Phase 2: Coordination & Agreement · ~75 minutes · Python (stdlib · `threading`)

Shared Memory and Blackboard Patterns

Two approaches coexist in 2026 multi-agent systems: the message pool (everyone sees everyone's messages, as in AutoGen GroupChat or MetaGPT) and the blackboard with subscription (agents subscribe to relevant events, as in Context-Aware MCP or the Matrix framework).

Hiring signal: Can operate shared memory and blackboard patterns in production

Introduction

Both are the only stateful part of a multi-agent system — which means both are where the interesting bugs live. The reference failure mode is memory poisoning: one agent hallucinates a "fact," other agents treat it as verified, and accuracy decays gradually in a way that is much harder to debug than an immediate crash. This lesson builds both structures from stdlib, injects a poisoning attack, and shows the three mitigations that actually work in production.

Type: Learn + Build Languages: Python (stdlib, threading) Prerequisites: Phase 16 · 04 (Primitive Model), Phase 16 · 09 (Parallel Swarm Networks) Time: ~75 minutes

Objective

Learning objectives

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You've read the first 2 sections. The rest of this lesson covers The Problem, The Concept, Build, Check Yourself, Key Terms & Next — plus a hands-on lab, quiz, and project artifact.

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