Files
sub2api/backend/internal/service/antigravity_gateway_service.go
ianshaw 26438f7232 feat(antigravity): 增强网关功能和 thinking 块处理
主要改进:
- 优化 thinking blocks 过滤策略,支持 Auto 模式降级
- 将无效 thinking block 内容转为普通 text
- 保留单个空白 text block,不过滤
- 重构配额刷新机制,统一与 Claude 一致
- 支持 cachedContentTokenCount 映射到 cache_read_input_tokens
- Haiku 模型映射到 Sonnet
- 添加 /antigravity/v1/models 端点支持
- countTokens 端点直接返回空值
2026-01-03 06:29:02 -08:00

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package service
import (
"bufio"
"bytes"
"context"
"encoding/json"
"errors"
"fmt"
"io"
"log"
"net/http"
"strings"
"time"
"github.com/Wei-Shaw/sub2api/internal/pkg/antigravity"
"github.com/gin-gonic/gin"
"github.com/google/uuid"
)
const (
antigravityStickySessionTTL = time.Hour
antigravityMaxRetries = 5
antigravityRetryBaseDelay = 1 * time.Second
antigravityRetryMaxDelay = 16 * time.Second
)
// Antigravity 直接支持的模型(精确匹配透传)
var antigravitySupportedModels = map[string]bool{
"claude-opus-4-5-thinking": true,
"claude-sonnet-4-5": true,
"claude-sonnet-4-5-thinking": true,
"gemini-2.5-flash": true,
"gemini-2.5-flash-lite": true,
"gemini-2.5-flash-thinking": true,
"gemini-3-flash": true,
"gemini-3-pro-low": true,
"gemini-3-pro-high": true,
"gemini-3-pro-image": true,
}
// Antigravity 前缀映射表(按前缀长度降序排列,确保最长匹配优先)
// 用于处理模型版本号变化(如 -20251111, -thinking, -preview 等后缀)
var antigravityPrefixMapping = []struct {
prefix string
target string
}{
// 长前缀优先
{"gemini-3-pro-image", "gemini-3-pro-image"}, // gemini-3-pro-image-preview 等
{"claude-3-5-sonnet", "claude-sonnet-4-5"}, // 旧版 claude-3-5-sonnet-xxx
{"claude-sonnet-4-5", "claude-sonnet-4-5"}, // claude-sonnet-4-5-xxx
{"claude-haiku-4-5", "claude-sonnet-4-5"}, // claude-haiku-4-5-xxx → sonnet
{"claude-opus-4-5", "claude-opus-4-5-thinking"},
{"claude-3-haiku", "claude-sonnet-4-5"}, // 旧版 claude-3-haiku-xxx → sonnet
{"claude-sonnet-4", "claude-sonnet-4-5"},
{"claude-haiku-4", "claude-sonnet-4-5"}, // → sonnet
{"claude-opus-4", "claude-opus-4-5-thinking"},
{"gemini-3-pro", "gemini-3-pro-high"}, // gemini-3-pro, gemini-3-pro-preview 等
}
// AntigravityGatewayService 处理 Antigravity 平台的 API 转发
type AntigravityGatewayService struct {
accountRepo AccountRepository
tokenProvider *AntigravityTokenProvider
rateLimitService *RateLimitService
httpUpstream HTTPUpstream
settingService *SettingService
}
func NewAntigravityGatewayService(
accountRepo AccountRepository,
_ GatewayCache,
tokenProvider *AntigravityTokenProvider,
rateLimitService *RateLimitService,
httpUpstream HTTPUpstream,
settingService *SettingService,
) *AntigravityGatewayService {
return &AntigravityGatewayService{
accountRepo: accountRepo,
tokenProvider: tokenProvider,
rateLimitService: rateLimitService,
httpUpstream: httpUpstream,
settingService: settingService,
}
}
// GetTokenProvider 返回 token provider
func (s *AntigravityGatewayService) GetTokenProvider() *AntigravityTokenProvider {
return s.tokenProvider
}
// getMappedModel 获取映射后的模型名
// 逻辑:账户映射 → 直接支持透传 → 前缀映射 → gemini透传 → 默认值
func (s *AntigravityGatewayService) getMappedModel(account *Account, requestedModel string) string {
// 1. 账户级映射(用户自定义优先)
if mapped := account.GetMappedModel(requestedModel); mapped != requestedModel {
return mapped
}
// 2. 直接支持的模型透传
if antigravitySupportedModels[requestedModel] {
return requestedModel
}
// 3. 前缀映射(处理版本号变化,如 -20251111, -thinking, -preview
for _, pm := range antigravityPrefixMapping {
if strings.HasPrefix(requestedModel, pm.prefix) {
return pm.target
}
}
// 4. Gemini 模型透传(未匹配到前缀的 gemini 模型)
if strings.HasPrefix(requestedModel, "gemini-") {
return requestedModel
}
// 5. 默认值
return "claude-sonnet-4-5"
}
// IsModelSupported 检查模型是否被支持
// 所有 claude- 和 gemini- 前缀的模型都能通过映射或透传支持
func (s *AntigravityGatewayService) IsModelSupported(requestedModel string) bool {
return strings.HasPrefix(requestedModel, "claude-") ||
strings.HasPrefix(requestedModel, "gemini-")
}
// TestConnectionResult 测试连接结果
