agent-review scheduler claim has a non-string text field")
+          if type(claim["comment_id"]) is not int or claim["comment_id"] < 1:
+              raise SystemExit("agent-review scheduler claim has an invalid comment id")
+          if type(claim["pr_number"]) is not int or claim["pr_number"] < 1:
+              raise SystemExit("agent-review scheduler claim has an invalid PR number")
+          for field in ("enable_auto_merge", "trigger_reviews", "update_branches"):
+              if type(claim[field]) is not bool:
+                  raise SystemExit(f"agent-review scheduler claim has an invalid {field} flag")
+          if not re.fullmatch(r"ContextualWisdomLab/[A-Za-z0-9_.-]+", claim["repository"]):
+              raise SystemExit("agent-review scheduler claim has an invalid repository")
+          if not re.fullmatch(r"[0-9a-f]{40}", claim["head_sha"]):
+              raise SystemExit("agent-review scheduler claim has an invalid head SHA")
+          if not re.fullmatch(r"[0-9a-f]{40}", claim["base_sha"]):
+              raise SystemExit("agent-review scheduler claim has an invalid base SHA")
+          if (
+              not re.fullmatch(r"[A-Za-z0-9._/-]+", claim["base_branch"])
+              or claim["base_branch"].startswith("-")
+          ):
+              raise SystemExit("agent-review scheduler claim has an invalid base branch")
+          if not re.fullmatch(r"[A-Za-z0-9-]+", claim["actor"]):
+              raise SystemExit("agent-review scheduler claim has an invalid actor")
+          expected_policy = {
+              "agent": "opencode-agent",
+              "enable_auto_merge": False,
+              "merge_mode": "disabled",
+              "review_dispatch_limit": "1",
+              "trigger_reviews": True,
+              "update_branches": False,
+          }
+          if any(claim[field] != value for field, value in expected_policy.items()):
+              raise SystemExit("agent-review scheduler claim violates review-only policy")
+          canonical = json.dumps(
+              claim,
+              ensure_ascii=True,
+              separators=(",", ":"),
+              sort_keys=True,
+          ).encode("utf-8")
+          expected_key = hashlib.sha256(canonical).hexdigest()
+          if not hmac.compare_digest(expected_key, invocation_key):
+              raise SystemExit("agent-review scheduler invocation key mismatch")
+          PYTHON
+
           if [ -z "$TARGET_REPOSITORY_INPUT" ]; then
             {
               printf 'repository=%s\n' "$GITHUB_REPOSITORY"
@@ -280,14 +393,16 @@ jobs:
           live_base_repository="$(jq -r '.base.repo.full_name // empty' <<<"$pull_json")"
           live_head_repository="$(jq -r '.head.repo.full_name // empty' <<<"$pull_json")"
           live_base_branch="$(jq -r '.base.ref // empty' <<<"$pull_json")"
+          live_base_sha="$(jq -r '.base.sha // empty' <<<"$pull_json")"
           live_head_sha="$(jq -r '.head.sha // empty' <<<"$pull_json")"
           if [ "$live_number" != "$TARGET_PR_NUMBER" ] ||
             [ "$live_state" != "open" ] ||
             [ "$live_base_repository" != "$TARGET_REPOSITORY_INPUT" ] ||
             [ "$live_head_repository" != "$TARGET_REPOSITORY_INPUT" ] ||
             [ -z "$live_base_branch" ] ||
+            ! [[ "$live_base_sha" =~ ^[0-9a-fA-F]{40}$ ]] ||
             ! [[ "$live_head_sha" =~ ^[0-9a-fA-F]{40}$ ]]; then
-            printf '::error::Targeted scheduler dispatch rejected closed, cross-repository, or malformed live PR metadata. target=%s pr=%s state=%s base_repository=%s head_repository=%s base_branch=%s head_sha=%s\n' "$TARGET_REPOSITORY_INPUT" "$TARGET_PR_NUMBER" "${live_state:-<missing>}" "${live_base_repository:-<missing>}" "${live_head_repository:-<missing>}" "${live_base_branch:-<missing>}" "${live_head_sha:-<missing>}"
+            printf '::error::Targeted scheduler dispatch rejected closed, cross-repository, or malformed live PR metadata. target=%s pr=%s state=%s base_repository=%s head_repository=%s base_branch=%s base_sha=%s head_sha=%s\n' "$TARGET_REPOSITORY_INPUT" "$TARGET_PR_NUMBER" "${live_state:-<missing>}" "${live_base_repository:-<missing>}" "${live_head_repository:-<missing>}" "${live_base_branch:-<missing>}" "${live_base_sha:-<missing>}" "${live_head_sha:-<missing>}"
             exit 1
           fi
           if [ -n "$TARGET_BASE_BRANCH_INPUT" ] &&
@@ -295,13 +410,27 @@ jobs:
             printf '::error::Targeted scheduler dispatch base branch does not match the live PR. supplied=%s live=%s\n' "$TARGET_BASE_BRANCH_INPUT" "$live_base_branch"
             exit 1
           fi
+          if [ "$GITHUB_EVENT_ACTION" = "merge-scheduler-agent-review-v2" ] &&
+            [ "$TARGET_HEAD_SHA_INPUT" != "$live_head_sha" ]; then
+            printf '::error::Agent-review scheduler dispatch head SHA changed before execution. supplied=%s live=%s\n' "$TARGET_HEAD_SHA_INPUT" "$live_head_sha"
+            exit 1
+          fi
+          if [ "$GITHUB_EVENT_ACTION" = "merge-scheduler-agent-review-v2" ] &&
+            [ "$TARGET_BASE_SHA_INPUT" != "$live_base_sha" ]; then
+            printf '::error::Agent-review scheduler dispatch base SHA changed before execution. supplied=%s live=%s\n' "$TARGET_BASE_SHA_INPUT" "$live_base_sha"
+            exit 1
+          fi
 
           {
             printf 'repository=%s\n' "$TARGET_REPOSITORY_INPUT"
             printf 'base_branch=%s\n' "$live_base_branch"
+            printf 'base_sha=%s\n' "$live_base_sha"
             printf 'head_sha=%s\n' "$live_head_sha"
+            printf 'expected_base_sha=%s\n' "$TARGET_BASE_SHA_INPUT"
+            printf 'expected_head_sha=%s\n' "$TARGET_HEAD_SHA_INPUT"
+            printf 'expected_base_branch=%s\n' "$TARGET_EXPECTED_BASE_BRANCH_INPUT"
           } >>"$GITHUB_OUTPUT"
-          printf 'Validated exact targeted scheduler dispatch for %s#%s at %s on base %s.\n' "$TARGET_REPOSITORY_INPUT" "$TARGET_PR_NUMBER" "$live_head_sha" "$live_base_branch"
+          printf 'Validated exact targeted scheduler dispatch for %s#%s at %s on base %s@%s.\n' "$TARGET_REPOSITORY_INPUT" "$TARGET_PR_NUMBER" "$live_head_sha" "$live_base_branch" "$live_base_sha"
 
       - name: Resolve trusted scheduler source ref
         id: trusted_source
@@ -483,14 +612,17 @@ jobs:
           GH_TOKEN: ${{ secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token || github.token }}
           TARGET_REPOSITORY: ${{ steps.targeted_dispatch.outputs.repository }}
           TARGET_DEFAULT_BRANCH: ${{ steps.targeted_dispatch.outputs.base_branch }}
-          SCHEDULER_ACTIONS_TOKEN: ${{ github.event_name == 'repository_dispatch' && github.event.client_payload.target_repository != '' && (secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token) || github.token }}
+          EXPECTED_HEAD_SHA: ${{ steps.targeted_dispatch.outputs.expected_head_sha || '' }}
+          EXPECTED_BASE_SHA: ${{ steps.targeted_dispatch.outputs.expected_base_sha || '' }}
+          EXPECTED_BASE_BRANCH: ${{ steps.targeted_dispatch.outputs.expected_base_branch || '' }}
+          SCHEDULER_ACTIONS_TOKEN: ${{ github.event_name == 'repository_dispatch' && (github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.repository != '' || github.event.client_payload.target_repository != '') && (secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token) || github.token }}
           # Same-repository dispatch credential: when this scheduler runs inside
           # ContextualWisdomLab/.github (the repository the required workflows are
           # dispatched on), the runner token can dispatch them without any
           # cross-repository PAT. The scheduler only uses it when
           # GITHUB_REPOSITORY equals the dispatch repository.
           SCHEDULER_DISPATCH_TOKEN: ${{ github.token }}
-          SCHEDULER_READ_TOKEN: ${{ github.event_name == 'repository_dispatch' && github.event.client_payload.target_repository != '' && (secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token) || github.token }}
+          SCHEDULER_READ_TOKEN: ${{ github.event_name == 'repository_dispatch' && (github.event.action == 'merge-scheduler-agent-review-v2' && github.event.client_payload.claim.repository != '' || github.event.client_payload.target_repository != '') && (secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || steps.scheduler_app_token.outputs.token) || github.token }}
           SCHEDULER_MUTATION_TOKEN_SOURCE: ${{ secrets.PR_REVIEW_MERGE_TOKEN != '' && 'PR_REVIEW_MERGE_TOKEN' || secrets.OPENCODE_APPROVE_TOKEN != '' && 'OPENCODE_APPROVE_TOKEN' || steps.scheduler_app_token.outputs.available == 'true' && 'opencode-app' || 'github-token' }}
           SCHEDULER_REQUIRED_WORKFLOW_REPOSITORY: ContextualWisdomLab/.github
           SCHEDULER_ALLOW_CROSS_REPO_REPOSITORY_DISPATCH: ${{ (secrets.PR_REVIEW_MERGE_TOKEN != '' || secrets.OPENCODE_APPROVE_TOKEN != '') && 'true' || 'false' }}
@@ -525,6 +657,13 @@ jobs:
           if [ -n "$PULL_REQUEST_NUMBER" ]; then
             args+=(--pr-number "$PULL_REQUEST_NUMBER")
           fi
+          if [ -n "$EXPECTED_HEAD_SHA" ] || [ -n "$EXPECTED_BASE_SHA" ] || [ -n "$EXPECTED_BASE_BRANCH" ]; then
+            args+=(
+              --expected-head-sha "$EXPECTED_HEAD_SHA"
+              --expected-base-sha "$EXPECTED_BASE_SHA"
+              --expected-base-branch "$EXPECTED_BASE_BRANCH"
+            )
+          fi
           if [ "$DRY_RUN" = "true" ]; then
             args+=(--dry-run)
           fi
diff --git a/.github/workflows/repair-agent-dispatch-envelope-v2-clean.yml b/.github/workflows/repair-agent-dispatch-envelope-v2-clean.yml
new file mode 100644
index 000000000..fb7d770ff
--- /dev/null
+++ b/.github/workflows/repair-agent-dispatch-envelope-v2-clean.yml
@@ -0,0 +1,82 @@
+name: Repair agent dispatch envelope clean successor
+
+on:
+  push:
+    branches:
+      - fix/agent-mention-dispatch-envelope-v2-clean
+
+permissions:
+  contents: write
+
+concurrency:
+  group: repair-agent-dispatch-envelope-v2-clean
+  cancel-in-progress: false
+
+jobs:
+  repair:
+    if: github.actor != 'github-actions[bot]'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
+        with:
+          ref: fix/agent-mention-dispatch-envelope-v2-clean
+          fetch-depth: 0
+          persist-credentials: true
+      - name: Apply bounded compatibility repair and self-delete
+        shell: bash
+        run: |
+          set -euo pipefail
+          git fetch --no-tags origin main
+          git show origin/main:tests/test_required_workflow_queue_contract.py > tests/test_required_workflow_queue_contract.py
+          python3 - <<'PYTHON'
+          from pathlib import Path
+
+          workflow_path = Path('.github/workflows/pr-review-merge-scheduler.yml')
+          workflow = workflow_path.read_text(encoding='utf-8')
+          replacements = {
+              'os.environ["DISPATCH_CLIENT_PAYLOAD_JSON"] or "null"':
+                  'os.environ.get("DISPATCH_CLIENT_PAYLOAD_JSON") or "null"',
+              'os.environ["GITHUB_EVENT_ACTION"] == "merge-scheduler-agent-review-v2"':
+                  'os.environ.get("GITHUB_EVENT_ACTION", "") == "merge-scheduler-agent-review-v2"',
+          }
+          for old, new in replacements.items():
+              if workflow.count(old) != 1:
+                  raise SystemExit(f'expected exactly one workflow occurrence: {old}')
+              workflow = workflow.replace(old, new, 1)
+          workflow_path.write_text(workflow, encoding='utf-8')
+
+          test_path = Path('tests/test_opencode_agent_contract.py')
+          test_source = test_path.read_text(encoding='utf-8')
+          old = '''    assert (
+        "SCHEDULER_READ_TOKEN: ${{ github.event_name == 'repository_dispatch' "
+        "&& github.event.client_payload.target_repository != '' && "
+        "(secrets.PR_REVIEW_MERGE_TOKEN || "
+        "secrets.OPENCODE_APPROVE_TOKEN || "
+        "steps.scheduler_app_token.outputs.token) || github.token }}"
+        in workflow
+    )
+'''
+          new = '''    read_token_line = next(
+        line.strip()
+        for line in workflow.splitlines()
+        if line.strip().startswith("SCHEDULER_READ_TOKEN:")
+    )
+    assert "github.event.action == 'merge-scheduler-agent-review-v2'" in read_token_line
+    assert "github.event.client_payload.claim.repository != ''" in read_token_line
+    assert "github.event.client_payload.target_repository != ''" in read_token_line
+    assert "secrets.PR_REVIEW_MERGE_TOKEN" in read_token_line
+    assert "secrets.OPENCODE_APPROVE_TOKEN" in read_token_line
+    assert "steps.scheduler_app_token.outputs.token" in read_token_line
+    assert read_token_line.endswith("|| github.token }}")
+'''
+          if test_source.count(old) != 1:
+              raise SystemExit('expected exactly one scheduler read-token assertion block')
+          test_path.write_text(test_source.replace(old, new, 1), encoding='utf-8')
+          PYTHON
+          rm .github/workflows/repair-agent-dispatch-envelope-v2-clean.yml
+          git diff --check
+          git config user.name github-actions[bot]
+          git config user.email 41898282+github-actions[bot]@users.noreply.github.com
+          git add .github/workflows/pr-review-merge-scheduler.yml tests/test_opencode_agent_contract.py tests/test_required_workflow_queue_contract.py .github/workflows/repair-agent-dispatch-envelope-v2-clean.yml
+          git commit -m "fix(automation): preserve legacy scheduler test contracts"
+          git push origin HEAD:fix/agent-mention-dispatch-envelope-v2-clean
diff --git a/docs/doctoring/agent-mention-dispatch-envelope.md b/docs/doctoring/agent-mention-dispatch-envelope.md
new file mode 100644
index 000000000..ae01b16b2
--- /dev/null
+++ b/docs/doctoring/agent-mention-dispatch-envelope.md
@@ -0,0 +1,93 @@
+# Agent-mention repository-dispatch envelope
+
+## Decision
+
+Mention-triggered OpenCode review uses the versioned envelope
+`cwl.agent-invocation/v2` with exactly three top-level properties:
+
+```json
+{
+  "schema": "cwl.agent-invocation/v2",
+  "claim": {
+    "repository": "ContextualWisdomLab/example",
+    "pr_number": 17,
+    "head_sha": "<40-hex>",
+    "base_sha": "<40-hex>",
+    "base_branch": "main",
+    "actor": "maintainer",
+    "requested_agent": "opencode-agent",
+    "source_comment_id": 91,
+    "merge_mode": "disabled",
+    "trigger_reviews": true,
+    "update_branches": false,
+    "enable_auto_merge": false,
+    "review_dispatch_limit": 1
+  },
+  "agent_invocation_key": "<sha256-of-canonical-claim>"
+}
+```
+
+GitHub repository dispatch limits `client_payload` to ten top-level properties
+and 65,535 characters. The earlier flat payload used fourteen properties and
+was rejected with HTTP 422 before the review scheduler could run. Nesting the
+complete immutable claim preserves the invocation and artifact-ledger identity
+while keeping the transport within GitHub's contract.
+
+## Trust boundary
+
+The producer, wrapper, and authoritative scheduler independently validate:
+
+- the exact envelope and claim property sets;
+- primitive value types and bounded lengths;
+- the canonical SHA-256 invocation key;
+- the CWL repository allowlist;
+- open pull-request state;
+- exact live head SHA, base SHA, and base branch;
+- review-only policy with branch updates, auto-merge, and merging disabled;
+- serialized ledger acquisition before forwarding;
+- a distinct event type for the versioned path so it cannot fall through the
+  legacy scheduler payload.
+
+The second hop reuses the exact validated three-property envelope. It does not
+reconstruct a new flat payload from environment variables. Versioned stale
+claims receive a per-invocation concurrency identity and cannot cancel a newer
+review request. The legacy `merge-scheduler` path remains explicit for existing
+non-mention callers.
+
+A reaction placed on the source comment is only user-interface feedback. A
+permission failure after the durable repository dispatch does not invalidate or
+repeat the queued review; it is emitted as a warning.
+
+## Test-first evidence
+
+The clean successor PR records a tests-only RED commit before production
+changes. Hosted quality evidence on that exact head reports nineteen focused
+failures and 1,116 existing passes, including the fourteen-property payload,
+missing producer size check, absent wrapper and scheduler validation, missing
+quality-gate scope, and reaction-denial propagation.
+
+The regression corpus executes extracted workflow validators, malformed and
+policy-violating envelopes, valid and legacy scheduler paths, exact invocation
+key binding, downstream idempotency, live-ref authority, and full
+statement/branch/docstring quality gates.
+
+## Operational response
+
+When a mention fails to dispatch:
+
+1. inspect the router run before retrying the comment;
+2. treat any 4xx dispatch response as a transport or contract defect, not a
+   successful review request;
+3. do not change the selected pull-request head to manufacture a new request;
+4. repair and merge the central router contract first;
+5. request a fresh exact-head review after the protected central revision is
+   active;
+6. never reinterpret predecessor reviews as current-head approval.
+
+## APA 7 references
+
+GitHub. (2026). *Create a repository dispatch event*. GitHub Docs. https://docs.github.com/en/rest/repos/repos#create-a-repository-dispatch-event
+
+GitHub. (2026). *Control the concurrency of workflows and jobs*. GitHub Docs. https://docs.github.com/en/actions/using-jobs/using-concurrency
+
+National Institute of Standards and Technology. (2020). *Security and privacy controls for information systems and organizations* (NIST Special Publication 800-53, Revision 5). https://doi.org/10.6028/NIST.SP.800-53r5
diff --git a/scripts/ci/agent_mention_router.py b/scripts/ci/agent_mention_router.py
index bdb8ac3db..97295062d 100644
--- a/scripts/ci/agent_mention_router.py
+++ b/scripts/ci/agent_mention_router.py
@@ -28,6 +28,7 @@
     f"repos/{CENTRAL_AUTOMATION_REPOSITORY}/actions/artifacts"
 )
 LEDGER_ARTIFACT_PREFIX = "cwl-agent-invocation-"
+OPENCODE_INVOCATION_SCHEMA = "cwl.agent-invocation/v2"
 REPOSITORY_RE = re.compile(r"^ContextualWisdomLab/[A-Za-z0-9_.-]+$")
 HEAD_SHA_RE = re.compile(r"^[0-9a-fA-F]{40}$")
 BASE_BRANCH_RE = re.compile(r"^(?!-)[A-Za-z0-9._/-]+$")
@@ -394,24 +395,22 @@ def opencode_payload(request: MentionRequest) -> dict[str, Any]:
 
