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Change V5.4.0: Multi-Model Agent Support Proposal

Leo Miranda edited this page 2026-01-29 02:44:10 +00:00

Table of Contents

• Change V5.4.0: Multi-Model Agent Support
• Summary
• Motivation
• Proposed Changes
• 1. Agent Frontmatter Extension
• 2. Plugin Default Model
• 3. Inheritance Chain
• Model Allocation Strategy
• Recommended Agent Assignments
• Backward Compatibility
• Implementation Sprints
• Files Affected

Change V5.4.0: Multi-Model Agent Support

Type: Feature Version: 5.4.0 Status: Proposed Date: 2026-01-28

Summary

Add model selection capability to the plugin system, allowing agents to specify preferred Claude models (opus, sonnet, haiku) with inheritance and backward compatibility.

Motivation

Different agent tasks have different complexity requirements:

• Architecture decisions need deep reasoning (Opus)
• Implementation work needs balanced capability (Sonnet)
• Simple validation needs speed and cost efficiency (Haiku)

Currently all agents use the session's default model with no way to optimize.

Proposed Changes

1. Agent Frontmatter Extension

Add optional model field to agent YAML frontmatter:

---
name: planner
description: Sprint planning agent
model: opus  # NEW: opus | sonnet | haiku
---

2. Plugin Default Model

Add optional defaultModel to plugin.json:

{
  "name": "projman",
  "defaultModel": "sonnet"
}

3. Inheritance Chain

Agent model (highest priority)
    ↓ if not set
Plugin defaultModel
    ↓ if not set
System default: sonnet

Model Allocation Strategy

Model	Use For	Cost	Speed
Opus	Architecture, security analysis, complex reasoning	Highest	Slower
Sonnet	Implementation, coordination, standard tasks	Medium	Balanced
Haiku	Simple validation, quick checks	Lowest	Fastest

Recommended Agent Assignments

Plugin	Agent	Model	Rationale
projman	planner	opus	Architecture decisions
projman	orchestrator	sonnet	Coordination
projman	executor	sonnet	Implementation
projman	code-reviewer	opus	Quality review
pr-review	security-reviewer	opus	Security analysis
code-sentinel	security-reviewer	opus	Security scanning
data-platform	data-analysis	opus	Complex analysis
viz-platform	component-check	haiku	Simple validation
contract-validator	agent-check	haiku	Quick verification

Backward Compatibility

• Agents without model field continue working (use defaults)
• Plugins without defaultModel use system default
• All changes are additive - no breaking changes

Implementation Sprints

• Sprint 7: Core implementation (this proposal)

Files Affected

• 7 agent files (model field additions)
• 6 plugin.json files (defaultModel additions)
• 3 documentation files
• 1 validation script

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Tags: feature, agents, model-selection, v5.4.0