feat: Add web research node with Tavily search integration

api/chk.py

@@ -2,6 +2,7 @@
 
 app = FastAPI()
 
+
 @app.get("/api/chk")
 async def check():
     return {"status": "ok", "message": "Standalone routing is working!"}

api/index.py

@@ -34,13 +34,15 @@ async def debug_root():
         # Only expose detailed error info in debug mode
         response = {"error": "Import failed", "message": _error_message}
         if _is_debug:
-            response.update({
-                "traceback": _error_traceback,
-                "sys_path": sys.path,
-                "cwd": os.getcwd(),
-                "api_dir_exists": Path("api").exists(),
-                "api_main_exists": Path("api/main.py").exists(),
-            })
+            response.update(
+                {
+                    "traceback": _error_traceback,
+                    "sys_path": sys.path,
+                    "cwd": os.getcwd(),
+                    "api_dir_exists": Path("api").exists(),
+                    "api_main_exists": Path("api/main.py").exists(),
+                }
+            )
         return response
 
     @app.get("/health")

api/routes/blog.py

@@ -104,7 +104,7 @@ async def start_blog_generation(
     """Start blog generation process.
 
     Runs until the keyword selection interrupt, then returns suggested keywords.
-    
+
     API keys can be provided via HTTP headers:
     - X-OpenAI-API-Key
     - X-Anthropic-API-Key
@@ -117,7 +117,7 @@ async def start_blog_generation(
     # Prepare input with api_keys in config
     config_dict = request.config.model_dump() if request.config else {}
     config_dict["api_keys"] = api_keys  # Inject API keys into config
-    
+
     input_state = {
         "url": str(request.url),
         "user_keywords": request.user_keywords,
@@ -159,9 +159,7 @@ async def start_blog_generation(
                 "error": str(e),  # Keep for internal diagnostics
                 "created_at": time.time(),
             }
-        raise HTTPException(
-            status_code=500, detail="Blog generation failed"
-        ) from None
+        raise HTTPException(status_code=500, detail="Blog generation failed") from None
 
 
 @router.post("/{job_id}/resume", response_model=BlogJobResponse)
@@ -199,7 +197,6 @@ async def resume_blog_generation(
     graph = get_blog_writer_graph()
 
     try:
-
         # Update state with selected keywords, then resume
         await graph.aupdate_state(
             config,
@@ -214,7 +211,9 @@ async def resume_blog_generation(
             html_content=result.get("html_content", ""),
             suggested_keywords=suggested_keywords,
             selected_keywords=request.selected_keywords,
-            seo_meta=SEOMeta(**(result.get("seo_meta") or {"title": "", "description": ""})),
+            seo_meta=SEOMeta(
+                **(result.get("seo_meta") or {"title": "", "description": ""})
+            ),
             image_urls=result.get("image_urls", []),
         )
 
@@ -233,9 +232,7 @@ async def resume_blog_generation(
         async with _jobs_lock:
             _jobs[job_id]["status"] = JobStatus.FAILED
             _jobs[job_id]["error"] = str(e)  # Keep for internal diagnostics
-        raise HTTPException(
-            status_code=500, detail="Blog generation failed"
-        ) from None
+        raise HTTPException(status_code=500, detail="Blog generation failed") from None
 
 
 @router.get("/{job_id}/status", response_model=BlogJobStatusResponse)
@@ -253,6 +250,8 @@ async def get_job_status(job_id: str) -> BlogJobStatusResponse:
         result=job.get("result"),
         error=job.get("error"),
     )
+
+
 @router.get("/jobs", response_model=list[BlogJobStatusResponse])
 async def list_jobs() -> list[BlogJobStatusResponse]:
     """List all blog generation jobs in memory."""

