> Markdown twin of https://adna.network/reference/specification/9-mission-system/
> 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.

# 9. Mission System — aDNA Specification

> **Scan**: Multi-session work decomposition — objectives, acceptance criteria, stages, claiming protocol, handoff between agents.

*Decisions: D12, D16, D17*

## 9.1 Mission Structure

Missions live in `how/missions/`. A mission decomposes work that spans multiple sessions into trackable objectives.

**Single-file missions** (small scope):
```
how/missions/mission_simple_task.md
```

**Subdirectory missions** (large scope with deliverables):
```
how/missions/mission_complex_project/
├── mission_complex_project.md    # Master mission
├── deliverable_a.md              # Phase/deliverable files
└── deliverable_b.md
```

The mission file MUST include:
- **Objectives**: What the mission achieves
- **Acceptance criteria**: How you know it is done
- **Constraints**: What limits apply (time, scope, dependencies)
- **Objective list**: Individual objectives with dependencies and status
- **Status tracking**: Per-objective status (pending, in_progress, completed, blocked)

## 9.2 Mission Stages

Missions MAY define stage-based subdirectories for multi-phase work:

```
how/missions/{mission_slug}/
├── mission_{slug}.md
├── 00_research/
├── 01_requirements/
├── 02_design/
└── 03_implementation/
```

Stage names and count are mission-specific. The convention is: numbered prefix for ordering, descriptive name for clarity.

## 9.3 Mission Handoff

Agents claim mission objectives by session. A session file's `plan_id` and `task` frontmatter fields (legacy names, retained for compatibility) link it to the mission. When an objective spans multiple sessions, each session's SITREP provides the handoff. Agents MUST NOT claim objectives already in progress by another active session.

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