Uptime

Keep an agent up when a provider goes down

List backup models in one request. If the primary model's providers are down or rate-limited, AnyRouter tries the next model.

Model fallbacks guide Routing anyrouter/auto

The problem

What this is for

An agent pinned to one model stops mid-task during a provider outage or a 429 burst. Retry loops in your code add latency and still hit the same provider.

What to do

Three steps, then copy

1.Keep your primary model in model.
2.Add backup ids in models, in the order you want them tried. Fallbacks run on /api/v1/chat/completions.
3.Read the model field in the response to see which one answered. Or use anyrouter/auto and let AnyRouter pick a healthy model.

curl · models fallback

bash

curl https://anyrouter.dev/api/v1/chat/completions \
  -H "Authorization: Bearer $ANYROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.4-mini",
    "models": ["anthropic/claude-sonnet-4.6", "z-ai/glm-4.7-flash"],
    "messages": [{ "role": "user", "content": "Plan the next step." }]
  }'

AI SDK

import { createAnyRouter } from "@anyr/ai-sdk-provider"
import { generateText } from "ai"

const anyrouter = createAnyRouter()

const { text } = await generateText({
  model: anyrouter("openai/gpt-5.4-mini"),
  prompt: "Plan the next step.",
  providerOptions: {
    anyrouter: {
      extraBody: { models: ["anthropic/claude-sonnet-4.6", "z-ai/glm-4.7-flash"] },
    },
  },
})
console.log(text)

Ready to try it

The guide has the full walkthrough. Sign up if you still need a key.

Model fallbacks guide Start free

Next playbooks

AUTO

Start on anyrouter/free or anyrouter/auto

Two built-in virtual models: Go+ free failover (anyrouter/free) and stable paid failover (anyrouter/auto). Do not pick a flaky SKU for your first request.

Open

Run Hermes Agent on AnyRouter

An open-source agent with 40+ tools. Swap the base URL once and it can call the catalog — start on anyrouter/auto.

Open

Run the Claude Agent SDK on any model

query() already reads ANTHROPIC_BASE_URL and ANTHROPIC_API_KEY. Point both at AnyRouter — no SDK fork.

Open