type TestConnectionResult struct {
Text string // 响应文本
MappedModel string // 实际使用的模型
}
// TestConnection 测试 Antigravity 账号连接(非流式,无重试、无计费)
// 支持 Claude 和 Gemini 两种协议,根据 modelID 前缀自动选择
func (s *AntigravityGatewayService) TestConnection(ctx context.Context, account *Account, modelID string) (*TestConnectionResult, error) {
// 获取 token
if s.tokenProvider == nil {
return nil, errors.New("antigravity token provider not configured")
}
accessToken, err := s.tokenProvider.GetAccessToken(ctx, account)
if err != nil {
return nil, fmt.Errorf("获取 access_token 失败: %w", err)
}
// 获取 project_id部分账户类型可能没有
projectID := strings.TrimSpace(account.GetCredential("project_id"))
// 模型映射
mappedModel := s.getMappedModel(account, modelID)
// 构建请求体
var requestBody []byte
if strings.HasPrefix(modelID, "gemini-") {
// Gemini 模型:直接使用 Gemini 格式
requestBody, err = s.buildGeminiTestRequest(projectID, mappedModel)
} else {
// Claude 模型:使用协议转换
requestBody, err = s.buildClaudeTestRequest(projectID, mappedModel)
}
if err != nil {
return nil, fmt.Errorf("构建请求失败: %w", err)
}
// 构建 HTTP 请求(非流式)
req, err := antigravity.NewAPIRequest(ctx, "generateContent", accessToken, requestBody)
if err != nil {
return nil, err
}
// 代理 URL
proxyURL := ""
if account.ProxyID != nil && account.Proxy != nil {
proxyURL = account.Proxy.URL()
}
// 发送请求
resp, err := s.httpUpstream.Do(req, proxyURL, account.ID, account.Concurrency)
if err != nil {
return nil, fmt.Errorf("请求失败: %w", err)
}
defer func() { _ = resp.Body.Close() }()
// 读取响应
respBody, err := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
if err != nil {
return nil, fmt.Errorf("读取响应失败: %w", err)
}
if resp.StatusCode >= 400 {
return nil, fmt.Errorf("API 返回 %d: %s", resp.StatusCode, string(respBody))
}
// 解包 v1internal 响应
unwrapped, err := s.unwrapV1InternalResponse(respBody)
if err != nil {
return nil, fmt.Errorf("解包响应失败: %w", err)
}
// 提取响应文本
text := extractGeminiResponseText(unwrapped)
return &TestConnectionResult{
Text: text,
MappedModel: mappedModel,
}, nil
}
// buildGeminiTestRequest 构建 Gemini 格式测试请求
func (s *AntigravityGatewayService) buildGeminiTestRequest(projectID, model string) ([]byte, error) {
payload := map[string]any{
"contents": []map[string]any{
{
"role": "user",
"parts": []map[string]any{
{"text": "hi"},
},
},
},
}
payloadBytes, _ := json.Marshal(payload)
return s.wrapV1InternalRequest(projectID, model, payloadBytes)
}
// buildClaudeTestRequest 构建 Claude 格式测试请求并转换为 Gemini 格式
func (s *AntigravityGatewayService) buildClaudeTestRequest(projectID, mappedModel string) ([]byte, error) {
claudeReq := &antigravity.ClaudeRequest{
Model: mappedModel,
Messages: []antigravity.ClaudeMessage{
{
Role: "user",
Content: json.RawMessage(`"hi"`),
},
},
MaxTokens: 1024,
Stream: false,
}
return antigravity.TransformClaudeToGemini(claudeReq, projectID, mappedModel)
}
// extractGeminiResponseText 从 Gemini 响应中提取文本
func extractGeminiResponseText(respBody []byte) string {
var resp map[string]any
if err := json.Unmarshal(respBody, &resp); err != nil {
return ""
}
candidates, ok := resp["candidates"].([]any)
if !ok || len(candidates) == 0 {
return ""
}
candidate, ok := candidates[0].(map[string]any)
if !ok {
return ""
}
content, ok := candidate["content"].(map[string]any)
if !ok {
return ""
}
parts, ok := content["parts"].([]any)
if !ok {
return ""
}
var texts []string
for _, part := range parts {
if partMap, ok := part.(map[string]any); ok {
if text, ok := partMap["text"].(string); ok && text != "" {
texts = append(texts, text)
}
}
}
return strings.Join(texts, "")
}
// wrapV1InternalRequest 包装请求为 v1internal 格式
func (s *AntigravityGatewayService) wrapV1InternalRequest(projectID, model string, originalBody []byte) ([]byte, error) {
var request any
if err := json.Unmarshal(originalBody, &request); err != nil {
return nil, fmt.Errorf("解析请求体失败: %w", err)
}
wrapped := map[string]any{
"project": projectID,
