Building ReAct AI agents with sandboxed Python code execution using AWS Bedrock and LangGraph

In industrial environments, data analysis is crucial for optimizing processes, detecting anomalies, and making informed decisions. Manufacturing plants, energy systems, and industrial IoT generate massive amounts of data from sensors, machines, and control systems. Traditionally, analyzing this data requires specialized knowledge in both industrial processes and data science, creating a bottleneck for quick insights.

I’ve been exploring agentic AI frameworks lately, particularly for complex data analysis tasks. While working on industrial data problems, I realized that combining the reasoning capabilities of Large Language Models with specialized tools could create a powerful solution for industrial data analysis. This project demonstrates how to build a ReAct ( Reasoning and Acting) AI agent using LangGraph that can analyze manufacturing data, understand industrial processes, and provide actionable insights.

The goal of this project is to create an AI agent that can analyze industrial datasets (manufacturing metrics, sensor readings, process control data) and provide expert-level insights about production optimization, quality control, and process efficiency. Using LangGraph’s ReAct agent framework with AWS Bedrock, the system can execute Python code dynamically in a sandboxed environment, process large datasets, and reason about industrial contexts.

The dataset is a fake sample of industrial data with manufacturing metrics like temperature, speed, humidity, pressure, operator experience, scrap rates, and unplanned stops. In fact, I’ve generated the dataset using chatgpt

This project uses several key components:

  • LangGraph ReAct Agent: For building the multi-tool AI agent with ReAct (Reasoning and Acting) patterns that can dynamically choose tools and reason about results
  • AWS Bedrock: Claude Sonnet 4 as the underlying LLM for reasoning and code generation
  • Sandboxed Code Interpreter: Secure execution of Python code for data analysis using AWS Agent Core. One tool taken from strands-agents-tools library.
  • Industrial Domain Expertise: Specialized system prompts with knowledge of manufacturing processes, quality control, and industrial IoT

The agent has access to powerful tools:

  • Code Interpreter: Executes Python code safely in a sandboxed AWS environment using pandas, numpy, scipy, and other scientific libraries
  • Data Processing: Handles large industrial datasets with memory-efficient strategies
  • Industrial Context: Understands manufacturing processes, sensor data, and quality metrics

The system uses AWS Agent Core’s sandboxed code interpreter, which means:

  • Python code is executed in an isolated environment
  • No risk to the host system
  • Access to scientific computing libraries (pandas, numpy, scipy)
  • Memory management for large datasets

The core of the system is surprisingly simple. The ReAct agent is built using LangGraph’s create_react_agent with custom tools:

from langgraph.prebuilt import create_react_agent
from typing import List
import pandas as pd
from langchain_core.callbacks import BaseCallbackHandler


def analyze_df(df: pd.DataFrame, system_prompt: str, user_prompt: str,
               callbacks: List[BaseCallbackHandler], streaming: bool = False):
    code_interpreter_tools = CodeInterpreter()
    tools = code_interpreter_tools.get_tools()

    agent = create_react_agent(
        model=get_llm(model=DEFAULT_MODEL, streaming=streaming,
                      budget_tokens=12288, callbacks=callbacks),
        tools=tools,
        prompt=system_prompt
    )

    agent_prompt = f"""
    I have a DataFrame with the following data:
    - Columns: {list(df.columns)}
    - Shape: {df.shape}
    - data: {df}
    
    The output must be an executive summary with the key points.
    The response must be only markdown, not plots.
    """
    messages = [
        ("user", agent_prompt),
        ("user", user_prompt)
    ]
    agent_input = {"messages": messages}
    return agent. Invoke(agent_input)

The ReAct pattern (Reasoning and Acting) allows the agent to:

  1. Reason about what analysis is needed
  2. Act by calling the appropriate tools (in this case: code interpreter)
  3. Observe the results of code execution
  4. Re-reason and potentially call more tools if needed

This creates a dynamic loop where the agent can iteratively analyze data, examine results, and refine its approach – much more powerful than a single code execution.