api/routes/chat.py

@@ -20,7 +20,7 @@ async def chat(
     api_keys: APIKeys = Depends(get_api_keys),
 ) -> ChatResponse:
     """Send a message to the chat agent.
-    
+
     API keys can be provided via HTTP headers:
     - X-OpenAI-API-Key
     - X-Anthropic-API-Key

api/routes/tools.py

@@ -14,7 +14,7 @@
 @router.get("/scrape")
 async def scrape_url(
     url: str = Query(..., description="URL to scrape"),
-    type: ScraperType = Query(ScraperType.BEAUTIFULSOUP, description="Scraper type")
+    type: ScraperType = Query(ScraperType.BEAUTIFULSOUP, description="Scraper type"),
 ):
     """Scrape content from a URL directly."""
     try:
@@ -28,7 +28,9 @@ async def scrape_url(
 @router.get("/images/search")
 async def search_images(
     query: str = Query(..., description="Search query"),
-    provider: ImageProvider = Query(ImageProvider.UNSPLASH, description="Image provider")
+    provider: ImageProvider = Query(
+        ImageProvider.UNSPLASH, description="Image provider"
+    ),
 ):
     """Search or generate images directly."""
     try:

api/schemas/api_keys.py

@@ -9,39 +9,48 @@
 
 class APIKeys(BaseModel):
     """Container for LLM API keys.
-    
+
     Holds API keys for various LLM providers. Keys can be provided via
     HTTP headers or fall back to environment variables.
     """
-    
+
     openai_api_key: Optional[str] = None
     anthropic_api_key: Optional[str] = None
     google_api_key: Optional[str] = None
     openrouter_api_key: Optional[str] = None
-
+    tavily_api_key: Optional[str] = None
+
     def get_openai_key(self) -> Optional[str]:
         """Get OpenAI API key (header or env fallback)."""
         return self.openai_api_key or os.getenv("OPENAI_API_KEY")
-    
+
     def get_anthropic_key(self) -> Optional[str]:
         """Get Anthropic API key (header or env fallback)."""
         return self.anthropic_api_key or os.getenv("ANTHROPIC_API_KEY")
-    
+
     def get_google_key(self) -> Optional[str]:
         """Get Google API key (header or env fallback)."""
-        return self.google_api_key or os.getenv("GOOGLE_API_KEY") or os.getenv("GEMINI_API_KEY")
-
+        return (
+            self.google_api_key
+            or os.getenv("GOOGLE_API_KEY")
+            or os.getenv("GEMINI_API_KEY")
+        )
+
     def get_openrouter_key(self) -> Optional[str]:
         """Get OpenRouter API key (header or env fallback)."""
         return self.openrouter_api_key or os.getenv("OPENROUTER_API_KEY")
-
+
+    def get_tavily_key(self) -> Optional[str]:
+        """Get Tavily API key (header or env fallback)."""
+        return self.tavily_api_key or os.getenv("TAVILY_API_KEY")
+
     def has_any_key(self) -> bool:
         """Check if at least one LLM API key is available."""
         return bool(
-            self.get_openai_key() or 
-            self.get_anthropic_key() or 
-            self.get_google_key() or
-            self.get_openrouter_key()
+            self.get_openai_key()
+            or self.get_anthropic_key()
+            or self.get_google_key()
+            or self.get_openrouter_key()
         )
 
 
@@ -50,20 +59,23 @@ async def get_api_keys(
     x_anthropic_api_key: Optional[str] = Header(None, alias="X-Anthropic-API-Key"),
     x_google_api_key: Optional[str] = Header(None, alias="X-Google-API-Key"),
     x_openrouter_api_key: Optional[str] = Header(None, alias="X-OpenRouter-API-Key"),
+    x_tavily_api_key: Optional[str] = Header(None, alias="X-Tavily-API-Key"),
 ) -> APIKeys:
     """FastAPI dependency to extract API keys from request headers.
-    
+
     Headers:
         X-OpenAI-API-Key: OpenAI API key
         X-Anthropic-API-Key: Anthropic API key
         X-Google-API-Key: Google/Gemini API key
         X-OpenRouter-API-Key: OpenRouter API key
-
+        X-Tavily-API-Key: Tavily API key
+
     Falls back to environment variables if headers are not provided.
     """
     return APIKeys(
         openai_api_key=x_openai_api_key,
         anthropic_api_key=x_anthropic_api_key,
         google_api_key=x_google_api_key,
         openrouter_api_key=x_openrouter_api_key,
+        tavily_api_key=x_tavily_api_key,
     )

