feat(claude-code): add settingsJson option merged into settings.json

src/claude-code/devcontainer-feature.json

@@ -1,6 +1,6 @@
 {
   "id": "claude-code",
-  "version": "1.0.2",
+  "version": "1.1.0",
   "name": "Claude Code CLI",
   "description": "Installs the Claude Code CLI on a selectable channel.",
   "documentationURL": "https://github.com/hansehart/devcontainer-features/tree/main/src/claude-code",
@@ -20,6 +20,11 @@
       "type": "boolean",
       "default": true,
       "description": "Set CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1 to suppress telemetry and other non-essential network calls."
+    },
+    "settingsJson": {
+      "type": "string",
+      "default": "",
+      "description": "Claude settings as a JSON object, merged into settings.json."
     }
   },
   "postCreateCommand": "/usr/local/share/claude-code/init.sh"

src/claude-code/init.sh

@@ -1,7 +1,17 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# postCreate hook: create the state dir once the volume is mounted.
 if [ -r /etc/profile.d/claude-code.sh ]; then . /etc/profile.d/claude-code.sh; fi
-[ -n "${CLAUDE_CONFIG_DIR:-}" ] || exit 0
-mkdir -p "${CLAUDE_CONFIG_DIR}"
+
+# Create the state dir once its volume is mounted.
+if [ -n "${CLAUDE_CONFIG_DIR:-}" ]; then mkdir -p "${CLAUDE_CONFIG_DIR}"; fi
+
+# Merge the requested settings into settings.json (empty leaves it untouched).
+req=/usr/local/share/claude-code/requested-settings.json
+if [ -s "$req" ]; then
+  target="${CLAUDE_CONFIG_DIR:-$HOME/.claude}/settings.json"
+  mkdir -p "$(dirname "$target")"
+  prev='{}'
+  if [ -f "$target" ]; then prev="$(cat "$target")"; fi
+  printf '%s' "$prev" | jq --argjson add "$(cat "$req")" '. + $add' > "$target"
+fi

src/claude-code/install.sh

@@ -1,17 +1,19 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# Options (uppercased by the CLI): VERSION, STATEDIR, DISABLENONESSENTIALTRAFFIC.
+# Options (uppercased by the CLI): VERSION, STATEDIR, DISABLENONESSENTIALTRAFFIC, SETTINGSJSON.
 STATE_DIR="$STATEDIR"
 DISABLE_NONESSENTIAL_TRAFFIC="$DISABLENONESSENTIALTRAFFIC"
+SETTINGS_JSON="$SETTINGSJSON"
 
 export DEBIAN_FRONTEND=noninteractive
 
 # Dependencies: packages this feature needs to install and run.
 apt-get update
 apt-get install -y --no-install-recommends \
   ca-certificates \
-  curl
+  curl \
+  jq
 rm -rf /var/lib/apt/lists/*
 
 # Install: run the upstream installer as the dev user so claude lands in ~/.local/bin.
@@ -29,9 +31,10 @@ su - "$_REMOTE_USER" -c "curl -fsSL https://claude.ai/install.sh | bash -s -- '$
 } > /etc/profile.d/claude-code.sh
 chmod 0644 /etc/profile.d/claude-code.sh
 
-# Hook: install the create-state-dir hook to run once at container create.
+# Hook: install the run-once hook and save the requested settings for it to merge.
 install -d /usr/local/share/claude-code
 install -m 0755 "$(dirname "$0")/init.sh" /usr/local/share/claude-code/init.sh
+printf '%s' "$SETTINGS_JSON" > /usr/local/share/claude-code/requested-settings.json
 
 # Verify: claude resolves on PATH (as the dev user).
 su - "$_REMOTE_USER" -c "claude --version"

test/claude-code/scenarios.json

@@ -0,0 +1,10 @@
+{
+  "settings_json": {
+    "image": "ubuntu:24.04",
+    "features": {
+      "claude-code": {
+        "settingsJson": "{\\\"env\\\":{\\\"IS_DEMO\\\":\\\"1\\\"}}"
+      }
+    }
+  }
+}

test/claude-code/settings_json.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+set -e
+
+source dev-container-features-test-lib
+
+# The merge runs at postCreate, so invoke the hook here to apply the baked settings.
+/usr/local/share/claude-code/init.sh
+
+target="${CLAUDE_CONFIG_DIR:-$HOME/.claude}/settings.json"
+check "settings merged" jq -e '.env.IS_DEMO == "1"' "$target"
+
+reportResults