A network of 18 agents processing hundreds of jobs, thousands of Truth Ledger events, and a growing Incubator pipeline generates communication volume that cannot be managed by assumption. Without Protocol 073, agents operate in silos — each executing its own job without awareness of what others are doing, what they need, or what they've flagged.

With Protocol 073, the agent network becomes coherent. Hurricane's classification feeds directly to Bundler. Sentinel's compliance flag reaches Weaver and Jermaine simultaneously. Pulse's health alert triggers an immediate Escalation message to the relevant agent. Mirror's cross-reference result informs Forge's job assignment. The agents talk. The system learns. The Sovereign stays informed without noise.

Prohibition 1 — No Impersonation: No agent may send a message that represents itself as another agent. Every message is signed with the sending agent's identifier and tier. Messages without valid agent signatures are rejected and flagged as a Protocol 071 Tier 1 breach.

Prohibition 2 — No Tier Override: A Tier 3 agent cannot send an Action Request (Type B) to a Tier 1 agent. Tier 3 agents can only send Data Share (Type A) and Escalation (Type C) messages upward. All Action Requests from Tier 3 to Tier 1 must be routed through the Agent Comms Manager who confirms tier-appropriateness before forwarding.

Prohibition 3 — No Lost Messages: Every Type B and Type C message requires an acknowledgement within the defined window. The Message Queue Monitor tracks all unacknowledged messages. Any Type B unacknowledged after 4h and any Type C unacknowledged after 1h trigger an escalation to the Agent Comms Manager.

Prohibition 4 — No Unlogged Communications: Every message — all five types — must produce a Communication Log entry: sender · receiver · message type · timestamp · content summary · acknowledgement timestamp. No off-ledger agent communication. Everything goes to the Truth Ledger.

Tier 1 → Tier 2: Action Requests (Type B) — Tier 1 can direct Tier 2 agents. Hurricane can instruct Oracle to calculate floor impact immediately upon classification. Entity #35 can issue constitutional directives to any agent. H.BLUE can request Lens to initiate an IP check.

Tier 2 → Tier 3: Action Requests (Type B) — Tier 2 can direct Tier 3 agents within their domain. Forge can request Weaver draft a protocol addendum. Bundler can request Scribe update an MD entry. Sentinel can request Pulse monitor a specific window.

Tier 3 → Tier 2/1: Data Share (Type A) and Escalation (Type C) only. Weaver shares a completed protocol draft with Forge (Type A). Pulse escalates a window breach to Jermaine (Type C). Scribe confirms MD update completion to Sentinel (Type A).

Any Agent → Jermaine: Escalation (Type C) for issues requiring Sovereign decision. Broadcast from Jermaine → all agents (Type E). Jermaine's Cognitive Command interface handles all Type E messages.

Type D messages (External Triggers) allow CircularOS agents to initiate actions in external systems via webhook. Current applications: Scribe triggering Truth Ledger API → external compliance platform. Oracle triggering floor impact notification → investor dashboard. Sentinel triggering BSI Flex check → external compliance database. Forge triggering job assignment → external project management tool.

All webhooks are authenticated, rate-limited, and logged. Every webhook response is logged alongside the trigger message — success, failure, or timeout. Webhook failures trigger an immediate Type C Escalation to the Communication Architect who investigates and resolves within 4h.

18 agents. 5 message types. 4 prohibitions. 1 Communication Log. Protocol 073 transforms the agent network from 18 individual functions into a coherent, coordinated, communicating system. When Hurricane classifies, Bundler knows. When Sentinel flags, Weaver and Jermaine know simultaneously. When Pulse detects a breach, the right agent responds immediately.

The agents are talking now. Every message is logged. No message is lost. The network is coherent. Keep communicating.