diff --git a/.claude/hooks/session-start.sh b/.claude/hooks/session-start.sh
new file mode 100755
index 00000000..18bd37af
--- /dev/null
+++ b/.claude/hooks/session-start.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+# Prepares a Claude Code cloud session: installs the web app, local API and
+# reminder worker dependencies, starts the container's PostgreSQL and creates a
+# disposable `commune_dev` database with every migration applied.
+# Cloud sessions only; it does nothing on a local machine.
+set -euo pipefail
+
+if [ "${CLAUDE_CODE_REMOTE:-}" != "true" ]; then
+  exit 0
+fi
+
+cd "$CLAUDE_PROJECT_DIR"
+
+pnpm install --frozen-lockfile --prefer-offline \
+  --filter workspace \
+  --filter @commune/web \
+  --filter @commune/local-api \
+  --filter @commune/reminder-worker
+
+# PostgreSQL is optional: skip the database step if the image has none.
+if ! command -v pg_ctlcluster >/dev/null 2>&1; then
+  echo "PostgreSQL not installed; skipping database setup." >&2
+  exit 0
+fi
+
+cluster=$(pg_lsclusters --no-header | awk 'NR==1 {print $1" "$2}')
+if [ -n "$cluster" ]; then
+  # shellcheck disable=SC2086
+  pg_ctlcluster $cluster start 2>/dev/null || true
+fi
+for _ in $(seq 1 20); do
+  pg_isready -q -h 127.0.0.1 && break
+  sleep 0.5
+done
+
+# A local superuser for disposable test databases. The password is not a
+# secret: this cluster only listens on loopback inside the cloud container.
+su postgres -c "psql -q -v ON_ERROR_STOP=1" <<'SQL'
+DO $$
+BEGIN
+  IF NOT EXISTS (SELECT 1 FROM pg_roles WHERE rolname = 'commune') THEN
+    CREATE ROLE commune SUPERUSER LOGIN PASSWORD 'commune';
+  END IF;
+END
+$$;
+SQL
+
+export PGHOST=127.0.0.1 PGPORT=5432 PGUSER=commune PGPASSWORD=commune
+if [ -n "${CLAUDE_ENV_FILE:-}" ]; then
+  {
+    echo "export PGHOST=127.0.0.1 PGPORT=5432 PGUSER=commune PGPASSWORD=commune"
+    echo "export COMMUNE_DEV_DATABASE_URL=postgres://commune:commune@127.0.0.1:5432/commune_dev"
+  } >> "$CLAUDE_ENV_FILE"
+fi
+
+# Build commune_dev once, as described in infra/local/README.md. An existing
+# database is left untouched; drop it to rebuild from the migrations.
+if ! psql -d postgres -Atc "SELECT 1 FROM pg_database WHERE datname = 'commune_dev'" | grep -q 1; then
+  createdb commune_dev
+  for file in infra/local/bootstrap.sql $(ls infra/neon/migrations/*.sql | sort) infra/local/after-core.sql; do
+    psql -d commune_dev -q -v ON_ERROR_STOP=1 -f "$file" >/dev/null
+  done
+fi
diff --git a/.claude/settings.json b/.claude/settings.json
new file mode 100644
index 00000000..e06b0338
--- /dev/null
+++ b/.claude/settings.json
@@ -0,0 +1,14 @@
+{
+  "hooks": {
+    "SessionStart": [
+      {
+        "hooks": [
+          {
+            "type": "command",
+            "command": "$CLAUDE_PROJECT_DIR/.claude/hooks/session-start.sh"
+          }
+        ]
+      }
+    ]
+  }
+}