diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..5570af6
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,95 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+The External Server is a component of the BringAuto Fleet Protocol that handles communication between a cloud instance and multiple cars. It bridges External Clients (Module Gateway) with car modules via MQTT and dynamically loaded shared libraries.
+
+## Common Commands
+
+### Setup
+```bash
+git submodule update --init --recursive
+python3 -m venv .venv && source .venv/bin/activate
+pip3 install -r requirements.txt
+pip install -e .
+```
+
+### Run Server
+```bash
+python3 -m external_server <config-path> [--tls] [--ca <path>] [--cert <path>] [--key <path>]
+```
+
+### Build Standalone Package (.pyz)
+```bash
+pip install shiv
+shiv -e external_server.__main__:main -o external_server.pyz . -r requirements.txt --compressed
+```
+
+### Run Tests
+```bash
+pip install -r tests/requirements.txt
+python -m tests                           # all tests
+python -m tests server/                   # specific directory
+python -m tests api_access/test_api.py   # specific file
+python -m tests -h                        # with HTML coverage report
+```
+
+### Build Example Module (required for tests)
+```bash
+pushd tests/utils/example_module && mkdir -p _build && cd _build && \
+cmake .. -DCMLIB_DIR=<path-to-cmakelib-dir> && make && popd
+```
+
+### Regenerate Protobuf Type Stubs
+```bash
+pushd lib/fleet-protocol/protobuf && \
+find ./definition -name "*.proto" -exec protoc -I=./definition \
+  --python_out=./compiled/python/fleet_protocol_protobuf_files \
+  --pyi_out=./compiled/python/fleet_protocol_protobuf_files {} + && popd
+```
+
+## Architecture
+
+### Threading Model
+- `ExternalServer` (all_cars.py) spawns one `CarServer` thread per configured car
+- Each `CarServer` (single_car.py) operates independently with its own MQTT connection and modules
+
+### State Machine (CarServer)
+`UNINITIALIZED → CONNECTED → INITIALIZED → RUNNING → STOPPED/ERROR`
+
+### Component Layers
+```
+ExternalServer
+└── CarServer (per car)
+    ├── MQTTClientAdapter - Paho MQTT client wrapper (QoS 1, 15s keepalive)
+    ├── EventQueue - Thread-safe event synchronization
+    ├── StatusChecker / CommandChecker - Message validation
+    └── ServerModule (per module ID)
+        ├── APIClientAdapter - Loads .so libraries via ctypes
+        └── CommandWaitingThread - Async command handling
+```
+
+### Key Directories
+- `external_server/server/` - Core server logic (CarServer, ExternalServer)
+- `external_server/adapters/mqtt/` - MQTT communication
+- `external_server/adapters/api/` - C library interface via ctypes
+- `external_server/checkers/` - Message validation and timeout handling
+- `external_server/models/` - Data structures, events, exceptions
+
+### Protocol
+- Uses Fleet Protocol (Protobuf-based) over MQTT
+- Protobuf definitions in `lib/fleet-protocol/` submodule
+- Generated Python files in `lib/fleet-protocol/protobuf/compiled/python/`
+
+## Configuration
+
+Config file (`config/config.json`) defines:
+- `company_name` - MQTT topic prefix (lowercase, numbers, underscores only)
+- `mqtt_address`, `mqtt_port` - Broker connection
+- `mqtt_timeout`, `timeout` - Message timeouts in seconds
+- `common_modules` - Modules shared by all cars (keyed by module ID)
+- `cars` - Per-car config with `specific_modules`
+
+Module IDs must be unique within each car (no overlap between common and specific).
diff --git a/README.md b/README.md
index 7d6bd9f..191002b 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,27 @@ Following arguments are used if argument `tls` is set:
 - `--cert <str>` = path to cert file
 - `--key <str>` = path to key file
 
+## Build Standalone Package (.pyz)
+
+The External Server can be packaged as a standalone `.pyz` file using [shiv](https://github.com/linkedin/shiv). This is useful for deployment or integration testing.
+
+### Prerequisites
+
+- Complete the [Install dependencies](#install-dependencies) steps
+- Install shiv: `pip install shiv`
+
+### Build
+
+```bash
+shiv -e external_server.__main__:main -o external_server.pyz . -r requirements.txt --compressed
+```
+
+This creates `external_server.pyz` which bundles the application with all dependencies. Run it with:
+
+```bash
+python3 external_server.pyz <config> [--tls] [--ca <str>] [--cert <str>] [--key <str>]
+```
+
 # Unit tests
 
 ## Necessary steps before testing
diff --git a/pyproject.toml b/pyproject.toml
index 9d62a0d..566cd0b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,4 +4,4 @@ version = "2.2.3"
 
 
 [tool.setuptools.packages.find]
-include = ["external_server", "config", "docs"]
+include = ["external_server", "external_server.*", "config", "docs"]