---
skill_id: fallback-model-router
evaluation: free
price_usd_full: 4.99
challenge: https://lvlltd.com/api/pay?skill=fallback-model-router
outline: https://lvlltd.com/skills/fallback-model-router/outline.json
standards: x402, ERC-7857
---

# Free sample — Fallback Model Router

**Skill ID:** `fallback-model-router`  
**Full unlock:** $4.99 USDC via x402 on Base  
**Challenge:** https://lvlltd.com/api/pay?skill=fallback-model-router  
**Outline JSON:** https://lvlltd.com/skills/fallback-model-router/outline.json

## Summary

Route to backup models when primary APIs are down, degraded, or rate-limited.

## When to use

- Primary model 500s or latency spikes
- Need cheaper model for bulk classification vs hard reasoning
- Multi-provider keys with different quotas

## Decision criteria (buy vs skip)

- You need this when: Primary model 500s or latency spikes
- You get capability: Task-class → model map
- Budget fits: full unlock is $4.99 USDC on Base
- You can automate unlock via HTTP 402 without a browser
- You only need teaser/outline first — sealed src/ops stay locked until payment

## Outline (preview)

1. Define task classes: extract, reason, code, chat
2. Map primary and fallback models per class with max cost
3. Probe health; on failure promote fallback and log reason
4. Degrade gracefully: smaller context or skip optional polish
5. Emit router-config.json + incident log schema

## Capabilities (preview)

- Task-class → model map
- Health probe + promote logic
- Cost ceiling per class
- Degraded-mode behavior notes

## What you get after payment

- SKILL.md (teaser public)
- agent-install.json (public meta)
- src/index.js (stub public; full after unlock)
- Full sealed: src/, schemas/, ops/* (when present) after verified X-PAYMENT

## Agent buy path (zero human UI)

```
GET  https://lvlltd.com/skills/fallback-model-router/outline.json
GET  https://lvlltd.com/api/pay?skill=fallback-model-router   → HTTP 402
# transfer maxAmountRequired USDC to payTo on Base
POST https://lvlltd.com/api/pay
  X-PAYMENT: {"txHash":"0x…","skill":"fallback-model-router"}
# response.sealed_pack.files = full pack
```

## Sample excerpt

# Fallback Model Router

Single-model agents fail when providers hiccup. This router maps task classes to primary/fallback models with cost ceilings and degraded modes (skip polish, shorter context). Logs promote reasons for later FinOps. Complements multi-model-router strategy with ops-ready config artifacts.

When to use: production fleets, mixed OpenAI/Anthropic/xAI stacks, cost-sensitive bulk jobs.

**Price:** $4.99 USDC on Base via x402 unlock.

**Standards:** x402 payments · ERC-7857 sealed skill model · agent-swarm ready.

Operator notes for Fallback Model Router: treat this as a capability pack you wire into real tools—not a certification or hosted SaaS. Pair it with free evaluation at /skills/fallback-model-router/outline.json before paying. Typical failure modes it reduces include silent misconfiguration, support thrash, and agents inventing process under load. After unlock, store sealed files in your private skill inventory, run a dry-run with non-production credentials, and only then attach the pack to live goals. Cross-sell naturally sits next to related ops, commerce, or networking skills already on lvlltd.com so agents can compose a ladder instead of a one-off purchase.