ADR-2026-09-04-07 — Work is the primary coordination unit

Status: ACCEPTED — 2026-09-04 (Founder Canon §6; final-architecture record §14)

Context

Human–AI collaboration that relies on conversational handoffs forces every participant to
re-derive the situation on every turn — the machine version of the Human-API problem. Agents that
coordinate only through free-form chat lose identity, authority, evidence and continuity.

Decision

• Work is the durable coordination object binding: work_id, objective, business-context
  references, owner/responsible human, current executor, state and lifecycle, subtasks and
  dependencies, evidence, commitments, proposals, policy/authority envelope, available
  capabilities, expected outcome, actual outcome, handoff history, and trace/continuity
  identifiers.
• No participating worker begins meaningful work without a Spine-derived authorized context and
  Work identity — human, Twin, Spine Agent, ADK runtime, workflow or provider.
• Spine Agents cooperate by reading and updating shared Work state and returning evidence — not
  by free-form agent-to-agent conversation. Handoffs are recorded so the next worker continues
  from the same authorized context.
• Work Allocation determines who/what performs each part of Work (human, Twin, agent, system,
  human+AI) based on capability, authority, responsibility, risk, context and policy.

Alternatives considered

• Chat-thread coordination — rejected: no durable identity, no authority envelope, no evidence
  trail; continuity dies with the session.
• Task-only coordination (tasks as the top object) — rejected: tasks are components; Work binds
  the goal, authority, evidence and outcome that tasks alone cannot.

Consequences

Work identity must survive projections, provider routes and model changes (register G-20). The
canonical Work record is a schema/coordination build, not a rename of activities.