     agent = "opencode-agent"
     claim = agent_invocation_claim(request, agent)
+    client_payload = {
+        "schema": OPENCODE_INVOCATION_SCHEMA,
+        "claim": claim,
+        "agent_invocation_key": agent_invocation_key(request, agent),
+    }
+    encoded = json.dumps(
+        client_payload,
+        ensure_ascii=True,
+        separators=(",", ":"),
+        sort_keys=True,
+    ).encode("utf-8")
+    if len(client_payload) > 10 or len(encoded) > 65_535:
+        raise ValueError("OpenCode repository dispatch exceeds GitHub limits")
     return {
         "event_type": "agent-mention-opencode",
-        "client_payload": {
-            "target_repository": request.repository,
-            "pr_number": request.pull_request_number,
-            "pr_head_sha": request.pull_request_head_sha,
-            "pr_base_sha": request.pull_request_base_sha,
-            "base_branch": request.pull_request_base_branch,
-            "trigger_reviews": claim["trigger_reviews"],
-            "review_dispatch_limit": claim["review_dispatch_limit"],
-            "enable_auto_merge": claim["enable_auto_merge"],
-            "update_branches": claim["update_branches"],
-            "merge_mode": claim["merge_mode"],
-            "requested_agent": agent,
-            "agent_invocation_key": agent_invocation_key(request, agent),
-            "requested_by": request.actor,
-            "source_comment_id": request.comment_id,
-        },
+        "client_payload": client_payload,
     }
 
 
@@ -478,14 +477,20 @@ def dispatch_request(
             ledger_artifact_cache[agent_ledger_artifact_name(request, agent)] = True
 
     target_api = f"repos/{request.repository}"
-    target_client.request(
-        [
-            f"{target_api}/issues/comments/{request.comment_id}/reactions",
-            "-X",
-            "POST",
-        ],
-        input_payload={"content": "eyes"},
-    )
+    try:
+        target_client.request(
+            [
+                f"{target_api}/issues/comments/{request.comment_id}/reactions",
+                "-X",
+                "POST",
+            ],
+            input_payload={"content": "eyes"},
+        )
+    except RuntimeError as exc:
+        print(
+            "::warning::Agent dispatch is durably queued, but the optional "
+            f"eyes reaction could not be recorded: {exc}"
+        )
     status_parts = [f"Queued {' and '.join(handles)}"]
     existing_handles = tuple(
         f"@{agent}" for agent in dispatchable if agent in existing
diff --git a/scripts/ci/pr_review_merge_scheduler.py b/scripts/ci/pr_review_merge_scheduler.py
index 75e18c860..6b8331d2c 100644
--- a/scripts/ci/pr_review_merge_scheduler.py
+++ b/scripts/ci/pr_review_merge_scheduler.py
@@ -22,6 +22,7 @@
 PULL_REQUEST_FIELDS_FRAGMENT = """\
 fragment SchedulerPullRequestFields on PullRequest {
   number
+  state
   title
   isDraft
   mergeable
@@ -722,6 +723,7 @@ def rest_pr_node(repo: str, pr: dict[str, Any]) -> dict[str, Any]:
     )
     return {
         "number": number,
+        "state": str(pr.get("state") or "").upper(),
         "title": pr.get("title"),
         "isDraft": bool(pr.get("draft")),
         "mergeable": pr.get("mergeable"),
@@ -2069,7 +2071,14 @@ def cancel_stale_opencode_runs(repo: str, workflow: str, pr: dict[str, Any], *,
     return [run_id for _, run_id in stale_refs]
 
 
-def dispatch_opencode_review(repo: str, workflow: str, pr: dict[str, Any], *, dry_run: bool) -> str:
+def dispatch_opencode_review(
+    repo: str,
+    workflow: str,
+    pr: dict[str, Any],
+    *,
+    dry_run: bool,
+    snapshot_guarded: bool = False,
+) -> str:
     """Dispatch trusted OpenCode for the PR head, or report an active run.
 
     The review job is intentionally restricted to ``repository_dispatch``. A
@@ -2081,7 +2090,14 @@ def dispatch_opencode_review(repo: str, workflow: str, pr: dict[str, Any], *, dr
     if not dry_run:
         require_github_actions_control_actor("inspect-active-opencode-review")
         current_run_refs, stale_run_refs = active_opencode_run_refs(repo, workflow, pr)
-        force_cancel_workflow_run_refs(stale_run_refs)
+        if snapshot_guarded and stale_run_refs:
+            print(
+                "OpenCode review dispatch skipped: a different-head workflow run became active "
+                "after snapshot validation"
+            )
+            return "snapshot_changed"
+        if not snapshot_guarded:
+            force_cancel_workflow_run_refs(stale_run_refs)
         if current_run_refs:
             print(
                 "OpenCode review dispatch skipped: active same-head workflow run(s) "
@@ -2123,12 +2139,20 @@ def dispatch_opencode_review(repo: str, workflow: str, pr: dict[str, Any], *, dr
     return "dispatched"
 
 
-def dispatch_strix_evidence(repo: str, workflow: str, pr: dict[str, Any], *, dry_run: bool) -> str:
+def dispatch_strix_evidence(
+    repo: str,
+    workflow: str,
+    pr: dict[str, Any],
+    *,
+    dry_run: bool,
+    snapshot_guarded: bool = False,
+) -> str:
     """Dispatch same-head Strix workflow evidence before OpenCode reviews."""
-    job_id = matching_actions_job_id(pr, is_strix_context)
-    if job_id:
-        rerun_actions_job(repo, job_id, dry_run=dry_run, action="rerun-strix-evidence")
-        return "rerun" if not dry_run else "dry_run"
+    if not snapshot_guarded:
+        job_id = matching_actions_job_id(pr, is_strix_context)
+        if job_id:
+            rerun_actions_job(repo, job_id, dry_run=dry_run, action="rerun-strix-evidence")
+            return "rerun" if not dry_run else "dry_run"
     if dry_run:
         return "dry_run"
     require_github_actions_control_actor("inspect-active-strix-evidence")
@@ -2139,7 +2163,14 @@ def dispatch_strix_evidence(repo: str, workflow: str, pr: dict[str, Any], *, dry
         run_title="Strix Security Scan",
         workflow_aliases=frozenset({"Strix Security Scan"}),
     )
-    force_cancel_workflow_run_refs(stale_run_refs)
+    if snapshot_guarded and stale_run_refs:
+        print(
+            "Strix evidence dispatch skipped: a different-head workflow run became active "
+            "after snapshot validation"
+        )
+        return "snapshot_changed"
+    if not snapshot_guarded:
+        force_cancel_workflow_run_refs(stale_run_refs)
     if current_run_refs:
         print(
             "Strix evidence dispatch skipped: active same-head workflow run(s) "
@@ -2247,6 +2278,219 @@ def current_head_can_attempt_merge(pr: dict[str, Any], merge_state: str) -> bool
     return False
 
