From cadca752c492ef923c66b7c7b4c50a97c16cc1b5 Mon Sep 17 00:00:00 2001
From: shaw <shaw-wei@foxmail.com>
Date: Wed, 28 Jan 2026 18:35:20 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8DSSE=E6=B5=81=E5=BC=8F?=
 =?UTF-8?q?=E5=93=8D=E5=BA=94=E4=B8=ADusage=E6=95=B0=E6=8D=AE=E8=A2=AB?=
 =?UTF-8?q?=E8=A6=86=E7=9B=96=E7=9A=84=E9=97=AE=E9=A2=98?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 backend/internal/service/gateway_service.go | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 5819f15a..2e3ba93e 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -3372,12 +3372,21 @@ func (s *GatewayService) parseSSEUsage(data string, usage *ClaudeUsage) {
 		} `json:"usage"`
 	}
 	if json.Unmarshal([]byte(data), &msgDelta) == nil && msgDelta.Type == "message_delta" {
-		// message_delta 是推理结束后的最终统计，应完全覆盖 message_start 的数据
-		// 这对于 Claude API 和 GLM 等兼容 API 都是正确的行为
-		usage.InputTokens = msgDelta.Usage.InputTokens
-		usage.OutputTokens = msgDelta.Usage.OutputTokens
-		usage.CacheCreationInputTokens = msgDelta.Usage.CacheCreationInputTokens
-		usage.CacheReadInputTokens = msgDelta.Usage.CacheReadInputTokens
+		// message_delta 仅覆盖存在且非0的字段
+		// 避免覆盖 message_start 中已有的值（如 input_tokens）
+		// Claude API 的 message_delta 通常只包含 output_tokens
+		if msgDelta.Usage.InputTokens > 0 {
+			usage.InputTokens = msgDelta.Usage.InputTokens
+		}
+		if msgDelta.Usage.OutputTokens > 0 {
+			usage.OutputTokens = msgDelta.Usage.OutputTokens
+		}
+		if msgDelta.Usage.CacheCreationInputTokens > 0 {
+			usage.CacheCreationInputTokens = msgDelta.Usage.CacheCreationInputTokens
+		}
+		if msgDelta.Usage.CacheReadInputTokens > 0 {
+			usage.CacheReadInputTokens = msgDelta.Usage.CacheReadInputTokens
+		}
 	}
 }