> Markdown twin of https://adna.network/reference/specification/11-coordination-protocol/
> Index: https://adna.network/llms.txt · Full corpus: https://adna.network/llms-full.txt
> State is a build-time snapshot generated 2026-08-30 (UTC); nothing here is live.

# 11. Coordination Protocol — aDNA Specification

> **Scan**: `who/coordination/` for cross-agent communication — urgency levels (urgent/info/fyi), ephemeral notes, required contents.

*Decisions: D9*

## 11.1 Cross-Agent Coordination

Cross-agent notes live in `who/coordination/`. This is the single location for agent-to-agent communication.

Coordination notes are **ephemeral by design**: created when needed, consumed by the target agent, and archived when resolved.

## 11.2 Urgency Levels

| Level | Meaning | When to Read |
|-------|---------|-------------|
| `urgent` | Immediate action needed | Read before any other work |
| `info` | Important context | Read during startup checklist |
| `fyi` | Non-blocking background information | Read when convenient |

## 11.3 Coordination Note Contents

A coordination note MUST include:
- **Who** created it and who it targets
- **What** the coordination concern is
- **When** it was created and when it expires
- **Action needed** — what the target agent should do

Agents MUST check `who/coordination/` during every session startup.

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