The Anatomy of Agents

Insights
May 22, 2024
March 18, 2024
Ravi Kokku

Co-Founder & CTO

Prasenjit Dey

Satya Nitta

Founder & CEO

The Anatomy of Agents

The concept of a software agent can be traced back to the model Hewitt, et al. [1] proposed as representing a self-contained, interactive, and concurrently-executing object which was called an ‘actor.’ This object had some encapsulated internal state and could respond to messages from other similar objects: by Hewitt’s definition, an actor “is a computational agent which has a mail address and a behaviour. Actors communicate by message-passing and carry out their actions concurrently.”

The notion of agency (the idea that an object can go and carry out an action concurrently with other similar objects) eventually evolved into the concept of intelligent agents that used AI to perform some complex decision-making. However, these agents were still of lower capability than ours today, as they made tactical decisions at various points in workflows without keeping in mind a notion of some larger goal. Most recently, we’ve seen the advent of autonomous agents that maintain a larger goal, can sense their environments, and can react to the state of that environment in order to progress toward their goal.

One of the earliest definitions of an autonomous agent, given by [2], is: an autonomous agent is a system situated within and a part of an environment that senses that environment and acts on it, over time, in pursuit of its own agenda and so as to affect what it senses in the future.

Defining Characteristics

Agents have been defined in various ways and have been a point of discussion for some time now, especially after the introduction of large language models (LLMs) [3, 4, 5] and large vision models (LVMs) [6]. It is useful to have one encompassing definition that is extensible as well as expressive, building on commonly understood concepts from the past. For Emergence’s definition of our notion of an agent, we refer back to a few basic principles that embody an agent, and we use them to develop the notion of an “agent object” in the world of LLMs and LVMs. We’ve distilled the following primary concepts that need to be embodied by an agent object in order for them to be programmed scalably to build robust systems.

  1. Autonomy: An agent is an autonomous, interactive, goal-driven entity with its own state, behavior, and decision-making capabilities. It has the capability of self-improvement when it sees that it is unable to meet the performance parameters for reaching its goal.
  2. Reactivity and Proactivity: Agents can be both reactive, meaning they can sense their environment and respond to changes by taking actions, and be proactive, meaning they can take initiative based on their goals. Agents can take actions that change the state of their environment, which can ensure their progress towards their goal.
  3. Beliefs, Desires, and Intentions (BDI): A common model used in agent-oriented programming (AOP) is the BDI model, where agents are characterized by their beliefs (information about the world), desires (goals or objectives), and intentions (plans of action).
  4. Social Ability & Communication: Agents have a communication mechanism and can interact with other agents or entities in their environment. This interaction can be highly complex, as it may involve negotiation, coordination, and cooperation. We believe that with the advent of LLMs, this communication can be completely based on natural language, which is both human- and machine-understandable.
  5. Constitution: An agent needs to adhere to some regulations and policies depending on the imperatives of its task and goals. It needs to protect itself from being compromised or destroyed as well as be trusted not to harm other agents sharing the environment in which it is operating.
  6. Memory: An agent needs to have long-term memory (LTM) of its past interactions and successfully past means of completing its task. LTM can help to greatly reduce the amount of computing that an agent has to perform in order to complete a new task by referencing relevant past plans and actions. The memory is also the place where an agent can store human demonstrations it has seen, which can expedite its progress without as rigorous a planning and reasoning loop. An agent also has short-term memory, which is typically its current context signified by prompts and any information available in its context length.

Agent-Oriented Programming (revisited for the LLM era)

Programming paradigms such as object-oriented programming (OOP) evolved from the need to design and develop code that was highly reusable, maintainable, and scalable. Simula, which came out in the 60s, is generally thought to be the first OOP language. However, it was not until the 80s that the use of OOP concepts to develop large-scale enterprise-class software became mainstream, with the introduction of C++ (80s) and later Java (90s). Even though COBOL and FORTRAN were extremely popular in the 70s for enterprise software, their key strengths were as means of accounting (COBOL) and scientific programming (FORTRAN), not as general-purpose OOP languages. The true power and deployment of OOP software in enterprise came to the fore with the advent of Java and Java Beans.

Similarly, we are on the cusp of another evolution in programming paradigms with LLM/LVM-driven systems that have the potential to completely change enterprise workflows. Recently, the community has been dabbling primarily in advanced experiments with LLM/LVM-driven systems. Now, with the validation of enterprise-scale possibilities, we need to extend the current agent-oriented programming (AOP) paradigms to include the power and capabilities of LLM/LVMs. These include capabilities as discussed above, such as advanced language understanding, communication with humans and other agents, self-improvement, various methods of “reasoning” (CoT, ToT, ReACT etc.), personalization and understanding of context based on LTM, and sensing, interpreting, and acting on environments through the use of tools. Several programming languages and frameworks have been developed specifically for AOP, such as AgentSpeak, JACK, and Jade. These frameworks provide structures and paradigms for creating agent-based systems, but they do not capture the new concepts of AOP made possible by LLM/LVMs. AOP is particularly useful in complex systems where individual components need to operate independently and interact in sophisticated ways, such as in multi-agent systems.

