Building AI Agents: A Platform-Agnostic Guide for Developers in 2025
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Introduction
The landscape of artificial intelligence has evolved dramatically in recent years, with Large Language Models (LLMs) becoming increasingly sophisticated and accessible. Among the most exciting developments is the rise of AI agents—autonomous systems that can understand, plan, and execute complex tasks with minimal human intervention. Building AI agents has emerged as a critical skill for organizations looking to leverage the full potential of LLMs across various business functions.
This comprehensive guide explores the fundamentals of building AI agents that work across multiple LLM platforms, including OpenAI, Anthropic’s Claude, Google’s Gemini, DeepSeek, Grok, Meta’s Llama, and others. Rather than focusing on a single platform, we’ll take a platform-agnostic approach that empowers you to create versatile agents adaptable to your specific needs and technology stack.
What Are AI Agents?
Before diving into the development process, it’s essential to understand what AI agents are and how they differ from traditional LLM applications.
Defining AI Agents
AI agents are autonomous systems that can perceive their environment, make decisions, and take actions to achieve specific goals. Unlike basic LLM applications that simply respond to prompts, agents can:
- Use tools and APIs to interact with external systems
- Maintain memory and context across interactions
- Break down complex tasks into manageable steps
- Make decisions based on predefined criteria
- Learn and adapt from experience

Building AI agents requires a solid understanding of both the underlying LLM capabilities and the specific business requirements. The most effective agents combine the natural language understanding of LLMs with structured decision-making processes and the ability to interact with external systems.
Types of AI Agents
Understanding the different types of AI agents helps in selecting the right approach for your specific needs. The five main types of AI agents include simple reflex agents, model-based agents, goal-based agents, utility-based agents, and learning agents.
- Simple Reflex Agents: Respond directly to current inputs without considering history
- Model-Based Agents: Maintain an internal model of the world to inform decisions
- Goal-Based Agents: Work toward achieving specific objectives
- Utility-Based Agents: Maximize a utility function that represents preferences
- Learning Agents: Improve performance over time through experience
Each of the types of AI agents has specific strengths and ideal use cases. For most modern applications, a combination of goal-based and learning approaches yields the best results.
When to Build AI Agents
Not every AI application requires an agent architecture. Understanding when building AI agents makes sense is crucial for efficient resource allocation.
Ideal Use Cases for AI Agents
AI agents excel in scenarios that require:
- Complex Task Execution: When tasks involve multiple steps and decision points
- Tool Usage: When the system needs to interact with external tools, APIs, or databases
- Persistent Context: When maintaining conversation history and context is essential
- Autonomous Operation: When minimal human intervention is desired
- Adaptability: When the system needs to handle varied inputs and scenarios
Many developers wonder how to build an AI agent that works across multiple LLM platforms. The key lies in designing modular systems with clear separation between the agent’s logic and the underlying LLM.

Real-World Applications
These real-world AI agents examples demonstrate the practical applications across various industries:
- Customer Service: Agents that can handle complex customer inquiries, access knowledge bases, and escalate issues when necessary
- Research Assistants: Agents that can search for information, synthesize findings, and generate reports
- Personal Productivity: Agents that manage calendars, draft emails, and automate routine tasks
- Data Analysis: Agents that can query databases, generate visualizations, and identify patterns
- Content Creation: Agents that can draft, edit, and optimize content based on specific guidelines
Studying successful AI agents examples can provide valuable insights for your own implementation.
Agent Design Foundations
Core Components of an Agent
When building AI agents from scratch gives you maximum control over their behavior and capabilities. Every effective agent consists of several key components:
- Instruction Layer: Defines the agent’s purpose, constraints, and operational guidelines
- Memory System: Stores conversation history, user preferences, and other relevant information
- Planning Module: Breaks down complex tasks into manageable steps
- Tool Integration: Connects the agent to external systems and capabilities
- Execution Engine: Carries out planned actions and processes results
- Feedback Mechanism: Evaluates outcomes and adjusts behavior accordingly

