Go SDK

// Install
// go get github.com/openai/openai-go

package main

import (
    "context"
    "fmt"
    openai "github.com/openai/openai-go"
)

func main() {
    client := openai.NewClient(
        openai.WithAPIKey(os.Getenv("API_KEY")),
        openai.WithBaseURL("https://api.example.com/v1"),
    )
    
    ctx := context.Background()
    
    resp, err := client.ChatCompletions.Create(ctx, &openai.ChatCompletionRequest{
        Model: "gpt-4o",
        Messages: []openai.Message{
            {Role: "user", Content: "Hello!"},
        },
    })
    
    if err != nil {
        panic(err)
    }
    
    fmt.Println(resp.Choices[0].Message.Content)
}