diff --git a/CLAUDE.md b/CLAUDE.md
new file mode 100644
index 0000000..d6025e3
--- /dev/null
+++ b/CLAUDE.md
@@ -0,0 +1,54 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## What This Is
+
+A minimal Docker Compose setup for running LabKey Community Edition locally. Two services: `community` (LabKey app on Tomcat) and `pg-community` (PostgreSQL 17).
+
+## Common Commands
+
+```bash
+# Start
+docker compose up community --detach
+
+# Stop
+docker compose down
+
+# Stop and discard all volumes
+docker compose down -v --remove-orphans
+
+# Override image version at launch
+export IDENT="labkeyteamcity/labkey-community:26.3.0" && docker compose up community --detach
+```
+
+Access at `https://localhost:8443` after startup (self-signed cert — expect browser warning).
+
+## Configuration
+
+All configuration is done via environment variables. `docker-compose.yml` uses `${VAR:-default}` expansion throughout — set variables in the shell or a `.env` file to override defaults.
+
+Key overridable variables:
+- `COMPOSE_IMAGE` — LabKey image tag (default: `labkeyteamcity/labkey-community:26.3.0`)
+- `HOST_PORT` — host HTTPS port (default: `8443`)
+- `PG_PORT` — host PostgreSQL port (default: `54321`)
+- `POSTGRES_PASSWORD` — shared between both services
+- `MAX_JVM_RAM_PERCENT` — JVM heap ceiling (default: `75.0`)
+- `LABKEY_CREATE_INITIAL_USER` / `LABKEY_CREATE_INITIAL_USER_APIKEY` — skip setup wizard if set
+- SMTP variables (`SMTP_HOST`, `SMTP_PORT`, etc.) — email is disabled by default
+
+## Persistent Data (./mounts/)
+
+`mounts/` is gitignored. Do not delete these without understanding the consequences:
+- `mounts/files/` — LabKey file storage
+- `mounts/logs/` — server logs
+- `mounts/pgdata/` — PostgreSQL data files (subdirectory keyed by `$IDENT`)
+- `mounts/modules/` — custom/external LabKey modules
+
+## Upgrading LabKey Version
+
+Edit the `image:` line in `docker-compose.yml` (or set `COMPOSE_IMAGE`). Only tagged versions are published to Docker Hub; there is no `latest` tag.
+
+## Branching and PR Workflow
+
+The `.github/workflows/workflow.yml` runs `LabKey/gitHubActions/validate-pr@develop` on all PRs. It only executes for PRs from the `LabKey` org. Feature branches follow the pattern `fb_<version>_<description>` based on recent history.
diff --git a/README.md b/README.md
index 6d74b65..1ff45d0 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,8 @@ If you need help installing Docker, see these links for instructions:
 - Install Docker on [Windows](https://docs.docker.com/desktop/setup/install/windows-install/)
 - Install Docker on [Linux](https://docs.docker.com/desktop/setup/install/linux/)
 
+> **Apple Silicon (M1/M2/M3/M4) note:** The LabKey image is built for AMD64. Docker Desktop on Apple Silicon runs it automatically via Rosetta emulation — no extra configuration needed.
+
 
 ## Quick start
 Once you have Docker installed, follow these steps to get started with LabKey Community Edition:
diff --git a/docker-compose.yml b/docker-compose.yml
index 28e4c37..cd835af 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -3,6 +3,7 @@
 services:
   community:
     image: ${COMPOSE_IMAGE:-labkeyteamcity/labkey-community:26.3.0}
+    platform: linux/amd64
     container_name: labkey-community
     depends_on:
       - pg-community