📚 Complete Tutorial

Multi-Provider LLM Proxy Tutorial

Build a unified proxy that routes requests across OpenAI, Anthropic Claude, Google Gemini, and more. Learn to implement automatic failover, load balancing, and cost optimization across multiple AI providers.

OpenAI

GPT-4, GPT-4 Turbo

Anthropic

Claude 3.5 Sonnet

Google

Gemini Pro, Ultra

Multi-Provider Architecture

How your proxy routes requests across different LLM providers.

Request Routing Flow

📱

Client

→

🔀

Proxy
Router

→

🎯

Provider
Selection

→

🤖

LLM
Provider

→

📤

Response

Step-by-Step Tutorial

Build your multi-provider proxy from scratch with these detailed steps.

Define Provider Configuration

Set up configuration for each LLM provider including API endpoints, authentication, and model mappings.

provider-config.ts

interface ProviderConfig {
  name: string;
  apiKey: string;
  baseUrl: string;
  models: string[];
  rateLimit: number;
}

const providers: ProviderConfig[] = [
  {
    name: 'openai',
    apiKey: process.env.OPENAI_API_KEY,
    baseUrl: 'https://api.openai.com/v1',
    models: ['gpt-4', 'gpt-4-turbo', 'gpt-3.5-turbo'],
    rateLimit: 500
  },
  {
    name: 'anthropic',
    apiKey: process.env.ANTHROPIC_API_KEY,
    baseUrl: 'https://api.anthropic.com/v1',
    models: ['claude-3-5-sonnet', 'claude-3-opus'],
    rateLimit: 300
  },
  {
    name: 'google',
    apiKey: process.env.GOOGLE_API_KEY,
    baseUrl: 'https://generativelanguage.googleapis.com/v1',
    models: ['gemini-pro', 'gemini-ultra'],
    rateLimit: 200
  }
];

Implement Provider Adapter

Create adapters that normalize requests and responses across different provider APIs.

provider-adapter.ts

class ProviderAdapter {
  async sendRequest(provider: string, request: LLMRequest) {
    switch (provider) {
      case 'openai':
        return this.sendOpenAI(request);
      case 'anthropic':
        return this.sendAnthropic(request);
      case 'google':
        return this.sendGoogle(request);
    }
  }

  private async sendAnthropic(request: LLMRequest) {
    // Convert to Anthropic format
    const anthropicRequest = {
      model: request.model.replace('gpt-4', 'claude-3-5-sonnet'),
      messages: request.messages,
      max_tokens: request.max_tokens || 4096
    };
    
    const response = await fetch('https://api.anthropic.com/v1/messages', {
      method: 'POST',
      headers: {
        'x-api-key': process.env.ANTHROPIC_API_KEY,
        'anthropic-version': '2023-06-01'
      },
      body: JSON.stringify(anthropicRequest)
    });
    
    return this.normalizeResponse(await response.json(), 'anthropic');
  }
}

Add Routing Logic

Implement intelligent routing that selects providers based on model, cost, latency, or custom rules.

router.ts

class ProviderRouter {
  selectProvider(request: LLMRequest): string {
    // Route by model name
    if (request.model.startsWith('gpt')) return 'openai';
    if (request.model.startsWith('claude')) return 'anthropic';
    if (request.model.startsWith('gemini')) return 'google';
    
    // Fallback to cost-optimized routing
    return this.getCheapestProvider(request);
  }

  async handleRequest(request: LLMRequest) {
    const provider = this.selectProvider(request);
    
    try {
      return await this.adapter.sendRequest(provider, request);
    } catch (error) {
      // Automatic failover
      return await this.failover(request, provider);
    }
  }
}

Implement Failover

Add automatic failover to switch providers when one fails or hits rate limits.

failover.ts

async function failover(request: LLMRequest, failedProvider: string) {
  const alternatives = providers
    .filter(p => p.name !== failedProvider)
    .sort((a, b) => a.latency - b.latency);

  for (const provider of alternatives) {
    try {
      console.log(`Failing over to ${provider.name}`);
      return await adapter.sendRequest(provider.name, request);
    } catch (error) {
      continue;
    }
  }
  
  throw new Error('All providers failed');
}

Multi-Provider Features

Key capabilities enabled by multi-provider proxy architecture.

🔄

Automatic Failover

When one provider fails or hits rate limits, automatically switch to alternative providers without service interruption.

💰

Cost Optimization

Route requests to the most cost-effective provider for each task. Balance quality and cost automatically.

⚡

Latency Routing

Route to the fastest provider based on real-time latency measurements. Optimize for user experience.

🔒

Provider Lock-in Prevention

Stay flexible by supporting multiple providers. Switch easily without changing client code.

📊

Unified Analytics

Track usage, costs, and performance across all providers in a single dashboard.

🎯

Model Fallbacks

Map equivalent models across providers. If GPT-4 is unavailable, use Claude 3.5 automatically.

Providers

99.9%

Uptime

30%

Cost Savings

<100ms

Routing Latency

Provider Comparison

Understanding the differences between major LLM providers.

Feature	OpenAI	Anthropic	Google	Meta
Best For	General Purpose	Long Context	Multimodal	Open Source
Context Window	128K	200K	1M	128K
Tool Calling	Excellent	Excellent	Good	Limited
Vision	Yes	Yes	Yes	Yes
Streaming	Yes	Yes	Yes	Yes
Cost (Input)	$$$	$$	$$	Free

Build Your Multi-Provider Proxy

Follow our complete tutorial to implement a unified proxy that works with all major LLM providers. Avoid lock-in and maximize reliability.

Start Tutorial View Examples

Related Resources

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