QueryGuard-Agen: A Self-Correcting Intelligent Query Agent System Based on LangGraph

QueryGuard-Agen is an innovative open-source project that builds an intelligent agent system capable of automatically extracting, verifying, and correcting natural language location queries. The system combines strategies such as fuzzy matching, large language model reasoning, and confidence-aware routing to address the pain points in unstructured query processing. It implements multi-round self-correction capabilities based on the LangGraph framework, providing reliable solutions for scenarios like geographic information services and intelligent customer service.

When processing natural language location queries, we often encounter unstandardized inputs such as spelling errors, confusing abbreviations, and place name aliases. Traditional rule-based methods struggle to handle such diversity, while relying solely on large language models can easily lead to hallucinations or inconsistent outputs. QueryGuard-Agen aims to address this pain point: as an intelligent agent system with self-correction capabilities, it purifies inputs through multi-round interactions and outputs structured, trustworthy results.

1. Query Extraction Module

Extract query intent from natural language input, perform semantic understanding based on OpenAI models, and identify location information that needs parsing.

2. Multi-Strategy Verification Layer

• Fuzzy Matching Strategy: Use string similarity algorithms (e.g., Levenshtein distance, Jaro-Winkler) to compare with place name databases and handle spelling variations.
• LLM Reasoning Strategy: When the confidence of fuzzy matching is insufficient, call large language models to reason about the existence of place names, aliases, or infer from context.
• Confidence Evaluation Mechanism: Each strategy outputs a confidence score; the routing layer comprehensively evaluates these scores, and if below the threshold, triggers the correction process.

3. Automatic Correction Loop

When the verification layer cannot confirm validity, it proactively generates correction plans and verifies again, implementing a controllable loop based on LangGraph state management.

4. Structured Output Generation

Output standardized location information, confidence scores, and correction strategy records, facilitating consumption by downstream applications and audit analysis.

The project uses the following technology combination:

• LangGraph: Core orchestration framework that supports building complex agent workflows.
• Pydantic: Defines strict data models to ensure type safety for inputs and outputs.
• OpenAI API: Provides language understanding and generation capabilities. This technology stack emphasizes engineering quality and maintainability; Pydantic type constraints can catch potential errors early.

• Geographic Information Services: Integrate with map, navigation, and location search services to understand fuzzy descriptions (e.g., "café near the Forbidden City").
• Intelligent Customer Service Systems: Standardize address-related requests to reduce manual intervention.
• Data Cleaning Pipelines: Preprocess unstructured location data into a standardized format.
• Multi-Language Query Processing: The underlying LLM natively supports multi-language inputs, adapting to global applications.

• Modular Design: Functional components have clear responsibilities, facilitating independent testing and iteration.
• Configuration-Driven: Key parameters such as confidence thresholds and retry counts can be adjusted via configuration without modifying code.
• Error Handling: A comprehensive exception handling mechanism ensures graceful degradation when encountering unexpected inputs.

1. Expand Query Types: Expand from location queries to entity types like time, people, and events.
2. Localization Enhancement: Integrate more localized place name databases to improve accuracy in specific regions.
3. Feedback Learning Mechanism: Record user correction feedback to continuously optimize the model.
4. Edge Deployment Optimization: Explore model compression and edge deployment solutions to adapt to latency-sensitive scenarios.

QueryGuard-Agen represents an emerging agent system design paradigm with self-verification and correction capabilities. It combines traditional algorithms and large language models to balance accuracy and flexibility. This project is not only a usable tool but also a learning example, demonstrating how to use LangGraph to build complex agent workflows and balance the value of multiple AI technologies in practical applications.