Smart Model Switching

Three-tier Claude routing: Haiku → Sonnet → Opus

Start with the cheapest model. Escalate only when needed. Save 50-90% on API costs.

The Golden Rule

If a human would need more than 30 seconds of focused thinking, escalate from Haiku to Sonnet. If the task involves architecture, complex tradeoffs, or deep reasoning, escalate to Opus.

Cost Reality

| Model | Input | Output | Relative Cost | |-------|-------|--------|---------------| | Haiku | $0.25/M | $1.25/M | 1x (baseline) | | Sonnet | $3.00/M | $15.00/M | 12x | | Opus | $15.00/M | $75.00/M | 60x |

Bottom line: Wrong model selection wastes money OR time. Haiku for simple, Sonnet for standard, Opus for complex.

💚 HAIKU — Default for Simple Tasks

Stay on Haiku for:

Factual Q&A — "what is X", "who is Y", "when did Z"
Quick lookups — definitions, unit conversions, short translations
Status checks — calendar, file reads, session monitoring
Heartbeats — periodic checks, HEARTBEAT_OK responses
Memory & reminders — "remember this", "remind me to..."
Casual conversation — greetings, small talk, acknowledgments
Simple file ops — read, list, basic writes
One-liner tasks — anything answerable in 1-2 sentences

NEVER do these on Haiku

❌ Write code longer than 10 lines
❌ Create comparison tables
❌ Write more than 3 paragraphs
❌ Do multi-step analysis
❌ Write reports or proposals

💛 SONNET — Standard Work (The Workhorse)

Escalate to Sonnet for:

Code & Technical

Code generation — write functions, build features, scripts
Code review — PR reviews, quality checks
Debugging — standard bug investigation
Documentation — README, comments, user guides

Analysis & Planning

Analysis & evaluation — compare options, assess trade-offs
Planning — project plans, roadmaps, task breakdowns
Research synthesis — combining multiple sources
Multi-step reasoning — "first... then... finally"

Writing & Content

Long-form writing — reports, proposals, articles (>3 paragraphs)
Creative writing — blog posts, descriptions, copy
Summarization — long documents, transcripts
Structured output — tables, outlines, formatted docs

❤️ OPUS — Complex Reasoning Only

Escalate to Opus for:

Architecture & Design

System architecture decisions
Major codebase refactoring
Design pattern selection with tradeoffs
Database schema design

Deep Analysis

Complex debugging (multi-file, race conditions)
Security reviews
Performance optimization strategy
Root cause analysis of subtle bugs

Strategic & Creative

Strategic planning — business decisions, roadmaps
Nuanced judgment — ethics, ambiguity, competing values
Deep research — comprehensive multi-source analysis

🔄 Implementation

For Subagents

```javascript // Routine monitoring sessions_spawn(task="Check backup status", model="haiku")

// Standard code work
sessions_spawn(task="Build the REST API endpoint", model="sonnet")

// Architecture decisions sessions_spawn(task="Design the database schema for multi-tenancy", model="opus") ```

For Cron Jobs

```json { "payload": { "kind": "agentTurn", "model": "haiku" } } ``` Always use Haiku for cron unless the task genuinely needs reasoning.

📊 Quick Decision Tree

``` Is it a greeting, lookup, status check, or 1-2 sentence answer? YES → HAIKU NO ↓

Is it code, analysis, planning, writing, or multi-step? YES → SONNET
NO ↓

Is it architecture, deep reasoning, or critical decision? YES → OPUS NO → Default to SONNET, escalate if struggling ```

📋 Quick Reference Card

``` ┌─────────────────────────────────────────────────────────────┐ │ SMART MODEL SWITCHING │ │ Haiku → Sonnet → Opus │ ├─────────────────────────────────────────────────────────────┤ │ 💚 HAIKU (cheapest) │ │ • Greetings, status checks, quick lookups │ │ • Factual Q&A, definitions, reminders │ │ • Simple file ops, 1-2 sentence answers │ ├─────────────────────────────────────────────────────────────┤ │ 💛 SONNET (standard) │ │ • Code > 10 lines, debugging │ │ • Analysis, comparisons, planning │ │ • Reports, proposals, long writing │ ├─────────────────────────────────────────────────────────────┤ │ ❤️ OPUS (complex) │ │ • Architecture decisions │ │ • Complex debugging, multi-file refactoring │ │ • Strategic planning, deep research │ ├─────────────────────────────────────────────────────────────┤ │ 💡 RULE: If a human needs > 30 sec thinking → escalate │ │ 💰 COST: Haiku 1x → Sonnet 12x → Opus 60x │ └─────────────────────────────────────────────────────────────┘ ```

Built for Claude-only setups with Haiku, Sonnet, and Opus. Inspired by save-money skill, extended with three-tier progression.