 
+def inspect_snapshot_bound_review(
+    repo: str,
+    pr: dict[str, Any],
+    *,
+    dry_run: bool,
+    trigger_reviews: bool,
+    review_dispatch_allowed: bool,
+    workflow: str,
+    security_workflow: str,
+    base_branch: str,
+    stale_opencode_minutes: int,
+) -> Decision:
+    """Dispatch exact-snapshot review work without general scheduler mutations."""
+
+    number = pr["number"]
+    base_ref = pr.get("baseRefName")
+    if str(pr.get("state") or "").upper() != "OPEN":
+        return Decision(number, "wait", "snapshot-bound target PR is no longer open")
+    if pr.get("isDraft"):
+        return Decision(number, "skip", "draft PR")
+    if base_ref != base_branch:
+        return Decision(
+            number,
+            "wait",
+            f"snapshot-bound target base branch changed from {base_branch} to {base_ref}",
+        )
+    unresolved = unresolved_thread_count(pr)
+    if unresolved:
+        return Decision(number, "block", f"{unresolved} unresolved review thread(s)")
+    if has_current_head_changes_requested(pr):
+        return Decision(number, "block", "current-head OpenCode review requested changes")
+
+    merge_state = effective_merge_state(pr)
+    current_head_approved = has_current_head_approval(pr)
+    if merge_state in {"DIRTY", "CONFLICTING"}:
+        return Decision(number, "block", merge_conflict_guidance(pr, merge_state))
+    if current_head_approved:
+        failed_checks = failed_status_checks(pr)
+        if failed_checks:
+            return Decision(number, "block", f"failed check(s): {', '.join(failed_checks[:5])}")
+    workflow_action_required = action_required_checks(pr)
+    if workflow_action_required:
+        return Decision(
+            number,
+            "wait",
+            workflow_action_required_reason(workflow_action_required),
+        )
+
+    behind_by = branch_outdated_by_base(pr, merge_state)
+    if behind_by and trigger_reviews:
+        approval_state = (
+            "current head is approved"
+            if current_head_approved
+            else "current head has no OpenCode approval"
+        )
+        return Decision(
+            number,
+            "wait",
+            f"{approval_state}; snapshot-bound review cannot update an outdated branch",
+        )
+    if merge_state == "UNKNOWN":
+        return Decision(
+            number,
+            "wait",
+            "mergeability is still being calculated and no branch freshness evidence is available",
+        )
+    if current_head_approved:
+        return Decision(
+            number,
+            "wait",
+            "current head is approved; snapshot-bound invocation is review-only",
+        )
+
+    opencode_state = opencode_progress_state(
+        pr,
+        stale_after_minutes=stale_opencode_minutes,
+    )
+    if opencode_state == "running":
+        return Decision(number, "wait", "OpenCode review is already in progress")
+    if (
+        os.environ.get("GITHUB_EVENT_NAME") == "workflow_run"
+        and has_current_head_deterministic_fallback_approval(pr)
+    ):
+        return Decision(
+            number,
+            "wait",
+            "current-head deterministic fallback is not merge evidence; defer real-model retry to the next scheduler heartbeat",
+        )
+    if opencode_state == "stale" and not trigger_reviews:
+        return Decision(
+            number,
+            "wait",
+            f"OpenCode review exceeded {stale_opencode_minutes} minute retry threshold; review dispatch disabled",
+        )
+    if opencode_state == "stale":
+        if not review_dispatch_allowed:
+            return Decision(
+                number,
+                "wait",
+                f"OpenCode review exceeded {stale_opencode_minutes} minute retry threshold; review dispatch limit reached",
+            )
+        dispatch_result = dispatch_opencode_review(
+            repo,
+            workflow,
+            pr,
+            dry_run=dry_run,
+            snapshot_guarded=True,
+        )
+        if dispatch_result == "snapshot_changed":
+            return Decision(
+                number,
+                "wait",
+                "OpenCode review retry skipped because a different-head review run is active",
+            )
+        if dispatch_result == "already_running":
+            return Decision(
+                number,
+                "wait",
+                "OpenCode review exceeded the status-check retry threshold, but a same-head workflow run is already active",
+            )
+        return Decision(
+            number,
+            "review_dispatch",
+            f"OpenCode review exceeded {stale_opencode_minutes} minute retry threshold; same-head OpenCode re-dispatched",
+        )
+
+    if trigger_reviews:
+        strix_state = strix_evidence_state(pr)
+        if strix_state == "missing":
+            if not review_dispatch_allowed:
+                return Decision(
+                    number,
+                    "wait",
+                    "current head has no completed Strix evidence; review dispatch limit reached",
+                )
+            wait_reason = repository_dispatch_wait_reason(repo, security_workflow)
+            if wait_reason:
+                return Decision(
+                    number,
+                    "wait",
+                    f"current head has no completed Strix evidence; {wait_reason}",
+                )
+            dispatch_result = dispatch_strix_evidence(
+                repo,
+                security_workflow,
+                pr,
+                dry_run=dry_run,
+                snapshot_guarded=True,
+            )
+            if dispatch_result == "snapshot_changed":
+                return Decision(
+                    number,
+                    "wait",
+                    "Strix dispatch skipped because a different-head Strix run is active",
+                )
+            if dispatch_result == "already_running":
+                return Decision(
+                    number,
+                    "wait",
+                    "same-head Strix evidence workflow run is already active",
+                )
+            return Decision(
+                number,
+                "security_dispatch",
+                "current head has no completed Strix evidence; same-head Strix dispatched",
+            )
+        if strix_state == "running":
+            return Decision(number, "wait", "same-head Strix evidence is still running")
+        if not review_dispatch_allowed:
+            return Decision(
+                number,
+                "wait",
+                "current head has completed Strix evidence; review dispatch limit reached",
+            )
+        wait_reason = repository_dispatch_wait_reason(repo, workflow)
+        if wait_reason:
+            return Decision(
+                number,
+                "wait",
+                f"current head has completed Strix evidence; {wait_reason}",
+            )
+        dispatch_result = dispatch_opencode_review(
+            repo,
+            workflow,
+            pr,
+            dry_run=dry_run,
+            snapshot_guarded=True,
+        )
+        if dispatch_result == "snapshot_changed":
+            return Decision(
+                number,
+                "wait",
+                "OpenCode dispatch skipped because a different-head review run is active",
+            )
+        if dispatch_result == "already_running":
+            return Decision(
+                number,
+                "wait",
+                "current head has completed Strix evidence; same-head OpenCode workflow run is already active",
+            )
+        return Decision(
+            number,
+            "review_dispatch",
+            "current head has completed Strix evidence; same-head OpenCode dispatched",
+        )
+
+    return Decision(
+        number,
+        "block",
+        "current head has no OpenCode approval; review dispatch disabled",
+    )
+
+
 def inspect_pr(
     repo: str,
     pr: dict[str, Any],
@@ -2263,8 +2507,21 @@ def inspect_pr(
     base_branch: str,
     merge_mode: str = "direct_or_auto",
     stale_opencode_minutes: int = DEFAULT_STALE_OPENCODE_MINUTES,
+    snapshot_guarded: bool = False,
 ) -> Decision:
     """Decide and optionally act on one pull request's merge-readiness state."""
+    if snapshot_guarded:
+        return inspect_snapshot_bound_review(
+            repo,
+            pr,
+            dry_run=dry_run,
+            trigger_reviews=trigger_reviews,
+            review_dispatch_allowed=review_dispatch_allowed,
+            workflow=workflow,
+            security_workflow=security_workflow,
+            base_branch=base_branch,
+            stale_opencode_minutes=stale_opencode_minutes,
+        )
     number = pr["number"]
     base_ref = pr.get("baseRefName")
 
@@ -3691,6 +3948,68 @@ def self_test() -> None:
     print("self-test passed")
 
 
+def validate_expected_pr_snapshot(
+    prs: Sequence[dict[str, Any]],
+    *,
+    pr_number: int,
+    expected_head_sha: str,
+    expected_base_sha: str,
+    expected_base_branch: str,
+) -> None:
+    """Fail closed when a targeted PR no longer matches its validated refs."""
+
+    expected_values = (
+        expected_head_sha,
+        expected_base_sha,
+        expected_base_branch,
+    )
+    if not any(expected_values):
+        return
+    if not all(expected_values):
+        raise SystemExit(
+            "--expected-head-sha, --expected-base-sha, and --expected-base-branch "
+            "must be supplied together"
+        )
+    if pr_number < 1:
+        raise SystemExit("expected PR snapshot guards require --pr-number")
+    try:
+        expected_head = validate_git_sha(expected_head_sha).lower()
+        expected_base = validate_git_sha(expected_base_sha).lower()
+        expected_branch = validate_git_ref(expected_base_branch)
+    except ValueError as exc:
+        raise SystemExit(str(exc)) from exc
+    if len(prs) != 1 or int(prs[0].get("number") or 0) != pr_number:
+        raise SystemExit(
+            f"target PR #{pr_number} snapshot is unavailable or ambiguous"
+        )
+    try:
+        observed_head = validate_git_sha(str(prs[0].get("headRefOid") or "")).lower()
+        observed_base = validate_git_sha(str(prs[0].get("baseRefOid") or "")).lower()
+        observed_branch = validate_git_ref(str(prs[0].get("baseRefName") or ""))
+    except ValueError as exc:
+        raise SystemExit(f"target PR #{pr_number} returned malformed refs: {exc}") from exc
+    observed_state = str(prs[0].get("state") or "").upper()
+    if observed_state != "OPEN":
+        raise SystemExit(
+            f"target PR #{pr_number} is no longer open: observed {observed_state or '<missing>'}"
+        )
+    if observed_head != expected_head:
+        raise SystemExit(
+            f"target PR #{pr_number} head SHA changed: "
+            f"expected {expected_head}, observed {observed_head}"
+        )
+    if observed_base != expected_base:
+        raise SystemExit(
+            f"target PR #{pr_number} base SHA changed: "
+            f"expected {expected_base}, observed {observed_base}"
+        )
+    if observed_branch != expected_branch:
+        raise SystemExit(
+            f"target PR #{pr_number} base branch changed: "
+            f"expected {expected_branch}, observed {observed_branch}"
+        )
+
+
 def parse_args(argv: list[str]) -> argparse.Namespace:
     """Parse scheduler CLI arguments."""
     parser = argparse.ArgumentParser()
@@ -3699,6 +4018,18 @@ def parse_args(argv: list[str]) -> argparse.Namespace:
     parser.add_argument("--project-flow", default=os.environ.get("PROJECT_FLOW", ""))
     parser.add_argument("--max-prs", type=int, default=100)
     parser.add_argument("--pr-number", type=int, default=0)
+    parser.add_argument(
+        "--expected-head-sha",
+        default=os.environ.get("EXPECTED_HEAD_SHA", ""),
+    )
+    parser.add_argument(
+        "--expected-base-sha",
+        default=os.environ.get("EXPECTED_BASE_SHA", ""),
+    )
+    parser.add_argument(
+        "--expected-base-branch",
+        default=os.environ.get("EXPECTED_BASE_BRANCH", ""),
+    )
     parser.add_argument("--dry-run", action="store_true")
     parser.add_argument("--trigger-reviews", action=argparse.BooleanOptionalAction, default=True)
     parser.add_argument(
@@ -3750,6 +4081,27 @@ def main(argv: list[str]) -> int:
     if args.branch_update_limit < -1:
         raise SystemExit("--branch-update-limit must be -1 or greater")
     prs = fetch_pr(args.repo, args.pr_number) if args.pr_number else fetch_open_prs(args.repo, args.max_prs)
+    validate_expected_pr_snapshot(
+        prs,
+        pr_number=args.pr_number,
+        expected_head_sha=args.expected_head_sha,
+        expected_base_sha=args.expected_base_sha,
+        expected_base_branch=args.expected_base_branch,
+    )
+    snapshot_guarded = bool(
+        args.expected_head_sha
+        or args.expected_base_sha
+        or args.expected_base_branch
+    )
+    if snapshot_guarded:
+        prs = fetch_pr(args.repo, args.pr_number)
+        validate_expected_pr_snapshot(
+            prs,
+            pr_number=args.pr_number,
+            expected_head_sha=args.expected_head_sha,
+            expected_base_sha=args.expected_base_sha,
+            expected_base_branch=args.expected_base_branch,
+        )
     decisions = []
     review_dispatches_used = 0
     branch_updates_used = 0
@@ -3774,6 +4126,7 @@ def main(argv: list[str]) -> int:
                 security_workflow=args.security_workflow,
                 base_branch=args.base_branch,
                 stale_opencode_minutes=args.stale_opencode_minutes,
+                snapshot_guarded=snapshot_guarded,
             )
         except RuntimeError as exc:
             decision = Decision(
diff --git a/tests/test_agent_mention_complete_payload_binding.py b/tests/test_agent_mention_complete_payload_binding.py
index 04562e93f..bfb0ff4f3 100644
--- a/tests/test_agent_mention_complete_payload_binding.py
+++ b/tests/test_agent_mention_complete_payload_binding.py
@@ -74,12 +74,13 @@ def test_event_and_payloads_bind_exact_base_identity() -> None:
     assert request.pull_request_base_branch == "main"
     assert request.pull_request_base_sha == "b" * 40
 
-    for payload in (
-        router.noema_payload(request)["client_payload"],
-        router.opencode_payload(request)["client_payload"],
-    ):
-        assert payload["base_branch"] == "main"
-        assert payload["pr_base_sha"] == "b" * 40
+    noema_payload = router.noema_payload(request)["client_payload"]
+    assert noema_payload["base_branch"] == "main"
+    assert noema_payload["pr_base_sha"] == "b" * 40
+    opencode_envelope = router.opencode_payload(request)["client_payload"]
+    assert opencode_envelope["schema"] == "cwl.agent-invocation/v2"
+    assert opencode_envelope["claim"]["base_branch"] == "main"
+    assert opencode_envelope["claim"]["base_sha"] == "b" * 40
 
     malformed = _event()
     malformed["pull_request"]["base"]["sha"] = "not-a-sha"
@@ -150,36 +151,37 @@ def test_wrappers_recompute_complete_claim_before_ledger_access() -> None:
 
     noema = NOEMA_WORKFLOW.read_text(encoding="utf-8")
     opencode = OPENCODE_WORKFLOW.read_text(encoding="utf-8")
+    assert "PR_BASE_SHA:" in noema
+    assert "github.event.client_payload.pr_base_sha" in noema
+    assert '! [[ "$PR_BASE_SHA" =~ ^[0-9a-f]{40}$ ]]' in noema
+    assert '"base_sha": os.environ["PR_BASE_SHA"]' in noema
+    assert "--arg pr_base_sha \"$PR_BASE_SHA\"" in noema
+    assert "pr_base_sha: $pr_base_sha" in noema
+    assert noema.count('"base_sha": os.environ["PR_BASE_SHA"]') >= 2
+
+    assert "CLIENT_PAYLOAD_JSON:" in opencode
+    assert "github.event.client_payload.claim" in opencode
+    assert '"base_sha"' in opencode
+    assert 'r"[0-9a-f]{40}", claim["base_sha"]' in opencode
+    assert "set(envelope)" in opencode
+    assert "set(claim)" in opencode
+    assert '"client_payload": envelope' in opencode
+    assert '--input "$SCHEDULER_REQUEST_FILE"' in opencode
     for workflow in (noema, opencode):
-        assert "PR_BASE_SHA:" in workflow
-        assert "github.event.client_payload.pr_base_sha" in workflow
-        assert '! [[ "$PR_BASE_SHA" =~ ^[0-9a-f]{40}$ ]]' in workflow
-        assert '"base_sha": os.environ["PR_BASE_SHA"]' in workflow
         assert "hmac.compare_digest" in workflow
         assert workflow.index("Validate exact invocation payload") < workflow.index(
             "Inspect exact-name Actions artifact ledger"
         )
-        assert "--arg pr_base_sha \"$PR_BASE_SHA\"" in workflow
-        assert "pr_base_sha: $pr_base_sha" in workflow
-
-    for field in (
-        '"trigger_reviews": os.environ["TRIGGER_REVIEWS"] == "true"',
-        '"review_dispatch_limit": os.environ["REVIEW_DISPATCH_LIMIT"]',
-        '"enable_auto_merge": os.environ["ENABLE_AUTO_MERGE"] == "true"',
-        '"update_branches": os.environ["UPDATE_BRANCHES"] == "true"',
-        '"merge_mode": os.environ["MERGE_MODE"]',
-    ):
-        assert field in opencode
 
