diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 00000000..3c01eed1
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,73 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+`pvecontrol` is a Python CLI tool for managing Proxmox VE clusters. It wraps the [proxmoxer](https://pypi.org/project/proxmoxer/) library to provide higher-level operations not available in the Proxmox web UI (bulk VM listing, node evacuation/migration, sanity checks).
+
+## Development Setup
+
+```shell
+# Activate the virtual environment
+source .env/bin/activate
+
+# Run the tool
+pvecontrol --help
+```
+
+To recreate the environment from scratch:
+
+```shell
+python3 -m venv .env
+.env/bin/pip install -r requirements.txt -r requirements-dev.txt -e .
+```
+
+## Commands
+
+```shell
+# Run all tests
+pytest src/
+
+# Run a single test file
+pytest src/tests/test_cluster.py
+
+# Lint
+pylint src/pvecontrol/
+
+# Format (line length 120)
+black src/
+```
+
+## Architecture
+
+The codebase follows a clean separation between CLI, business logic (actions), and domain models.
+
+**Entry point**: `src/pvecontrol/__init__.py` — defines the Click group `pvecontrol`, wires all subcommands, and exports `main()`.
+
+**CLI decorators**: `src/pvecontrol/cli.py` — reusable Click decorators (`with_table_options`, `task_related_command`, `migration_related_command`, `ResourceGroup`) shared across action modules.
+
+**Actions** (`src/pvecontrol/actions/`): One module per resource type (`cluster`, `node`, `vm`, `storage`, `task`). Each module defines Click commands and calls into models. Actions instantiate `PVECluster.create_from_config(cluster_name)` to get a connected cluster object.
+
+**Models** (`src/pvecontrol/models/`): Domain objects wrapping the Proxmox API:
+- `PVECluster` — top-level object; holds `nodes`, `storages`, lazy-loaded `tasks`, `ha`, `backups`, `backup_jobs`; created via `create_from_config()`
+- `PVENode` — holds a list of `PVEVm` instances; computes `allocatedcpu` / `allocatedmem`
+- `PVEVm`, `PVEStorage`, `PVEVolume`, `PVETask`, `PVEBackupJob` — thin wrappers around API data
+
+**Configuration**: `src/pvecontrol/config.py` uses [confuse](https://confuse.readthedocs.io/) to load `~/.config/pvecontrol/config.yaml`. Supports `$()` shell command substitution in `user`, `password`, `token_name`, `token_value`, and `proxy_certificate` fields.
+
+**Output**: `src/pvecontrol/utils.py` — `print_output()` / `render_output()` render data via `prettytable` in text/json/csv/yaml/md formats. Memory/disk keys in `NATURALSIZE_KEYS` are automatically humanized.
+
+**Sanity checks** (`src/pvecontrol/sanitycheck/`):
+- `checks.py` — abstract base `Check` class with `CheckCode` (OK/WARN/INFO/CRIT) and `CheckType` enums
+- `tests/` — concrete check implementations: `Nodes`, `HaGroups`, `HaVms`, `VmsStartOnBoot`, `VmBackups`, `DiskUnused`
+- `sanitychecks.py` — `SanityCheck` orchestrates running checks and displaying results; exits with code 1 on any CRIT
+
+**Tests** (`src/tests/`): Use `unittest` + `responses` for HTTP mocking. `PVEControlTestcase` in `testcase.py` provides a pre-wired cluster fixture with fake nodes, VMs, backups. Test fixtures live in `src/tests/fixtures/api.py`.
+
+## Conventions
+
+- Commits must follow [Angular Conventional Commits](https://github.com/angular/angular/blob/master/CONTRIBUTING.md#-commit-message-format) — releases are automated via `python-semantic-release`
+- Allowed commit tags: `build`, `chore`, `ci`, `docs`, `feat`, `fix`, `perf`, `style`, `refactor`, `test`
+- All changes must go through a PR with review; `main` is protected
+- Line length: 120 (black) / 150 (pylint)
diff --git a/src/pvecontrol/actions/cluster.py b/src/pvecontrol/actions/cluster.py
index 7b9e91df..c09eddfd 100644
--- a/src/pvecontrol/actions/cluster.py
+++ b/src/pvecontrol/actions/cluster.py
@@ -16,6 +16,7 @@
 def status(ctx):
     """Show cluster status"""
     proxmox = PVECluster.create_from_config(ctx.obj["args"].cluster)
+    cluster_version = proxmox.version
     cluster_status = "healthy" if proxmox.is_healthy else "not healthy"
 
