Nemo Router works with the official openai-go SDK. Set the base URL to https://api.nemorouter.ai/v1 and pass your sk-nemo-... key — guardrails, caching, and rate-limits auto-apply from your org config.

Installation

go get github.com/openai/openai-go

Setup

import (
    "github.com/openai/openai-go"
    "github.com/openai/openai-go/option"
)

client := openai.NewClient(
    option.WithAPIKey(os.Getenv("NEMOROUTER_API_KEY")),
    option.WithBaseURL("https://api.nemorouter.ai/v1"),
)

Chat Completion

package main

import (
    "context"
    "fmt"
    "os"

    "github.com/openai/openai-go"
    "github.com/openai/openai-go/option"
)

func main() {
    client := openai.NewClient(
        option.WithAPIKey(os.Getenv("NEMOROUTER_API_KEY")),
        option.WithBaseURL("https://api.nemorouter.ai/v1"),
    )

    response, err := client.Chat.Completions.New(context.Background(),
        openai.ChatCompletionNewParams{
            Model: "claude-sonnet-4-20250514",
            Messages: []openai.ChatCompletionMessageParamUnion{
                openai.UserMessage("Hello!"),
            },
        },
    )
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    fmt.Println(response.Choices[0].Message.Content)
}

Per-Request Overrides

The Go SDK does not yet support extra_body fields natively. To pass nemo_* fields per request (guardrails, prompt templates, cache toggle), use a raw HTTP POST and include them in the JSON body:

{
  "model": "gpt-4o",
  "messages": [{"role": "user", "content": "Summarize Q1 earnings..."}],
  "nemo_guardrail_ids": ["uuid1", "uuid2"],
  "nemo_prompt_template_id": "your-summarizer-id",
  "nemo_prompt_variables": {"language": "Spanish"},
  "nemo_cache": false
}

Response Headers

Every successful response carries:

x-nemo-request-cost — exact USD spend for this call
x-nemo-guardrails-applied — comma-separated guardrail names that ran
x-nemo-prompt-version — version of the prompt template applied (if any)

Next Steps

cURL Examples — Inspect raw request/response shape
Authentication — API key best practices
Chat Completions API — Full API reference

Go SDK