diff --git a/app/nodes.py b/app/nodes.py
index 891f56d..04f557a 100644
--- a/app/nodes.py
+++ b/app/nodes.py
@@ -11,11 +11,13 @@ Module-level globals follow the set_config_dir() testability pattern from cforch
 from __future__ import annotations
 
 import logging
+import os
 from pathlib import Path
 from urllib.parse import urlparse
 
 import yaml
 from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel
 
 logger = logging.getLogger(__name__)
 
@@ -187,3 +189,105 @@ def list_nodes() -> list:
         })
 
     return result
+
+
+@router.get("/nodes/{node_id}/profile")
+def get_node_profile(node_id: str) -> dict:
+    """Return the full parsed profile YAML for a node."""
+    p = _profile_path(node_id)
+    if p is None or not p.exists():
+        raise HTTPException(404, f"No profile found for node {node_id}")
+    try:
+        data = yaml.safe_load(p.read_text(encoding="utf-8")) or {}
+    except yaml.YAMLError as exc:
+        raise HTTPException(500, f"Malformed profile YAML: {exc}")
+    return data
+
+
+class UpdateServicesRequest(BaseModel):
+    services: list[str]
+
+
+@router.post("/nodes/{node_id}/gpu/{gpu_id}/services")
+def update_gpu_services(node_id: str, gpu_id: int, body: UpdateServicesRequest) -> dict:
+    """Set service assignment for a GPU with compatibility validation, then atomic write."""
+    import httpx
+
+    cfg = _load_config()
+    coordinator_url = cfg.get("coordinator_url", "") or ""
+
+    p = _profile_path(node_id)
+    if p is None or not p.exists():
+        raise HTTPException(404, f"No profile found for node {node_id}")
+
+    try:
+        profile = yaml.safe_load(p.read_text(encoding="utf-8")) or {}
+    except yaml.YAMLError as exc:
+        raise HTTPException(500, f"Malformed profile YAML: {exc}")
+
+    nodes_section = profile.get("nodes", {}) or {}
+    node_entry = nodes_section.get(node_id, {}) or {}
+    gpu_list = node_entry.get("gpus", []) or []
+
+    gpu_entry = next(
+        (g for g in gpu_list if isinstance(g, dict) and g.get("id") == gpu_id),
+        None,
+    )
+    if gpu_entry is None:
+        raise HTTPException(404, f"GPU {gpu_id} not found in profile for node {node_id}")
+
+    gpu_compute_cap: float = gpu_entry.get("compute_cap") or 0.0
+    gpu_vram_mb: int = gpu_entry.get("vram_mb") or 0
+    services_def = profile.get("services", {}) or {}
+
+    for svc_name in body.services:
+        if svc_name not in services_def:
+            raise HTTPException(422, f"Service '{svc_name}' not defined in profile services dict")
+        svc = services_def[svc_name]
+        min_cap: float = svc.get("min_compute_cap", 0.0) or 0.0
+        if gpu_compute_cap < min_cap:
+            raise HTTPException(
+                422,
+                f"Service '{svc_name}' requires compute_cap >= {min_cap}; GPU has {gpu_compute_cap}",
+            )
+        catalog = svc.get("catalog", {}) or {}
+        min_catalog_vram = (
+            min((m.get("vram_mb", 0) for m in catalog.values()), default=0)
+            if catalog else svc.get("max_mb", 0)
+        )
+        if gpu_vram_mb < min_catalog_vram:
+            raise HTTPException(
+                422,
+                f"Service '{svc_name}' requires {min_catalog_vram} MB VRAM; GPU has {gpu_vram_mb} MB",
+            )
+
+    # Immutable update of GPU services list
+    new_gpu_list = [
+        ({**g, "services": body.services} if isinstance(g, dict) and g.get("id") == gpu_id else g)
+        for g in gpu_list
+    ]
+    new_profile = {
+        **profile,
+        "nodes": {
+            **nodes_section,
+            node_id: {**node_entry, "gpus": new_gpu_list},
+        },
+    }
+
+    # Atomic write: write to .tmp then rename
+    tmp_yaml = Path(str(p) + ".tmp")
+    tmp_yaml.write_text(yaml.dump(new_profile, default_flow_style=False), encoding="utf-8")
+    os.replace(tmp_yaml, p)
+
+    # Trigger coordinator profile reload
+    reloaded = False
+    if coordinator_url:
+        try:
+            rr = httpx.post(
+                f"{coordinator_url}/api/nodes/{node_id}/reload-profile", timeout=5.0
+            )
+            reloaded = rr.status_code < 300
+        except Exception:
+            pass
+
+    return {"ok": True, "reloaded": reloaded, "warnings": []}
diff --git a/tests/test_nodes.py b/tests/test_nodes.py
index 52df098..a475286 100644
--- a/tests/test_nodes.py
+++ b/tests/test_nodes.py
@@ -164,3 +164,37 @@ def test_list_nodes_marks_running_services(client, tmp_path):
 
     data = r.json()
     assert data[0]["gpus"][0]["services_running"] == ["cf-text"]
+
+
+# ── GET /api/nodes-mgmt/nodes/{node_id}/profile ────────────────────────────────
+
+def test_get_profile_returns_parsed_yaml(client, tmp_path):
+    profiles_dir = tmp_path / "profiles"
+    _write_config(tmp_path, {"profiles_dir": str(profiles_dir)})
+    profile = {
+        "services": {"cf-text": {"min_compute_cap": 7.0, "max_mb": 8192, "catalog": {}}},
+        "nodes": {"heimdall": {"gpus": [], "agent_url": "http://10.1.10.71:7701"}},
+    }
+    _write_profile(profiles_dir, "heimdall", profile)
+
+    r = client.get("/api/nodes-mgmt/nodes/heimdall/profile")
+    assert r.status_code == 200
+    data = r.json()
+    assert "services" in data
+    assert "cf-text" in data["services"]
+
+
+def test_get_profile_404_when_missing(client, tmp_path):
+    _write_config(tmp_path, {"profiles_dir": str(tmp_path / "profiles")})
+    r = client.get("/api/nodes-mgmt/nodes/nonexistent/profile")
+    assert r.status_code == 404
+
+
+def test_get_profile_500_on_malformed_yaml(client, tmp_path):
+    profiles_dir = tmp_path / "profiles"
+    profiles_dir.mkdir()
+    _write_config(tmp_path, {"profiles_dir": str(profiles_dir)})
+    (profiles_dir / "bad.yaml").write_text("key: [unclosed", encoding="utf-8")
+
+    r = client.get("/api/nodes-mgmt/nodes/bad/profile")
+    assert r.status_code == 500