Give durable user context its producer-owned source kind instead of a generic plugin wrapper. The V3-to-V4 conversion preserves the frozen rename and collision rules, all own JSON metadata, event coordinates, and historical request-only kinds. Native catalog and JSONL admission retain source validation so unknown attribution can survive without its producer while malformed owned sources are refused. Use an explicit user-only RequestUserInput for auxiliary LLM prompts that do not own durable message identity. Auto Review and compaction remove their request-only source registrations while retaining prompt content and freezing; provider serializers and projections keep the same wire data, assistant replay isolation, image ordering, and tool correlation. Session writes, Agent delivery, and recorded title requests continue to require identified durable messages. Bind the saved compatibility policy only to user sources and qualify tmux location attribution without weakening fixed system, model, or tool semantics. Rebuild the current inventory and unpublished V4 acknowledgement on the actual tool-role parent, preserving its rationale and all accepted historical records. The catalog format version records tooling metadata; Session remains V4. Developer-role policy and activation belong to their own feature. The latest-master Messages adapter, serialization, request-input typing, EpochHeader reservation, and attribution checks pass 103 tests across five files. The retained V3 Messages input-history snapshot passes through the source profile; Host/Client typechecks and all 41 documentation gates pass. The generated comparison records four changed roots and 447 unchanged type fingerprints. Latest-master ARIA changes are retained, with producer source labels applied independently; new Messages fixtures retain their producer names as declared source kinds and use the fixed system-message helper; recorded Session generations are unchanged by this regrouping. Co-authored-by: Tianyi Cui <[email protected]>
description, kind
| description | kind |
|---|---|
| The subagent package group: the delegation seam, its in-process and out-of-process backends, and the model-facing delegation tools. | package-group |
subagent/ — subagent capability family
English | 中文
Summary
The subagent package family lets an agent delegate a task to a child, continue the child's work, and discover every child it created. Choose a fresh in-process child for isolated work, a history-seeded in-process child when prior conversation matters, or an out-of-process child backed by ACP, Codex, Claude Code, or another Harness runtime. Model-facing tools also let agents message adjacent agents, interrupt work, and list child status. Each child remains visible to its parent whether it is running or stored; the package READMEs document provider-specific setup and limits.
Table of Contents
Packages
| Package | Role | ctx key |
|---|---|---|
subagent/ |
Defines the delegation service: provider registry, one-shot runs, continuable children, and discovery | ctx.subagents |
subagent-in-process-driver/ |
Provides the shared in-process run driver | — |
subagent-spawn-in-process/ |
Runs a fresh in-process child | registers on ctx.subagents |
subagent-fork-in-process/ |
Runs an in-process child seeded from the parent's completed history | registers on ctx.subagents |
subagent-acp/ |
Runs an out-of-process child over the Agent Client Protocol | registers on ctx.subagents |
subagent-codex/ |
Runs a real Codex child through the official app-server protocol | registers on ctx.subagents |
subagent-claude-code/ |
Runs a real Claude Code child through the official Agent SDK | registers on ctx.subagents |
subagent-dsh-sdk/ |
Runs an out-of-process Harness child through the TypeScript SDK | registers on ctx.subagents |
tool-subagent/ |
Exposes delegation to the model | registers on ctx.tools |
tool-subagent-control/ |
Exposes adjacent-agent messaging, interrupt, and listing to the model | registers on ctx.tools |
Related documentation
- Subagent subsystem — the service contract, provider contract, and terminal result semantics.
- Subagent capability seam — the design record for the delegation capability family.
- Continuable subagents — durable children that accept follow-up turns.
- tool-subagent-control README — the follow-up, interrupt, and listing surface.
Dev Note
None.