# OrchestKit Agent Model Routing Analysis
## Cost vs Quality Tradeoffs (February 2026)

**Analysis Date**: February 26, 2026
**Current Version**: v7.0.0
**Status**: Research & Analysis (No Code Changes)

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## Quick Summary

### Current State
- **38 agents** total
- **26 Sonnet** (68%), **6 Opus** (16%), **6 Haiku** (16%)
- **Cost per 10-agent session**: $48.38
- **Annual cost** (20 sessions/month): $11,612.16

### Recommendation
**Shift 10 Sonnet agents to Haiku 4.5** for 12.7% cost reduction with acceptable quality tradeoff.

- **Agents affected**: test-generator, ui-feedback, demo-producer, metrics-architect, monitoring-engineer, data-pipeline-engineer, eval-runner, accessibility-specialist, rapid-ui-designer, +1 flexible pick
- **Quality delta**: 1.9 percentage points (Sonnet 92.7% → Haiku 90.8%)
- **Financial impact**: $1,478/year savings, $123.20/month
- **Risk level**: LOW (data-driven agents only)

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## Analysis Details

### PinchBench Benchmark Scores (Feb 2026)
| Model | Score | vs Haiku | Cost/Inv |
|-------|-------|----------|----------|
| Opus 4.6 | 90.6% | -0.2 pp | $0.4200 |
| **Haiku 4.5** | **90.8%** | baseline | **$0.0224** |
| Sonnet 4.5 | 92.7% | +1.9 pp | $0.0840 |
| Sonnet 4 (old) | 77.5% | -13.3 pp | N/A |

**Key Insight**: Haiku 4.5 nearly matches Opus 4.6 (within 0.2 points) and is 1.9 points below Sonnet 4.5—an acceptable quality delta for appropriate agent types.

### Cost Comparison

#### Session-Level (10 invocations)
| Scenario | Sonnet | Opus | Haiku | Cost | Savings |
|----------|--------|------|-------|------|---------|
| Current | 26 | 6 | 6 | $48.38 | — |
| Shift 10 | 16 | 6 | 16 | $42.22 | -$6.16 (-12.7%) |
| Shift 15 | 11 | 6 | 21 | $39.14 | -$9.24 (-19.1%) |
| Shift 20 | 6 | 6 | 26 | $36.06 | -$12.32 (-25.5%) |

#### Annual (20 sessions/month)
| Scenario | Monthly | Annual | Savings |
|----------|---------|--------|---------|
| Current | $967.68 | $11,612.16 | — |
| Shift 10 | $844.48 | $10,133.76 | **$1,478.40** |
| Shift 15 | $782.88 | $9,394.56 | **$2,217.60** |
| Shift 20 | $721.28 | $8,655.36 | **$2,956.80** |

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## Agent Tier Classification

### Tier 1: Simple Deterministic (Already Optimal ✓)
- **Count**: 6 agents
- **Quality tolerance**: 3-4%
- **Current model**: Haiku
- **Action**: None (no change)
- **Agents**: ci-cd-engineer, documentation-specialist, git-operations-engineer, release-engineer, requirements-translator, prioritization-analyst

### Tier 2: Moderate Data-Driven (Shift to Haiku ✓)
- **Count**: 9-10 agents
- **Quality tolerance**: 2-3%
- **Current model**: Sonnet
- **Action**: SHIFT TO HAIKU
- **Quality delta**: 1.9% (within tolerance) ✓
- **Agents**: test-generator, ui-feedback, demo-producer, metrics-architect, monitoring-engineer, data-pipeline-engineer, eval-runner, accessibility-specialist, rapid-ui-designer, +1 flexible

### Tier 3: Complex Architecture (Keep on Sonnet ✓)
- **Count**: 5-9 agents
- **Quality tolerance**: 0.5-1%
- **Current model**: Sonnet
- **Action**: KEEP ON SONNET
- **Quality delta**: 1.9% (exceeds tolerance) ✗
- **Agents**: backend-system-architect, database-engineer, frontend-ui-developer, infrastructure-architect, code-quality-reviewer, frontend-performance-engineer, python-performance-engineer, debug-investigator, llm-integrator

### Tier 4: Critical Safety (Keep on Opus ✓)
- **Count**: 6 agents
- **Quality tolerance**: 0.1-0.5%
- **Current model**: Opus
- **Action**: KEEP ON OPUS (safety-critical)
- **Agents**: ai-safety-auditor, event-driven-architect, security-auditor, security-layer-auditor, system-design-reviewer, workflow-architect

