diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8ac7af3..0e92c49 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -85,4 +85,15 @@ jobs:
       - run: npm run db:migrate
       - run: npm run db:seed:ci
       - run: npx playwright install --with-deps chromium
-      - run: npm run test:e2e:smoke
+      - name: Integration E2E
+        run: ./scripts/integration-e2e.sh
+
+      - name: Adversarial tier
+        run: |
+          npm run build
+          node .next/standalone/server.js &
+          for _ in $(seq 1 60); do
+            curl -fsS http://localhost:3000 >/dev/null 2>&1 && break
+            sleep 2
+          done
+          bash ./scripts/adversarial.sh
diff --git a/.harness/profile.yaml b/.harness/profile.yaml
index 05ebe4f..e782638 100644
--- a/.harness/profile.yaml
+++ b/.harness/profile.yaml
@@ -17,11 +17,14 @@ requires:
   - .cursor/hooks.json
   - .harness/profile.yaml
   - .harness/VERSION
+  - specs/threat-model.yaml
+  - docs/adr/0000-threat-model.md
   hooks:
     stop: verify-on-stop
   commands:
     verify: ./scripts/verify.sh
     integration: ./scripts/integration-e2e.sh
+    adversarial: ./scripts/adversarial.sh
 bundles_applied:
 - cloud-guards
 - verify-on-stop
@@ -38,7 +41,9 @@ extensions:
   compose:
     deny_compose_from_worktree: true
     integration_cmd: ./scripts/integration-e2e.sh
+    adversarial_cmd: ./scripts/adversarial.sh
     integration_ci_required: true
+    adversarial_ci_required: true
 harness_disclosure:
   schema: harness-disclosure/v1
   scope: repo
diff --git a/AGENTS.md b/AGENTS.md
index 35b7059..e93d172 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -17,6 +17,8 @@ Full check including smoke E2E (signed-in smoke **skips locally** unless `PLAYWR
 
 ```bash
 npm run verify:all
+# Or integration script (same as CI e2e-smoke job):
+./scripts/integration-e2e.sh
 ```
 
 ## Smoke E2E (must stay green on PR)
diff --git a/docs/adr/0000-threat-model.md b/docs/adr/0000-threat-model.md
new file mode 100644
index 0000000..ef636ba
--- /dev/null
+++ b/docs/adr/0000-threat-model.md
@@ -0,0 +1,33 @@
+# ADR 0000: Threat Model — Caller, Trust Boundary, Authentication
+
+**Status:** Accepted  
+**Date:** 2026-07-13  
+**Product:** Autonomous EHS Management System
+
+## Context
+
+EHS inbound integration and cron routes accept authenticated callers only. Cooperative Playwright smoke validates configured flows. Tier-3 adversarial tests unauthenticated inbound integration posts.
+
+See `specs/threat-model.yaml` and `scripts/adversarial.sh`.
+
+## Decision
+
+### Principals
+
+| Principal | Routes |
+|-----------|--------|
+| `anonymous` | none on integration inbound |
+| `integration_service` | bearer/integration secret on inbound webhook |
+| `cron_scheduler` | `CRON_SECRET` bearer on cron routes |
+
+### Trust boundary
+
+`POST /api/integration/inbound` requires integration authentication before payload processing.
+
+### Authentication
+
+API route validates integration credentials; missing auth → `401 Unauthorized`.
+
+## References
+
+- `specs/threat-model.yaml`, `scripts/adversarial.sh`
diff --git a/scripts/adversarial.sh b/scripts/adversarial.sh
new file mode 100755
index 0000000..e714892
--- /dev/null
+++ b/scripts/adversarial.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+# Tier-3 adversarial oracle — unauthenticated inbound integration.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+
+BASE="${ADVERSARIAL_BASE_URL:-http://localhost:3000}"
+
+log() { echo ""; echo "== adversarial: $* =="; }
+
+if ! curl -fsS "$BASE" >/dev/null 2>&1; then
+  echo "App not running at $BASE — start dev server or run integration-e2e first" >&2
+  exit 1
+fi
+
+# deny_case: anonymous_integration_inbound
+log "anonymous_integration_inbound (expect 401)"
+code=$(curl -s -o /tmp/ehs-adversarial.json -w "%{http_code}" \
+  -X POST "$BASE/api/integration/inbound" \
+  -H "Content-Type: application/json" \
+  -d '{"kind":"hris_membership_sync","organizationId":"00000000-0000-4000-8000-000000000001","workerEmail":"adversarial@example.com"}')
+[[ "$code" == "401" ]]
+grep -qi 'Unauthorized' /tmp/ehs-adversarial.json
+echo "  ${code} (as expected)"
+
+echo ""
+echo "adversarial: ok"
diff --git a/scripts/check-threat-model.sh b/scripts/check-threat-model.sh
new file mode 100755
index 0000000..c913c6a
--- /dev/null
+++ b/scripts/check-threat-model.sh
@@ -0,0 +1,112 @@
+#!/usr/bin/env bash
+# Validate threat-model artifact + adversarial tier for integration repos.
