diff --git a/tests/integration/test_live_server.py b/tests/integration/test_live_server.py
index d4f23f3..0714874 100644
--- a/tests/integration/test_live_server.py
+++ b/tests/integration/test_live_server.py
@@ -1,41 +1,124 @@
 """
 Integration tests against a live Cycles server.
 Skipped unless CYCLES_BASE_URL is set.
+
+These tests run in the nightly integration workflow which:
+1. Starts Redis + cycles-server (7878) + cycles-server-admin (7979)
+2. Provisions a tenant, API key, and budget via the admin API
+3. Passes CYCLES_BASE_URL, CYCLES_API_KEY, CYCLES_TENANT as env vars
 """
 import os
+from uuid import uuid4
 
 import pytest
+import requests
 
 pytestmark = pytest.mark.skipif(
     not os.environ.get("CYCLES_BASE_URL"),
-    reason="CYCLES_BASE_URL not set -- skipping live server tests"
+    reason="CYCLES_BASE_URL not set -- skipping live server tests",
 )
 
-# These will be fleshed out once the nightly workflow is configured with secrets
+BASE = os.environ.get("CYCLES_BASE_URL", "")
+KEY = os.environ.get("CYCLES_API_KEY", "")
+TENANT = os.environ.get("CYCLES_TENANT", "integration-test")
+HEADERS = {"X-Cycles-API-Key": KEY, "Content-Type": "application/json"}
 
 
 def test_health_check():
     """Server responds to health endpoint."""
-    import urllib.request
-    base = os.environ["CYCLES_BASE_URL"]
-    req = urllib.request.Request(f"{base}/actuator/health")
-    with urllib.request.urlopen(req, timeout=5) as resp:
-        assert resp.status == 200
+    res = requests.get(f"{BASE}/actuator/health", timeout=5)
+    assert res.status_code == 200
 
 
 def test_reservation_lifecycle():
-    """Create, commit, and verify a reservation."""
-    # TODO: implement once API key provisioning is set up
-    pass
+    """Create a reservation, commit it, verify balance decreased."""
+    # Reserve
+    res = requests.post(
+        f"{BASE}/v1/reservations",
+        headers=HEADERS,
+        json={
+            "idempotency_key": str(uuid4()),
+            "subject": {"tenant": TENANT},
+            "action": {"kind": "llm.completion", "name": "test-model"},
+            "estimate": {"unit": "USD_MICROCENTS", "amount": 10000},
+            "ttl_ms": 60000,
+        },
+        timeout=5,
+    )
+    assert res.status_code == 201, f"Reserve failed: {res.text}"
+    data = res.json()
+    assert "reservation_id" in data
+    rid = data["reservation_id"]
+
+    # Commit with lower actual
+    res = requests.post(
+        f"{BASE}/v1/reservations/{rid}/commit",
+        headers=HEADERS,
+        json={
+            "idempotency_key": str(uuid4()),
+            "actual": {"unit": "USD_MICROCENTS", "amount": 8000},
+        },
+        timeout=5,
+    )
+    assert res.status_code == 200, f"Commit failed: {res.text}"
+
+
+def test_reserve_and_release():
+    """Create a reservation, release it, verify budget is returned."""
+    res = requests.post(
+        f"{BASE}/v1/reservations",
+        headers=HEADERS,
+        json={
+            "idempotency_key": str(uuid4()),
+            "subject": {"tenant": TENANT},
+            "action": {"kind": "llm.completion", "name": "test-model"},
+            "estimate": {"unit": "USD_MICROCENTS", "amount": 5000},
+            "ttl_ms": 60000,
+        },
+        timeout=5,
+    )
+    assert res.status_code == 201
+    rid = res.json()["reservation_id"]
+
+    # Release
+    res = requests.post(
+        f"{BASE}/v1/reservations/{rid}/release",
+        headers=HEADERS,
+        json={
+            "idempotency_key": str(uuid4()),
+            "reason": "integration-test-release",
+        },
+        timeout=5,
+    )
+    assert res.status_code == 200, f"Release failed: {res.text}"
 
 
 def test_decide_endpoint():
     """POST /v1/decide returns a valid decision."""
-    # TODO: implement
-    pass
+    res = requests.post(
+        f"{BASE}/v1/decide",
+        headers=HEADERS,
+        json={
+            "idempotency_key": str(uuid4()),
+            "subject": {"tenant": TENANT},
+            "action": {"kind": "llm.completion", "name": "test-model"},
+            "estimate": {"unit": "USD_MICROCENTS", "amount": 1000},
+        },
+        timeout=5,
+    )
+    assert res.status_code == 200, f"Decide failed: {res.text}"
+    data = res.json()
+    assert data["decision"] in ("ALLOW", "ALLOW_WITH_CAPS", "DENY")
 
 
 def test_balance_query():
-    """GET /v1/balances returns balance data."""
-    # TODO: implement
-    pass
+    """GET /v1/balances returns budget data."""
+    res = requests.get(
+        f"{BASE}/v1/balances",
+        headers=HEADERS,
+        params={"tenant_id": TENANT},
+        timeout=5,
+    )
+    assert res.status_code == 200, f"Balance query failed: {res.text}"
+    data = res.json()
+    assert "balances" in data