OpenRouter

OpenRouter multi-provider routing gateway using the OpenAI-compatible Chat Completions API. Access models from multiple providers through a single API key.

Setup

go get github.com/zendev-sh/goai@latest

import "github.com/zendev-sh/goai/provider/openrouter"

Set the OPENROUTER_API_KEY environment variable, or pass WithAPIKey() directly.

Models

Models use a provider/model prefix format:

• anthropic/claude-sonnet-4
• openai/gpt-4o
• google/gemini-2.5-pro
• meta-llama/llama-3.3-70b-instruct

See openrouter.ai/models for the full catalog.

Tested Models

Unit tested (mock HTTP server, 2026-03-15): anthropic/claude-sonnet-4

Usage

model := openrouter.Chat("anthropic/claude-sonnet-4")

result, err := goai.GenerateText(ctx, model, goai.WithPrompt("Hello"))
if err != nil {
    log.Fatal(err)
}
fmt.Println(result.Text)

Options

Option	Type	Description
WithAPIKey(key)	string	Set a static API key
WithTokenSource(ts)	provider.TokenSource	Set a dynamic token source
WithBaseURL(url)	string	Override the default https://openrouter.ai/api/v1 endpoint
WithHeaders(h)	map[string]string	Set additional HTTP headers
WithHTTPClient(c)	*http.Client	Set a custom *http.Client

Notes

• Supports image inputs (depends on the underlying model).
• Automatically sends HTTP-Referer and X-Title headers as recommended by OpenRouter's API.
• Usage reporting is enabled by default (usage: {include: true} in request body).
• Environment variable OPENROUTER_BASE_URL can override the default endpoint.