Support ANTHROPIC_API_KEY for Docker, fix auth hierarchy

Auth methods (priority order):
1. ANTHROPIC_API_KEY env var - works everywhere including Docker
2. System claude CLI - shares auth with Claude Code (local dev)
3. Mounted .credentials.json - OAuth tokens from K8s host

Detect .claude.json without system CLI and give clear error message.
Update mcpproxy registry entry with ANTHROPIC_API_KEY as optional env.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Dumbris

src/mcp_scanner/auth.py

@@ -1,4 +1,10 @@
-"""Claude OAuth token handling for Agent SDK."""
+"""Claude authentication for Agent SDK.
+
+Supports three auth methods (in priority order):
+1. ANTHROPIC_API_KEY env var - works everywhere (API billing)
+2. System `claude` CLI - shares auth with Claude Code (local dev)
+3. Mounted .credentials.json - OAuth tokens from K8s/Docker host
+"""
 
 from __future__ import annotations
 
@@ -30,25 +36,61 @@ def _find_credentials(config_dir: str) -> str | None:
     return None
 
 
+def has_api_key() -> bool:
+    """Check if ANTHROPIC_API_KEY is set."""
+    return bool(os.environ.get("ANTHROPIC_API_KEY"))
+
+
+def has_system_claude() -> bool:
+    """Check if system claude CLI is available."""
+    return shutil.which("claude") is not None
+
+
 def ensure_writable_config() -> str:
     """Ensure a writable config dir with Claude credentials exists.
 
-    Two deployment scenarios:
-    1. **Local (dev)**: ~/.claude/ is writable and has .claude.json from Claude Code.
-       System `claude` CLI is available and handles auth natively.
-    2. **Docker (mcpproxy)**: ~/.claude/ is mounted read-only with .credentials.json.
-       Bundled SDK CLI is used. We copy credentials to a writable tmpdir.
+    Auth priority:
+    1. ANTHROPIC_API_KEY env var - SDK uses it directly, no config dir needed
+    2. System claude CLI - handles auth natively from ~/.claude
+    3. Mounted .credentials.json - copy to writable tmpdir for bundled CLI
 
     Returns the path to the (writable) config directory.
+    Raises RuntimeError if no auth method is available.
     """
+    # If API key is set, the SDK handles auth directly
+    if has_api_key():
+        logger.info("Using ANTHROPIC_API_KEY for authentication")
+        # Still need a writable config dir for SDK session files
+        tmp_dir = tempfile.mkdtemp(prefix="mcp_scanner_claude_")
+        return tmp_dir
+
     src_dir = get_claude_config_dir()
     creds_path = _find_credentials(src_dir)
 
+    # System claude CLI handles its own auth (reads ~/.claude internally)
+    if has_system_claude():
+        if creds_path:
+            logger.info("Found credentials at %s (system claude CLI will use natively)", creds_path)
+        else:
+            logger.info("System claude CLI found, will use its own auth")
+        return src_dir
+
+    # Docker/bundled CLI: need actual .credentials.json with OAuth tokens
     if not creds_path:
         raise RuntimeError(
-            f"No credentials found in {src_dir}. "
-            f"Looked for: {', '.join(CREDENTIAL_FILES)}. "
-            "Run 'claude login' to authenticate."
+            "No authentication available. Options:\n"
+            "  1. Set ANTHROPIC_API_KEY environment variable\n"
+            "  2. Install claude CLI and run 'claude login'\n"
+            "  3. Mount ~/.claude with .credentials.json (Docker/K8s)"
+        )
+
+    # .claude.json from desktop app doesn't have raw tokens - bundled CLI can't use it
+    if creds_path.endswith(".claude.json") and not has_system_claude():
+        raise RuntimeError(
+            f"Found {creds_path} but bundled CLI needs .credentials.json with OAuth tokens.\n"
+            "Options:\n"
+            "  1. Set ANTHROPIC_API_KEY environment variable\n"
+            "  2. Mount .credentials.json from a host with 'claude login' (K8s pattern)"
         )
 
     logger.info("Found credentials at %s", creds_path)
@@ -63,7 +105,7 @@ def ensure_writable_config() -> str:
     except OSError:
         pass
 
-    # Source is read-only (Docker mount) - copy to writable tmpdir
+    # Read-only mount - copy to writable tmpdir
     tmp_dir = tempfile.mkdtemp(prefix="mcp_scanner_claude_")
 
     for name in CREDENTIAL_FILES:

src/mcp_scanner/source_analyzer.py

@@ -29,14 +29,25 @@
 
 
 def _sdk_kwargs(config_dir: str) -> dict:
-    """Build SDK kwargs - local uses system CLI, Docker uses bundled with env."""
+    """Build ClaudeAgentOptions kwargs based on available auth method.
+
+    Local: system claude CLI, no env override needed.
+    Docker with API key: bundled CLI + ANTHROPIC_API_KEY in env.
+    Docker with OAuth: bundled CLI + CLAUDE_CONFIG_DIR in env.
+    """
     import shutil
     kwargs: dict = {}
     system_claude = shutil.which("claude")
     if system_claude:
+        # Local: system CLI handles its own auth
         kwargs["cli_path"] = system_claude
     else:
-        kwargs["env"] = {"CLAUDE_CONFIG_DIR": config_dir}
+        # Docker: bundled CLI needs env vars
+        env = {"CLAUDE_CONFIG_DIR": config_dir}
+        api_key = os.environ.get("ANTHROPIC_API_KEY")
+        if api_key:
+            env["ANTHROPIC_API_KEY"] = api_key
+        kwargs["env"] = env
     return kwargs
 
 

src/mcp_scanner/tool_analyzer.py

@@ -21,22 +21,27 @@
 
 
 def _sdk_kwargs(config_dir: str) -> dict:
-    """Build ClaudeAgentOptions kwargs for SDK invocation.
+    """Build ClaudeAgentOptions kwargs based on available auth method.
 
-    Locally: use system claude CLI (shares auth with Claude Code), don't override env.
-    Docker: use bundled CLI, set CLAUDE_CONFIG_DIR via env.
+    Local: system claude CLI, no env override needed.
+    Docker with API key: bundled CLI + ANTHROPIC_API_KEY in env.
+    Docker with OAuth: bundled CLI + CLAUDE_CONFIG_DIR in env.
     """
     import shutil
     kwargs: dict = {}
     system_claude = shutil.which("claude")
     if system_claude:
-        # Local: system CLI handles its own auth, don't pass env to avoid breaking it
         logger.info("Using system Claude CLI: %s", system_claude)
         kwargs["cli_path"] = system_claude
     else:
-        # Docker: bundled CLI needs CLAUDE_CONFIG_DIR to find mounted credentials
-        logger.info("Using SDK bundled CLI with CLAUDE_CONFIG_DIR=%s", config_dir)
-        kwargs["env"] = {"CLAUDE_CONFIG_DIR": config_dir}
+        env = {"CLAUDE_CONFIG_DIR": config_dir}
+        api_key = os.environ.get("ANTHROPIC_API_KEY")
+        if api_key:
+            env["ANTHROPIC_API_KEY"] = api_key
+            logger.info("Using SDK bundled CLI with ANTHROPIC_API_KEY")
+        else:
+            logger.info("Using SDK bundled CLI with CLAUDE_CONFIG_DIR=%s", config_dir)
+        kwargs["env"] = env
     return kwargs
 
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