     templates = sum(len(node.templates) for node in proxmox.nodes)
@@ -44,6 +45,7 @@ def _get_disk_output():
 
     if ctx.obj["args"].output == OutputFormats.TEXT:
         print(f"""\n\
+  Version: {cluster_version['version']}
   Status: {cluster_status}
   VMs: {vms - templates}
   Templates: {templates}
diff --git a/src/pvecontrol/models/cluster.py b/src/pvecontrol/models/cluster.py
index e0b0e485..7c3cba38 100644
--- a/src/pvecontrol/models/cluster.py
+++ b/src/pvecontrol/models/cluster.py
@@ -32,6 +32,7 @@ def __init__(self, name, host, config, timeout, verify_ssl=False, **auth):
         self._initstatus()
 
     def _initstatus(self):
+        self.version = self.api.version.get()
         self.status = self.api.cluster.status.get()
         self.resources = self.api.cluster.resources.get()
 
@@ -74,8 +75,13 @@ def ha(self):
         if self._ha is not None:
             return self._ha
 
+        # use rules instead of ha in newer versions
+        if float(self.version["release"]) >= 9.1:
+            _ha_groups = self.api.cluster.ha.rules.get()
+        else:
+            _ha_groups = self.api.cluster.ha.groups.get()
         self._ha = {
-            "groups": self.api.cluster.ha.groups.get(),
+            "groups": _ha_groups,
             "manager_status": self.api.cluster.ha.status.manager_status.get(),
             "resources": self.api.cluster.ha.resources.get(),
         }
diff --git a/src/pvecontrol/models/vm.py b/src/pvecontrol/models/vm.py
index 27e4cf20..37f90f04 100644
--- a/src/pvecontrol/models/vm.py
+++ b/src/pvecontrol/models/vm.py
@@ -10,6 +10,7 @@ class VmStatus(Enum):
     SUSPENDED = 3
     POSTMIGRATE = 4
     PRELAUNCH = 5
+    UNKNOWN = 6
 
 
 class PVEVm:
diff --git a/src/tests/fixtures/api.py b/src/tests/fixtures/api.py
index 23f14152..2f8c894f 100644
--- a/src/tests/fixtures/api.py
+++ b/src/tests/fixtures/api.py
@@ -78,6 +78,7 @@ def wrapper(path, data=None, **kwargs):
 def generate_routes(nodes, vms, backup_jobs, storage_resources=None, storage_contents=None):
     storage_resources = storage_resources or []
     routes = {
+        "/api2/json/version": {"version": "9.1.4", "release": "9.1", "repoid": "5ac30304265fbd8e"},
         "/api2/json/cluster/status": get_status(nodes),
         "/api2/json/cluster/resources": get_resources(nodes, vms, storage_resources),
         "/api2/json/nodes": get_node_resources(nodes),
diff --git a/src/tests/testcase.py b/src/tests/testcase.py
index 77f575d0..2b881dd3 100644
--- a/src/tests/testcase.py
+++ b/src/tests/testcase.py
@@ -49,6 +49,7 @@ def setUp(self):
             self.nodes, self.vms, self.backup_jobs, self.storage_resources, self.storages_contents
         )
 
+        self.responses_get("/api2/json/version")
         self.responses_get("/api2/json/cluster/status")
         self.responses_get("/api2/json/cluster/resources")