nRouter works directly with the official Go client module, verified on pkg.go.dev. Set the base URL to https://api.nrouter.ai/v1 and pass your sk-nrouter-... key — guardrails, caching, smart routing, and rate-limits auto-apply from your org config.

Installation

go get github.com/nRouterAI/nrouter-sdk/sdks/go/v2@v2.2.1

Package Reference: pkg.go.dev/github.com/nRouterAI/nrouter-sdk/sdks/go/v2

Setup

Export your virtual API key in your environment:

export NROUTER_API_KEY="sk-nrouter-your-key-here"

Initialize the client with your virtual key and nRouter base URL:

import (
    "os"

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

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

Chat Completion

package main

import (
    "context"
    "fmt"
    "log"
    "os"

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

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

    response, err := client.Chat.Completions.New(context.Background(),
        openai.ChatCompletionNewParams{
            Model: "gpt-5.4-mini",
            Messages: []openai.ChatCompletionMessageParamUnion{
                openai.UserMessage("Hello, nRouter!"),
            },
        },
    )
    if err != nil {
        log.Fatalf("Error: %v", err)
    }

    fmt.Println(response.Choices[0].Message.Content)
}

Per-Request Overrides

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

{
  "model": "gpt-5.5",
  "messages": [{"role": "user", "content": "Summarize Q1 earnings..."}],
  "nrouter_prompt_template_id": "your-summarizer-id",
  "nrouter_prompt_variables": {"language": "Spanish"},
  "nrouter_cache": false
}

Guardrails are not part of this body. You assign them in the dashboard at key, team, or organization scope — the narrowest scope that mentions a guardrail wins — and they run automatically on every request that scope covers.

Response Headers

Every successful response carries:

x-nr-request-id — id for this call, and the join key for its spend row
x-nr-model — the model that actually served the request
x-nr-cost-status — exact when we priced the call, unpriced when we could not
x-nr-request-cost — USD spend for this call. Absent when x-nr-cost-status is unpriced: nRouter never reports a cost of 0 for a call it could not price
x-nr-input-tokens, x-nr-output-tokens, x-nr-total-tokens — token counts as reported by the provider

Next Steps

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

Go SDK