"requestId": "agent-" + uuid.New().String(),
"userAgent": "sub2api",
"requestType": "agent",
"model": model,
"request": request,
}
return json.Marshal(wrapped)
}
// unwrapV1InternalResponse 解包 v1internal 响应
func (s *AntigravityGatewayService) unwrapV1InternalResponse(body []byte) ([]byte, error) {
var outer map[string]any
if err := json.Unmarshal(body, &outer); err != nil {
return nil, err
}
if resp, ok := outer["response"]; ok {
return json.Marshal(resp)
}
return body, nil
}
// isSignatureRelatedError 检测是否为 signature 相关的 400 错误
// 注意:不包含 "thinking" 关键词,避免误判消息格式错误为 signature 错误
func isSignatureRelatedError(statusCode int, body []byte) bool {
if statusCode != 400 {
return false
}
bodyStr := strings.ToLower(string(body))
keywords := []string{
"signature",
"thought_signature",
"thoughtsignature",
"invalid signature",
"signature validation",
}
for _, keyword := range keywords {
if strings.Contains(bodyStr, keyword) {
return true
}
}
return false
}
// isModelNotFoundError 检测是否为模型不存在的 404 错误
func isModelNotFoundError(statusCode int, body []byte) bool {
if statusCode != 404 {
return false
}
bodyStr := strings.ToLower(string(body))
keywords := []string{
"model not found",
"model does not exist",
"unknown model",
"invalid model",
}
for _, keyword := range keywords {
if strings.Contains(bodyStr, keyword) {
return true
}
}
return false
}
// stripThinkingFromClaudeRequest 从 Claude 请求中移除有问题的 thinking 块
// 策略:只移除历史消息中带 dummy signature 的 thinking 块,保留本次 thinking 配置
// 这样可以让本次对话仍然使用 thinking 功能,只是清理历史中可能导致问题的内容
func stripThinkingFromClaudeRequest(req *antigravity.ClaudeRequest) *antigravity.ClaudeRequest {
// 创建副本
stripped := *req
// 保留 thinking 配置,让本次对话仍然可以使用 thinking
// stripped.Thinking = nil // 不再移除
// 只移除消息中带 dummy signature 的 thinking 块
if len(stripped.Messages) > 0 {
newMessages := make([]antigravity.ClaudeMessage, 0, len(stripped.Messages))
for _, msg := range stripped.Messages {
newMsg := msg
// 如果 content 是数组,过滤有问题的 thinking 块
var blocks []map[string]any
if err := json.Unmarshal(msg.Content, &blocks); err == nil {
filtered := make([]map[string]any, 0, len(blocks))
for _, block := range blocks {
// 跳过带 dummy signature 的 thinking 块
if blockType, ok := block["type"].(string); ok && blockType == "thinking" {
if sig, ok := block["signature"].(string); ok {
// 移除 dummy signature 的 thinking 块
if sig == "skip_thought_signature_validator" || sig == "" {
continue
}
} else {
// 没有 signature 字段的 thinking 块也移除
continue
}
}
// 跳过没有 type 但有 thinking 字段的块untyped thinking blocks
if _, hasType := block["type"]; !hasType {
if _, hasThinking := block["thinking"]; hasThinking {
continue
}
}
filtered = append(filtered, block)
}
if newContent, err := json.Marshal(filtered); err == nil {
newMsg.Content = newContent
}
}
newMessages = append(newMessages, newMsg)
}
stripped.Messages = newMessages
}
return &stripped
}
// Forward 转发 Claude 协议请求Claude → Gemini 转换)
func (s *AntigravityGatewayService) Forward(ctx context.Context, c *gin.Context, account *Account, body []byte) (*ForwardResult, error) {
startTime := time.Now()
// 解析 Claude 请求
var claudeReq antigravity.ClaudeRequest
if err := json.Unmarshal(body, &claudeReq); err != nil {
return nil, fmt.Errorf("parse claude request: %w", err)
}
if strings.TrimSpace(claudeReq.Model) == "" {
return nil, fmt.Errorf("missing model")
}
originalModel := claudeReq.Model
mappedModel := s.getMappedModel(account, claudeReq.Model)
// 获取 access_token
if s.tokenProvider == nil {
return nil, errors.New("antigravity token provider not configured")
}
accessToken, err := s.tokenProvider.GetAccessToken(ctx, account)
if err != nil {
return nil, fmt.Errorf("获取 access_token 失败: %w", err)
}
// 获取 project_id部分账户类型可能没有
projectID := strings.TrimSpace(account.GetCredential("project_id"))
// 代理 URL
proxyURL := ""
if account.ProxyID != nil && account.Proxy != nil {
proxyURL = account.Proxy.URL()
}
// 转换 Claude 请求为 Gemini 格式
