Document ID: PRT-2024-001 Revision: 2.4 Date: 2024

AI API Proxy Porting Guide

Technical implementation manual for porting existing AI integrations to a unified proxy architecture. Includes code samples, API mapping tables, and step-by-step migration procedures.

Difficulty

Medium

Time Estimate

2-5 Days

Prerequisites

API Access

Downtime

Zero

§ 1.0

Architecture Overview

Your Application

Existing AI integrations
Direct API calls
Multiple SDKs
Provider-specific code

→ → →

Unified Proxy

Single endpoint
Request translation
Response normalization
Caching layer

→ → →

Multiple Providers

OpenAI (GPT-4/3.5)
Anthropic (Claude)
Google (Gemini)
Other providers

§ 2.0

Code Migration Examples

                    before.js
                    LEGACY
                

// Direct OpenAI Integration
import OpenAI from 'openai';

const client = new OpenAI({
  apiKey: process.env.OPENAI_KEY
});

const completion = await client.chat.completions.create({
  model: 'gpt-4',
  messages: [
    { role: 'system', content: 'You are helpful' },
    { role: 'user', content: userInput }
  ],
  temperature: 0.7,
  max_tokens: 2000
});

// Provider-specific error handling
try {
  const response = await completion;
  return response.choices[0].message.content;
} catch (error) {
  if (error.code === 'rate_limit') {
    // Custom retry logic
  }
}

                    after.js
                    GATEWAY
                

// Unified Gateway Integration
import Gateway from '@gateway/sdk';

const gateway = new Gateway({
  apiKey: process.env.GATEWAY_KEY
});

const completion = await gateway.chat({
  model: 'gpt-4',  // or any other model
  messages: [
    { role: 'system', content: 'You are helpful' },
    { role: 'user', content: userInput }
  ],
  temperature: 0.7,
  max_tokens: 2000,
  // Built-in features
  fallback: true,
  cache: true,
  retries: 3
});

// Unified error handling
return completion.choices[0].message.content;

§ 3.0

Porting Procedure

STEP 01

Environment Setup

Install gateway SDK, configure credentials, and establish staging environment for parallel testing.

✓

Install @gateway/sdk package

✓

Set GATEWAY_API_KEY environment variable

✓

Create staging configuration

STEP 02

API Mapping

Map existing provider-specific parameters to gateway standard format. Document any custom logic.

✓

Identify all model references

✓

Map parameter translations

✓

Document custom error handling

STEP 03

Code Refactoring

Replace direct API calls with gateway methods. Update imports, remove provider-specific SDKs.

✓

Replace OpenAI/Anthropic imports

✓

Update API call patterns

✓

Simplify error handling

STEP 04

Testing & Validation

Run parallel tests comparing direct API vs gateway responses. Validate accuracy and latency.

✓

Compare response structures

✓

Test edge cases

✓

Measure performance metrics

§ 4.0

Provider Compatibility Matrix

Feature	OpenAI	Anthropic	Google	Mistral
Chat Completions	✓ Supported	✓ Supported	✓ Supported	✓ Supported
Streaming	✓ Supported	✓ Supported	△ Partial	✓ Supported
Function Calling	✓ Supported	△ Partial	△ Partial	✓ Supported
Vision	✓ Supported	✓ Supported	✓ Supported	△ Partial
Embeddings	✓ Supported	✗ N/A	✓ Supported	✓ Supported

§ 5.0

Important Considerations

Rate Limiting

Gateway implements unified rate limiting across all providers. Default: 1000 requests/minute. Configure limits per endpoint if needed.

Response Format

All responses normalized to OpenAI-compatible format. Provider-specific fields available in metadata object for advanced use cases.

Error Codes

Provider-specific error codes translated to standard HTTP status codes. Original error details preserved in response body.