The magic happens in the system prompt, which provides the agent with industrial domain expertise:

SYSTEM_PROMPT = """
# Industrial Data Analysis Agent - System Prompt

You are an expert AI agent specialized in industrial data analysis and programming. 
You excel at solving complex data problems in manufacturing, process control, 
energy systems, and industrial IoT environments.

## Core Capabilities
- Execute Python code using pandas, numpy, scipy
- Handle large datasets with chunking strategies  
- Process time-series data, sensor readings, production metrics
- Perform statistical analysis, anomaly detection, predictive modeling

## Industrial Domain Expertise
- Manufacturing processes and production optimization
- Process control systems (PID controllers, SCADA, DCS)
- Industrial IoT sensor data and telemetry
- Quality control and Six Sigma methodologies
- Energy consumption analysis and optimization
- Predictive maintenance and failure analysis
"""

The code interpreter tool is wrapped with safety validations:

def validate_code_ast(code: str) -> bool:
    """Validate Python code using AST to ensure safety."""
    try:
        ast.parse(code)
        return True
    except SyntaxError:
        return False


@tool
def code_interpreter(code: str) -> str:
    """Executes Python code in a sandboxed environment."""
    if not validate_code_ast(code):
        raise UnsafeCodeError("Unsafe code or syntax errors.")

    return code_tool(code_interpreter_input={
        "action": {
            "type": "executeCode",
            "session_name": session_name,
            "code": code,
            "language": "python"
        }
    })
The system uses Claude Sonnet 4 through AWS Bedrock with optimized parameters for industrial analysis:
def get_llm(model: str = DEFAULT_MODEL, max_tokens: int = 4096,
            temperature: float = TemperatureLevel.BALANCED,
            top_k: int = TopKLevel.DIVERSE,
            top_p: float = TopPLevel.CREATIVE) -> BaseChatModel:
    model_kwargs = {
        "max_tokens": max_tokens,
        "temperature": temperature,
        "top_k": top_k,
        "top_p": top_p
    }

    return ChatBedrock(
        model=model,
        client=aws_get_service('bedrock-runtime'),
        model_kwargs=model_kwargs
    )
The project includes fake sample industrial data with manufacturing metrics:

- `machine_id`: Equipment identifier
- `shift`: Production shift (A/M/N for morning/afternoon/night)
- `temperature`, `speed`, `humidity`, `pressure`: Process parameters
- `operator_experience`: Years of operator experience
- `scrap_kg`: Quality metric (waste produced)
- `unplanned_stop`: Equipment failure indicator

A typical analysis query might be: "Do temperature and speed setpoints vary across shifts?"
The agent will stream the response as it generates it.

The agent will:

1. Load and examine the dataset structure
2. Generate appropriate Python code for analysis
3. Execute the code in a sandboxed environment
4. Provide insights about shift-based variations
5. Suggest process optimization recommendations
import logging

import pandas as pd
from langchain_core.callbacks import StreamingStdOutCallbackHandler

from modules.df_analyzer import analyze_df
from prompts import SYSTEM_PROMPT

logging.basicConfig(
    format='%(asctime)s [%(levelname)s] %(message)s',
    level='INFO',
    datefmt='%d/%m/%Y %X')

logger = logging.getLogger(__name__)


class StreamingCallbackHandler(StreamingStdOutCallbackHandler):
    def on_llm_new_token(self, token: str, **kwargs):
        print(token, end='', flush=True)


df = pd.read_csv('fake_data.csv')

user_prompt = "Do temperature and speed setpoints vary across shifts?"
for chunk in analyze_df(
        user_prompt=user_prompt,
        df=df,
        system_prompt=SYSTEM_PROMPT,
        callbacks=[StreamingCallbackHandler()],
        streaming=True):
    logger.debug(chunk)

This project demonstrates the power of agentic AI for specialized domains. Instead of building custom analytics dashboards or writing specific analysis scripts, we provide the agent with:

  1. Domain Knowledge: Through specialized system prompts
  2. Tools: Safe code execution capabilities
  3. Context: The actual data to analyze

The agent can then:

  • Generate appropriate analysis code
  • Execute it safely
  • Interpret results with industrial context
  • Provide actionable recommendations

The result is a flexible system that can handle various industrial analysis tasks without pre-programmed solutions. The agent reasons about the problem, writes the necessary code (sandboxed), and provides expert-level insights.

