Files
CLIProxyAPI/internal/api/modules/amp/fallback_handlers.go
Ben Vargas 8193392bfe Add AMP fallback proxy and shared Gemini normalization
- add fallback handler that forwards Amp provider requests to ampcode.com when the provider isn’t configured locally
- wrap AMP provider routes with the fallback so requests always have a handler
- share Gemini thinking model normalization helper between core handlers and AMP fallback
2025-11-19 18:23:17 -07:00

106 lines
3.3 KiB
Go

package amp
import (
"bytes"
"encoding/json"
"io"
"net/http/httputil"
"strings"
"github.com/gin-gonic/gin"
"github.com/router-for-me/CLIProxyAPI/v6/internal/util"
log "github.com/sirupsen/logrus"
)
// FallbackHandler wraps a standard handler with fallback logic to ampcode.com
// when the model's provider is not available in CLIProxyAPI
type FallbackHandler struct {
getProxy func() *httputil.ReverseProxy
}
// NewFallbackHandler creates a new fallback handler wrapper
// The getProxy function allows lazy evaluation of the proxy (useful when proxy is created after routes)
func NewFallbackHandler(getProxy func() *httputil.ReverseProxy) *FallbackHandler {
return &FallbackHandler{
getProxy: getProxy,
}
}
// WrapHandler wraps a gin.HandlerFunc with fallback logic
// If the model's provider is not configured in CLIProxyAPI, it forwards to ampcode.com
func (fh *FallbackHandler) WrapHandler(handler gin.HandlerFunc) gin.HandlerFunc {
return func(c *gin.Context) {
// Read the request body to extract the model name
bodyBytes, err := io.ReadAll(c.Request.Body)
if err != nil {
log.Errorf("amp fallback: failed to read request body: %v", err)
handler(c)
return
}
// Restore the body for the handler to read
c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
// Try to extract model from request body or URL path (for Gemini)
modelName := extractModelFromRequest(bodyBytes, c)
if modelName == "" {
// Can't determine model, proceed with normal handler
handler(c)
return
}
// Normalize model (handles Gemini thinking suffixes)
normalizedModel, _ := util.NormalizeGeminiThinkingModel(modelName)
// Check if we have providers for this model
providers := util.GetProviderName(normalizedModel)
if len(providers) == 0 {
// No providers configured - check if we have a proxy for fallback
proxy := fh.getProxy()
if proxy != nil {
// Fallback to ampcode.com
log.Infof("amp fallback: model %s has no configured provider, forwarding to ampcode.com", modelName)
// Restore body again for the proxy
c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
// Forward to ampcode.com
proxy.ServeHTTP(c.Writer, c.Request)
return
}
// No proxy available, let the normal handler return the error
log.Debugf("amp fallback: model %s has no configured provider and no proxy available", modelName)
}
// Providers available or no proxy for fallback, restore body and use normal handler
c.Request.Body = io.NopCloser(bytes.NewReader(bodyBytes))
handler(c)
}
}
// extractModelFromRequest attempts to extract the model name from various request formats
func extractModelFromRequest(body []byte, c *gin.Context) string {
// First try to parse from JSON body (OpenAI, Claude, etc.)
var payload map[string]interface{}
if err := json.Unmarshal(body, &payload); err == nil {
// Check common model field names
if model, ok := payload["model"].(string); ok {
return model
}
}
// For Gemini requests, model is in the URL path: /models/{model}:generateContent
// Extract from :action parameter (e.g., "gemini-pro:generateContent")
if action := c.Param("action"); action != "" {
// Split by colon to get model name (e.g., "gemini-pro:generateContent" -> "gemini-pro")
parts := strings.Split(action, ":")
if len(parts) > 0 && parts[0] != "" {
return parts[0]
}
}
return ""
}