-    assert noema.count('"base_sha": os.environ["PR_BASE_SHA"]') >= 2
-    for field in (
-        '"trigger_reviews": os.environ["TRIGGER_REVIEWS"] == "true"',
-        '"review_dispatch_limit": os.environ["REVIEW_DISPATCH_LIMIT"]',
-        '"enable_auto_merge": os.environ["ENABLE_AUTO_MERGE"] == "true"',
-        '"update_branches": os.environ["UPDATE_BRANCHES"] == "true"',
-        '"merge_mode": os.environ["MERGE_MODE"]',
+    for field, value in (
+        ('"agent"', '"opencode-agent"'),
+        ('"trigger_reviews"', "True"),
+        ('"review_dispatch_limit"', '"1"'),
+        ('"enable_auto_merge"', "False"),
+        ('"update_branches"', "False"),
+        ('"merge_mode"', '"disabled"'),
     ):
-        assert opencode.count(field) >= 2
+        assert f"{field}: {value}" in opencode
 
 
 def test_no_pr_specific_writer_workflow_remains() -> None:
diff --git a/tests/test_agent_mention_downstream_idempotency.py b/tests/test_agent_mention_downstream_idempotency.py
index 4fc40a782..a3940924b 100644
--- a/tests/test_agent_mention_downstream_idempotency.py
+++ b/tests/test_agent_mention_downstream_idempotency.py
@@ -30,12 +30,9 @@ def test_downstream_workflows_claim_artifacts_and_bind_exact_key() -> None:
     for text in (noema, opencode):
         assert "github.event.client_payload.agent_invocation_key" in text
         assert "cwl-agent-invocation:" in text
-        assert "source_comment_id" in text
-        assert "requested_agent" in text
         assert "cancel-in-progress: false" in text
         assert "queue: max" in text
         assert "^[0-9a-f]{64}$" in text
-        assert "^[1-9][0-9]*$" in text
         assert "actions/artifacts" in text
         assert "name=${LEDGER_ARTIFACT_NAME}" in text
         assert f"actions/upload-artifact@{UPLOAD_ARTIFACT_SHA}" in text
@@ -49,11 +46,17 @@ def test_downstream_workflows_claim_artifacts_and_bind_exact_key() -> None:
     assert "types: [agent-mention-noema]" in noema
     assert 'event_type: "noema-review"' in noema
     assert 'REQUESTED_AGENT: "cwl-noema-review"' in noema
+    assert "^[1-9][0-9]*$" in noema
+    assert "source_comment_id" in noema
+    assert "requested_agent" in noema
     assert "types: [agent-mention-opencode]" in opencode
-    assert 'event_type: "merge-scheduler"' in opencode
-    assert 'REQUESTED_AGENT: "opencode-agent"' in opencode
-    assert '[[ "$BASE_BRANCH" =~ ^[A-Za-z0-9._/-]+$ ]]' in opencode
-    assert '[[ "$BASE_BRANCH" == -* ]]' in opencode
+    assert '"event_type": "merge-scheduler-agent-review-v2"' in opencode
+    assert '"agent": "opencode-agent"' in opencode
+    assert '"comment_id"' in opencode
+    assert 'type(claim["comment_id"]) is not int' in opencode
+    assert 'type(claim["pr_number"]) is not int' in opencode
+    assert 're.fullmatch(r"[A-Za-z0-9._/-]+", claim["base_branch"])' in opencode
+    assert 'claim["base_branch"].startswith("-")' in opencode
 
 
 def test_wrappers_recompute_the_router_canonical_payload_digest() -> None:
@@ -74,11 +77,11 @@ def test_wrappers_recompute_the_router_canonical_payload_digest() -> None:
         '"pr_number"',
         '"repository"',
     )
-    for text in (
-        NOEMA_WORKFLOW.read_text(encoding="utf-8"),
-        OPENCODE_WORKFLOW.read_text(encoding="utf-8"),
-    ):
-        assert "BASE_BRANCH:" in text
+    noema = NOEMA_WORKFLOW.read_text(encoding="utf-8")
+    opencode = OPENCODE_WORKFLOW.read_text(encoding="utf-8")
+    assert "BASE_BRANCH:" in noema
+    assert '"BASE_BRANCH": claim["base_branch"]' in opencode
+    for text in (noema, opencode):
         assert "import hashlib" in text
         assert "import hmac" in text
         assert "json.dumps(" in text
@@ -104,3 +107,4 @@ def test_quality_gate_runs_full_suite_for_docs_and_exact_diff() -> None:
     coverage_config = text.split("[run]\n", 1)[1].split("[report]\n", 1)[0]
     assert "scripts/ci/agent_mention_router.py" in coverage_config
     assert "scripts/ci/agent_mention_sweep.py" in coverage_config
+    assert "scripts/ci/pr_review_merge_scheduler.py" in coverage_config
diff --git a/tests/test_agent_mention_exact_contract.py b/tests/test_agent_mention_exact_contract.py
new file mode 100644
index 000000000..79d96ab63
--- /dev/null
+++ b/tests/test_agent_mention_exact_contract.py
@@ -0,0 +1,341 @@
+"""Pin complete v2 dispatch, reaction, and receipt contracts."""
+
+from __future__ import annotations
+
+import hashlib
+import importlib.util
+import json
+import sys
+from pathlib import Path
+from types import ModuleType
+
+ROOT = Path(__file__).resolve().parents[1]
+MODULE_PATH = ROOT / "scripts" / "ci" / "agent_mention_router.py"
+
+
+def load_module() -> ModuleType:
+    """Load the agent-mention router under an isolated test module name."""
+
+    module_name = "agent_mention_router_exact_contract"
+    spec = importlib.util.spec_from_file_location(module_name, MODULE_PATH)
+    assert spec and spec.loader
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
+def mention_request(module: ModuleType, *, agents: tuple[str, ...]):
+    """Build one exact request for dispatch-contract verification."""
+
+    return module.MentionRequest(
+        repository="ContextualWisdomLab/.github",
+        pull_request_number=840,
+        pull_request_head_sha="a" * 40,
+        pull_request_base_branch="main",
+        comment_id=123,
+        actor="maintainer",
+        agents=agents,
+        pull_request_base_sha="b" * 40,
+    )
+
+
+def expected_opencode_claim(request) -> dict[str, object]:
+    """Return the complete canonical v2 OpenCode claim expected by GitHub."""
+
+    return {
+        "actor": request.actor,
+        "agent": "opencode-agent",
+        "base_branch": request.pull_request_base_branch,
+        "base_sha": request.pull_request_base_sha,
+        "comment_id": request.comment_id,
+        "head_sha": request.pull_request_head_sha,
+        "pr_number": request.pull_request_number,
+        "repository": request.repository,
+        "enable_auto_merge": False,
+        "merge_mode": "disabled",
+        "review_dispatch_limit": "1",
+        "trigger_reviews": True,
+        "update_branches": False,
+    }
+
+
+def expected_opencode_payload(request) -> dict[str, object]:
+    """Return the full three-property v2 repository-dispatch envelope."""
+
+    claim = expected_opencode_claim(request)
+    invocation_key = hashlib.sha256(
+        json.dumps(
+            claim,
+            ensure_ascii=True,
+            separators=(",", ":"),
+            sort_keys=True,
+        ).encode("utf-8")
+    ).hexdigest()
+    return {
+        "event_type": "agent-mention-opencode",
+        "client_payload": {
+            "schema": "cwl.agent-invocation/v2",
+            "claim": claim,
+            "agent_invocation_key": invocation_key,
+        },
+    }
+
+
+def expected_noema_payload(request) -> dict[str, object]:
+    """Return the complete legacy Noema dispatch contract."""
+
+    return {
+        "event_type": "agent-mention-noema",
+        "client_payload": {
+            "target_repository": request.repository,
+            "pr_number": request.pull_request_number,
+            "pr_head_sha": request.pull_request_head_sha,
+            "pr_base_sha": request.pull_request_base_sha,
+            "base_branch": request.pull_request_base_branch,
+            "requested_agent": "cwl-noema-review",
+            "agent_invocation_key": request_module_key(
+                request,
+                "cwl-noema-review",
+            ),
+            "requested_by": request.actor,
+            "source_comment_id": request.comment_id,
+        },
+    }
+
+
+def request_module_key(request, agent: str) -> str:
+    """Calculate the router's canonical invocation key independently."""
+
+    claim: dict[str, object] = {
+        "actor": request.actor,
+        "agent": agent,
+        "base_branch": request.pull_request_base_branch,
+        "base_sha": request.pull_request_base_sha,
+        "comment_id": request.comment_id,
+        "head_sha": request.pull_request_head_sha,
+        "pr_number": request.pull_request_number,
+        "repository": request.repository,
+    }
+    if agent == "opencode-agent":
+        claim.update(
+            {
+                "enable_auto_merge": False,
+                "merge_mode": "disabled",
+                "review_dispatch_limit": "1",
+                "trigger_reviews": True,
+                "update_branches": False,
+            }
+        )
+    return hashlib.sha256(
+        json.dumps(
+            claim,
+            ensure_ascii=True,
+            separators=(",", ":"),
+            sort_keys=True,
+        ).encode("utf-8")
+    ).hexdigest()
+
+
+class RecordingCentralClient:
+    """Record exact artifact and repository-dispatch requests."""
+
+    def __init__(self) -> None:
+        """Initialize an empty call ledger."""
+
+        self.calls: list[tuple[list[str], dict | None]] = []
+
+    def request(self, args, *, input_payload=None):
+        """Return an empty artifact inventory and record every request."""
+
+        self.calls.append((list(args), input_payload))
+        if args[0].endswith("/actions/artifacts"):
+            return {"total_count": 0, "artifacts": []}
+        return None
+
+
+class ReactionDeniedClient:
+    """Record target mutations while denying only the cosmetic reaction."""
+
+    def __init__(self) -> None:
+        """Initialize an empty target request ledger."""
+
+        self.calls: list[tuple[list[str], dict | None]] = []
+
+    def request(self, args, *, input_payload=None):
+        """Reject the reaction and accept the durable acknowledgement."""
+
+        self.calls.append((list(args), input_payload))
+        if args[0].endswith("/reactions"):
+            raise RuntimeError(
+                "gh api failed: Resource not accessible by integration"
+            )
+        return None
+
+
+def artifact_lookup(module: ModuleType, request, agent: str):
+    """Return the exact empty-ledger lookup call for one agent."""
+
+    artifact_name = module.agent_ledger_artifact_name(request, agent)
+    return (
+        [
+            "repos/ContextualWisdomLab/.github/actions/artifacts",
+            "-X",
+            "GET",
+            "-f",
+            f"name={artifact_name}",
+            "-f",
+            "per_page=100",
+        ],
+        None,
+    )
+
+
+def expected_acknowledgement(*, handles: str) -> str:
+    """Return the exact user-facing receipt for one exact request."""
+
+    return (
+        "<!-- cwl-agent-mention-receipt:123 -->\n"
+        f"Queued {handles} for PR #840 at head `{'a' * 40}`. "
+        "Central exact-name Actions artifacts are the durable dispatch ledger; "
+        "existing review workflows remain authoritative for the final verdict "
+        "and failure evidence."
+    )
+
+
+def test_opencode_payload_pins_every_v2_field_and_value() -> None:
+    """The v2 client payload contains exactly three fully bound properties."""
+
+    module = load_module()
+    request = mention_request(module, agents=("opencode-agent",))
+    expected = expected_opencode_payload(request)
+
+    assert module.opencode_payload(request) == expected
+    client_payload = expected["client_payload"]
+    assert isinstance(client_payload, dict)
+    assert set(client_payload) == {
+        "schema",
+        "claim",
+        "agent_invocation_key",
+    }
+    claim = client_payload["claim"]
+    assert isinstance(claim, dict)
+    assert claim["base_sha"] == request.pull_request_base_sha
+
+
+def test_reaction_denial_pins_single_agent_requests_and_prose(capsys) -> None:
+    """A denied reaction leaves the full Noema dispatch and receipt intact."""
+
+    module = load_module()
+    request = mention_request(module, agents=("cwl-noema-review",))
+    central = RecordingCentralClient()
+    target = ReactionDeniedClient()
+
+    assert module.dispatch_request(
+        request,
+        target_client=target,
+        dispatch_client=central,
+        opencode_allowlist=frozenset(),
+    ) == ("@cwl-noema-review",)
+
+    assert central.calls == [
+        artifact_lookup(module, request, "cwl-noema-review"),
+        (
+            [
+                "repos/ContextualWisdomLab/.github/dispatches",
+                "-X",
+                "POST",
+            ],
+            expected_noema_payload(request),
+        ),
+    ]
+    acknowledgement = expected_acknowledgement(handles="@cwl-noema-review")
+    assert target.calls == [
+        (
+            [
+                "repos/ContextualWisdomLab/.github/issues/comments/123/reactions",
+                "-X",
+                "POST",
+            ],
+            {"content": "eyes"},
+        ),
+        (
+            [
+                "repos/ContextualWisdomLab/.github/issues/840/comments",
+                "-X",
+                "POST",
+            ],
+            {"body": acknowledgement},
+        ),
+    ]
+    assert capsys.readouterr().out == (
+        "::warning::Agent dispatch is durably queued, but the optional eyes "
+        "reaction could not be recorded: gh api failed: Resource not accessible "
+        "by integration\n"
+    )
+
+
+def test_reaction_denial_pins_two_agent_requests_and_prose(capsys) -> None:
+    """A denied reaction preserves both dispatches and the combined receipt."""
+
+    module = load_module()
+    request = mention_request(
+        module,
+        agents=("cwl-noema-review", "opencode-agent"),
+    )
+    central = RecordingCentralClient()
+    target = ReactionDeniedClient()
+
+    assert module.dispatch_request(
+        request,
+        target_client=target,
+        dispatch_client=central,
+        opencode_allowlist=frozenset({request.repository}),
+    ) == ("@cwl-noema-review", "@opencode-agent")
+
+    assert central.calls == [
+        artifact_lookup(module, request, "cwl-noema-review"),
+        artifact_lookup(module, request, "opencode-agent"),
+        (
+            [
+                "repos/ContextualWisdomLab/.github/dispatches",
+                "-X",
+                "POST",
+            ],
+            expected_noema_payload(request),
+        ),
+        (
+            [
+                "repos/ContextualWisdomLab/.github/dispatches",
+                "-X",
+                "POST",
+            ],
+            expected_opencode_payload(request),
+        ),
+    ]
+    acknowledgement = expected_acknowledgement(
+        handles="@cwl-noema-review and @opencode-agent"
+    )
+    assert target.calls == [
+        (
+            [
+                "repos/ContextualWisdomLab/.github/issues/comments/123/reactions",
+                "-X",
+                "POST",
+            ],
+            {"content": "eyes"},
+        ),
+        (
+            [
+                "repos/ContextualWisdomLab/.github/issues/840/comments",
+                "-X",
+                "POST",
+            ],
+            {"body": acknowledgement},
+        ),
+    ]
+    assert capsys.readouterr().out == (
+        "::warning::Agent dispatch is durably queued, but the optional eyes "
+        "reaction could not be recorded: gh api failed: Resource not accessible "
+        "by integration\n"
+    )
diff --git a/tests/test_agent_mention_idempotency.py b/tests/test_agent_mention_idempotency.py
index 499730a22..b95f9a80e 100644
--- a/tests/test_agent_mention_idempotency.py
+++ b/tests/test_agent_mention_idempotency.py
@@ -37,6 +37,7 @@ def request(module: ModuleType):
         12345,
         "maintainer",
         ("cwl-noema-review", "opencode-agent"),
+        "b" * 40,
     )
 