+set -euo pipefail
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+cd "$ROOT"
+
+errors=0
+PROFILE="$(grep '^profile:' .harness/profile.yaml 2>/dev/null | awk '{print $2}' || echo solo)"
+INTEGRATION_CMD="$(grep -A5 'commands:' .harness/profile.yaml 2>/dev/null | grep 'integration:' | head -1 | awk '{print $2}' || true)"
+
+if [[ -z "$INTEGRATION_CMD" || "$INTEGRATION_CMD" == "null" ]]; then
+  for candidate in scripts/demo.sh scripts/integration-e2e.sh scripts/integration-smoke.sh scripts/smoke-test.sh; do
+    if [[ -f "$ROOT/$candidate" ]]; then
+      INTEGRATION_CMD="./$candidate"
+      break
+    fi
+  done
+  if [[ -z "$INTEGRATION_CMD" ]]; then
+    shopt -s nullglob
+    for candidate in "$ROOT"/scripts/smoke-test*.sh; do
+      INTEGRATION_CMD="./scripts/$(basename "$candidate")"
+      break
+    done
+    shopt -u nullglob
+  fi
+fi
+
+EXEMPT=0
+case "$PROFILE" in
+  harness-lab|eval) EXEMPT=1 ;;
+esac
+if [[ -z "$INTEGRATION_CMD" || "$INTEGRATION_CMD" == "null" ]]; then
+  echo "check-threat-model: skip (no integration tier; profile=$PROFILE)"
+  exit 0
+fi
+if [[ "$EXEMPT" -eq 1 ]]; then
+  echo "check-threat-model: skip (exempt profile=$PROFILE)"
+  exit 0
+fi
+
+echo "== threat-model: integration=$INTEGRATION_CMD profile=$PROFILE =="
+
+require_file() {
+  local path="$1"
+  if [[ ! -f "$path" ]]; then
+    echo "MISSING: $path" >&2
+    errors=$((errors + 1))
+  fi
+}
+
+require_file "specs/threat-model.yaml"
+if [[ ! -f docs/adr/0000-threat-model.md && ! -f specs/decisions/0000-threat-model.md ]]; then
+  echo "MISSING: docs/adr/0000-threat-model.md or specs/decisions/0000-threat-model.md" >&2
+  errors=$((errors + 1))
+fi
+require_file "scripts/adversarial.sh"
+
+if ! grep -q 'adversarial:' .harness/profile.yaml; then
+  echo "MISSING: requires.commands.adversarial in .harness/profile.yaml" >&2
+  errors=$((errors + 1))
+fi
+
+echo "== threat-model: yaml schema =="
+python3 - <<'PY' || errors=$((errors + 1))
+import pathlib, re, sys
+
+root = pathlib.Path(".")
+text = (root / "specs/threat-model.yaml").read_text()
+if "schema: threat-model/v1" not in text:
+    print("BAD SCHEMA: specs/threat-model.yaml (want threat-model/v1)", file=sys.stderr)
+    raise SystemExit(1)
+cells_part = text.split("deny_cases:")[0]
+cell_ids = re.findall(r"^\s*- id: (\S+)", cells_part, re.M)
+deny_part = text.split("deny_cases:")[-1] if "deny_cases:" in text else ""
+deny_ids = re.findall(r"^\s*- id: (\S+)", deny_part, re.M)
+deny_cells = re.findall(r"^\s*cell: (\S+)", deny_part, re.M)
+if not cell_ids or not deny_ids:
+    print("EMPTY: cells or deny_cases", file=sys.stderr)
+    raise SystemExit(1)
+cell_set = set(cell_ids)
+for cid in deny_cells:
+    if cid not in cell_set:
+        print(f"BAD deny_case cell: {cid!r}", file=sys.stderr)
+        raise SystemExit(1)
+adv = (root / "scripts/adversarial.sh").read_text()
+for did in deny_ids:
+    if did not in adv:
+        print(f"TRACEABILITY: deny_case {did!r} not in adversarial.sh", file=sys.stderr)
+        raise SystemExit(1)
+print(f"yaml ok: {len(cell_ids)} cells, {len(deny_ids)} deny_cases")
+PY
+
+ADR=""
+[[ -f docs/adr/0000-threat-model.md ]] && ADR="docs/adr/0000-threat-model.md"
+[[ -z "$ADR" && -f specs/decisions/0000-threat-model.md ]] && ADR="specs/decisions/0000-threat-model.md"
+if [[ -n "$ADR" ]]; then
+  lower="$(tr '[:upper:]' '[:lower:]' < "$ADR")"
+  for kw in principal "trust bound" authentication; do
+    if ! grep -qi "$kw" <<< "$lower"; then
+      echo "ADR-0000 missing keyword: $kw ($ADR)" >&2
+      errors=$((errors + 1))
+    fi
+  done
+fi
+
+if [[ "$errors" -gt 0 ]]; then
+  echo "check-threat-model: FAILED ($errors errors)" >&2
+  exit 1
+fi
+
+echo "check-threat-model: ok"
diff --git a/scripts/verify.sh b/scripts/verify.sh
index 7bff21c..47a2f40 100755
--- a/scripts/verify.sh
+++ b/scripts/verify.sh
@@ -17,3 +17,8 @@ echo "==> verify (lint + typecheck + unit tests)"
 npm run verify
 
 echo "verify: ok (ci/web parity; add DATABASE_URL + test:e2e:smoke for full QA)"
+
+if [[ -f ./scripts/check-threat-model.sh ]]; then
+  echo "==> threat model gate"
+  bash ./scripts/check-threat-model.sh
+fi
diff --git a/specs/threat-model.yaml b/specs/threat-model.yaml
new file mode 100644
index 0000000..f399d7a
--- /dev/null
+++ b/specs/threat-model.yaml
@@ -0,0 +1,23 @@
+schema: threat-model/v1
+product: Autonomous EHS Management System
+updated: "2026-07-13"
+
+cells:
+  - id: integration_inbound
+    method: POST
+    path: /api/integration/inbound
+    principals: [integration_service]
+    auth_mechanism: integration_bearer
+    trust_boundary: integration_authenticated
+    establishment_failure: "401 Unauthorized"
+
+deny_cases:
+  - id: anonymous_integration_inbound
+    cell: integration_inbound
+    principal: anonymous
+    fixture:
+      path: /api/integration/inbound
+      body: '{}'
+    expect:
+      status: 401
+      reason_substring: Unauthorized