Guide · Updated June 2026

LLM failover for AI agents

The single biggest reason agents fail in production isn't a dumb model — it's a missing model. A provider rate-limits mid-loop, or returns an empty tool turn, and the whole task aborts. LLM failover is the fix: reroute to a healthy provider within the same request, and recover from empty tool turns, so the loop finishes. Here's why agents need it more than anything else, and how to add it without writing retry code.

Why agents are uniquely exposed

Failure probability compounds with call count. If one call has a 1% chance of hitting a rate limit, a 50-call agent task has a ~40% chance of hitting at least one. A chatbot rarely notices; an agent aborts the task. Two failure modes dominate:

What real failover looks like

LevelBehavior
NoneProvider error is returned to your agent; the task aborts.
Retry same modelWaits out the rate limit — slow, and useless if the provider is down.
Multi-provider failoverReroutes to a healthy provider in the same request; the call still succeeds.
+ Tool-call repairDetects empty tool turns and retries with a corrected format — recovers the stall, not just the error.

Add it without writing retry code

You can build failover yourself — health checks, provider rotation, backoff — or point your agent at a router that does it. With CodeBurst, every model name is already a multi-provider chain with tool-call repair:

from openai import OpenAI

client = OpenAI(base_url="https://codeburst.ai/api/v1", api_key="YOUR_CODEBURST_KEY")

resp = client.chat.completions.create(
    model="codeburst-agent",   # multi-provider chain + tool-call repair
    messages=[...],
    tools=[...],
)

No retry loop, no provider list, no backoff logic in your agent — the failover lives behind the model name. Health probes keep the chain fresh, so a degraded provider is dropped before it reaches you.

Get started

Get an API key Best LLM for AI agents →

FAQ

What is LLM failover?
Automatically rerouting to another model/provider when the first fails — ideally within the same request so the agent never sees the error.

Why do agents need it more than chatbots?
Many calls per task compound failure probability; one failure mid-loop can abort the whole task.

How do I add it?
Point your OpenAI-compatible client at CodeBurst and use codeburst-agent — failover and tool-call repair are built in.