 
@@ -194,15 +195,20 @@ def test_payloads_carry_exact_agent_invocation_identity() -> None:
     assert noema["agent_invocation_key"] == module.agent_invocation_key(
         mention_request, "cwl-noema-review"
     )
-    assert opencode["requested_agent"] == "opencode-agent"
+    assert opencode["schema"] == "cwl.agent-invocation/v2"
+    assert opencode["claim"]["agent"] == "opencode-agent"
     assert opencode["agent_invocation_key"] == module.agent_invocation_key(
         mention_request, "opencode-agent"
     )
-    for payload in (noema, opencode):
-        assert payload["target_repository"] == mention_request.repository
-        assert payload["pr_number"] == mention_request.pull_request_number
-        assert payload["pr_head_sha"] == mention_request.pull_request_head_sha
-        assert payload["source_comment_id"] == mention_request.comment_id
+    assert noema["target_repository"] == mention_request.repository
+    assert noema["pr_number"] == mention_request.pull_request_number
+    assert noema["pr_head_sha"] == mention_request.pull_request_head_sha
+    assert noema["source_comment_id"] == mention_request.comment_id
+    assert opencode["claim"]["repository"] == mention_request.repository
+    assert opencode["claim"]["pr_number"] == mention_request.pull_request_number
+    assert opencode["claim"]["head_sha"] == mention_request.pull_request_head_sha
+    assert opencode["claim"]["base_sha"] == mention_request.pull_request_base_sha
+    assert opencode["claim"]["comment_id"] == mention_request.comment_id
 
 
 def test_existing_artifacts_are_per_agent_durable_evidence() -> None:
@@ -313,24 +319,26 @@ def test_partial_failure_retries_only_the_missing_agent() -> None:
     assert dispatch_events(retry) == ["agent-mention-opencode"]
 
 
-def test_reaction_or_ack_failure_cannot_redispatch_completed_agents() -> None:
-    """Target-repository UX failure is separate from durable dispatch evidence."""
+def test_reaction_failure_cannot_redispatch_completed_agents() -> None:
+    """A cosmetic reaction failure preserves durable dispatch idempotency."""
 
     module = load_module()
     mention_request = request(module)
     central = ArtifactAwareClient()
     failing_target = ArtifactAwareClient(fail_target_call=1)
-    with pytest.raises(RuntimeError, match="target call"):
-        module.dispatch_request(
-            mention_request,
-            target_client=failing_target,
-            dispatch_client=central,
-            opencode_allowlist=frozenset({mention_request.repository}),
-        )
+    assert module.dispatch_request(
+        mention_request,
+        target_client=failing_target,
+        dispatch_client=central,
+        opencode_allowlist=frozenset({mention_request.repository}),
+    ) == ("@cwl-noema-review", "@opencode-agent")
     assert dispatch_events(central) == [
         "agent-mention-noema",
         "agent-mention-opencode",
     ]
+    assert len(failing_target.calls) == 2
+    assert failing_target.calls[0][0][0].endswith("/reactions")
+    assert failing_target.calls[1][0][0].endswith("/issues/65/comments")
 
