Module subagent 

Delegated Agent System

Provides a system for delegating specialized tasks to focused child agents. Each delegated child run uses an isolated child session with restricted permissions.

Architecture

Parent Session
  └── Task Tool
        ├── AgentRegistry (lookup agent definitions)
        └── Child Session (isolated execution)
              ├── Restricted permissions
              ├── Optional model override
              └── Event forwarding to parent

Built-in Agents

• explore: Fast codebase exploration (read-only)
• general: Multi-step task execution
• plan: Read-only planning mode
• verification: Adversarial verification specialist
• review: Code review specialist

Loading Agents from Files

Agents can be loaded from YAML or Markdown files:

YAML Format

name: my-agent
description: Custom agent for specific tasks
hidden: false
max_steps: 30
permissions:
  allow:
    - read
    - grep
  deny:
    - write
prompt: |
  You are a specialized agent...

Markdown Format

---
name: my-agent
description: Custom agent
max_steps: 30
---
# System Prompt
You are a specialized agent...

Structs

AgentDefinition

Agent definition

AgentRegistry

Agent registry for managing agent definitions

ModelConfig

Model configuration for agent.

WorkerAgentSpec

Reproducible recipe for a disposable worker/subagent.

Enums

ConfirmationInheritance

How a child run resolves tools that require confirmation (PermissionDecision::Ask).

WorkerAgentKind

Cattle-style worker agent role.

Functions

builtin_agents

Create built-in agent definitions

load_agents_from_dir

Load all agent definitions from a directory

parse_agent_md

Parse an agent definition from Markdown with YAML frontmatter

parse_agent_yaml

Parse an agent definition from YAML content.

Type Aliases

CattleAgentKind

Backward-friendly alias for callers that name this pattern cattle mode.

CattleAgentSpec

Backward-friendly alias for callers that name this pattern cattle mode.