diff --git a/.env.example b/.env.example
index b9aab986..e3620184 100644
--- a/.env.example
+++ b/.env.example
@@ -5,9 +5,15 @@
 CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000
 
 # =============================================================================
-# OPTION 1: Direct Anthropic (default, no router)
+# OPTION 1: Claude Code login (easiest — no API key needed)
 # =============================================================================
-ANTHROPIC_API_KEY=your-api-key-here
+# Just run `claude login` on the host. Shannon mounts ~/.claude into Docker
+# automatically. You only need this file with the line above.
+
+# =============================================================================
+# OPTION 2: Direct Anthropic API key
+# =============================================================================
+# ANTHROPIC_API_KEY=your-api-key-here
 
 # OR use OAuth token instead
 # CLAUDE_CODE_OAUTH_TOKEN=your-oauth-token-here
diff --git a/README.md b/README.md
index 1ec4552c..49c424c2 100644
--- a/README.md
+++ b/README.md
@@ -104,7 +104,8 @@ Shannon is available in two editions:
 
 - **Docker** - Container runtime ([Install Docker](https://docs.docker.com/get-docker/))
 - **AI Provider Credentials** (choose one):
-  - **Anthropic API key** (recommended) - Get from [Anthropic Console](https://console.anthropic.com)
+  - **Claude Code login** (easiest) - Just run `claude login` on the host
+  - **Anthropic API key** - Get from [Anthropic Console](https://console.anthropic.com)
   - **Claude Code OAuth token**
   - **[EXPERIMENTAL - UNSUPPORTED] Alternative providers via Router Mode** - OpenAI or Google Gemini via OpenRouter (see [Router Mode](#experimental---unsupported-router-mode-alternative-providers))
 
@@ -117,11 +118,17 @@ cd shannon
 
 # 2. Configure credentials (choose one method)
 
-# Option A: Export environment variables
+# Option A: Use Claude Code login (easiest — no API key needed)
+claude login
+cat > .env << 'EOF'
+CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000
+EOF
+
+# Option B: Export environment variables
 export ANTHROPIC_API_KEY="your-api-key"              # or CLAUDE_CODE_OAUTH_TOKEN
 export CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000           # recommended
 
-# Option B: Create a .env file
+# Option C: Create a .env file with API key
 cat > .env << 'EOF'
 ANTHROPIC_API_KEY=your-api-key
 CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000
diff --git a/docker-compose.yml b/docker-compose.yml
index 26cbdfa9..2e345f30 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -34,6 +34,7 @@ services:
       - ${OUTPUT_DIR:-./audit-logs}:/app/output
       - ${TARGET_REPO:-.}:/target-repo
       - ${BENCHMARKS_BASE:-.}:/benchmarks
+      - ${HOME}/.claude:/tmp/.claude
     shm_size: 2gb
     ipc: host
     security_opt:
diff --git a/shannon b/shannon
index b1a7ffec..e0684fbe 100755
--- a/shannon
+++ b/shannon
@@ -128,9 +128,11 @@ cmd_start() {
     if [ "$ROUTER" = "true" ] && { [ -n "$OPENAI_API_KEY" ] || [ -n "$OPENROUTER_API_KEY" ]; }; then
       # Router mode with alternative provider - set a placeholder for SDK init
       export ANTHROPIC_API_KEY="router-mode"
+    elif [ -f "$HOME/.claude/.credentials.json" ]; then
+      echo "Using Claude Code login credentials..."
     else
       echo "ERROR: Set ANTHROPIC_API_KEY or CLAUDE_CODE_OAUTH_TOKEN in .env"
-      echo "       (or use ROUTER=true with OPENAI_API_KEY or OPENROUTER_API_KEY)"
+      echo "       Or log in with: claude login"
       exit 1
     fi
   fi