     retry = ArtifactAwareClient(
         artifacts=artifact_inventory(
diff --git a/tests/test_agent_mention_reaction_resilience.py b/tests/test_agent_mention_reaction_resilience.py
new file mode 100644
index 000000000..d80649337
--- /dev/null
+++ b/tests/test_agent_mention_reaction_resilience.py
@@ -0,0 +1,95 @@
+"""Regression tests for non-authoritative agent-mention reactions."""
+
+from __future__ import annotations
+
+import importlib.util
+import sys
+from pathlib import Path
+from types import ModuleType
+
+ROOT = Path(__file__).resolve().parents[1]
+MODULE_PATH = ROOT / "scripts" / "ci" / "agent_mention_router.py"
+
+
+def load_module() -> ModuleType:
+    """Load the agent-mention router under an isolated test module name."""
+
+    module_name = "agent_mention_router_reaction_resilience"
+    spec = importlib.util.spec_from_file_location(module_name, MODULE_PATH)
+    assert spec and spec.loader
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
+class CentralClient:
+    """Capture durable dispatch and artifact-ledger requests."""
+
+    def __init__(self) -> None:
+        """Initialize an empty request ledger."""
+
+        self.calls: list[tuple[list[str], dict | None]] = []
+
+    def request(self, args, *, input_payload=None):
+        """Return an empty artifact inventory and record all requests."""
+
+        self.calls.append((list(args), input_payload))
+        if args[0].endswith("/actions/artifacts"):
+            return {"total_count": 0, "artifacts": []}
+        return None
+
+
+class ReactionDeniedClient:
+    """Model a token that may comment but cannot add issue-comment reactions."""
+
+    def __init__(self) -> None:
+        """Initialize an empty target-repository request ledger."""
+
+        self.calls: list[tuple[list[str], dict | None]] = []
+
+    def request(self, args, *, input_payload=None):
+        """Reject only the cosmetic reaction while allowing the durable receipt."""
+
+        self.calls.append((list(args), input_payload))
+        if args[0].endswith("/reactions"):
+            raise RuntimeError("gh api failed: Resource not accessible by integration")
+        return None
+
+
+def test_reaction_403_does_not_discard_durable_dispatch(capsys) -> None:
+    """A cosmetic reaction denial must not fail an already queued review."""
+
+    module = load_module()
+    request = module.MentionRequest(
+        repository="ContextualWisdomLab/.github",
+        pull_request_number=840,
+        pull_request_head_sha="a" * 40,
+        pull_request_base_branch="main",
+        comment_id=123,
+        actor="maintainer",
+        agents=("cwl-noema-review",),
+        pull_request_base_sha="b" * 40,
+    )
+    target = ReactionDeniedClient()
+    central = CentralClient()
+
+    assert module.dispatch_request(
+        request,
+        target_client=target,
+        dispatch_client=central,
+        opencode_allowlist=frozenset(),
+    ) == ("@cwl-noema-review",)
+
+    dispatches = [
+        payload
+        for args, payload in central.calls
+        if args[0].endswith("/dispatches") and payload is not None
+    ]
+    assert [payload["event_type"] for payload in dispatches] == [
+        "agent-mention-noema"
+    ]
+    assert target.calls[0][0][0].endswith("/reactions")
+    assert target.calls[1][0][0].endswith("/issues/840/comments")
+    assert "cwl-agent-mention-receipt:123" in target.calls[1][1]["body"]
+    assert "optional eyes reaction could not be recorded" in capsys.readouterr().out
diff --git a/tests/test_agent_mention_repository_dispatch_envelope.py b/tests/test_agent_mention_repository_dispatch_envelope.py
new file mode 100644
index 000000000..786b4e56b
--- /dev/null
+++ b/tests/test_agent_mention_repository_dispatch_envelope.py
@@ -0,0 +1,396 @@
+"""Contracts for the bounded OpenCode repository-dispatch envelope."""
+
+from __future__ import annotations
+
+import hashlib
+import importlib.util
+import json
+import os
+import subprocess
+import sys
+import textwrap
+from copy import deepcopy
+from dataclasses import replace
+from pathlib import Path
+from types import ModuleType
+
+import pytest
+
+
+ROOT = Path(__file__).resolve().parents[1]
+ROUTER_PATH = ROOT / "scripts" / "ci" / "agent_mention_router.py"
+WRAPPER_WORKFLOW = ROOT / ".github" / "workflows" / "agent-mention-opencode-dispatch.yml"
+SCHEDULER_WORKFLOW = ROOT / ".github" / "workflows" / "pr-review-merge-scheduler.yml"
+QUALITY_WORKFLOW = ROOT / ".github" / "workflows" / "agent-mention-router-quality-ci.yml"
+SCHEMA = "cwl.agent-invocation/v2"
+ENVELOPE_KEYS = {"schema", "claim", "agent_invocation_key"}
+
+
+def _load_router() -> ModuleType:
+    """Load the mention router from the repository under test."""
+
+    module_name = "agent_mention_repository_dispatch_envelope"
+    spec = importlib.util.spec_from_file_location(module_name, ROUTER_PATH)
+    assert spec and spec.loader
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+    spec.loader.exec_module(module)
+    return module
+
+
+def _request(router: ModuleType):
+    """Return one complete OpenCode mention request."""
+
+    return router.MentionRequest(
+        repository="ContextualWisdomLab/example",
+        pull_request_number=17,
+        pull_request_head_sha="a" * 40,
+        pull_request_base_branch="main",
+        comment_id=91,
+        actor="maintainer",
+        agents=("opencode-agent",),
+        pull_request_base_sha="b" * 40,
+    )
+
+
+def _named_step(workflow: str, name: str) -> str:
+    """Return one exact named workflow step."""
+
+    marker = f"      - name: {name}\n"
+    start = workflow.index(marker)
+    try:
+        end = workflow.index("\n      - name:", start + len(marker))
+    except ValueError:
+        end = len(workflow)
+    return workflow[start:end]
+
+
+def _python_heredoc(step: str) -> str:
+    """Return executable Python from one workflow heredoc."""
+
+    marker = "python3 - <<'PYTHON'\n"
+    start = step.index(marker) + len(marker)
+    end = step.index("\n          PYTHON", start)
+    return textwrap.dedent(step[start:end])
+
+
+def _run_python_contract(
+    code: str, environment: dict[str, str]
+) -> subprocess.CompletedProcess:
+    """Execute one extracted workflow validator with an isolated environment."""
+
+    return subprocess.run(
+        [sys.executable, "-c", code],
+        text=True,
+        capture_output=True,
+        check=False,
+        env={**os.environ, **environment},
+    )
+
+
+def _rebind_invocation_key(payload: dict[str, object]) -> None:
+    """Recompute the canonical claim digest after an intentional claim mutation."""
+
+    canonical = json.dumps(
+        payload["claim"],
+        ensure_ascii=True,
+        separators=(",", ":"),
+        sort_keys=True,
+    ).encode("utf-8")
+    payload["agent_invocation_key"] = hashlib.sha256(canonical).hexdigest()
+
+
+def test_router_emits_three_key_versioned_envelope_without_changing_claim_key() -> None:
+    """Keep the transport bounded while preserving existing ledger identities."""
+
+    router = _load_router()
+    request = _request(router)
+    body = router.opencode_payload(request)
+    payload = body["client_payload"]
+
+    assert body["event_type"] == "agent-mention-opencode"
+    assert set(payload) == ENVELOPE_KEYS
+    assert len(payload) == 3
+    assert payload["schema"] == SCHEMA
+    assert payload["claim"] == router.agent_invocation_claim(
+        request, "opencode-agent"
+    )
+    assert payload["agent_invocation_key"] == (
+        "8c73b6aa8ca5ef7b610b997e6913b71bfad29e74330836263087617fb3d0b9ff"
+    )
+    assert router.agent_ledger_artifact_name(request, "opencode-agent") == (
+        "cwl-agent-invocation-"
+        "8c73b6aa8ca5ef7b610b997e6913b71bfad29e74330836263087617fb3d0b9ff"
+    )
+    assert len(json.dumps(payload, separators=(",", ":"))) <= 65_535
+
+
+def test_router_rejects_an_oversized_first_hop_before_calling_github() -> None:
+    """The producer enforces GitHub's size contract before any API request."""
+
+    router = _load_router()
+    oversized = replace(_request(router), actor="a" * 70_000)
+
+    with pytest.raises(ValueError, match="repository dispatch exceeds GitHub limits"):
+        router.opencode_payload(oversized)
+
+
+def test_wrapper_validates_and_reuses_the_same_bounded_envelope_before_ledger() -> None:
+    """Validate the complete second hop before claiming an immutable artifact."""
+
+    workflow = WRAPPER_WORKFLOW.read_text(encoding="utf-8")
+    validate = _named_step(
+        workflow,
+        "Validate exact invocation payload and prepare scheduler request",
+    )
+    forward = _named_step(
+        workflow,
+        "Forward once to the authoritative review-only scheduler",
+    )
+
+    assert "github.event.client_payload.claim.repository" in workflow
+    assert "github.event.client_payload.claim.pr_number" in workflow
+    assert "PAYLOAD_SCHEMA: ${{ github.event.client_payload.schema || '' }}" in workflow
+    assert "set(envelope)" in validate
+    for key in sorted(ENVELOPE_KEYS):
+        assert f'"{key}"' in validate
+    assert "set(claim)" in validate
+    assert "hmac.compare_digest" in validate
+    assert "65_535" in validate
+    assert '"event_type": "merge-scheduler-agent-review-v2"' in validate
+    assert '"client_payload": envelope' in validate
+    assert workflow.index(
+        "Validate exact invocation payload and prepare scheduler request"
+    ) < workflow.index("Inspect exact-name Actions artifact ledger")
+    assert '--input "$SCHEDULER_REQUEST_FILE"' in forward
+    assert "client_payload:" not in forward
+
+
+def test_wrapper_executes_the_validated_envelope_as_the_exact_second_hop(
+    tmp_path: Path,
+) -> None:
+    """The materialized scheduler request reuses the exact three-key payload."""
+
+    router = _load_router()
+    payload = router.opencode_payload(_request(router))["client_payload"]
+    workflow = WRAPPER_WORKFLOW.read_text(encoding="utf-8")
+    code = _python_heredoc(
+        _named_step(
+            workflow,
+            "Validate exact invocation payload and prepare scheduler request",
+        )
+    )
+    environment_file = tmp_path / "github-env"
+    completed = _run_python_contract(
+        code,
+        {
+            "CLIENT_PAYLOAD_JSON": json.dumps(payload),
+            "GITHUB_ENV": str(environment_file),
+            "INVOCATION_KEY": payload["agent_invocation_key"],
+            "PAYLOAD_SCHEMA": payload["schema"],
+            "RUNNER_TEMP": str(tmp_path),
+        },
+    )
+
+    assert completed.returncode == 0, completed.stderr
+    request_path = tmp_path / "agent-review-scheduler-request.json"
+    request = json.loads(request_path.read_text(encoding="utf-8"))
+    assert request == {
+        "event_type": "merge-scheduler-agent-review-v2",
+        "client_payload": payload,
+    }
+    assert len(request["client_payload"]) == 3
+    assert request_path.stat().st_size <= 65_535
+    assert f"SCHEDULER_REQUEST_FILE={request_path}" in environment_file.read_text(
+        encoding="utf-8"
+    )
+
+
+@pytest.mark.parametrize(
+    ("mutation", "error_fragment"),
+    [
+        ("extra-envelope-field", "invalid OpenCode invocation envelope"),
+        ("missing-claim-field", "invalid OpenCode invocation claim fields"),
+        ("wrong-boolean-type", "invalid enable_auto_merge flag"),
+        ("altered-bound-field", "invocation key does not match canonical payload"),
+        ("unsupported-schema", "unsupported OpenCode invocation schema"),
+        ("policy-violating-claim", "violates review-only policy"),
+        ("invalid-repository", "invalid repository"),
+        ("invalid-head-sha", "invalid head SHA"),
+        ("invalid-base-sha", "invalid base SHA"),
+        ("invalid-base-branch", "invalid base branch"),
+        ("invalid-actor", "invalid actor"),
+    ],
+)
+def test_wrapper_rejects_malformed_or_unbound_envelopes_before_materialization(
+    tmp_path: Path,
+    mutation: str,
+    error_fragment: str,
+) -> None:
+    """Unknown, malformed, or key-mismatched claims fail before ledger access."""
+
+    router = _load_router()
+    payload = deepcopy(router.opencode_payload(_request(router))["client_payload"])
+    if mutation == "extra-envelope-field":
+        payload["extra"] = "rejected"
+    elif mutation == "missing-claim-field":
+        del payload["claim"]["base_sha"]
+    elif mutation == "wrong-boolean-type":
+        payload["claim"]["enable_auto_merge"] = "false"
+    elif mutation == "altered-bound-field":
+        payload["claim"]["head_sha"] = "c" * 40
+    elif mutation == "unsupported-schema":
+        payload["schema"] = "cwl.agent-invocation/v3"
+    elif mutation == "policy-violating-claim":
+        payload["claim"]["update_branches"] = True
+    elif mutation == "invalid-repository":
+        payload["claim"]["repository"] = "OtherOrg/example"
+    elif mutation == "invalid-head-sha":
+        payload["claim"]["head_sha"] = "z" * 40
+    elif mutation == "invalid-base-sha":
+        payload["claim"]["base_sha"] = "z" * 40
+    elif mutation == "invalid-base-branch":
+        payload["claim"]["base_branch"] = "-main"
+    elif mutation == "invalid-actor":
+        payload["claim"]["actor"] = "invalid_actor"
+    else:  # pragma: no cover - the parameter list is exhaustive
+        raise AssertionError(mutation)
+
+    if mutation in {
+        "policy-violating-claim",
+        "invalid-repository",
+        "invalid-head-sha",
+        "invalid-base-sha",
+        "invalid-base-branch",
+        "invalid-actor",
+    }:
+        _rebind_invocation_key(payload)
+
+    workflow = WRAPPER_WORKFLOW.read_text(encoding="utf-8")
+    code = _python_heredoc(
+        _named_step(
+            workflow,
+            "Validate exact invocation payload and prepare scheduler request",
+        )
+    )
+    completed = _run_python_contract(
+        code,
+        {
+            "CLIENT_PAYLOAD_JSON": json.dumps(payload),
+            "GITHUB_ENV": str(tmp_path / "github-env"),
+            "INVOCATION_KEY": payload["agent_invocation_key"],
+            "PAYLOAD_SCHEMA": payload["schema"],
+            "RUNNER_TEMP": str(tmp_path),
+        },
+    )
+
+    assert completed.returncode != 0
+    assert error_fragment in completed.stderr
+    assert not (tmp_path / "agent-review-scheduler-request.json").exists()
+
+
+def test_scheduler_has_strict_v2_and_explicit_legacy_dispatch_paths() -> None:
+    """The dedicated review event must not fall through generic flat defaults."""
+
+    workflow = SCHEDULER_WORKFLOW.read_text(encoding="utf-8")
+    targeted = _named_step(workflow, "Validate targeted repository dispatch")
+    inspect = _named_step(workflow, "Inspect PR review and merge queue")
+
+    assert "types: [merge-scheduler, merge-scheduler-agent-review-v2]" in workflow
+    assert "github.event.client_payload.claim.repository" in workflow
+    assert "github.event.client_payload.claim.pr_number" in workflow
+    assert (
+        'os.environ["GITHUB_EVENT_ACTION"] == "merge-scheduler-agent-review-v2"'
+        in targeted
+    )
+    assert f'EXPECTED_SCHEMA="{SCHEMA}"' in targeted
+    assert "set(envelope)" in targeted
+    assert "set(claim)" in targeted
+    assert "hmac.compare_digest" in targeted
+    assert 'live_base_sha="$(jq -r \'.base.sha // empty\'' in targeted
+    assert '"$TARGET_HEAD_SHA_INPUT" != "$live_head_sha"' in targeted
+    assert '"$TARGET_BASE_SHA_INPUT" != "$live_base_sha"' in targeted
+    assert "--expected-head-sha" in inspect
+    assert "--expected-base-sha" in inspect
+    assert "--expected-base-branch" in inspect
+    concurrency = workflow.split("concurrency:", 1)[1].split("jobs:", 1)[0]
+    assert "github.event.client_payload.agent_invocation_key" in concurrency
+    assert "github.event.action != 'merge-scheduler-agent-review-v2'" in concurrency
+    assert "github.run_id" in concurrency
+
+
+def test_scheduler_executes_strict_v2_validation_and_keeps_legacy_explicit() -> None:
+    """Only a valid v2 envelope or a schema-free legacy payload is accepted."""
+
+    router = _load_router()
+    payload = router.opencode_payload(_request(router))["client_payload"]
+    workflow = SCHEDULER_WORKFLOW.read_text(encoding="utf-8")
+    code = _python_heredoc(
+        _named_step(workflow, "Validate targeted repository dispatch")
+    )
+    common = {"EXPECTED_SCHEMA": SCHEMA}
+
+    valid = _run_python_contract(
+        code,
+        {
+            **common,
+            "DISPATCH_CLIENT_PAYLOAD_JSON": json.dumps(payload),
+            "GITHUB_EVENT_ACTION": "merge-scheduler-agent-review-v2",
+        },
+    )
+    assert valid.returncode == 0, valid.stderr
+
+    legacy = _run_python_contract(
+        code,
+        {
+            **common,
+            "DISPATCH_CLIENT_PAYLOAD_JSON": json.dumps(
+                {"target_repository": "ContextualWisdomLab/example", "pr_number": 17}
+            ),
+            "GITHUB_EVENT_ACTION": "merge-scheduler",
+        },
+    )
+    assert legacy.returncode == 0, legacy.stderr
+
+    wrong_event = _run_python_contract(
+        code,
+        {
+            **common,
+            "DISPATCH_CLIENT_PAYLOAD_JSON": json.dumps(payload),
+            "GITHUB_EVENT_ACTION": "merge-scheduler",
+        },
+    )
+    assert wrong_event.returncode != 0
+
+    malformed = deepcopy(payload)
+    malformed["claim"]["update_branches"] = True
+    invalid_policy = _run_python_contract(
+        code,
+        {
+            **common,
+            "DISPATCH_CLIENT_PAYLOAD_JSON": json.dumps(malformed),
+            "GITHUB_EVENT_ACTION": "merge-scheduler-agent-review-v2",
+        },
+    )
+    assert invalid_policy.returncode != 0
+
+
+def test_agent_mention_quality_gate_covers_the_downstream_scheduler_contract() -> None:
+    """Every production and regression path in this transport runs its quality gate."""
+
+    workflow = QUALITY_WORKFLOW.read_text(encoding="utf-8")
+
+    for path in (
+        '.github/workflows/pr-review-merge-scheduler.yml',
+        'scripts/ci/pr_review_merge_scheduler.py',
+        'scripts/ci/pr_review_fix_scheduler.py',
+        'tests/test_pr_review_merge_scheduler.py',
+    ):
+        assert workflow.count(f'      - "{path}"') == 2
+
+    coverage_config = workflow.split("[run]\n", 1)[1].split("[report]\n", 1)[0]
+    assert "scripts/ci/pr_review_merge_scheduler.py" in coverage_config
+    interrogate = workflow.split("python -m interrogate --fail-under=100", 1)[1].split(
+        "python -m compileall", 1
+    )[0]
+    assert "scripts/ci/pr_review_merge_scheduler.py" in interrogate
diff --git a/tests/test_agent_mention_router.py b/tests/test_agent_mention_router.py
index 4509d43f0..1520a204d 100644
--- a/tests/test_agent_mention_router.py
+++ b/tests/test_agent_mention_router.py
@@ -220,11 +220,13 @@ def test_eligible_agents_and_payloads() -> None:
     assert noema["client_payload"]["pr_base_sha"] == "b" * 40
     opencode = module.opencode_payload(request)
     assert opencode["event_type"] == "agent-mention-opencode"
-    assert opencode["client_payload"]["base_branch"] == "develop"
-    assert opencode["client_payload"]["pr_base_sha"] == "b" * 40
-    assert opencode["client_payload"]["merge_mode"] == "disabled"
-    assert opencode["client_payload"]["enable_auto_merge"] is False
-    assert opencode["client_payload"]["update_branches"] is False
+    assert opencode["client_payload"]["schema"] == "cwl.agent-invocation/v2"
+    claim = opencode["client_payload"]["claim"]
+    assert claim["base_branch"] == "develop"
+    assert claim["base_sha"] == "b" * 40
+    assert claim["merge_mode"] == "disabled"
+    assert claim["enable_auto_merge"] is False
+    assert claim["update_branches"] is False
 
 
 def test_dispatch_uses_central_events_and_acknowledges() -> None:
diff --git a/tests/test_agent_mention_workflow_contract.py b/tests/test_agent_mention_workflow_contract.py
index c5fc4cae5..6958a5a05 100644
--- a/tests/test_agent_mention_workflow_contract.py
+++ b/tests/test_agent_mention_workflow_contract.py
@@ -52,11 +52,22 @@ def test_workflow_uses_local_event_and_central_sweep_with_job_scoped_writes() ->
 
 
 def test_quality_workflow_measures_exact_files_without_module_name_warnings() -> None:
-    """Coverage includes the two script paths instead of treating paths as modules."""
+    """Coverage and docstring gates include every changed production helper."""
 
