Multi-Agent

Stigmergic Coordination

Agents coordinate indirectly by leaving and reading marks in a shared environment (files, queues, scratchpads, world model) so that one agent's trace stimulates another's next action, with no direct messaging.

Problem

Forcing every coordination event through direct messaging adds overhead and creates an N×N communication graph. Agents must know each other's identities and protocols. Asynchronous coordination across time windows (one agent finishing a task hours before the next picks it up) needs persistence the messaging layer doesn't have. Without environment-mediated coordination, multi-agent systems either over-couple through direct chatter or fail to coordinate at all when direct channels aren't available.

Solution

Define a structured trace format the environment carries — a TODO file, a queue of jobs, status markers in a scratchpad, named entries in a vector store. Each agent's action writes a trace; each agent's next decision reads traces left by others. Traces include enough context that a fresh agent can act on them. Traces decay or are explicitly cleared. No direct messaging is required. Inspired by stigmergy in social insects (ants follow pheromone trails; termites build mounds via local rules).

When to use

  • Agents share an environment they all read and write.
  • Coordination crosses time windows or process boundaries direct messaging cannot.
  • Trace format can be made readable by future agents without prior protocol agreement.

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