geminiBody, err := antigravity.TransformClaudeToGemini(&claudeReq, projectID, mappedModel)
if err != nil {
return nil, fmt.Errorf("transform request: %w", err)
}
// 构建上游 action
action := "generateContent"
if claudeReq.Stream {
action = "streamGenerateContent?alt=sse"
}
// 重试循环
var resp *http.Response
for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
upstreamReq, err := antigravity.NewAPIRequest(ctx, action, accessToken, geminiBody)
if err != nil {
return nil, err
}
resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
if err != nil {
if attempt < antigravityMaxRetries {
log.Printf("Antigravity account %d: upstream request failed, retry %d/%d: %v", account.ID, attempt, antigravityMaxRetries, err)
sleepAntigravityBackoff(attempt)
continue
}
return nil, s.writeClaudeError(c, http.StatusBadGateway, "upstream_error", "Upstream request failed after retries")
}
if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
_ = resp.Body.Close()
if attempt < antigravityMaxRetries {
log.Printf("Antigravity account %d: upstream status %d, retry %d/%d", account.ID, resp.StatusCode, attempt, antigravityMaxRetries)
sleepAntigravityBackoff(attempt)
continue
}
// 所有重试都失败,标记限流状态
if resp.StatusCode == 429 {
s.handleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
}
// 最后一次尝试也失败
resp = &http.Response{
StatusCode: resp.StatusCode,
Header: resp.Header.Clone(),
Body: io.NopCloser(bytes.NewReader(respBody)),
}
break
}
break
}
defer func() { _ = resp.Body.Close() }()
// 处理错误响应
if resp.StatusCode >= 400 {
respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
s.handleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
// Auto 模式:检测 signature 错误并自动降级重试
if isSignatureRelatedError(resp.StatusCode, respBody) && claudeReq.Thinking != nil {
log.Printf("[Antigravity] Detected signature-related error, retrying without thinking blocks (account: %s, model: %s)", account.Name, mappedModel)
// 关闭原始响应释放连接respBody 已读取到内存)
_ = resp.Body.Close()
// 移除 thinking 块并重试一次
strippedReq := stripThinkingFromClaudeRequest(&claudeReq)
strippedBody, err := antigravity.TransformClaudeToGemini(strippedReq, projectID, mappedModel)
if err != nil {
log.Printf("[Antigravity] Failed to transform stripped request: %v", err)
// 降级失败,返回原始错误
if s.shouldFailoverWithTempUnsched(ctx, account, resp.StatusCode, respBody) {
return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
}
return nil, s.writeMappedClaudeError(c, resp.StatusCode, respBody)
}
// 发送降级请求
retryReq, err := antigravity.NewAPIRequest(ctx, action, accessToken, strippedBody)
if err != nil {
log.Printf("[Antigravity] Failed to create retry request: %v", err)
if s.shouldFailoverWithTempUnsched(ctx, account, resp.StatusCode, respBody) {
return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
}
return nil, s.writeMappedClaudeError(c, resp.StatusCode, respBody)
}
retryResp, err := s.httpUpstream.Do(retryReq, proxyURL, account.ID, account.Concurrency)
if err != nil {
log.Printf("[Antigravity] Retry request failed: %v", err)
if s.shouldFailoverWithTempUnsched(ctx, account, resp.StatusCode, respBody) {
return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
}
return nil, s.writeMappedClaudeError(c, resp.StatusCode, respBody)
}
// 如果重试成功,使用重试的响应(不要 return让后面的代码处理响应
if retryResp.StatusCode < 400 {
log.Printf("[Antigravity] Retry succeeded after stripping thinking blocks (account: %s, model: %s)", account.Name, mappedModel)
resp = retryResp
} else {
// 重试也失败,返回重试的错误
retryRespBody, _ := io.ReadAll(io.LimitReader(retryResp.Body, 2<<20))
_ = retryResp.Body.Close()
log.Printf("[Antigravity] Retry also failed with status %d: %s", retryResp.StatusCode, string(retryRespBody))
s.handleUpstreamError(ctx, account, retryResp.StatusCode, retryResp.Header, retryRespBody)
if s.shouldFailoverWithTempUnsched(ctx, account, retryResp.StatusCode, retryRespBody) {
return nil, &UpstreamFailoverError{StatusCode: retryResp.StatusCode}
}
