magent

Child-Agent Jobs

Magent uses durable child-agent jobs for collaborative agent work. This replaces the old one-shot delegate tool with a small lifecycle that the root agent can coordinate explicitly.

Tool Surface

The public child-agent tool surface is:

Tool	Purpose
spawn_agent	Start a child-agent job and return a stable job id.
send_agent_message	Send follow-up input to an existing child job.
wait_agent	Wait for one or more jobs and return status/result data.
list_agents	List child jobs for the current parent session.
close_agent	Close a job and abort its live request when present.

These tools share the agent permission key. The old delegate tool is not kept as a compatibility wrapper.

Data Model

magent-agent-job.el defines magent-agent-job, the durable record for a child job. Each job stores:

• id
• parent-session-id
• agent-name
• task-name
• status
• prompt
• created-at
• updated-at
• transcript
• result
• error
• metadata

Valid statuses are queued, running, waiting, completed, failed, closed, and cancelled.

The parent magent-session persists child jobs in its agent-jobs slot. Runtime-only state for active loops lives in magent-tools--agent-job-runtimes, keyed by job id. This keeps parent session JSON sufficient for resume/inspection while avoiding serializing live request handles.

Runtime Flow

1. spawn_agent creates a magent-agent-job in the parent session.
2. The child request starts through the Magent-owned loop in magent-agent-loop.el.
3. The child runs with summary-only UI so it does not write its full transcript into the parent conversation body.
4. Completion, failure, close, and wait events update the durable job record.
5. Tool results return model-visible JSON summaries to the root agent.

The provider boundary remains gptel-request through magent-llm-gptel.el. Magent owns orchestration, tool dispatch, persistence, abort behavior, and child-job coordination.

Inheritance

Child jobs inherit the parent request context where practical:

• project root and session scope
• backend/model names
• temperature and top-p
• active skill names and capability context
• effective permission profile bounded by the parent and child agent
• request depth for recursive spawn guards

magent-child-agent-max-depth controls recursive spawning. The default allows direct children and blocks recursive child spawning.

UI And Resume

The parent *magent* buffer renders compact lifecycle blocks as #+begin_agent / #+end_agent. Full child prompt, metadata, result/error, and transcript state remain inspectable with:

• M-x magent-show-agent-transcript
• C-c m j

magent-resume-session restores persisted agent-jobs with the parent session. Active request handles are not restored after Emacs restart, but saved job metadata, result/error state, and transcripts remain available for inspection.

Boundaries

This lifecycle intentionally preserves Magent’s Emacs-native workflow:

• live Emacs buffers
• emacs_eval
• org-mode output
• project-scoped sessions
• gptel transport

Codex sandbox, seatbelt, bubblewrap, and shell-isolation parity are out of scope.

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