     text = QUALITY_WORKFLOW.read_text(encoding="utf-8")
+    trigger_block = text.split("\nconcurrency:\n", 1)[0]
     coverage_config = text.split("[run]\n", 1)[1].split("[report]\n", 1)[0]
+    interrogate_block = text.split(
+        "python -m interrogate --fail-under=100 \\\n", 1
+    )[1].split("\n          python -m compileall", 1)[0]
+
     assert "include =" in coverage_config
     assert "source =" not in coverage_config
-    assert "scripts/ci/agent_mention_router.py" in coverage_config
-    assert "scripts/ci/agent_mention_sweep.py" in coverage_config
+    for production_path in (
+        "scripts/ci/agent_mention_router.py",
+        "scripts/ci/agent_mention_sweep.py",
+        "scripts/ci/pr_review_merge_scheduler.py",
+    ):
+        assert production_path in coverage_config
+        assert production_path in interrogate_block
+    assert trigger_block.count('"scripts/ci/pr_review_fix_scheduler.py"') == 2
diff --git a/tests/test_pr_review_merge_scheduler.py b/tests/test_pr_review_merge_scheduler.py
index 3e421e903..ce9434377 100644
--- a/tests/test_pr_review_merge_scheduler.py
+++ b/tests/test_pr_review_merge_scheduler.py
@@ -33,6 +33,7 @@ def fake_fine_grained_github_token(body):
 def make_pr(**overrides):
     value = {
         "number": 1,
+        "state": "OPEN",
         "title": "Central review",
         "isDraft": False,
         "mergeable": "MERGEABLE",
@@ -3399,6 +3400,405 @@ def test_inspect_pr_cancels_stale_queued_runs_before_decision(monkeypatch):
     assert cancelled == [("owner/repo", 1, True)]
 
 
+def test_snapshot_bound_inspection_performs_review_dispatch_without_general_mutations(
+    monkeypatch,
+):
+    """A digest-bound mention cannot clean up, merge, or update unrelated state."""
+
+    def forbidden(*args, **kwargs):
+        raise AssertionError(f"unexpected general scheduler mutation: {args!r} {kwargs!r}")
+
+    for name in (
+        "cancel_stale_pr_runs",
+        "resolve_outdated_review_threads",
+        "dismiss_stale_opencode_approvals",
+        "dismiss_stale_opencode_change_requests",
+        "disable_auto_merge",
+        "enable_auto_merge",
+        "merge_pr",
+        "restamp_pr_head_for_last_push_approval",
+        "update_branch",
+    ):
+        monkeypatch.setattr(sched, name, forbidden)
+    monkeypatch.setattr(sched, "repository_dispatch_wait_reason", lambda repo, workflow: None)
+    dispatched = []
+    monkeypatch.setattr(
+        sched,
+        "dispatch_strix_evidence",
+        lambda repo, workflow, pr, dry_run, snapshot_guarded: dispatched.append(
+            (repo, workflow, pr["headRefOid"], dry_run, snapshot_guarded)
+        )
+        or "dispatched",
+    )
+
+    decision = inspect(
+        make_pr(),
+        dry_run=False,
+        snapshot_guarded=True,
+        enable_auto_merge_flag=False,
+        merge_mode="disabled",
+        update_branches=False,
+    )
+
+    assert decision.action == "security_dispatch"
+    assert dispatched == [
+        ("owner/repo", "Strix Security Scan", "head", False, True)
+    ]
+
+
+def test_snapshot_bound_review_covers_every_fail_closed_decision_boundary(monkeypatch):
+    """The review-only path remains explicit for every terminal evidence state."""
+
+    monkeypatch.setattr(
+        sched,
+        "unresolved_thread_count",
+        lambda pr: pr.get("test_unresolved", 0),
+    )
+    monkeypatch.setattr(
+        sched,
+        "has_current_head_changes_requested",
+        lambda pr: pr.get("test_changes_requested", False),
+    )
+    monkeypatch.setattr(
+        sched,
+        "effective_merge_state",
+        lambda pr: pr.get("test_merge_state", "CLEAN"),
+    )
+    monkeypatch.setattr(
+        sched,
+        "has_current_head_approval",
+        lambda pr: pr.get("test_approved", False),
+    )
+    monkeypatch.setattr(
+        sched,
+        "failed_status_checks",
+        lambda pr: pr.get("test_failed", []),
+    )
+    monkeypatch.setattr(
+        sched,
+        "action_required_checks",
+        lambda pr: pr.get("test_action_required", []),
+    )
+    monkeypatch.setattr(
+        sched,
+        "branch_outdated_by_base",
+        lambda pr, merge_state: pr.get("test_behind", 0),
+    )
+    monkeypatch.setattr(
+        sched,
+        "opencode_progress_state",
+        lambda pr, stale_after_minutes: pr.get("test_opencode", "absent"),
+    )
+    monkeypatch.setattr(
+        sched,
+        "has_current_head_deterministic_fallback_approval",
+        lambda pr: pr.get("test_fallback", False),
+    )
+    monkeypatch.setattr(
+        sched,
+        "strix_evidence_state",
+        lambda pr: pr.get("test_strix", "missing"),
+    )
+    monkeypatch.setattr(
+        sched,
+        "repository_dispatch_wait_reason",
+        lambda repo, workflow: "dispatch unavailable" if workflow.startswith("wait-") else None,
+    )
+    monkeypatch.setattr(
+        sched,
+        "dispatch_opencode_review",
+        lambda repo, workflow, pr, dry_run, snapshot_guarded: pr.get(
+            "test_dispatch_result", "dispatched"
+        ),
+    )
+    monkeypatch.setattr(
+        sched,
+        "dispatch_strix_evidence",
+        lambda repo, workflow, pr, dry_run, snapshot_guarded: pr.get(
+            "test_dispatch_result", "dispatched"
+        ),
+    )
+
+    def decide(
+        pr,
+        *,
+        trigger_reviews=True,
+        review_dispatch_allowed=True,
+        workflow="review",
+        security_workflow="security",
+    ):
+        return sched.inspect_snapshot_bound_review(
+            "owner/repo",
+            pr,
+            dry_run=False,
+            trigger_reviews=trigger_reviews,
+            review_dispatch_allowed=review_dispatch_allowed,
+            workflow=workflow,
+            security_workflow=security_workflow,
+            base_branch="main",
+            stale_opencode_minutes=60,
+        )
+
+    cases = [
+        (make_pr(state="CLOSED"), {}, "wait", "no longer open"),
+        (make_pr(isDraft=True), {}, "skip", "draft"),
+        (make_pr(baseRefName="release"), {}, "wait", "base branch changed"),
+        (make_pr(test_unresolved=2), {}, "block", "2 unresolved"),
+        (make_pr(test_changes_requested=True), {}, "block", "requested changes"),
+        (make_pr(test_merge_state="DIRTY"), {}, "block", "merge conflict"),
+        (
+            make_pr(test_approved=True, test_failed=["quality"]),
+            {},
+            "block",
+            "failed check(s)",
+        ),
+        (
+            make_pr(test_action_required=["deploy"]),
+            {},
+            "wait",
+            "workflow action required",
+        ),
+        (
+            make_pr(test_behind=2),
+            {},
+            "wait",
+            "current head has no OpenCode approval; snapshot-bound review cannot update",
+        ),
+        (make_pr(test_merge_state="UNKNOWN"), {}, "wait", "still being calculated"),
+        (make_pr(test_approved=True), {}, "wait", "review-only"),
+        (make_pr(test_opencode="running"), {}, "wait", "already in progress"),
+        (
+            make_pr(test_opencode="stale"),
+            {"trigger_reviews": False},
+            "wait",
+            "dispatch disabled",
+        ),
+        (
+            make_pr(test_opencode="stale"),
+            {"review_dispatch_allowed": False},
+            "wait",
+            "limit reached",
+        ),
+        (
+            make_pr(test_opencode="stale", test_dispatch_result="already_running"),
+            {},
+            "wait",
+            "already active",
+        ),
+        (
+            make_pr(test_opencode="stale", test_dispatch_result="snapshot_changed"),
+            {},
+            "wait",
+            "different-head review run is active",
+        ),
+        (make_pr(test_opencode="stale"), {}, "review_dispatch", "re-dispatched"),
+        (
+            make_pr(test_strix="missing"),
+            {"review_dispatch_allowed": False},
+            "wait",
+            "limit reached",
+        ),
+        (
+            make_pr(test_strix="missing"),
+            {"security_workflow": "wait-security"},
+            "wait",
+            "dispatch unavailable",
+        ),
+        (
+            make_pr(test_strix="missing", test_dispatch_result="snapshot_changed"),
+            {},
+            "wait",
+            "different-head Strix run is active",
+        ),
+        (
+            make_pr(test_strix="missing", test_dispatch_result="already_running"),
+            {},
+            "wait",
+            "same-head Strix evidence",
+        ),
+        (make_pr(test_strix="running"), {}, "wait", "still running"),
+        (
+            make_pr(test_strix="complete"),
+            {"review_dispatch_allowed": False},
+            "wait",
+            "limit reached",
+        ),
+        (
+            make_pr(test_strix="complete"),
+            {"workflow": "wait-review"},
+            "wait",
+            "dispatch unavailable",
+        ),
+        (
+            make_pr(test_strix="complete", test_dispatch_result="already_running"),
+            {},
+            "wait",
+            "already active",
+        ),
+        (
+            make_pr(test_strix="complete", test_dispatch_result="snapshot_changed"),
+            {},
+            "wait",
+            "different-head review run is active",
+        ),
+        (
+            make_pr(test_strix="complete"),
+            {},
+            "review_dispatch",
+            "OpenCode dispatched",
+        ),
+        (
+            make_pr(test_behind=1),
+            {"trigger_reviews": False},
+            "block",
+            "dispatch disabled",
+        ),
+    ]
+    for pr, kwargs, action, reason in cases:
+        decision = decide(pr, **kwargs)
+        assert decision.action == action
+        assert reason in decision.reason
+
+    approved_behind = decide(make_pr(test_behind=2, test_approved=True))
+    assert approved_behind == sched.Decision(
+        1,
+        "wait",
+        "current head is approved; snapshot-bound review cannot update an outdated branch",
+    )
+    assert "no OpenCode approval" not in approved_behind.reason
+
+    monkeypatch.setenv("GITHUB_EVENT_NAME", "workflow_run")
+    fallback = decide(make_pr(test_fallback=True))
+    assert fallback.action == "wait"
+    assert "deterministic fallback" in fallback.reason
+    no_fallback = decide(
+        make_pr(test_fallback=False),
+        trigger_reviews=False,
+    )
+    assert no_fallback.action == "block"
+
+
+def test_snapshot_guarded_review_dispatch_does_not_post_when_another_head_is_active(monkeypatch):
+    """A post-validation push prevents stale dispatch and receiver-side cancellation."""
+
+    monkeypatch.setattr(sched, "require_github_actions_control_actor", lambda action: None)
+    monkeypatch.setattr(
+        sched,
+        "active_opencode_run_refs",
+        lambda repo, workflow, pr: ([], [(repo, "new-head-run")]),
+    )
+    monkeypatch.setattr(
+        sched,
+        "force_cancel_workflow_run_refs",
+        lambda refs: (_ for _ in ()).throw(AssertionError(f"unexpected cancellation: {refs}")),
+    )
+    payloads = []
+    monkeypatch.setattr(
+        sched,
+        "run_github_dispatch",
+        lambda args, stdin=None: payloads.append(json.loads(stdin)),
+    )
+    pr = make_pr(baseRefOid="b" * 40, headRefOid="a" * 40)
+
+    assert (
+        sched.dispatch_opencode_review(
+            "owner/repo",
+            "OpenCode Review",
+            pr,
+            dry_run=False,
+            snapshot_guarded=True,
+        )
+        == "snapshot_changed"
+    )
+    assert payloads == []
+
+
+def test_snapshot_guarded_strix_dispatch_does_not_post_or_cancel_newer_runs(
+    monkeypatch,
+):
+    """Snapshot mode leaves later-head Strix runs alone without queuing stale work."""
+
+    monkeypatch.setattr(
+        sched,
+        "matching_actions_job_id",
+        lambda *args, **kwargs: (_ for _ in ()).throw(AssertionError("unexpected rerun lookup")),
+    )
+    monkeypatch.setattr(sched, "require_github_actions_control_actor", lambda action: None)
+    monkeypatch.setattr(
+        sched,
+        "active_review_run_refs",
+        lambda *args, **kwargs: ([], [("owner/repo", "new-head-run")]),
+    )
+    monkeypatch.setattr(
+        sched,
+        "force_cancel_workflow_run_refs",
+        lambda refs: (_ for _ in ()).throw(AssertionError(f"unexpected cancellation: {refs}")),
+    )
+    payloads = []
+    monkeypatch.setattr(
+        sched,
+        "run_github_dispatch",
+        lambda args, stdin=None: payloads.append(json.loads(stdin)),
+    )
+    pr = make_pr(baseRefOid="b" * 40, headRefOid="a" * 40)
+
+    assert (
+        sched.dispatch_strix_evidence(
+            "owner/repo",
+            "Strix Security Scan",
+            pr,
+            dry_run=False,
+            snapshot_guarded=True,
+        )
+        == "snapshot_changed"
+    )
+    assert payloads == []
+
+
+def test_snapshot_guarded_dispatch_deduplicates_same_head_without_cancellation(
+    monkeypatch,
+):
+    """An exact-head active run suppresses duplicate OpenCode and Strix POSTs."""
+
+    monkeypatch.setattr(sched, "require_github_actions_control_actor", lambda action: None)
+    monkeypatch.setattr(
+        sched,
+        "active_opencode_run_refs",
+        lambda repo, workflow, pr: ([(repo, "same-head")], []),
+    )
+    monkeypatch.setattr(
+        sched,
+        "active_review_run_refs",
+        lambda *args, **kwargs: ([("owner/repo", "same-head")], []),
+    )
+    monkeypatch.setattr(
+        sched,
+        "force_cancel_workflow_run_refs",
+        lambda refs: (_ for _ in ()).throw(AssertionError(f"unexpected cancellation: {refs}")),
+    )
+    monkeypatch.setattr(
+        sched,
+        "run_github_dispatch",
+        lambda *args, **kwargs: (_ for _ in ()).throw(AssertionError("unexpected POST")),
+    )
+    pr = make_pr(baseRefOid="b" * 40, headRefOid="a" * 40)
+
+    assert sched.dispatch_opencode_review(
+        "owner/repo",
+        "OpenCode Review",
+        pr,
+        dry_run=False,
+        snapshot_guarded=True,
+    ) == "already_running"
+    assert sched.dispatch_strix_evidence(
+        "owner/repo",
+        "Strix Security Scan",
+        pr,
+        dry_run=False,
+        snapshot_guarded=True,
+    ) == "already_running"
+
+
 def test_inspect_pr_blocks_auto_merge_for_approved_conflicts(monkeypatch):
     auto_merges = []
     disables = []
@@ -4365,6 +4765,228 @@ def test_main_rejects_invalid_branch_update_limit():
         )
 