api/schemas/post.py

@@ -5,25 +5,29 @@
 
 class PostBase(BaseModel):
     """블로그 포스트 기본 스키마"""
+
     title: str = Field(..., min_length=1, max_length=200, description="포스트 제목")
     content: str = Field(..., min_length=1, description="포스트 본문")
     tags: List[str] = Field(default_factory=list, description="태그 목록")
 
 
 class PostCreate(PostBase):
     """포스트 생성 스키마"""
+
     pass
 
 
 class PostUpdate(BaseModel):
     """포스트 수정 스키마 - 모든 필드 선택적"""
+
     title: Optional[str] = Field(None, min_length=1, max_length=200)
     content: Optional[str] = Field(None, min_length=1)
     tags: Optional[List[str]] = None
 
 
 class PostResponse(PostBase):
     """포스트 응답 스키마"""
+
     id: int
     created_at: datetime
     updated_at: Optional[datetime] = None

api/services/post_service.py

@@ -6,7 +6,7 @@
 
 class PostService:
     """블로그 포스트 서비스 (인메모리 저장소)"""
-    
+
     # 인메모리 저장소 (데모용)
     _posts: dict[int, dict] = {}
     _counter: int = 0
@@ -50,32 +50,33 @@ def get_multi(
     ) -> List[PostResponse]:
         """포스트 목록 조회"""
         posts = list(cls._posts.values())
-        
+
         if search:
             posts = [
-                p for p in posts
+                p
+                for p in posts
                 if search.lower() in p["title"].lower()
                 or search.lower() in p["content"].lower()
             ]
-        
+
         posts = sorted(posts, key=lambda x: x["created_at"], reverse=True)
-        return [PostResponse(**p) for p in posts[skip:skip + limit]]
+        return [PostResponse(**p) for p in posts[skip : skip + limit]]
 
     @classmethod
     def update(cls, post_id: int, post_update: PostUpdate) -> Optional[PostResponse]:
         """포스트 수정"""
         if post_id not in cls._posts:
             return None
-        
+
         post_data = cls._posts[post_id]
         update_dict = post_update.model_dump(exclude_unset=True)
-        
+
         for key, value in update_dict.items():
             post_data[key] = value
-        
+
         post_data["updated_at"] = datetime.now()
         cls._posts[post_id] = post_data
-        
+
         return PostResponse(**post_data)
 
