Add OpenRouter backend

completion/openrouter/openrouter.go

@@ -0,0 +1,94 @@
+package openrouter
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+type Message struct {
+	Role    string `json:"role"` // "system" | "user" | "assistant"
+	Content string `json:"content"`
+}
+
+type ChatCompletionRequest struct {
+	Model       string          `json:"model"`
+	Messages    []Message       `json:"messages"`
+	Temperature *float64        `json:"temperature,omitempty"`
+	MaxTokens   *int            `json:"max_tokens,omitempty"`
+	TopP        *float64        `json:"top_p,omitempty"`
+	Stop        json.RawMessage `json:"stop,omitempty"` // string or []string; keep flexible
+}
+
+type ChatCompletionResponse struct {
+	ID      string `json:"id"`
+	Choices []struct {
+		Index   int `json:"index"`
+		Message struct {
+			Role    string `json:"role"`
+			Content string `json:"content"`
+		} `json:"message"`
+		FinishReason string `json:"finish_reason"`
+	} `json:"choices"`
+}
+
+func ChatCompletion(ctx context.Context, req ChatCompletionRequest) (ChatCompletionResponse, error) {
+	httpClient := http.Client{Timeout: 10 * time.Second}
+
+	body, err := json.Marshal(req)
+	if err != nil {
+		return ChatCompletionResponse{}, err
+	}
+
+	httpReq, err := http.NewRequestWithContext(ctx, "POST", "https://openrouter.ai/api/v1/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		return ChatCompletionResponse{}, err
+	}
+
+	httpReq.Header.Set("Authorization", "Bearer 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")
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	resp, err := httpClient.Do(httpReq)
+	if err != nil {
+		return ChatCompletionResponse{}, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		// You may want to decode OpenRouter's error JSON here for better messages
+		return ChatCompletionResponse{}, fmt.Errorf("openrouter status %d", resp.StatusCode)
+	}
+
+	var out ChatCompletionResponse
+	if err := json.NewDecoder(resp.Body).Decode(&out); err != nil {
+		return ChatCompletionResponse{}, err
+	}
+	return out, nil
+}
+
+func doLLM() {
+
+	req := ChatCompletionRequest{
+		Model: "openai/gpt-oss-20b:free",
+		Messages: []Message{
+			{
+				Role:    "user",
+				Content: "Write a short poem about software development.",
+			},
+		},
+	}
+
+	ctx := context.Background()
+	resp, err := client.ChatCompletion(ctx, req)
+	if err != nil {
+		fmt.Println("Error:", err)
+		return
+	}
+
+	for _, choice := range resp.Choices {
+		fmt.Printf("Response: %s\n", choice.Message.Content)
+	}
+}