---
name: handoff-protocol
description: 'Apply a portable multi-agent handoff and persistence protocol: choose bounded subagents versus resumable independent tasks, dispatch four-part packets, require evidence-backed return and closure receipts, verify durable writes from the authoritative root, serialize central-board updates, and degrade honestly when host adapters are unavailable. Use when delegating, handing work between agents, preserving delegated work in memory/logs/boards, or reviewing delegated results. 多 agent 派活、交接、持久化与回包复核时触发。'
---

**English** | [简体中文](SKILL.zh-CN.md)

# Handoff Protocol

Use this Skill to prepare, route, receive, persist, and verify delegated work.
It defines portable contracts; it does not bundle an agent registry,
spawn/task/message runtime, inbox, workspace resolver, or atomic log writer.

## Apply the rule pack

1. Read [`references/rule-pack.md`](references/rule-pack.md) before dispatching
   or closing work. Select `bounded_subagent` for a contained result returned
   to the parent; select `independent_task` only when the recipient needs a
   separately resumable task/thread. Treat execution mode and persistence as
   separate choices: either mode may carry required durable closeout.
2. Discover host capabilities through
   [`references/adapter-contracts.md`](references/adapter-contracts.md).
   Prefer `agent.task.create` for `independent_task`; do not simulate it with a
   nested child unless the packet explicitly allows degradation.
3. Validate packets and receipts against [`contracts/`](contracts/). Treat an
   omitted `execution_mode` as `bounded_subagent` for v1.2 compatibility.
4. For durable work, resolve the authoritative root before writing, attach the
   four-target persistence contract, bind packet/contract/dispatch/return/
   closure/verification with `handoff_id`, `contract_id`, and `dispatch_id`,
   give every required target a fresh parent-issued `evidence_nonce`, and derive
   its `evidence_anchor` with the real `dispatch_id`. Return one closure receipt
   per target. Let the parent or named single writer serialize central-board
   changes.
5. Re-read every required artifact from the resolved authoritative root before
   claiming completion, and require the real file/provider event to contain the
   nonce-and-dispatch-bound `evidence_anchor`. A child message, relabelled stale
   receipt, prior-dispatch artifact, overlay write, or worktree-local file is
   not proof that this task's artifact landed.
6. If an adapter is absent or exits nonzero, report the failure and follow the
   documented degradation path. Never claim a dispatch, follow-up, delivery,
   atomic append, or verification without provider or readback evidence.
7. Keep external routing, safety, and data policy authoritative. This Skill
   consumes those policies; it does not redefine them.

## First success

A successful bounded use produces a four-field dispatch packet, a real host
receipt, a four-field return packet, and a parent verification trace. If either
mode has a persistence contract, it additionally produces four closure
receipts and four parent readbacks. Only `independent_task` adds a separately
resumable task/thread and authoritative-workspace receipt; durable file writes
alone never supply that status. With no delivery adapter, success is an
explicitly `undelivered` copyable packet, not a simulated child result.

## Contracts and evidence

- Rules: [`references/rule-pack.md`](references/rule-pack.md).
- Adapter ports and degradation behavior:
  [`references/adapter-contracts.md`](references/adapter-contracts.md).
- Machine-checkable packet, persistence, dispatch, closure, return, and parent
  verification Schemas: [`contracts/`](contracts/).
- Deterministic mock/failure evaluations: [`evals/`](evals/).

Install the **whole Skill directory**. A lone `SKILL.md` is an incomplete
installation because the required references and Schemas will be missing. If
any linked file is absent, stop and report `invalid_install`; do not improvise
the missing contract.

The execution model remains documentation discipline. Adapter capabilities are
external dependencies, not bundled runtime features.

## Version & update self-check

- Current version: **1.3.0** (matches `.claude-plugin/plugin.json`).
- Repository: `https://github.com/LucioLiu/handoff-protocol`
- Self-check: for plugin installs, follow the host update mechanism. For manual
  installs, compare the entire Skill directory with the repository; never
  update only this file.

---

> Both language editions are maintained in sync. If they ever diverge, the **English edition** is authoritative — please open an [issue](https://github.com/LucioLiu/handoff-protocol/issues) if you spot one.