Initial commit: OpenCode Zen Proxy

Proxy translating OpenAI/Anthropic Messages API to OpenCode Zen's free models.
Pure stdlib Go 1.22, no external dependencies.

- OpenAI Chat Completions (/v1/chat/completions) with streaming
- Anthropic Messages API (/v1/messages) with streaming
- Model aliases for 5 free models
- Auth middleware support
- Session rotation (30min per user key)

cmd/vision/main.go

@@ -0,0 +1,143 @@
+package main
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+const defaultAPIKey = "opx-57ffcb013651f7acae558cd9ab094dbd719fdec980a6ad53"
+
+type visionRequest struct {
+	Model    string         `json:"model"`
+	Messages []visionMessage `json:"messages"`
+	Stream   bool           `json:"stream"`
+}
+
+type visionMessage struct {
+	Role    string      `json:"role"`
+	Content interface{} `json:"content"`
+}
+
+type visionResponse struct {
+	ID      string         `json:"id"`
+	Object  string         `json:"object"`
+	Created int64          `json:"created"`
+	Model   string         `json:"model"`
+	Choices []visionChoice `json:"choices"`
+}
+
+type visionChoice struct {
+	Index        int           `json:"index"`
+	Message      visionContent `json:"message"`
+	FinishReason string        `json:"finish_reason"`
+}
+
+type visionContent struct {
+	Role    string      `json:"role"`
+	Content interface{} `json:"content"`
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintf(os.Stderr, "Usage: vision <image-path> [prompt]\n")
+		fmt.Fprintf(os.Stderr, "Example: vision C:\\path\\to\\photo.jpg \"Describe this image\"\n")
+		os.Exit(1)
+	}
+
+	imagePath := os.Args[1]
+	prompt := "Describe esta imagen en detalle."
+	if len(os.Args) > 2 {
+		prompt = strings.Join(os.Args[2:], " ")
+	}
+
+	ext := strings.ToLower(filepath.Ext(imagePath))
+	var mediaType string
+	switch ext {
+	case ".jpg", ".jpeg":
+		mediaType = "image/jpeg"
+	case ".png":
+		mediaType = "image/png"
+	case ".webp":
+		mediaType = "image/webp"
+	default:
+		fmt.Fprintf(os.Stderr, "Unsupported image format: %s (supported: jpg, png, webp)\n", ext)
+		os.Exit(1)
+	}
+
+	data, err := os.ReadFile(imagePath)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading file: %v\n", err)
+		os.Exit(1)
+	}
+
+	b64 := base64.StdEncoding.EncodeToString(data)
+	dataURL := fmt.Sprintf("data:%s;base64,%s", mediaType, b64)
+
+	reqBody := visionRequest{
+		Model: "mimo-v2.5-free",
+		Messages: []visionMessage{
+			{
+				Role: "user",
+				Content: []map[string]interface{}{
+					{"type": "text", "text": prompt},
+					{"type": "image_url", "image_url": map[string]string{"url": dataURL}},
+				},
+			},
+		},
+	}
+
+	body, _ := json.Marshal(reqBody)
+
+	httpReq, err := http.NewRequest("POST", "https://opencode.ai/zen/v1/chat/completions", bytes.NewReader(body))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error creating request: %v\n", err)
+		os.Exit(1)
+	}
+
+	httpReq.Header.Set("Content-Type", "application/json")
+	httpReq.Header.Set("Authorization", "Bearer "+defaultAPIKey)
+	httpReq.Header.Set("User-Agent", "vision-tool/1.0")
+	httpReq.Header.Set("x-opencode-client", "cli")
+	httpReq.Header.Set("x-opencode-project", "vision")
+	httpReq.Header.Set("x-opencode-request", fmt.Sprintf("req_%d", time.Now().UnixNano()))
+	httpReq.Header.Set("x-opencode-session", fmt.Sprintf("ses_%d", time.Now().UnixNano()))
+
+	client := &http.Client{Timeout: 2 * time.Minute}
+	resp, err := client.Do(httpReq)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+	defer resp.Body.Close()
+
+	respData, _ := io.ReadAll(resp.Body)
+
+	if resp.StatusCode != 200 {
+		fmt.Fprintf(os.Stderr, "API error %d: %s\n", resp.StatusCode, string(respData))
+		os.Exit(1)
+	}
+
+	var result visionResponse
+	if err := json.Unmarshal(respData, &result); err != nil {
+		fmt.Fprintf(os.Stderr, "Error parsing response: %v\n%s\n", err, string(respData))
+		os.Exit(1)
+	}
+
+	if len(result.Choices) > 0 {
+		switch c := result.Choices[0].Message.Content.(type) {
+		case string:
+			fmt.Println(c)
+		default:
+			b, _ := json.MarshalIndent(c, "", "  ")
+			fmt.Println(string(b))
+		}
+	}
+}