How Multi-Agent Systems Work Under the Hood

Study Guide · Chapter 5: Multi-Agent · 7 min read

Strip away the sci-fi language and a multi-agent system is message passing plus contracts: agents exchange structured envelopes, and each envelope carries exactly what the next role needs.

Role contracts and task envelopes

Every agent has an explicit contract: what input format it accepts, what output schema it produces, and when it must escalate instead of guessing. Narrow contracts make behavior predictable.

Work moves in signed task envelopes — structured messages containing the objective, relevant context references, constraints, and acceptance criteria. Agents receive only the data their assignment requires, which improves both focus and security.

Routing, parallelism, and merging

The supervisor splits goals into subtasks, routes each to the right specialist, and can run independent subtasks in parallel — research while drafting, testing while documenting.

Merging is deliberate, not automatic. Results arrive with confidence scores and evidence; the supervisor reconciles conflicts before assembling the final output.

Review loops and consensus

Specialist outputs pass through reviewer agents that check quality, policy compliance, and evidence. Disagreements between producer and reviewer escalate to adjudication rather than being averaged away.

This mirrors how human engineering organizations work: authors are not their own reviewers, and sign-off is a distinct, accountable step.

Key Points

Explicit role contracts (input, output schema, escalation path) make specialists reliable.
Task envelopes carry scoped context only — better focus and better security.
Independent subtasks run in parallel; merging is supervised and evidence-based.
Producer–reviewer separation catches defects single-agent pipelines wave through.

All study guides for this chapter: Multi-Agent Systems, Explained Simply · How Multi-Agent Systems Work Under the Hood · Multi-Agent Systems in the Real World