feat: support multi-language

src/graph/nodes.py

@@ -1,22 +1,23 @@
 # Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
-import logging
 import json
-from typing import Literal, Annotated
+import logging
+from typing import Annotated, Literal
 
-from langchain_core.messages import HumanMessage, AIMessage
+from langchain_core.messages import AIMessage, HumanMessage
-from langchain_core.tools import tool
 from langchain_core.runnables import RunnableConfig
+from langchain_core.tools import tool
 from langgraph.types import Command, interrupt
 
-from src.llms.llm import get_llm_by_type
+from src.agents.agents import coder_agent, research_agent
 from src.config.agents import AGENT_LLM_MAP
 from src.config.configuration import Configuration
-from src.prompts.template import apply_prompt_template
+from src.llms.llm import get_llm_by_type
 from src.prompts.planner_model import Plan, StepType
+from src.prompts.template import apply_prompt_template
 from src.utils.json_utils import repair_json_output
-from src.agents.agents import research_agent, coder_agent
+
 from .types import State
 
 logger = logging.getLogger(__name__)
@@ -117,6 +118,7 @@ def human_feedback_node(
         update={
             "current_plan": Plan.model_validate(new_plan),
             "plan_iterations": plan_iterations,
+            "locale": new_plan["locale"],
         },
         goto=goto,
     )
@@ -209,7 +211,7 @@ def _execute_agent_step(
     agent_input = {
         "messages": [
             HumanMessage(
-                content=f"#Task\n\n##title\n\n{step.title}\n\n##description\n\n{step.description}"
+                content=f"#Task\n\n##title\n\n{step.title}\n\n##description\n\n{step.description}\n\n##locale\n\n{state.get('locale', 'en-US')}"
             )
         ]
     }

src/graph/types.py

@@ -2,9 +2,10 @@
 # SPDX-License-Identifier: MIT
 
 import operator
+from typing import Annotated
 
 from langgraph.graph import MessagesState
-from typing import Annotated
+
 from src.prompts.planner_model import Plan
 
 
@@ -12,6 +13,7 @@ class State(MessagesState):
     """State for the agent system, extends MessagesState with next field."""
 
     # Runtime Variables
+    locale: str = "en-US"
     observations: Annotated[list[str], operator.add] = []
     plan_iterations: int = 0
     current_plan: Plan | str = None

src/prompts/coder.md

@@ -23,7 +23,6 @@ You are a professional software engineer proficient in Python scripting. Your ta
 - Use comments in code to improve readability and maintainability.
 - If you want to see the output of a value, you MUST print it out with `print(...)`.
 - Always and only use Python to do the math.
-- Always use the same language as the initial question.
 - Always use `yfinance` for financial market data:
     - Get historical data with `yf.download()`
     - Access company info with `Ticker` objects
@@ -32,3 +31,4 @@ You are a professional software engineer proficient in Python scripting. Your ta
     - `pandas` for data manipulation
     - `numpy` for numerical operations
     - `yfinance` for financial market data
+- Always output in the locale of **{{ locale }}**.

src/prompts/planner.md

@@ -163,6 +163,7 @@ interface Step {
 }
 
 interface Plan {
+  locale: string; // e.g. "en-US" or "zh-CN", based on the user's language or specific request
   has_enough_context: boolean;
   thought: string;
   title: string;
@@ -182,4 +183,4 @@ interface Plan {
     - Research steps (`need_web_search: true`) for gathering information
     - Processing steps (`need_web_search: false`) for calculations and data processing
 - Default to gathering more information unless the strictest sufficient context criteria are met
-- Always Use the same language as the user
+- Always use the same language as the user

src/prompts/planner_model.py

@@ -1,9 +1,10 @@
 # Copyright (c) 2025 Bytedance Ltd. and/or its affiliates
 # SPDX-License-Identifier: MIT
 
-from pydantic import BaseModel, Field
-from typing import List, Optional
 from enum import Enum
+from typing import List, Optional
+
+from pydantic import BaseModel, Field
 
 
 class StepType(str, Enum):
@@ -24,6 +25,9 @@ class Step(BaseModel):
 
 
 class Plan(BaseModel):
+    locale: str = Field(
+        ..., description="e.g. 'en-US' or 'zh-CN', based on the user's language"
+    )
     has_enough_context: bool
     thought: str
     title: str

src/prompts/researcher.md

@@ -33,7 +33,7 @@ You are dedicated to conducting thorough investigations and providing comprehens
 
       - [Source Title](https://example.com/page2)
       ```
-- Always use the same language as the initial question.
+- Always output in the locale of **{{ locale }}**.
 - DO NOT include inline citations in the text. Instead, track all sources and list them in the References section at the end using link reference format.
 
 # Notes
@@ -49,4 +49,4 @@ You are dedicated to conducting thorough investigations and providing comprehens
 - When presenting information from multiple sources, clearly indicate which source each piece of information comes from.
 - Include images using `![Image Description](image_url)` in a separate section.
 - The included images should **only** be from the information gathered **from the search results or the crawled content**. **Never** include images that are not from the search results or the crawled content.
-- Always use the same language as the initial question.
+- Always use the locale of **{{ locale }}** for the output.