diff --git a/circuitforge_core/resources/coordinator/lease_manager.py b/circuitforge_core/resources/coordinator/lease_manager.py
new file mode 100644
index 0000000..f16259a
--- /dev/null
+++ b/circuitforge_core/resources/coordinator/lease_manager.py
@@ -0,0 +1,88 @@
+from __future__ import annotations
+
+import asyncio
+from collections import defaultdict
+
+from circuitforge_core.resources.models import VRAMLease
+
+
+class LeaseManager:
+    def __init__(self) -> None:
+        self._leases: dict[str, VRAMLease] = {}
+        self._gpu_total: dict[tuple[str, int], int] = {}
+        self._gpu_used: dict[tuple[str, int], int] = defaultdict(int)
+        self._lock = asyncio.Lock()
+
+    def register_gpu(self, node_id: str, gpu_id: int, total_mb: int) -> None:
+        self._gpu_total[(node_id, gpu_id)] = total_mb
+
+    def gpu_total_mb(self, node_id: str, gpu_id: int) -> int:
+        return self._gpu_total.get((node_id, gpu_id), 0)
+
+    def used_mb(self, node_id: str, gpu_id: int) -> int:
+        return self._gpu_used[(node_id, gpu_id)]
+
+    async def try_grant(
+        self,
+        node_id: str,
+        gpu_id: int,
+        mb: int,
+        service: str,
+        priority: int,
+        ttl_s: float = 0.0,
+    ) -> VRAMLease | None:
+        async with self._lock:
+            total = self._gpu_total.get((node_id, gpu_id), 0)
+            used = self._gpu_used[(node_id, gpu_id)]
+            if total - used < mb:
+                return None
+            lease = VRAMLease.create(
+                gpu_id=gpu_id, node_id=node_id, mb=mb,
+                service=service, priority=priority, ttl_s=ttl_s,
+            )
+            self._leases[lease.lease_id] = lease
+            self._gpu_used[(node_id, gpu_id)] += mb
+            return lease
+
+    async def release(self, lease_id: str) -> bool:
+        async with self._lock:
+            lease = self._leases.pop(lease_id, None)
+            if lease is None:
+                return False
+            self._gpu_used[(lease.node_id, lease.gpu_id)] -= lease.mb_granted
+            return True
+
+    def get_eviction_candidates(
+        self,
+        node_id: str,
+        gpu_id: int,
+        needed_mb: int,
+        requester_priority: int,
+    ) -> list[VRAMLease]:
+        candidates = [
+            lease for lease in self._leases.values()
+            if lease.node_id == node_id
+            and lease.gpu_id == gpu_id
+            and lease.priority > requester_priority
+        ]
+        candidates.sort(key=lambda l: l.priority, reverse=True)
+        selected: list[VRAMLease] = []
+        freed = 0
+        for candidate in candidates:
+            selected.append(candidate)
+            freed += candidate.mb_granted
+            if freed >= needed_mb:
+                break
+        return selected
+
+    def list_leases(
+        self, node_id: str | None = None, gpu_id: int | None = None
+    ) -> list[VRAMLease]:
+        return [
+            lease for lease in self._leases.values()
+            if (node_id is None or lease.node_id == node_id)
+            and (gpu_id is None or lease.gpu_id == gpu_id)
+        ]
+
+    def all_leases(self) -> list[VRAMLease]:
+        return list(self._leases.values())
diff --git a/pyproject.toml b/pyproject.toml
index 7215dcb..1ee3704 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -19,3 +19,4 @@ include = ["circuitforge_core*"]
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]
+asyncio_mode = "auto"
diff --git a/tests/test_resources/test_lease_manager.py b/tests/test_resources/test_lease_manager.py
new file mode 100644
index 0000000..0b2385c
--- /dev/null
+++ b/tests/test_resources/test_lease_manager.py
@@ -0,0 +1,85 @@
+import asyncio
+import pytest
+from circuitforge_core.resources.coordinator.lease_manager import LeaseManager
+
+
+@pytest.fixture
+def mgr():
+    m = LeaseManager()
+    m.register_gpu(node_id="heimdall", gpu_id=0, total_mb=8192)
+    return m
+
+
+@pytest.mark.asyncio
+async def test_grant_succeeds_when_vram_available(mgr):
+    lease = await mgr.try_grant(
+        node_id="heimdall", gpu_id=0, mb=4096,
+        service="peregrine", priority=1
+    )
+    assert lease is not None
+    assert lease.mb_granted == 4096
+    assert lease.node_id == "heimdall"
+    assert lease.gpu_id == 0
+
+
+@pytest.mark.asyncio
+async def test_grant_fails_when_vram_insufficient(mgr):
+    await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=7000,
+                         service="vllm", priority=1)
+    lease = await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=2000,
+                                 service="kiwi", priority=2)
+    assert lease is None
+
+
+@pytest.mark.asyncio
+async def test_release_frees_vram(mgr):
+    lease = await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=7000,
+                                 service="vllm", priority=1)
+    assert lease is not None
+    released = await mgr.release(lease.lease_id)
+    assert released is True
+    lease2 = await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=7000,
+                                   service="comfyui", priority=4)
+    assert lease2 is not None
+
+
+@pytest.mark.asyncio
+async def test_release_unknown_lease_returns_false(mgr):
+    result = await mgr.release("nonexistent-id")
+    assert result is False
+
+
+@pytest.mark.asyncio
+async def test_get_eviction_candidates_returns_lower_priority_leases(mgr):
+    await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=3000,
+                         service="comfyui", priority=4)
+    await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=2000,
+                         service="ollama", priority=1)
+    candidates = mgr.get_eviction_candidates(
+        node_id="heimdall", gpu_id=0,
+        needed_mb=3000, requester_priority=2
+    )
+    assert len(candidates) == 1
+    assert candidates[0].holder_service == "comfyui"
+
+
+@pytest.mark.asyncio
+async def test_list_leases_for_gpu(mgr):
+    await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=1024,
+                         service="peregrine", priority=1)
+    await mgr.try_grant(node_id="heimdall", gpu_id=0, mb=512,
+                         service="kiwi", priority=2)
+    leases = mgr.list_leases(node_id="heimdall", gpu_id=0)
+    assert len(leases) == 2
+
+
+def test_register_gpu_sets_total(mgr):
+    assert mgr.gpu_total_mb("heimdall", 0) == 8192
+
+
+def test_used_mb_tracks_grants():
+    mgr = LeaseManager()
+    mgr.register_gpu("heimdall", 0, 8192)
+    asyncio.run(mgr.try_grant("heimdall", 0, 3000, "a", 1))
+    asyncio.run(mgr.try_grant("heimdall", 0, 2000, "b", 2))
+    assert mgr.used_mb("heimdall", 0) == 5000