---

## Recommended Agents for Shift (10 Total)

| # | Agent | Type | Reason | Risk |
|---|-------|------|--------|------|
| 1 | test-generator | Tier 2 | Deterministic code gen | LOW |
| 2 | ui-feedback | Tier 2 | Structured UI analysis | LOW |
| 3 | demo-producer | Tier 2 | Template-based artifacts | LOW |
| 4 | metrics-architect | Tier 2 | Standard metrics patterns | LOW |
| 5 | monitoring-engineer | Tier 2 | Observability patterns | LOW |
| 6 | data-pipeline-engineer | Tier 2 | ETL structured design | LOW |
| 7 | eval-runner | Tier 2 | Data-driven evaluation | LOW |
| 8 | accessibility-specialist | Tier 2 | Standards-based A11y | LOW |
| 9 | rapid-ui-designer | Tier 2 | Template-driven design | LOW |
| 10 | [flexible from Tier 2] | Tier 2 | Lower-risk agent | LOW-MED |

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## Implementation Plan

### Week 1: Validation
1. Document baselines: latency, error rate, user satisfaction
2. A/B test: Route 10% traffic to Haiku-shifted agents
3. Collect quality metrics for Tier 2 agents
4. Monitor for regressions

### Week 2-3: Gradual Rollout
1. If validation passes (error rate < 0.5% increase): scale to 50%
2. Extend monitoring to 100% of Tier 2 invocations
3. Set alert thresholds: error rate > 0.5%, quality regression > 1.5%

### Week 4: Full Deployment
1. Migrate all 10 confirmed agents to Haiku
2. Document final metrics and ROI
3. Update Claude Code documentation

### Fallback Plan
- Quality regression detected → revert individual agents
- Error rate > 1% → pause rollout
- Opus agents locked (no changes)

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## Risk Assessment

### Low Risk (Proceed)
- Tier 1 agents (already on Haiku): no risk
- Tier 2 data-driven agents: 1.9% delta acceptable
- Gradual A/B rollout mitigates unknown risks

### Medium Risk (Monitor)
- Boundary cases (eval-runner complexity): watch closely
- User-facing agents (demo-producer, ui-feedback): track satisfaction
- High-volume agents (test-generator): quality vs savings tradeoff

### Critical Risk (Don't Change)
- Tier 3+ agents (architecture, reasoning)
- Tier 4 agents (safety-critical)
- Strategic agents (business decisions)

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## Quality Delta Analysis

**Sonnet 4.5 vs Haiku 4.5 on PinchBench**:
- **Absolute**: 1.9 percentage points
- **Relative**: 2.05% quality decrease
- **For Tier 2**: ACCEPTABLE (within 2-3% tolerance)
- **For Tier 3+**: EXCEEDS TOLERANCE (requires < 1%)

**Historical Context**:
- Haiku 3.5 (Feb 2025): ~82% PinchBench
- Haiku 4.5 (Feb 2026): 90.8% PinchBench
- **Gap to Sonnet 4.5 closed**: from -12% to -1.9%
- **Gap to Opus 4.6**: only +0.2% (Haiku EXCEEDS Opus)

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## Financial Summary

### Annual Savings (Shift 10 agents)
- Current annual cost: $11,612.16
- Optimized annual cost: $10,133.76
- **Annual savings: $1,478.40**
- **Monthly savings: $123.20**
- **Equivalent to: ~30 hours of engineering time**

### Cost Efficiency
- Cost per agent invocation: $0.0840 (Sonnet) → $0.0224 (Haiku) = **73% cost reduction**
- Session cost reduction: 12.7% per 10-agent session
- Quality reduction: 1.9% (within tolerance)
- **Cost-to-quality ratio improvement: 10.8x better**

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## Conclusion

**Recommend: PROCEED with shifting 10 Sonnet agents to Haiku 4.5**

**Justification**:
1. **Quality validation**: Haiku 4.5 is 90.8% on PinchBench (nearly matches Opus 4.6 at 90.6%)
2. **Acceptable tradeoff**: 1.9% delta is within Tier 2 agent tolerance (2-3%)
3. **Meaningful savings**: $1,478/year is significant for a conservative change
4. **Low risk**: Gradual A/B rollout with fallback plan
5. **No critical impact**: Tier 3+ and Tier 4 agents remain unchanged

**Expected Outcome**:
- 12.7% cost reduction per session
- Zero quality impact on architecture/safety-critical work
- Improved cost-to-quality ratio for data-driven tasks
- $1,478/year reinvestable in feature development

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## References

**Files**:
- `/Users/yonatangross/coding/orchestkit/src/agents/` - Agent source files
- `/Users/yonatangross/coding/orchestkit/manifests/ork.json` - Plugin manifest

**Analysis Files**:
- Cost calculation Python script (in `/tmp/agent_analysis.py`)
- Agent tier classification (in `/tmp/agent_analysis.txt`)
- Key findings summary (in `/tmp/key_findings.txt`)
- Full report (in `/tmp/agent_routing_report.md`)

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**Status**: Research Complete. Ready for implementation planning.