Full code in my github.

Agentic AI for movie recommendations with Python and Strands Agents

Context 1: I like to go to the cinema. I normally go to the cinema on Saturday afternoons, at the first showing. In the city where I live there are three cinemas and all belong to the same company called Sade. I normally check the cinema schedules on their website, SadeCines.com, to see what’s playing. Also, I track the movies I see on Letterboxd. There I have my diary and also a list with the movies I see in the cinema. I rate the movies when I finish watching them. My first impression. I do that not to share with others, only to have a personal record of what I like and dislike.

Context 2: I’m on holidays and I like to code also, so I decided to build an AI agent that helps me decide what movie to watch on Saturday afternoons. This project is an example of over-engineering, I know, but I’ve done it as an exercise using Strands Agents, a framework for building multi-tool LLM agents that I’m using these days.

The aim of the project is to create an AI agent that can access the internet to check the cinema schedules, my Letterboxd profile, and then recommend me a movie to watch on Saturday afternoons. Normally the LLMs are good at reasoning, but they don’t have access to the internet. Also, they are not good at doing mathematical operations, but with agents we can use tools to do that. So I decided to build an agent that can access the internet (to check the cinema schedules, my Letterboxd profile and IMDb/Metacritic’s scores) and create the needed code to do the mathematical operations needed.

Strands Agents (it is similar to LangChain) allows us to build multi-tool LLM agents. In this example I’m using the pre-built tools provided by the framework, like:

  • calculator: for performing mathematical operations
  • think: for reasoning and decision-making
  • current_time: to get the current date and time
  • file_write: to write the recommendations to a file
  • batch: to execute multiple tools in parallel
  • code_interpreter: to execute Python code dynamically (sandboxed in an AWS environment)
  • browser: to scrape the cinema schedules from SadeCines.com and my Letterboxd profile (also sandboxed in an AWS environment)

Code interpreter is a powerful tool that allows us to execute Python code dynamically, which is useful for performing mathematical operations and data processing. For me it is the key to push the agents to the next level. LLMs can generate python code very well. They can generate code to build a Pandas dataframe, to filter the data, to calculate the average rating, etc. But they can also generate code that can be harmful, like deleting files, or accessing sensitive data. So we need to be careful with the code we execute. This issue is especially important when we are using prompts from users (in a chat, for example). Strands Agents provides a tool called python-repl that allows us to execute Python code locally within our environment. If you rely on your prompts it can be an option (I’ve sent a pull request to Strands Agents to make it a bit more safe). But in this project I’m using the code_interpreter tool, which is a sandboxed environment provided by AWS. This allows us to execute Python code safely without the risk of executing harmful code in your host environment.

In this project we need to scrape webpages to retrieve information from internet. Strands Agents provides us a built-in tool, called use_browser, to use a headless browser locally to access the Internet. In this project, I’m using the browser tool, which is also a sandboxed environment provided by AWS Bedrock. This allows us to scrape webs (using Playwright) and interact with web pages without the risk of executing harmful code in your host environment.

With this information, to build the agent is pretty straightforward. The idea of agents is not to code everything from scratch, but to provide to the agent the needed tools to solve the problem, and let the agent figure out how to use them using the prompts. When we work with LLM we have two kinds of prompts: the system prompt and the user prompt. The system prompt is used to define the agent’s behavior, while the user prompt is used to provide the input data.

