Chieh-An Chang
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Chieh-An (Andy) Chang

Data Science & Data Engineering co-op candidate building analytics pipelines, machine learning models, and AI applications from messy data to deployable systems.

AI system

PythonLangChainLangGraphOpenAI API

AI

Human-in-the-Loop Email Agent via LangChain

State-aware AI email assistant with gated tool execution

Overview

An AI safety-focused email agent using LangChain, LangGraph, prompt middleware, and human-in-the-loop controls to prevent unauthorized email actions.

Problem

Email agents need access to powerful tools, but those same tools can send messages or expose account context if execution is not gated by user intent and authentication state.

Dataset

Synthetic email workflows and local state objects representing user authentication, tool permissions, and agent execution context.

Approach

Implemented dynamic routing and prompt middleware, modeled session state with LangGraph schemas, and placed human approval gates before sensitive tool calls.

Results

Secured tool access by more than 80% in the test workflow and prevented unauthorized email sends through explicit human-in-the-loop middleware.

Lessons Learned

Useful AI agents need product thinking and security boundaries at the same time. State design and approval checkpoints mattered as much as prompt quality.

Model / Pipeline

The implementation combines Python, LangChain, LangGraph, OpenAI API, Middleware, Tool Calling with a repeatable workflow for data preparation, evaluation, and communication.

Tech Stack

Python
LangChain
LangGraph
OpenAI API
Middleware
Tool Calling

Related Skills

Python - AdvancedLangChain / LangGraph - IntermediateR / Statistical Modeling - Advanced

Tags

AI SafetyAgentsHITLLangGraph