return nil, s.writeMappedClaudeError(c, retryResp.StatusCode, retryRespBody)
}
}
// 不是 signature 错误,或者已经没有 thinking 块,直接返回错误
if resp.StatusCode >= 400 {
if s.shouldFailoverWithTempUnsched(ctx, account, resp.StatusCode, respBody) {
return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
}
return nil, s.writeMappedClaudeError(c, resp.StatusCode, respBody)
}
}
requestID := resp.Header.Get("x-request-id")
if requestID != "" {
c.Header("x-request-id", requestID)
}
var usage *ClaudeUsage
var firstTokenMs *int
if claudeReq.Stream {
streamRes, err := s.handleClaudeStreamingResponse(c, resp, startTime, originalModel)
if err != nil {
return nil, err
}
usage = streamRes.usage
firstTokenMs = streamRes.firstTokenMs
} else {
usage, err = s.handleClaudeNonStreamingResponse(c, resp, originalModel)
if err != nil {
return nil, err
}
}
return &ForwardResult{
RequestID: requestID,
Usage: *usage,
Model: originalModel, // 使用原始模型用于计费和日志
Stream: claudeReq.Stream,
Duration: time.Since(startTime),
FirstTokenMs: firstTokenMs,
}, nil
}
// ForwardGemini 转发 Gemini 协议请求
func (s *AntigravityGatewayService) ForwardGemini(ctx context.Context, c *gin.Context, account *Account, originalModel string, action string, stream bool, body []byte) (*ForwardResult, error) {
startTime := time.Now()
if strings.TrimSpace(originalModel) == "" {
return nil, s.writeGoogleError(c, http.StatusBadRequest, "Missing model in URL")
}
if strings.TrimSpace(action) == "" {
return nil, s.writeGoogleError(c, http.StatusBadRequest, "Missing action in URL")
}
if len(body) == 0 {
return nil, s.writeGoogleError(c, http.StatusBadRequest, "Request body is empty")
}
switch action {
case "generateContent", "streamGenerateContent":
// ok
case "countTokens":
return nil, s.writeGoogleError(c, http.StatusNotImplemented, "countTokens is not supported")
default:
return nil, s.writeGoogleError(c, http.StatusNotFound, "Unsupported action: "+action)
}
mappedModel := s.getMappedModel(account, originalModel)
// 获取 access_token
if s.tokenProvider == nil {
return nil, errors.New("antigravity token provider not configured")
}
accessToken, err := s.tokenProvider.GetAccessToken(ctx, account)
if err != nil {
return nil, fmt.Errorf("获取 access_token 失败: %w", err)
}
// 获取 project_id部分账户类型可能没有
projectID := strings.TrimSpace(account.GetCredential("project_id"))
// 代理 URL
proxyURL := ""
if account.ProxyID != nil && account.Proxy != nil {
proxyURL = account.Proxy.URL()
}
// 包装请求
wrappedBody, err := s.wrapV1InternalRequest(projectID, mappedModel, body)
if err != nil {
return nil, err
}
// 构建上游 action
upstreamAction := action
if action == "generateContent" && stream {
upstreamAction = "streamGenerateContent"
}
if stream || upstreamAction == "streamGenerateContent" {
upstreamAction += "?alt=sse"
}
// 重试循环
var resp *http.Response
for attempt := 1; attempt <= antigravityMaxRetries; attempt++ {
upstreamReq, err := antigravity.NewAPIRequest(ctx, upstreamAction, accessToken, wrappedBody)
if err != nil {
return nil, err
}
resp, err = s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
if err != nil {
if attempt < antigravityMaxRetries {
log.Printf("Antigravity account %d: upstream request failed, retry %d/%d: %v", account.ID, attempt, antigravityMaxRetries, err)
sleepAntigravityBackoff(attempt)
continue
}
return nil, s.writeGoogleError(c, http.StatusBadGateway, "Upstream request failed after retries")
}
if resp.StatusCode >= 400 && s.shouldRetryUpstreamError(resp.StatusCode) {
respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
_ = resp.Body.Close()
if attempt < antigravityMaxRetries {
log.Printf("Antigravity account %d: upstream status %d, retry %d/%d", account.ID, resp.StatusCode, attempt, antigravityMaxRetries)
sleepAntigravityBackoff(attempt)
continue
}
// 所有重试都失败,标记限流状态
if resp.StatusCode == 429 {
s.handleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
}
resp = &http.Response{
