Skip to content
mono-agent

Multi-Model Fallback Chain

This playbook builds an ordered cloud-to-local fallback chain with exact effort and explicit provider safety. Failover is visible in results and traces; no model substitution or safety projection happens silently.

Who this is for

Section titled “Who this is for”

Reliability-minded builders who want multiple provider families without giving up an auditable safety contract.

Features used

Section titled “Features used”

Configuration

Section titled “Configuration”
{
  "agent": { "name": "Resilient Research Agent" },
  "runtime": {
    "model": "anthropic:claude-sonnet-5",
    "effort": "high",
    "fallbacks": [
      { "model": "openai-codex:gpt-5.6-sol", "effort": "xhigh" },
      { "model": "ollama:gemma4:31b" }
    ]
  },
  "providers": {
    "ollama": {
      "type": "ollama",
      "baseUrl": "http://localhost:11434",
      "enabled": true,
      "models": [{ "name": "gemma4:31b" }]
    },
    "piNative": {
      "transport": "auto",
      "piMaxRetries": 2,
      "maxRetryDelayMs": 60000
    }
  }
}

The primary uses runtime.effort. The first fallback explicitly uses xhigh; the local route omits effort and therefore uses its provider default. The fallback list is ordered and has no product-imposed count limit.

Steps

Section titled “Steps”
  1. Pull the local last resort: ollama pull gemma4:31b.
  2. Run guided mono-agent init, search for each route, and choose the exact supported effort per model.
  3. Read the Creation review: it lists all routes, efforts, provider actions, route contracts, and the number of real/potentially billed readiness calls.
  4. Let readiness verify each route sequentially. If interrupted, choose resume to reuse only successful checks under the unchanged plan fingerprint.
  5. Run mono-agent validate, then start the agent.
  6. Force a retryable provider/auth failure. Confirm the run summary’s failoverHistory identifies failed routes.

Non-retryable application errors and mid-turn safety failures are not masked by failover.

Section titled “Related”