Sub-Agents

The subagents server lets agents spawn other agents as children, enabling delegation and parallel work. See Tools for configuration.

Tools

Tool	Description
spawn_subagent	Spawn one or more child agents in parallel

Configuration

Agents available for spawning must have agentInvocable: true in settings.json:

.aether/settings.json

{
  "agents": [
    {
      "name": "coder",
      "description": "General coding agent",
      "model": "anthropic:claude-sonnet-4-5",
      "userInvocable": true,
      "agentInvocable": true
    },
    {
      "name": "researcher",
      "description": "Read-only research agent",
      "model": "anthropic:claude-haiku-4-5",
      "agentInvocable": true,
      "tools": {
        "allow": ["coding__read_file", "coding__grep", "coding__find", "coding__web_*"]
      }
    }
  ]
}

Example

A parent agent can spawn multiple researchers in parallel:

{
  "tasks": [
    {
      "agentName": "researcher",
      "prompt": "Find all database queries in the codebase and list them"
    },
    {
      "agentName": "researcher",
      "prompt": "Read the README and summarize the project architecture"
    }
  ]
}

Each child agent runs independently with its own model, prompts, MCP server refs, and tool filters. Results are returned to the parent after all child agents complete.

Structured output

Sub-agents are encouraged to return structured JSON so the parent can summarize their work. The recommended fields are:

Field	Description
summary	Brief summary of what the agent accomplished
artifacts	Files or resources the agent read or changed
decisions	Key findings or decisions
nextSteps	Recommended follow-up actions