StatusCode: resp.StatusCode,
Header: resp.Header.Clone(),
Body: io.NopCloser(bytes.NewReader(respBody)),
}
break
}
break
}
defer func() { _ = resp.Body.Close() }()
requestID := resp.Header.Get("x-request-id")
if requestID != "" {
c.Header("x-request-id", requestID)
}
// 处理错误响应
if resp.StatusCode >= 400 {
respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
s.handleUpstreamError(ctx, account, resp.StatusCode, resp.Header, respBody)
// Check if model fallback is enabled and this is a model not found error
if s.settingService != nil && s.settingService.IsModelFallbackEnabled(ctx) &&
isModelNotFoundError(resp.StatusCode, respBody) {
fallbackModel := s.settingService.GetFallbackModel(ctx, PlatformAntigravity)
// Only retry if fallback model is different from current model
if fallbackModel != "" && fallbackModel != mappedModel {
log.Printf("[Antigravity] Model not found (%s), retrying with fallback model %s (account: %s)",
mappedModel, fallbackModel, account.Name)
// Close original response
_ = resp.Body.Close()
// Rebuild request with fallback model
fallbackBody, err := s.wrapV1InternalRequest(projectID, fallbackModel, body)
if err == nil {
fallbackReq, err := antigravity.NewAPIRequest(ctx, upstreamAction, accessToken, fallbackBody)
if err == nil {
fallbackResp, err := s.httpUpstream.Do(fallbackReq, proxyURL, account.ID, account.Concurrency)
if err == nil && fallbackResp.StatusCode < 400 {
log.Printf("[Antigravity] Fallback succeeded with %s (account: %s)", fallbackModel, account.Name)
resp = fallbackResp
originalModel = fallbackModel // Update for billing
// Continue to normal response handling
goto handleSuccess
} else if fallbackResp != nil {
_ = fallbackResp.Body.Close()
}
}
}
log.Printf("[Antigravity] Fallback failed, returning original error")
}
}
if s.shouldFailoverWithTempUnsched(ctx, account, resp.StatusCode, respBody) {
return nil, &UpstreamFailoverError{StatusCode: resp.StatusCode}
}
// 解包并返回错误
unwrapped, _ := s.unwrapV1InternalResponse(respBody)
contentType := resp.Header.Get("Content-Type")
if contentType == "" {
contentType = "application/json"
}
c.Data(resp.StatusCode, contentType, unwrapped)
return nil, fmt.Errorf("antigravity upstream error: %d", resp.StatusCode)
}
handleSuccess:
var usage *ClaudeUsage
var firstTokenMs *int
if stream || upstreamAction == "streamGenerateContent" {
streamRes, err := s.handleGeminiStreamingResponse(c, resp, startTime)
if err != nil {
return nil, err
}
usage = streamRes.usage
firstTokenMs = streamRes.firstTokenMs
} else {
usageResp, err := s.handleGeminiNonStreamingResponse(c, resp)
if err != nil {
return nil, err
}
usage = usageResp
}
if usage == nil {
usage = &ClaudeUsage{}
}
return &ForwardResult{
RequestID: requestID,
Usage: *usage,
Model: originalModel,
Stream: stream,
Duration: time.Since(startTime),
FirstTokenMs: firstTokenMs,
}, nil
}
func (s *AntigravityGatewayService) shouldRetryUpstreamError(statusCode int) bool {
switch statusCode {
case 429, 500, 502, 503, 504, 529:
return true
default:
return false
}
}
func (s *AntigravityGatewayService) shouldFailoverUpstreamError(statusCode int) bool {
switch statusCode {
case 401, 403, 429, 529:
return true
default:
return statusCode >= 500
}
}
func (s *AntigravityGatewayService) shouldFailoverWithTempUnsched(ctx context.Context, account *Account, statusCode int, body []byte) bool {
if s.rateLimitService != nil {
if s.rateLimitService.HandleTempUnschedulable(ctx, account, statusCode, body) {
return true
}
}
return s.shouldFailoverUpstreamError(statusCode)
}
func sleepAntigravityBackoff(attempt int) {
sleepGeminiBackoff(attempt) // 复用 Gemini 的退避逻辑
}
func (s *AntigravityGatewayService) handleUpstreamError(ctx context.Context, account *Account, statusCode int, headers http.Header, body []byte) {
// 429 使用 Gemini 格式解析(从 body 解析重置时间)
if statusCode == 429 {
resetAt := ParseGeminiRateLimitResetTime(body)
if resetAt == nil {