Object Oriented Programming Agent-Oriented Programming
Encapsulation Helps set boundaries of data and methods to wrap related data, and the methods that act on that data, into one single entity called an object. Encapsulation makes code highly scalable and reusable, and it alows an object ot be self-contained with its data and the operations that can happen on that data. The concept of encapsulation is very similar in AOP. It involves bundling the data (like the state of the environment) and the methods that operate on that data (like decision-making algorithms) into a single unit, or agent. Each agent ni a system can maintain its state and behavior, alowing for modular and maintainable code. For example, ni a multi-agent simulation, each agent can have its own set of properties and behaviors, encapsulated as an object.
Abstraction Focuses on the high-level strategy of problem-solving rather than the details. Abstraction improves system design by hiding implementation details that may not be relevant at a particular user level (for example, a system designer). It is also possible that the system's creator may not want to reveal the implementation details for intellectual property reasons. The spirit of abstraction is very similar in AOP. This can mean designing a general- purpose algorithm (like a search algorithm or a reinforcement learning policy) that can be applied to various specific problems. This high-level approach allows Al developers to work with complex concepts without getting bogged down ni every detail of implementation.
Inheritance An extremely powerful concept that helps in code reuse and extensibility, and ti alows for better human understanding of the developed code. Alows new Al agents to be created using the characteristics of existing ones. This is particularly useful in hierarchical Al systems, where more specialized agents can inherit common features from more general ones. For example, ageneral agent class might include basic sensory and action capabilities, while a more specialized agent class inherits these and adds additional, more specific capabilities.
Polymorphism Primarily refers to the concepts of overloading and overriding. It helps one to use familiar function semantics, but these have acompletely different set of parameters or implementations respectively. Overloading is used to improve the readability of the code, while overriding si used to change the inherited behavior of the parent class. Refers to the ability of different agent classes to be treated as instances of a parent class. This is particularly useful ni scenarios where different types of agents are needed, but al of these agents must be interacted with uniformly. For instance, different kinds of robotic agents (like drones, ground vehicles, etc.) might have unique abilities, but they may share common interfaces for control and data gathering.

To enable efficient programming of agent-based systems, some of the base characteristics of an agent need to be available as superclass templates. Developers can derive from these and reuse concepts rapidly as well as maintain a semblance of uniformity in how agents are defined and programmed. [5] is an example of an agent communication and collaboration paradigm which has made it extremely easy to build multi-agent collaboration systems. However, many more base characteristics of agents need to be standardized and frameworks built to enable large-scale agent-oriented programming paradigms. A few of these are as shown in the figure below. For example, security templates are a must-have to ensure that agents are born with alignment to some basic constitution and rules of the game. Similarly, self-improvement is inherent to an agent since it needs to continuously improve itself on its task. However, self-improvement is connected to changing the capabilities of an agent, and we need to ensure that whatever tools, child agents, or code that an agent creates to self-improve, they adhere to some properties of goodness and the agent’s constitution. Therefore, alignment is very closely connected to self-improvement.

In conclusion, developing the right abstractions and templates for agent-oriented programming is important to ensure that we can build systems that can scale, that their components are reusable, and that they are interoperable and safe to operate. We believe that building this framework is going to be an extremely complex endeavor and that the best way to build it is in the open source community. We will be doing our part by subsequently releasing pieces of our larger framework into the community, in the hope of rallying like-minded developers around the project. In our next blog, we delve deeper into self-improvement, a characteristic fundamental to any agent, and its potential tradeoff with goals for alignment.

References

  1. Hewitt, C. (1977), “Viewing Control Structures as Patterns of Passing Messages”, Artificial Intelligence 8(3), 323-364.
  2. Franklin, S. and Graesser, A. (1997) Is It an Agent, or Just a Program? A Taxonomy for Autonomous Agents, In: Müller, J.P., Wooldridge, M.J. and Jennings, N.R., Eds., Intelligent Agents III Agent Theories, Architectures, and Languages, Springer, Berlin Heidelberg, 21-35.
  3. Shen, Y., Song, K., Tan, X., Li, D., Lu, W., & Zhuang, Y. (2024). Hugginggpt: Solving ai tasks with chatgpt and its friends in hugging face. Advances in Neural Information Processing Systems, 36.
  4. Task-driven Autonomous Agent Utilizing GPT-4, Pinecone, and LangChain for Diverse Applications
  5. Wu, Q., Bansal, G., Zhang, J., Wu, Y., Zhang, S., Zhu, E., … & Wang, C. (2023). Autogen: Enabling next-gen llm applications via multi-agent conversation framework. arXiv preprint arXiv:2308.08155.
  6. https://arxiv.org/pdf/2403.10517.pdf

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