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Category Theory for Multi-Agent Systems

Overview

Category theory provides a mathematical foundation for modeling multi-agent systems in Timestep. This formal approach enables us to reason about agent composition, handoffs, tool usage, and workflow execution using rigorous mathematical structures.

Core Concepts

Categories

A category consists of: - Objects: The entities in the system (agents, tools, sessions, workflows) - Morphisms: The relationships/transformations between objects (handoffs, tool invocations, state transitions) - Composition: How morphisms combine (sequential handoffs, tool chaining) - Identity: Trivial morphisms (self-handoffs, no-op operations)

Category of Agents (Agt)

  • Objects: Individual agents (e.g., weather_agent, assistant)
  • Morphisms: Handoffs between agents (handoff: A → B)
  • Composition: Sequential handoffs form composition
  • Identity: Self-handoff (trivial)

Category of Tools (Tool)

  • Objects: Individual tools (e.g., get_weather, WebSearchTool)
  • Morphisms: Tool invocations (invoke: Tool → Result)
  • Composition: Tool chaining (when tools output feeds into next tool)

Functors

Functors map between categories while preserving structure:

  • Agent-Tool Functor: Maps agents to their available tools
  • Handoff Functor: Maps agents to their handoff targets (delegation structure)
  • State Functor: Maps agent-session pairs to execution states

Monoidal Structure

The monoidal structure enables parallel composition:

  • Tensor product: Parallel agent execution
  • Unit: Empty agent (identity)
  • Composition: Sequential agent workflows

Benefits

  • Formal Verification: Prove properties about agent compositions (associativity, identity, termination)
  • Type Safety: Verify tool outputs match expected inputs
  • Composition: Reason about complex agent workflows mathematically
  • Optimization: Identify redundant patterns and optimize compositions

Implementation

See the analysis module for the implementation of these concepts in both Python and TypeScript.