// 解析失败Gemini 有重试时间用 5 分钟Claude 没有用 1 分钟
defaultDur := 1 * time.Minute
if bytes.Contains(body, []byte("Please retry in")) || bytes.Contains(body, []byte("retryDelay")) {
defaultDur = 5 * time.Minute
}
ra := time.Now().Add(defaultDur)
_ = s.accountRepo.SetRateLimited(ctx, account.ID, ra)
return
}
_ = s.accountRepo.SetRateLimited(ctx, account.ID, time.Unix(*resetAt, 0))
return
}
// 其他错误码继续使用 rateLimitService
if s.rateLimitService == nil {
return
}
s.rateLimitService.HandleUpstreamError(ctx, account, statusCode, headers, body)
}
type antigravityStreamResult struct {
usage *ClaudeUsage
firstTokenMs *int
}
func (s *AntigravityGatewayService) handleGeminiStreamingResponse(c *gin.Context, resp *http.Response, startTime time.Time) (*antigravityStreamResult, error) {
c.Status(resp.StatusCode)
c.Header("Cache-Control", "no-cache")
c.Header("Connection", "keep-alive")
c.Header("X-Accel-Buffering", "no")
contentType := resp.Header.Get("Content-Type")
if contentType == "" {
contentType = "text/event-stream; charset=utf-8"
}
c.Header("Content-Type", contentType)
flusher, ok := c.Writer.(http.Flusher)
if !ok {
return nil, errors.New("streaming not supported")
}
reader := bufio.NewReader(resp.Body)
usage := &ClaudeUsage{}
var firstTokenMs *int
for {
line, err := reader.ReadString('\n')
if len(line) > 0 {
trimmed := strings.TrimRight(line, "\r\n")
if strings.HasPrefix(trimmed, "data:") {
payload := strings.TrimSpace(strings.TrimPrefix(trimmed, "data:"))
if payload == "" || payload == "[DONE]" {
_, _ = io.WriteString(c.Writer, line)
flusher.Flush()
} else {
// 解包 v1internal 响应
inner, parseErr := s.unwrapV1InternalResponse([]byte(payload))
if parseErr == nil && inner != nil {
payload = string(inner)
}
// 解析 usage
var parsed map[string]any
if json.Unmarshal(inner, &parsed) == nil {
if u := extractGeminiUsage(parsed); u != nil {
usage = u
}
}
if firstTokenMs == nil {
ms := int(time.Since(startTime).Milliseconds())
firstTokenMs = &ms
}
_, _ = fmt.Fprintf(c.Writer, "data: %s\n\n", payload)
flusher.Flush()
}
} else {
_, _ = io.WriteString(c.Writer, line)
flusher.Flush()
}
}
if errors.Is(err, io.EOF) {
break
}
if err != nil {
return nil, err
}
}
return &antigravityStreamResult{usage: usage, firstTokenMs: firstTokenMs}, nil
}
func (s *AntigravityGatewayService) handleGeminiNonStreamingResponse(c *gin.Context, resp *http.Response) (*ClaudeUsage, error) {
respBody, err := io.ReadAll(resp.Body)
if err != nil {
return nil, err
}
// 解包 v1internal 响应
unwrapped := respBody
if inner, unwrapErr := s.unwrapV1InternalResponse(respBody); unwrapErr == nil && inner != nil {
unwrapped = inner
}
var parsed map[string]any
if json.Unmarshal(unwrapped, &parsed) == nil {
if u := extractGeminiUsage(parsed); u != nil {
c.Data(resp.StatusCode, "application/json", unwrapped)
return u, nil
}
}
c.Data(resp.StatusCode, "application/json", unwrapped)
return &ClaudeUsage{}, nil
}
func (s *AntigravityGatewayService) writeClaudeError(c *gin.Context, status int, errType, message string) error {
c.JSON(status, gin.H{
"type": "error",
"error": gin.H{"type": errType, "message": message},
})
return fmt.Errorf("%s", message)
}
func (s *AntigravityGatewayService) writeMappedClaudeError(c *gin.Context, upstreamStatus int, body []byte) error {
// 记录上游错误详情便于调试
log.Printf("Antigravity upstream error %d: %s", upstreamStatus, string(body))
var statusCode int
var errType, errMsg string
switch upstreamStatus {
case 400:
statusCode = http.StatusBadRequest
errType = "invalid_request_error"
errMsg = "Invalid request"
case 401:
statusCode = http.StatusBadGateway
errType = "authentication_error"
errMsg = "Upstream authentication failed"
case 403:
statusCode = http.StatusBadGateway
errType = "permission_error"
errMsg = "Upstream access forbidden"
case 429:
statusCode = http.StatusTooManyRequests
errType = "rate_limit_error"
errMsg = "Upstream rate limit exceeded"
case 529:
statusCode = http.StatusServiceUnavailable
errType = "overloaded_error"
errMsg = "Upstream service overloaded"
default:
statusCode = http.StatusBadGateway
errType = "upstream_error"
errMsg = "Upstream request failed"
}
c.JSON(statusCode, gin.H{
"type": "error",
"error": gin.H{"type": errType, "message": errMsg},
})
return fmt.Errorf("upstream error: %d", upstreamStatus)
}
func (s *AntigravityGatewayService) writeGoogleError(c *gin.Context, status int, message string) error {
statusStr := "UNKNOWN"
switch status {
case 400:
statusStr = "INVALID_ARGUMENT"
case 404:
statusStr = "NOT_FOUND"
case 429:
statusStr = "RESOURCE_EXHAUSTED"
case 500:
statusStr = "INTERNAL"
case 501:
statusStr = "UNIMPLEMENTED"
case 502, 503:
statusStr = "UNAVAILABLE"
}
c.JSON(status, gin.H{
"error": gin.H{
"code": status,
"message": message,
"status": statusStr,
},
})
return fmt.Errorf("%s", message)
}
// handleClaudeNonStreamingResponse 处理 Claude 非流式响应Gemini → Claude 转换)
func (s *AntigravityGatewayService) handleClaudeNonStreamingResponse(c *gin.Context, resp *http.Response, originalModel string) (*ClaudeUsage, error) {
body, err := io.ReadAll(io.LimitReader(resp.Body, 8<<20))
if err != nil {
return nil, s.writeClaudeError(c, http.StatusBadGateway, "upstream_error", "Failed to read upstream response")
}
// 转换 Gemini 响应为 Claude 格式
claudeResp, agUsage, err := antigravity.TransformGeminiToClaude(body, originalModel)
if err != nil {
log.Printf("Transform Gemini to Claude failed: %v, body: %s", err, string(body))
return nil, s.writeClaudeError(c, http.StatusBadGateway, "upstream_error", "Failed to parse upstream response")
}
c.Data(http.StatusOK, "application/json", claudeResp)
// 转换为 service.ClaudeUsage
usage := &ClaudeUsage{
InputTokens: agUsage.InputTokens,
OutputTokens: agUsage.OutputTokens,
CacheCreationInputTokens: agUsage.CacheCreationInputTokens,
CacheReadInputTokens: agUsage.CacheReadInputTokens,
}
return usage, nil
}
// handleClaudeStreamingResponse 处理 Claude 流式响应Gemini SSE → Claude SSE 转换)
func (s *AntigravityGatewayService) handleClaudeStreamingResponse(c *gin.Context, resp *http.Response, startTime time.Time, originalModel string) (*antigravityStreamResult, error) {
c.Header("Content-Type", "text/event-stream")
c.Header("Cache-Control", "no-cache")
c.Header("Connection", "keep-alive")
c.Header("X-Accel-Buffering", "no")
c.Status(http.StatusOK)
flusher, ok := c.Writer.(http.Flusher)
if !ok {
return nil, errors.New("streaming not supported")
}
processor := antigravity.NewStreamingProcessor(originalModel)
var firstTokenMs *int
reader := bufio.NewReader(resp.Body)
// 辅助函数:转换 antigravity.ClaudeUsage 到 service.ClaudeUsage
convertUsage := func(agUsage *antigravity.ClaudeUsage) *ClaudeUsage {
if agUsage == nil {
return &ClaudeUsage{}
}
return &ClaudeUsage{
InputTokens: agUsage.InputTokens,
OutputTokens: agUsage.OutputTokens,
CacheCreationInputTokens: agUsage.CacheCreationInputTokens,
CacheReadInputTokens: agUsage.CacheReadInputTokens,
}
}
for {
line, err := reader.ReadString('\n')
if err != nil && !errors.Is(err, io.EOF) {
return nil, fmt.Errorf("stream read error: %w", err)
}
if len(line) > 0 {
// 处理 SSE 行,转换为 Claude 格式
claudeEvents := processor.ProcessLine(strings.TrimRight(line, "\r\n"))
if len(claudeEvents) > 0 {
if firstTokenMs == nil {
ms := int(time.Since(startTime).Milliseconds())
firstTokenMs = &ms
}
if _, writeErr := c.Writer.Write(claudeEvents); writeErr != nil {
finalEvents, agUsage := processor.Finish()
if len(finalEvents) > 0 {
_, _ = c.Writer.Write(finalEvents)
}
return &antigravityStreamResult{usage: convertUsage(agUsage), firstTokenMs: firstTokenMs}, writeErr
}
flusher.Flush()
}
}
if errors.Is(err, io.EOF) {
break
}
}
// 发送结束事件
finalEvents, agUsage := processor.Finish()
if len(finalEvents) > 0 {
_, _ = c.Writer.Write(finalEvents)
flusher.Flush()
}
return &antigravityStreamResult{usage: convertUsage(agUsage), firstTokenMs: firstTokenMs}, nil
}