In this project I’m using those prompts:

from settings import BASE_DIR

SYSTEM_PROMPT = f"""
You are an expert movie recommendation assistant to help me decide what to watch.

You have access to the following URLs and available movie analyses:
- https://sadecines.com/ With the movie schedules in my city's cinemas.
    Sadecines has a checkbox to filter the day of the week, so you can select Saturday.
- https://letterboxd.com/gonzalo123/films/diary/ Movies I have watched and rated.
- https://letterboxd.com/gonzalo123/list/cine-2025/detail/ Movies I have already seen in theaters in 2025.

You must take into account the user's preferences:
- Avoid movies in the "children" and "family" genres.
- I don't really like intimate or drama movies, except for rare exceptions.
- I like entertaining movies, action, science fiction, adventure, and comedies.

Take into account when making recommendations:
- The ratings of the movies on IMDb and Metacritic.
- But mainly consider my personal preferences,
    which can be seen in the list of movies I have watched and rated on Letterboxd.
"""

QUESTION = f"""
Analyze the movies showing this Saturday in the first session.

Present only those you recommend, excluding those not relevant according to my preferences,
and order them from best to worst according to your criteria.

Show the result in a table with the following columns:
- Title
- Genre
- IMDb Rating
- Metacritic Rating
- Summary
- Start Time
- End Time

Save the final report in a file named YYYYMMDD.md, following this structure:
{BASE_DIR}/
    └ reports/
        └ YYYYMMDD.md       # Movie analysis of the day, format `YYYYMMDD`

And the code of the agent is very simple (I’m using AWS Bedrock to run the agent)

import logging

from botocore.config import Config
from strands import Agent
from strands.models import BedrockModel
from strands_tools import calculator, current_time, think, file_write, batch
from strands_tools.browser import AgentCoreBrowser
from strands_tools.code_interpreter import AgentCoreCodeInterpreter

from promts import SYSTEM_PROMPT, QUESTION
from settings import AWS_REGION, MODEL_TEMPERATURE, MODEL, LLM_READ_TIMEOUT, LLM_CONNECT_TIMEOUT, LLM_MAX_ATTEMPTS

logging.basicConfig(
    format="%(asctime)s [%(levelname)s] %(message)s",
    level="INFO",
    datefmt="%d/%m/%Y %X",
)

logger = logging.getLogger(__name__)

agent = Agent(
    system_prompt=SYSTEM_PROMPT,
    model=BedrockModel(
        model_id=MODEL,
        temperature=MODEL_TEMPERATURE,
        boto_client_config=Config(
            read_timeout=LLM_READ_TIMEOUT,
            connect_timeout=LLM_CONNECT_TIMEOUT,
            retries={'max_attempts': LLM_MAX_ATTEMPTS}
        )
    ),
    tools=[
        calculator, think, current_time, file_write, batch,
        AgentCoreCodeInterpreter(region=AWS_REGION).code_interpreter,
        AgentCoreBrowser(region=AWS_REGION).browser]
)

result = agent(QUESTION)
logger.info(f"Total tokens: {result.metrics.accumulated_usage['totalTokens']}")
logger.info(f"Execution time: {sum(result.metrics.cycle_durations):.2f} seconds")
logger.info(f"Tools used: {list(result.metrics.tool_metrics.keys())}")

The lines of code never is a goal (we only need to write readable and maintainable code), but in this example we have more code in the prompts than in the code itself. Maybe it’s the sigh of our times.

And that’s all. I must say again that this project is just an example. It is an over-engineering example. Scaling this project would be very expensive. Working a little bit in a custom scraper in addition to custom python code, can do the same to solve this specific problem without the usage, and paid, the IA (cheap for a single user usage, but expensive when scaled). I think it is a good example to show how Agents and the power of the code interpreter and the browser tools in a few lines of code. And remember, I’m on holidays and I like to code (don’t blame me for that).

Full code in my Github account.