     @classmethod

casts/blog_writer/CLAUDE.md

@@ -12,13 +12,16 @@
 
 ## 아키텍처 다이어그램
 
+> 키워드 선택 후 Tavily 웹 리서치를 거쳐 최신 정보를 반영한 블로그를 작성합니다.
+
 ```mermaid
 graph TD
     START([START]) --> FetchContent
     FetchContent --> AnalyzeContent
     AnalyzeContent --> SuggestKeywords
     SuggestKeywords --> HumanSelectKeywords
-    HumanSelectKeywords --> WriteBlog
+    HumanSelectKeywords --> WebResearch
+    WebResearch --> WriteBlog
     WriteBlog --> OptimizeSEO
     OptimizeSEO --> GenerateImages
     GenerateImages --> ConvertToHTML
@@ -63,6 +66,7 @@ class BlogState(TypedDict):
     analyzed_content: dict        # 분석된 핵심 내용
     suggested_keywords: list[str] # 제안된 키워드
     selected_keywords: list[str]  # 선택된 키워드
+    search_results: list[dict]    # 웹 리서치 결과
     blog_markdown: str            # 블로그 마크다운 초안
     image_urls: list[str]         # 이미지 URL들
 
@@ -79,7 +83,8 @@ class BlogState(TypedDict):
 | `AnalyzeContent` | 핵심 내용 분석 및 요약 | raw_content | analyzed_content |
 | `SuggestKeywords` | 키워드 3개 제안 | analyzed_content, user_keywords | suggested_keywords |
 | `HumanSelectKeywords` | 사용자 키워드 선택 (interrupt) | suggested_keywords | selected_keywords |
-| `WriteBlog` | 블로그 마크다운 작성 | analyzed_content, selected_keywords | blog_markdown |
+| `WebResearch` | 선택된 키워드로 웹 리서치 (Tavily) | selected_keywords | search_results |
+| `WriteBlog` | 블로그 마크다운 작성 | analyzed_content, selected_keywords, search_results | blog_markdown |
 | `OptimizeSEO` | SEO 메타 정보 생성 | blog_markdown, selected_keywords | seo_meta |
 | `GenerateImages` | 이미지 생성/수집 | analyzed_content | image_urls |
 | `ConvertToHTML` | 최종 HTML 변환 | blog_markdown, image_urls, seo_meta | html_content |
@@ -93,6 +98,7 @@ class BlogState(TypedDict):
 langchain-openai = "*"
 langchain-anthropic = "*"
 langchain-google-genai = "*"
+langchain-tavily = "*"
 beautifulsoup4 = "*"
 playwright = "*"
 openai = "*"       # DALL-E
@@ -108,6 +114,9 @@ OPENAI_API_KEY=
 ANTHROPIC_API_KEY=
 GOOGLE_API_KEY=
 
+# Web Search
+TAVILY_API_KEY=
+
 # Image Generation (사용자 선택)
 STABILITY_API_KEY=
 UNSPLASH_ACCESS_KEY=
@@ -132,6 +141,9 @@ class ScraperType(str, Enum):
     BEAUTIFULSOUP = "beautifulsoup"
     PLAYWRIGHT = "playwright"
 
+class SearchProvider(str, Enum):
+    TAVILY = "tavily"
+
 class BlogWriterConfig(BaseModel):
     llm_provider: LLMProvider = LLMProvider.OPENAI
     image_provider: ImageProvider = ImageProvider.DALLE

casts/blog_writer/graph.py

@@ -1,9 +1,9 @@
 """Entry point for the Blog Writer graph.
 
-Assembles 8 nodes into a Sequential + Human-in-the-loop graph:
+Assembles 9 nodes into a Sequential + Human-in-the-loop graph:
 START → FetchContent → AnalyzeContent → SuggestKeywords →
-HumanSelectKeywords (interrupt) → WriteBlog → OptimizeSEO →
-GenerateImages → ConvertToHTML → END
+HumanSelectKeywords (interrupt) → WebResearch → WriteBlog →
+OptimizeSEO → GenerateImages → ConvertToHTML → END
 """
 
 from langgraph.graph import END, START, StateGraph
@@ -17,6 +17,7 @@
     HumanSelectKeywords,
     OptimizeSEO,
     SuggestKeywords,
+    WebResearch,
     WriteBlog,
 )
 from casts.blog_writer.modules.state import BlogState, InputState, OutputState
@@ -52,6 +53,7 @@ def build(self):
         builder.add_node("analyze_content", AnalyzeContent())
         builder.add_node("suggest_keywords", SuggestKeywords())
         builder.add_node("human_select_keywords", HumanSelectKeywords())
+        builder.add_node("web_research", WebResearch())
         builder.add_node("write_blog", WriteBlog())
         builder.add_node("optimize_seo", OptimizeSEO())
         builder.add_node("generate_images", GenerateImages())
@@ -62,7 +64,8 @@ def build(self):
         builder.add_edge("fetch_content", "analyze_content")
         builder.add_edge("analyze_content", "suggest_keywords")
         builder.add_edge("suggest_keywords", "human_select_keywords")
-        builder.add_edge("human_select_keywords", "write_blog")
+        builder.add_edge("human_select_keywords", "web_research")
+        builder.add_edge("web_research", "write_blog")
         builder.add_edge("write_blog", "optimize_seo")
         builder.add_edge("optimize_seo", "generate_images")
         builder.add_edge("generate_images", "convert_to_html")