While frameworks simplify the process, building AI agents from scratch can be beneficial for specialized use cases. This approach requires careful attention to each component’s design and integration.
Agent Orchestration Patterns
The architecture of your agent system significantly impacts its capabilities and performance. Common orchestration patterns include:
- Single-Agent Systems: One agent handles all tasks and tool interactions
- Manager-Worker Systems: A manager agent delegates tasks to specialized worker agents
- Peer-Based Systems: Multiple agents collaborate as equals to solve problems
- Hierarchical Systems: Agents are organized in a hierarchy with different levels of authority
The architecture patterns used in OpenAI agents can be adapted for use with other LLM providers. Understanding how OpenAI agents work provides insights applicable to agent development on any platform.
Platform-Agnostic Frameworks and Tools
Leading Frameworks for Agent Development
The frameworks available for building AI agents have evolved significantly in the past year. Here’s an overview of the most popular platform-agnostic frameworks:
- LangChain: Provides components for building complex agent workflows with memory, tools, and chains
- AutoGen: Focuses on multi-agent conversations and collaboration
- Semantic Kernel: Microsoft’s framework for integrating AI with programming languages
- CrewAI: Specializes in creating collaborative agent teams
- LlamaIndex: Excels at data connection and retrieval augmentation

We’ve compiled a list of the best tools for building AI agents based on real-world implementation experience. The best tools for building AI agents often provide cross-platform compatibility and extensive documentation.
Selecting the Right Framework
When evaluating the best tools for building AI agents, consider factors like community support and integration capabilities. Your choice should be based on:
- Development Experience: Some frameworks require more coding expertise than others
- Customization Needs: How much control do you need over the agent’s behavior?
- Integration Requirements: Which external systems does your agent need to interact with?
- Deployment Environment: Where will your agent run (cloud, on-premises, edge)?
- Performance Considerations: What are your latency and throughput requirements?
The landscape of tools for building ai agents continues to evolve rapidly in 2025. Selecting the right tools for building AI agents depends on your specific requirements and technical expertise.
How to Build an AI Agent: Step-by-Step Guide
Learning how to build an AI agent starts with defining its purpose and the tasks it needs to perform. This section outlines a platform-agnostic approach to agent development.