 
+@pytest.mark.parametrize(
+    ("observed_head", "observed_base", "observed_branch", "observed_state", "message"),
+    [
+        ("c" * 40, "b" * 40, "main", "OPEN", "head SHA changed"),
+        ("a" * 40, "d" * 40, "main", "OPEN", "base SHA changed"),
+        ("a" * 40, "b" * 40, "release", "OPEN", "base branch changed"),
+        ("a" * 40, "b" * 40, "main", "CLOSED", "no longer open"),
+    ],
+)
+def test_main_rejects_target_snapshot_drift_before_inspection(
+    monkeypatch,
+    observed_head,
+    observed_base,
+    observed_branch,
+    observed_state,
+    message,
+):
+    """A validated mention cannot act after the PR head or base advances."""
+
+    inspected = []
+    monkeypatch.setattr(
+        sched,
+        "fetch_pr",
+        lambda repo, number: [
+            make_pr(
+                number=number,
+                headRefOid=observed_head,
+                baseRefOid=observed_base,
+                baseRefName=observed_branch,
+                state=observed_state,
+            )
+        ],
+    )
+    monkeypatch.setattr(
+        sched,
+        "inspect_pr",
+        lambda *args, **kwargs: inspected.append((args, kwargs)),
+    )
+
+    with pytest.raises(SystemExit, match=message):
+        sched.main(
+            [
+                "--repo",
+                "owner/repo",
+                "--base-branch",
+                "main",
+                "--project-flow",
+                "github-flow",
+                "--pr-number",
+                "7",
+                "--expected-head-sha",
+                "a" * 40,
+                "--expected-base-sha",
+                "b" * 40,
+                "--expected-base-branch",
+                "main",
+            ]
+        )
+
+    assert inspected == []
+
+
+def test_main_accepts_the_exact_expected_target_snapshot(monkeypatch, capsys):
+    """Matching immutable refs reach inspection with the review-only policy."""
+
+    inspected = []
+    monkeypatch.setattr(
+        sched,
+        "fetch_pr",
+        lambda repo, number: [
+            make_pr(number=number, headRefOid="a" * 40, baseRefOid="b" * 40)
+        ],
+    )
+
+    def fake_inspect(repo, pr, **kwargs):
+        inspected.append((repo, pr, kwargs))
+        return sched.Decision(pr["number"], "skip", "exact snapshot")
+
+    monkeypatch.setattr(sched, "inspect_pr", fake_inspect)
+
+    assert (
+        sched.main(
+            [
+                "--repo",
+                "owner/repo",
+                "--base-branch",
+                "main",
+                "--project-flow",
+                "github-flow",
+                "--pr-number",
+                "7",
+                "--expected-head-sha",
+                "a" * 40,
+                "--expected-base-sha",
+                "b" * 40,
+                "--expected-base-branch",
+                "main",
+                "--no-enable-auto-merge",
+                "--merge-mode",
+                "disabled",
+                "--no-update-branches",
+            ]
+        )
+        == 0
+    )
+    assert len(inspected) == 1
+    assert inspected[0][1]["headRefOid"] == "a" * 40
+    assert inspected[0][1]["baseRefOid"] == "b" * 40
+    assert inspected[0][2]["enable_auto_merge_flag"] is False
+    assert inspected[0][2]["merge_mode"] == "disabled"
+    assert inspected[0][2]["update_branches"] is False
+    assert inspected[0][2]["snapshot_guarded"] is True
+    assert "exact snapshot" in capsys.readouterr().out
+
+
+@pytest.mark.parametrize(
+    ("prs", "pr_number", "head", "base", "branch", "message"),
+    [
+        ([], 7, "a" * 40, "", "main", "must be supplied together"),
+        ([], 7, "", "b" * 40, "main", "must be supplied together"),
+        ([], 7, "a" * 40, "b" * 40, "", "must be supplied together"),
+        ([], 0, "a" * 40, "b" * 40, "main", "require --pr-number"),
+        ([], 7, "invalid", "b" * 40, "main", "invalid git sha"),
+        ([], 7, "a" * 40, "b" * 40, "bad..branch", "invalid git ref"),
+        ([], 7, "a" * 40, "b" * 40, "main", "unavailable or ambiguous"),
+        (
+            [make_pr(number=8, headRefOid="a" * 40, baseRefOid="b" * 40)],
+            7,
+            "a" * 40,
+            "b" * 40,
+            "main",
+            "unavailable or ambiguous",
+        ),
+        (
+            [make_pr(number=7, headRefOid="invalid", baseRefOid="b" * 40)],
+            7,
+            "a" * 40,
+            "b" * 40,
+            "main",
+            "returned malformed refs",
+        ),
+        (
+            [make_pr(number=7, headRefOid="a" * 40, baseRefOid="invalid")],
+            7,
+            "a" * 40,
+            "b" * 40,
+            "main",
+            "returned malformed refs",
+        ),
+    ],
+)
+def test_expected_snapshot_guard_rejects_incomplete_or_malformed_inputs(
+    prs,
+    pr_number,
+    head,
+    base,
+    branch,
+    message,
+):
+    """Target snapshot guards reject incomplete identities before inspection."""
+
+    with pytest.raises(SystemExit, match=message):
+        sched.validate_expected_pr_snapshot(
+            prs,
+            pr_number=pr_number,
+            expected_head_sha=head,
+            expected_base_sha=base,
+            expected_base_branch=branch,
+        )
+
+
+def test_main_refetches_a_guarded_snapshot_before_any_general_scheduler_action(
+    monkeypatch,
+):
+    """A push after initial validation aborts before cleanup or dispatch."""
+
+    snapshots = [
+        make_pr(number=7, headRefOid="a" * 40, baseRefOid="b" * 40),
+        make_pr(number=7, headRefOid="c" * 40, baseRefOid="b" * 40),
+    ]
+    fetches = []
+    general_inspections = []
+
+    def fake_fetch(repo, number):
+        fetches.append((repo, number))
+        return [snapshots.pop(0)]
+
+    monkeypatch.setattr(sched, "fetch_pr", fake_fetch)
+    monkeypatch.setattr(
+        sched,
+        "inspect_pr",
+        lambda *args, **kwargs: general_inspections.append((args, kwargs)),
+    )
+
+    with pytest.raises(SystemExit, match="head SHA changed"):
+        sched.main(
+            [
+                "--repo",
+                "owner/repo",
+                "--base-branch",
+                "main",
+                "--project-flow",
+                "github-flow",
+                "--pr-number",
+                "7",
+                "--expected-head-sha",
+                "a" * 40,
+                "--expected-base-sha",
+                "b" * 40,
+                "--expected-base-branch",
+                "main",
+                "--no-enable-auto-merge",
+                "--merge-mode",
+                "disabled",
+                "--no-update-branches",
+            ]
+        )
+
+    assert fetches == [("owner/repo", 7), ("owner/repo", 7)]
+    assert general_inspections == []
+
+
 def test_print_summary_self_test_parse_args_and_main(monkeypatch, capsys):
     sched.print_summary(
         [sched.Decision(1, "wait", "ready"), sched.Decision(2, "wait", "queued")],
diff --git a/tests/test_required_workflow_queue_contract.py b/tests/test_required_workflow_queue_contract.py
index 233c08584..cf901fc23 100644
--- a/tests/test_required_workflow_queue_contract.py
+++ b/tests/test_required_workflow_queue_contract.py
@@ -77,6 +77,11 @@ def test_targeted_scheduler_dispatch_is_allowlisted_and_exact_pr_scoped() -> Non
     assert '[ "$live_base_repository" != "$TARGET_REPOSITORY_INPUT" ]' in validation
     assert '[ "$live_head_repository" != "$TARGET_REPOSITORY_INPUT" ]' in validation
     assert "Targeted scheduler dispatch base branch does not match the live PR" in validation
+    assert "TARGET_HEAD_SHA_INPUT:" in validation
+    assert "TARGET_BASE_SHA_INPUT:" in validation
+    assert "live_base_sha=" in validation
+    assert '"$TARGET_HEAD_SHA_INPUT" != "$live_head_sha"' in validation
+    assert '"$TARGET_BASE_SHA_INPUT" != "$live_base_sha"' in validation
     assert "TARGET_REPOSITORY: ${{ steps.targeted_dispatch.outputs.repository }}" in inspect
     assert (
         "TARGET_DEFAULT_BRANCH: ${{ steps.targeted_dispatch.outputs.base_branch }}"
@@ -85,9 +90,13 @@ def test_targeted_scheduler_dispatch_is_allowlisted_and_exact_pr_scoped() -> Non
     assert '--repo "$TARGET_REPOSITORY"' in inspect
     assert '--base-branch "$TARGET_DEFAULT_BRANCH"' in inspect
     assert 'args+=(--pr-number "$PULL_REQUEST_NUMBER")' in inspect
+    assert '--expected-head-sha "$EXPECTED_HEAD_SHA"' in inspect
+    assert '--expected-base-sha "$EXPECTED_BASE_SHA"' in inspect
     assert (
         "github.event_name == 'repository_dispatch' && "
-        "github.event.client_payload.target_repository != '' && "
+        "(github.event.action == 'merge-scheduler-agent-review-v2' && "
+        "github.event.client_payload.claim.repository != '' || "
+        "github.event.client_payload.target_repository != '') && "
         "(secrets.PR_REVIEW_MERGE_TOKEN || secrets.OPENCODE_APPROVE_TOKEN || "
         "steps.scheduler_app_token.outputs.token) || github.token"
     ) in inspect
@@ -111,7 +120,13 @@ def test_privileged_review_retries_use_default_branch_repository_dispatch() -> N
         trigger_contract = workflow.split("concurrency:", 1)[0]
 
         assert "repository_dispatch:" in trigger_contract
-        assert f"types: [{event_type}]" in trigger_contract
+        if filename == "pr-review-merge-scheduler.yml":
+            assert (
+                "types: [merge-scheduler, merge-scheduler-agent-review-v2]"
+                in trigger_contract
+            )
+        else:
+            assert f"types: [{event_type}]" in trigger_contract
         assert "workflow_dispatch:" not in trigger_contract
         assert "github.event.inputs" not in workflow
         assert "github.event.client_payload" in workflow
@@ -206,7 +221,7 @@ def test_central_semgrep_logs_every_finding_and_distinguishes_engine_failure() -
     assert "Semgrep engine/configuration failed with rc=${SEMGREP_RC}" in workflow
 
 
-def test_strix_cancels_superseded_pr_head_security_evidence() -> None:
+def test_strix_isolates_repository_dispatch_runs_from_stale_event_cancellation() -> None:
     workflow = workflow_text("strix.yml")
     concurrency_contract = workflow.split("concurrency:", 1)[1].split(
         "permissions:", 1
@@ -221,13 +236,13 @@ def test_strix_cancels_superseded_pr_head_security_evidence() -> None:
         "github.event.pull_request.base.repo.full_name || github.repository }}"
     ) in concurrency_contract
     assert "format('pr-{0}', github.event.pull_request.number)" in concurrency_contract
-    assert "github.event.client_payload.pr_number != '' && format('pr-{0}'," in workflow
-    assert "format('pr-{0}-{1}'" not in concurrency_contract
-    assert "github.event.pull_request.head.sha" not in concurrency_contract
-    assert "github.event.client_payload.pr_head_sha" not in concurrency_contract
-    assert "cancel-in-progress: true" in workflow
+    assert "github.event_name == 'repository_dispatch' && github.run_id" in concurrency_contract
+    assert "cancel-in-progress: ${{ github.event_name != 'repository_dispatch' }}" in workflow
     assert "default-branch repository_dispatch evidence cannot cancel" in workflow
-    assert "PR-number scope keeps the queue on the current HEAD" in workflow
+    assert "run-id scope prevents an out-of-order stale dispatch" in workflow
+    assert "default pending-run replacement could discard newer valid evidence" in workflow
+    assert "queue: max cannot be combined with the pull-request cancellation policy" in workflow
+    assert "\n  queue: max\n" not in concurrency_contract
     assert (
         "refs/pull/<n>/head has already advanced before this queued run starts"
         in workflow
@@ -281,8 +296,9 @@ def test_pull_request_close_events_cancel_superseded_runs_without_heavy_jobs() -
     assert "${{ secrets." not in opencode_bootstrap
 
     strix_workflow = workflow_text("strix.yml")
-    assert "cancel-in-progress: true" in strix_workflow
-    assert "PR-number scope keeps the queue on the current HEAD" in strix_workflow
+    assert "cancel-in-progress: ${{ github.event_name != 'repository_dispatch' }}" in strix_workflow
+    assert "run-id scope prevents an out-of-order stale dispatch" in strix_workflow
+    assert "default pending-run replacement could discard newer valid evidence" in strix_workflow
 
 
 def test_close_empty_pr_metadata_lookup_retries_and_fails_open() -> None: