feat: add Anthropic Claude provider support with flexible authentication

.env.example

@@ -60,6 +60,34 @@
 # CYPHER_MODEL=gemini-2.5-flash
 # CYPHER_API_KEY=your-google-api-key
 
+# Example 7: Anthropic Claude (Direct API)
+# ORCHESTRATOR_PROVIDER=anthropic
+# ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+# ORCHESTRATOR_API_KEY=sk-ant-your-key
+
+# CYPHER_PROVIDER=anthropic
+# CYPHER_MODEL=claude-haiku-4-20250514
+# CYPHER_API_KEY=sk-ant-your-key
+
+# Example 8: Anthropic Claude (via Portkey proxy)
+# ORCHESTRATOR_PROVIDER=anthropic
+# ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+# ORCHESTRATOR_ENDPOINT=https://your-portkey-gateway.com
+# ORCHESTRATOR_CUSTOM_HEADERS="x-portkey-api-key: pk-xxx\nx-portkey-config: pc-xxx"
+
+# CYPHER_PROVIDER=anthropic
+# CYPHER_MODEL=claude-haiku-4-20250514
+# CYPHER_ENDPOINT=https://your-portkey-gateway.com
+# CYPHER_CUSTOM_HEADERS="x-portkey-api-key: pk-xxx\nx-portkey-config: pc-xxx"
+
+# Example 9: Anthropic Claude (uses ~/.claude/settings.json automatically)
+# Just set provider and model - will auto-detect from Claude Code settings
+# ORCHESTRATOR_PROVIDER=anthropic
+# ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+
+# CYPHER_PROVIDER=anthropic
+# CYPHER_MODEL=claude-haiku-4-20250514
+
 # Thinking budget for reasoning models (optional)
 # ORCHESTRATOR_THINKING_BUDGET=10000
 # CYPHER_THINKING_BUDGET=5000

README.md

@@ -58,8 +58,8 @@ An accurate Retrieval-Augmented Generation (RAG) system that analyzes multi-lang
 - **🌳 Tree-sitter Parsing**: Uses Tree-sitter for robust, language-agnostic AST parsing
 - **📊 Knowledge Graph Storage**: Uses Memgraph to store codebase structure as an interconnected graph
 - **🗣️ Natural Language Querying**: Ask questions about your codebase in plain English
-- **🤖 AI-Powered Cypher Generation**: Supports both cloud models (Google Gemini), local models (Ollama), and OpenAI models for natural language to Cypher translation
-- **🤖 OpenAI Integration**: Leverage OpenAI models to enhance AI functionalities.
+- **🤖 AI-Powered Cypher Generation**: Supports cloud models (Google Gemini, Anthropic Claude), local models (Ollama), and OpenAI models for natural language to Cypher translation
+- **🤖 Multiple LLM Providers**: Supports OpenAI, Anthropic Claude, Google Gemini, and Ollama with flexible authentication (direct API keys, Claude Code settings, or proxy services like Portkey)
 - **📝 Code Snippet Retrieval**: Retrieves actual source code snippets for found functions/methods
 - **✍️ Advanced File Editing**: Surgical code replacement with AST-based function targeting, visual diff previews, and exact code block modifications
 - **⚡️ Shell Command Execution**: Can execute terminal commands for tasks like running tests or using CLI tools.
@@ -195,6 +195,55 @@ CYPHER_MODEL=codellama
 CYPHER_ENDPOINT=http://localhost:11434/v1
 ```
 
+#### Option 5: Anthropic Claude Models
+
+Anthropic Claude is now supported with multiple authentication methods:
+
+**5a. Direct API Key (recommended for development)**:
+```bash
+# .env file
+ORCHESTRATOR_PROVIDER=anthropic
+ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+ORCHESTRATOR_API_KEY=sk-ant-your-key
+
+CYPHER_PROVIDER=anthropic
+CYPHER_MODEL=claude-haiku-4-20250514
+CYPHER_API_KEY=sk-ant-your-key
+```
+
+**5b. Claude Code Settings (automatic)**:
+If you're using Claude Code CLI, the provider will automatically read from `~/.claude/settings.json`. Just set the provider and model:
+```bash
+# .env file
+ORCHESTRATOR_PROVIDER=anthropic
+ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+
+CYPHER_PROVIDER=anthropic
+CYPHER_MODEL=claude-haiku-4-20250514
+# No API key needed - uses ANTHROPIC_BASE_URL and ANTHROPIC_CUSTOM_HEADERS from settings
+```
+
+**5c. Portkey or Other Proxies (for enterprise)**:
+For centralized key management systems like Portkey:
+```bash
+# .env file
+ORCHESTRATOR_PROVIDER=anthropic
+ORCHESTRATOR_MODEL=claude-sonnet-4.5-20250929
+ORCHESTRATOR_ENDPOINT=https://your-portkey-gateway.com
+ORCHESTRATOR_CUSTOM_HEADERS="x-portkey-api-key: pk-xxx\nx-portkey-config: pc-xxx"
+
+CYPHER_PROVIDER=anthropic
+CYPHER_MODEL=claude-haiku-4-20250514
+CYPHER_ENDPOINT=https://your-portkey-gateway.com
+CYPHER_CUSTOM_HEADERS="x-portkey-api-key: pk-xxx\nx-portkey-config: pc-xxx"
+```
+
+**Recommended Anthropic Models**:
+- **Orchestrator**: `claude-opus-4.5-20251101` (most capable) or `claude-sonnet-4.5-20250929` (balanced)
+- **Cypher**: `claude-sonnet-4.5-20250929` or `claude-haiku-4-20250514` (faster, cheaper)
+
+Get your Anthropic API key from [Anthropic Console](https://console.anthropic.com/).
+
 Get your Google API key from [Google AI Studio](https://aistudio.google.com/app/apikey).
 
 **Install and run Ollama**:

codebase_rag/config.py

@@ -13,6 +13,7 @@
 from . import exceptions as ex
 from . import logs
 from .types_defs import CgrignorePatterns, ModelConfigKwargs
+from .utils.claude_settings import parse_custom_headers
 
 load_dotenv()
 
@@ -105,6 +106,7 @@ class ModelConfig:
     provider_type: str | None = None
     thinking_budget: int | None = None
     service_account_file: str | None = None
+    custom_headers: dict[str, str] | None = None
 
     def to_update_kwargs(self) -> ModelConfigKwargs:
         result = asdict(self)
@@ -153,6 +155,7 @@ class AppConfig(BaseSettings):
     ORCHESTRATOR_PROVIDER_TYPE: str | None = None
     ORCHESTRATOR_THINKING_BUDGET: int | None = None
     ORCHESTRATOR_SERVICE_ACCOUNT_FILE: str | None = None
+    ORCHESTRATOR_CUSTOM_HEADERS: str | None = None
 
     CYPHER_PROVIDER: str = ""
     CYPHER_MODEL: str = ""
@@ -163,6 +166,7 @@ class AppConfig(BaseSettings):
     CYPHER_PROVIDER_TYPE: str | None = None
     CYPHER_THINKING_BUDGET: int | None = None
     CYPHER_SERVICE_ACCOUNT_FILE: str | None = None
+    CYPHER_CUSTOM_HEADERS: str | None = None
 
     OLLAMA_BASE_URL: str = "http://localhost:11434"
 
@@ -260,6 +264,11 @@ def _get_default_config(self, role: str) -> ModelConfig:
         model = getattr(self, f"{role_upper}_MODEL", None)
 
         if provider and model:
+            custom_headers_str = getattr(self, f"{role_upper}_CUSTOM_HEADERS", None)
+            custom_headers = (
+                parse_custom_headers(custom_headers_str) if custom_headers_str else None
+            )
+
             return ModelConfig(
                 provider=provider.lower(),
                 model_id=model,
@@ -272,6 +281,7 @@ def _get_default_config(self, role: str) -> ModelConfig:
                 service_account_file=getattr(
                     self, f"{role_upper}_SERVICE_ACCOUNT_FILE", None
                 ),
+                custom_headers=custom_headers,
             )
 
         return ModelConfig(

codebase_rag/constants.py

@@ -131,6 +131,9 @@ class FileAction(StrEnum):
 
 ENV_OPENAI_API_KEY = "OPENAI_API_KEY"
 ENV_GOOGLE_API_KEY = "GOOGLE_API_KEY"
+ENV_ANTHROPIC_API_KEY = "ANTHROPIC_API_KEY"
+ENV_ANTHROPIC_BASE_URL = "ANTHROPIC_BASE_URL"
+ENV_ANTHROPIC_CUSTOM_HEADERS = "ANTHROPIC_CUSTOM_HEADERS"
 
 HELP_ARG = "help"
 
@@ -142,6 +145,9 @@ class GoogleProviderType(StrEnum):
 
 # (H) Provider endpoints
 OPENAI_DEFAULT_ENDPOINT = "https://api.openai.com/v1"
+ANTHROPIC_DEFAULT_ENDPOINT = "https://api.anthropic.com/v1"
+OLLAMA_DEFAULT_BASE_URL = "http://localhost:11434"
+OLLAMA_DEFAULT_ENDPOINT = f"{OLLAMA_DEFAULT_BASE_URL}/v1"
 OLLAMA_HEALTH_PATH = "/api/tags"
 GOOGLE_CLOUD_SCOPE = "https://www.googleapis.com/auth/cloud-platform"
 V1_PATH = "/v1"

codebase_rag/exceptions.py

@@ -11,6 +11,18 @@
     "OpenAI provider requires api_key. "
     "Set ORCHESTRATOR_API_KEY or CYPHER_API_KEY in .env file."
 )
+ANTHROPIC_NO_AUTH = (
+    "Anthropic provider requires either api_key or custom_headers (for proxy auth). "
+    "Set ORCHESTRATOR_API_KEY/CYPHER_API_KEY, or configure ORCHESTRATOR_CUSTOM_HEADERS/CYPHER_CUSTOM_HEADERS, "
+    "or set up ~/.claude/settings.json with ANTHROPIC_BASE_URL and ANTHROPIC_CUSTOM_HEADERS."
+)
+ANTHROPIC_CLAUDE_SETTINGS_ERROR = (
+    "Failed to read Claude Code settings from ~/.claude/settings.json: {error}"
+)
+ANTHROPIC_MALFORMED_HEADER = (
+    "Malformed custom header line: '{line}'. "
+    "Expected format 'Header-Name: value'. Each header must contain a colon separator."
+)
 OLLAMA_NOT_RUNNING = (
     "Ollama server not responding at {endpoint}. "
     "Make sure Ollama is running: ollama serve"

codebase_rag/logs.py

@@ -621,3 +621,8 @@
 MODEL_SWITCHED = "Model switched to: {model}"
 MODEL_SWITCH_FAILED = "Failed to switch model: {error}"
 MODEL_CURRENT = "Current model: {model}"
+
+# (H) Custom headers logs
+CUSTOM_HEADERS_EMPTY = (
+    "Empty custom headers string received, treating as no headers set"
+)

codebase_rag/providers/base.py

@@ -6,25 +6,30 @@
 
 import httpx
 from loguru import logger
+from pydantic_ai.models.anthropic import AnthropicModel
 from pydantic_ai.models.google import GoogleModel, GoogleModelSettings
 from pydantic_ai.models.openai import OpenAIChatModel, OpenAIResponsesModel
+from pydantic_ai.providers.anthropic import (
+    AnthropicProvider as PydanticAnthropicProvider,
+)
 from pydantic_ai.providers.google import GoogleProvider as PydanticGoogleProvider
 from pydantic_ai.providers.openai import OpenAIProvider as PydanticOpenAIProvider
 
 from .. import constants as cs
 from .. import exceptions as ex
 from .. import logs as ls
 from ..config import ModelConfig, settings
+from ..utils.claude_settings import get_anthropic_config_from_claude_settings
 
 
 class ModelProvider(ABC):
-    def __init__(self, **config: str | int | None) -> None:
+    def __init__(self, **config: str | int | dict[str, str] | None) -> None:
         self.config = config
 
     @abstractmethod
     def create_model(
         self, model_id: str, **kwargs: str | int | None
-    ) -> GoogleModel | OpenAIResponsesModel | OpenAIChatModel:
+    ) -> GoogleModel | OpenAIResponsesModel | OpenAIChatModel | AnthropicModel:
         pass
 
     @abstractmethod
@@ -72,7 +77,6 @@ def create_model(self, model_id: str, **kwargs: str | int | None) -> GoogleModel
         if self.provider_type == cs.GoogleProviderType.VERTEX:
             credentials = None
             if self.service_account_file:
-                # (H) Convert service account file to credentials object for pydantic-ai
                 from google.oauth2 import service_account
 
                 credentials = service_account.Credentials.from_service_account_file(
@@ -85,7 +89,6 @@ def create_model(self, model_id: str, **kwargs: str | int | None) -> GoogleModel
                 credentials=credentials,
             )
         else:
-            # (H) api_key is guaranteed to be set by validate_config for gla type
             assert self.api_key is not None
             provider = PydanticGoogleProvider(api_key=self.api_key)
 
@@ -155,15 +158,86 @@ def create_model(
         return OpenAIChatModel(model_id, provider=provider)
 
 
+class AnthropicProvider(ModelProvider):
+    def __init__(
+        self,
+        api_key: str | None = None,
+        endpoint: str | None = None,
+        custom_headers: dict[str, str] | None = None,
+        **kwargs: str | int | None,
+    ) -> None:
+        super().__init__(**kwargs)
+        self.api_key = api_key
+        self.endpoint = endpoint
+        self.custom_headers = custom_headers or {}
+
+        if not self.api_key and not self.custom_headers and not self.endpoint:
+            self._load_from_claude_settings()
+
+    def _load_from_claude_settings(self) -> None:
+        """Load configuration from Claude Code settings if available."""
+        try:
+            base_url, headers = get_anthropic_config_from_claude_settings()
+
+            if base_url:
+                self.endpoint = base_url
+
+            if headers:
+                self.custom_headers = headers
+        except Exception as e:
+            logger.debug(f"Could not load Anthropic config from Claude settings: {e}")
+
+    @property
+    def provider_name(self) -> cs.Provider:
+        return cs.Provider.ANTHROPIC
+
+    def validate_config(self) -> None:
+        """Validate configuration.
+
+        Either API key OR custom headers (for proxy) must be provided.
+        """
+        has_api_key = bool(self.api_key)
+        has_custom_headers = bool(self.custom_headers)
+
+        if not has_api_key and not has_custom_headers:
+            raise ValueError(ex.ANTHROPIC_NO_AUTH)
+
+    def create_model(self, model_id: str, **kwargs: str | int | None) -> AnthropicModel:
+        """Create an Anthropic model instance."""
+        self.validate_config()
+
+        base_url = self.endpoint or cs.ANTHROPIC_DEFAULT_ENDPOINT
+        api_key = self.api_key or "proxy-auth-via-headers"
+        http_client = None
+        if self.custom_headers:
+            http_client = httpx.AsyncClient(
+                headers=self.custom_headers,
+                timeout=30.0,
+            )
+
+        provider = PydanticAnthropicProvider(
+            api_key=api_key,
+            base_url=base_url,
+            http_client=http_client,
+        )
+
+        return AnthropicModel(
+            model_name=model_id,
+            provider=provider,
+        )
+
+
 PROVIDER_REGISTRY: dict[str, type[ModelProvider]] = {
     cs.Provider.GOOGLE: GoogleProvider,
     cs.Provider.OPENAI: OpenAIProvider,
     cs.Provider.OLLAMA: OllamaProvider,
+    cs.Provider.ANTHROPIC: AnthropicProvider,
 }
 
 
 def get_provider(
-    provider_name: str | cs.Provider, **config: str | int | None
+    provider_name: str | cs.Provider,
+    **config: str | int | dict[str, str] | None,
 ) -> ModelProvider:
     provider_key = str(provider_name)
     if provider_key not in PROVIDER_REGISTRY:
@@ -186,6 +260,7 @@ def get_provider_from_config(config: ModelConfig) -> ModelProvider:
         provider_type=config.provider_type,
         thinking_budget=config.thinking_budget,
         service_account_file=config.service_account_file,
+        custom_headers=config.custom_headers,
     )