Step 1: Define Agent Purpose and Scope
Begin by clearly defining:
- The agent’s primary objective
- Key tasks it should perform
- Success metrics
- Constraints and limitations
This foundation ensures your development efforts remain focused and aligned with business needs.
Step 2: Select Your Tech Stack
Choose the components of your agent system:
- Base LLM: Select a model that balances capability and cost (e.g., GPT-4, Claude 3, Gemini, Llama 3)
- Framework: Choose a framework that aligns with your development approach
- Tools and APIs: Identify external systems your agent needs to access
- Deployment Platform: Determine where your agent will run
This guide explains how to build an AI agent using platform-agnostic frameworks and tools. Many developers wonder how to build an AI agent that works across multiple LLM platforms.
Step 3: Design the Agent Architecture
Map out your agent’s components and their interactions:
- Memory systems (short-term and long-term)
- Decision-making processes
- Tool integration points
- Error handling mechanisms
Consider creating a visual diagram to clarify the architecture.
Step 4: Implement Core Components
Understanding how to create an AI agent begins with selecting the right framework for your needs. Develop each component of your agent:
- Instruction Layer: Create clear, comprehensive instructions that define the agent’s behavior
- Memory System: Implement conversation history and relevant context storage
- Planning Module: Develop logic for breaking down tasks and creating execution plans
- Tool Integration: Connect external tools and APIs with appropriate authentication
- Execution Engine: Build the system that carries out actions and processes results
This section details how to create an AI agent that can effectively use tools and APIs. Developers looking to learn how to create an AI agent will benefit from a modular approach.
Step 5: Test and Refine
Thoroughly test your agent across various scenarios:
- Common use cases
- Edge cases and unusual inputs
- Error conditions
- Performance under load
Use the results to refine your agent’s behavior and capabilities.
Step 6: Deploy and Monitor
Deploy your agent to your chosen environment and implement:
- Logging and monitoring
- Performance tracking
- User feedback collection
- Continuous improvement processes
When building AI agents, it’s important to consider the orchestration patterns that will best serve your use case.
Best Tools for Building AI Agents in 2025
The best tools for building AI agents often provide cross-platform compatibility and extensive documentation. Here’s our assessment of the top tools available:
Development Frameworks
- LangChain: Excellent for complex workflows and tool integration
- Strengths: Extensive documentation, active community, rich component library
- Weaknesses: Steep learning curve, can be resource-intensive
- AutoGen: Ideal for multi-agent systems
- Strengths: Built-in support for agent collaboration, user-friendly
- Weaknesses: Less mature than some alternatives, limited customization
- Semantic Kernel: Strong enterprise integration
- Strengths: Excellent programming language integration, enterprise-ready
- Weaknesses: Microsoft-centric ecosystem, complex for beginners
Open-source tools for building AI agents often provide more flexibility but may require more development effort.
Orchestration Tools
- Langfuse: For monitoring and observability
- Portkey: For managing multiple LLM providers
- Flowise: Visual builder for agent workflows
- E2B: Development environment for AI agents
Evaluation and Testing
- Ragas: Framework for evaluating RAG systems
- Promptfoo: For testing and comparing prompts
- LLM Guard: For safety and security testing
We’ve compiled a list of the best tools for building AI agents based on real-world implementation experience.
Common Challenges and Solutions
Building effective AI agents comes with several challenges. Here are the most common issues and their solutions:
Challenge 1: Hallucinations and Factual Accuracy
Solution: Implement:
- Retrieval-augmented generation (RAG)
- Tool-calling for fact verification
- Structured output validation
- Self-consistency checks
Challenge 2: Context Management
Solution:
- Implement hierarchical memory systems
- Use summarization techniques for long conversations
- Prioritize information based on relevance
- Implement forgetting mechanisms for outdated information
Challenge 3: Tool Integration Complexity
Solution:
- Create standardized tool interfaces
- Implement robust error handling
- Use tool-specific instruction templates
- Test tool interactions thoroughly
Challenge 4: Multi-Platform Compatibility
Solution:
- Abstract LLM-specific code behind interfaces
- Use provider-agnostic frameworks
- Implement adapter patterns for different LLMs
- Test across multiple platforms
Best Practices for Building AI Agents
Design Principles
- Start Simple: Begin with a minimal viable agent and add complexity incrementally
- Modular Architecture: Design components that can be replaced or upgraded independently
- Clear Instructions: Provide detailed, unambiguous instructions to your agent
- Robust Error Handling: Anticipate and gracefully handle failures
- User-Centric Design: Focus on the end-user experience throughout development
Implementation Tips
- Prompt Engineering: Craft effective prompts that guide the agent’s behavior
- Effective Memory Management: Balance context retention with token efficiency
- Tool Design: Create tools with clear inputs, outputs, and error messages
- Testing Strategy: Develop comprehensive test cases covering various scenarios
- Monitoring and Logging: Implement detailed logging for debugging and improvement
Conclusion
Building AI agents represents one of the most promising frontiers in artificial intelligence. By taking a platform-agnostic approach, you can create versatile agents that leverage the strengths of various LLM providers while avoiding vendor lock-in.
The journey of building AI agents requires a solid understanding of both the underlying LLM capabilities and the specific business requirements. Whether you’re creating customer service assistants, research tools, or productivity enhancers, the principles and practices outlined in this guide will help you develop effective, reliable agents.
As the technology continues to evolve, staying adaptable and focusing on fundamentals will ensure your agent implementations remain relevant and valuable. By mastering the art and science of building AI agents, you’ll be well-positioned to harness the full potential of this transformative technology. Reach out to MLVeda for your Agentic-AI needs.
FAQs About Building AI Agents
Q: What’s the difference between an AI agent and a simple LLM application?
A: AI agents can use tools, maintain context, make decisions, and execute multi-step plans autonomously, while simple LLM applications typically just respond to prompts without these capabilities.
Q: Do I need coding experience to build AI agents?
A: While no-code tools exist, building sophisticated agents typically requires programming knowledge. The level of expertise needed depends on the complexity of your agent and the tools you choose.
Q: How do I ensure my agent is secure and ethical?
A: Implement robust authentication, data validation, output filtering, and regular security testing. Establish clear ethical guidelines and monitor agent behavior for compliance.
Q: Can I switch between different LLM providers with my agent?
A: Yes, if you design your agent with platform-agnostic principles. Use abstraction layers and standardized interfaces to make your agent portable across providers.
Q: What’s the typical development timeline for an AI agent?
A: Simple agents can be developed in days or weeks, while complex, enterprise-grade agents may take months to build, test, and refine.