> ## Documentation Index
> Fetch the complete documentation index at: https://praison.ai/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Failover

> Automatic fallback to backup LLM providers

Failover automatically switches to backup providers when the primary fails.

```mermaid theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
graph LR
    subgraph "Failover"
        A[🤖 Agent] --> P1[🟢 Primary]
        P1 --> |Fails| P2[🟡 Backup]
        P2 --> |Fails| P3[🔴 Fallback]
    end
    
    classDef agent fill:#6366F1,stroke:#7C90A0,color:#fff
    classDef primary fill:#10B981,stroke:#7C90A0,color:#fff
    classDef backup fill:#F59E0B,stroke:#7C90A0,color:#fff
    classDef fallback fill:#EF4444,stroke:#7C90A0,color:#fff
    
    class A agent
    class P1 primary
    class P2 backup
    class P3 fallback
```

## Quick Start

<Steps>
  <Step title="Create Failover-Ready Agent">
    ```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
    use praisonai::Agent;

    // Primary agent with fast model
    let primary = Agent::new()
        .name("Primary Assistant")
        .model("gpt-4o")
        .build()?;

    // Backup agent with different provider
    let backup = Agent::new()
        .name("Backup Assistant")
        .model("claude-3-sonnet")
        .build()?;

    // Implement failover at application level
    async fn chat_with_failover(query: &str) -> Result<String> {
        match primary.chat(query).await {
            Ok(response) => Ok(response),
            Err(_) => backup.chat(query).await,
        }
    }
    ```
  </Step>

  <Step title="Local Fallback">
    ```rust theme={"theme":{"light":"vitesse-light","dark":"vitesse-dark"}}
    use praisonai::Agent;

    // Cloud-first, local fallback
    let cloud = Agent::new()
        .name("Cloud Assistant")
        .model("gpt-4o")
        .build()?;

    let local = Agent::new()
        .name("Local Assistant")
        .model("ollama/llama3")
        .base_url("http://localhost:11434")
        .build()?;

    // Try cloud, fall back to local if unavailable
    ```
  </Step>
</Steps>

***

## When Failover Triggers

| Trigger      | Action            |
| ------------ | ----------------- |
| API timeout  | Try next provider |
| Rate limit   | Try next provider |
| Service down | Try next provider |
| All fail     | Return error      |

***

## Best Practices

<AccordionGroup>
  <Accordion title="Order by preference">
    Put best provider first, cheapest backup last.
  </Accordion>

  <Accordion title="Include local fallback">
    Add Ollama as last resort for offline resilience.
  </Accordion>
</AccordionGroup>

***

## Related

<CardGroup cols={2}>
  <Card title="LLM" icon="microchip" href="/docs/rust/llm">
    LLM providers
  </Card>

  <Card title="Gateway" icon="network-wired" href="/docs/rust/gateway">
    Unified API
  </Card>
</CardGroup>