feat(ai-security-guard): add fallback JSON paths for response content extraction

plugins/wasm-go/extensions/ai-security-guard/README.md

@@ -29,6 +29,8 @@ description: 阿里云内容安全检测
 | `requestContentJsonPath` | string | optional | `messages.@reverse.0.content` | 指定要检测内容在请求body中的jsonpath |
 | `responseContentJsonPath` | string | optional | `choices.0.message.content` | 指定要检测内容在响应body中的jsonpath |
 | `responseStreamContentJsonPath` | string | optional | `choices.0.delta.content` | 指定要检测内容在流式响应body中的jsonpath |
+| `responseContentFallbackJsonPaths` | array | optional | [`choices.0.message.content`, `content.#(type=="text")#.text`] | 当 `responseContentJsonPath` 提取为空时，按顺序尝试这些兜底路径；与主路径相同的项会自动跳过；显式配置为空数组 `[]` 可禁用兜底 |
+| `responseStreamContentFallbackJsonPaths` | array | optional | [`choices.0.delta.content`, `delta.text`] | 当 `responseStreamContentJsonPath` 提取为空时，按顺序尝试这些流式兜底路径；与主路径相同的项会自动跳过；显式配置为空数组 `[]` 可禁用兜底 |
 | `denyCode` | int | optional | 200 | 指定内容非法时的响应状态码 |
 | `denyMessage` | string | optional | openai格式的流式/非流式响应 | 指定内容非法时的响应内容 |
 | `protocol` | string | optional | openai | 协议格式，非openai协议填`original` |
@@ -211,6 +213,34 @@ denyMessage: "很抱歉，我无法回答您的问题"
 protocol: original
 ```
 
+### 配置响应内容兜底提取路径
+
+当主路径提取不到内容时，可按优先级顺序配置兜底路径，兼容多种返回协议：
+
+```yaml
+serviceName: safecheck.dns
+servicePort: 443
+serviceHost: "green-cip.cn-shanghai.aliyuncs.com"
+accessKey: "XXXXXXXXX"
+secretKey: "XXXXXXXXXXXXXXX"
+checkResponse: true
+responseContentJsonPath: "choices.0.message.content"
+responseStreamContentJsonPath: "choices.0.delta.content"
+responseContentFallbackJsonPaths:
+  - "output.text"
+  - 'content.#(type=="text")#.text'
+responseStreamContentFallbackJsonPaths:
+  - "payload.delta"
+  - "delta.text"
+```
+
+如需严格模式（主路径未命中即跳过，不走兜底），可显式关闭兜底：
+
+```yaml
+responseContentFallbackJsonPaths: []
+responseStreamContentFallbackJsonPaths: []
+```
+
 ## 可观测
 ### Metric
 ai-security-guard 插件提供了以下监控指标：

plugins/wasm-go/extensions/ai-security-guard/README_EN.md

@@ -29,6 +29,8 @@ Plugin Priority: `300`
 | `requestContentJsonPath` | string | optional | `messages.@reverse.0.content` | Specify the jsonpath of the content to be detected in the request body |
 | `responseContentJsonPath` | string | optional | `choices.0.message.content` | Specify the jsonpath of the content to be detected in the response body |
 | `responseStreamContentJsonPath` | string | optional | `choices.0.delta.content` | Specify the jsonpath of the content to be detected in the streaming response body |
+| `responseContentFallbackJsonPaths` | array | optional | [`choices.0.message.content`, `content.#(type=="text")#.text`] | Fallback paths tried in order when `responseContentJsonPath` extracts empty content; entries equal to the primary path are skipped automatically; set to `[]` to disable fallback explicitly |
+| `responseStreamContentFallbackJsonPaths` | array | optional | [`choices.0.delta.content`, `delta.text`] | Streaming fallback paths tried in order when `responseStreamContentJsonPath` extracts empty content; entries equal to the primary path are skipped automatically; set to `[]` to disable fallback explicitly |
 | `denyCode` | int | optional | 200 | Response status code when the specified content is illegal |
 | `denyMessage` | string | optional | Drainage/non-streaming response in openai format, the answer content is the suggested answer from Alibaba Cloud content security | Response content when the specified content is illegal |
 | `protocol` | string | optional | openai | protocol format, `openai` or `original` |
@@ -129,6 +131,34 @@ checkRequest: true
 checkResponse: true
 ```
 
+### Configure response fallback extraction paths
+
+When primary extraction paths are empty, you can configure ordered fallback paths to support multiple response formats:
+
+```yaml
+serviceName: safecheck.dns
+servicePort: 443
+serviceHost: green-cip.cn-shanghai.aliyuncs.com
+accessKey: "XXXXXXXXX"
+secretKey: "XXXXXXXXXXXXXXX"
+checkResponse: true
+responseContentJsonPath: "choices.0.message.content"
+responseStreamContentJsonPath: "choices.0.delta.content"
+responseContentFallbackJsonPaths:
+  - "output.text"
+  - 'content.#(type=="text")#.text'
+responseStreamContentFallbackJsonPaths:
+  - "payload.delta"
+  - "delta.text"
+```
+
+To enforce strict mode (no fallback), configure both fields as empty arrays:
+
+```yaml
+responseContentFallbackJsonPaths: []
+responseStreamContentFallbackJsonPaths: []
+```
+
 ## Observability
 ### Metric
 ai-security-guard plugin provides following metrics:

plugins/wasm-go/extensions/ai-security-guard/config/config.go

@@ -67,6 +67,26 @@ const (
 	DefaultTextModerationPlusTextOutputCheckService = "llm_response_moderation"
 )
 
+var (
+	// Keep these defaults aligned with previous hardcoded fallback extraction behavior.
+	defaultResponseFallbackJsonPaths = []string{
+		"choices.0.message.content",
+		`content.#(type=="text")#.text`,
+	}
+	defaultStreamingResponseFallbackJsonPaths = []string{
+		"choices.0.delta.content",
+		"delta.text",
+	}
+)
+
+func DefaultResponseFallbackJsonPaths() []string {
+	return append([]string(nil), defaultResponseFallbackJsonPaths...)
+}
+
+func DefaultStreamingResponseFallbackJsonPaths() []string {
+	return append([]string(nil), defaultStreamingResponseFallbackJsonPaths...)
+}
+
 // api types
 
 const (
@@ -143,38 +163,40 @@ func (m *Matcher) match(consumer string) bool {
 }
 
 type AISecurityConfig struct {
-	Client                        wrapper.HttpClient
-	Host                          string
-	AK                            string
-	SK                            string
-	Token                         string
-	Action                        string
-	CheckRequest                  bool
-	CheckRequestImage             bool
-	RequestCheckService           string
-	RequestImageCheckService      string
-	RequestContentJsonPath        string
-	CheckResponse                 bool
-	ResponseCheckService          string
-	ResponseImageCheckService     string
-	ResponseContentJsonPath       string
-	ResponseStreamContentJsonPath string
-	DenyCode                      int64
-	DenyMessage                   string
-	ProtocolOriginal              bool
-	RiskLevelBar                  string
-	ContentModerationLevelBar     string
-	PromptAttackLevelBar          string
-	SensitiveDataLevelBar         string
-	MaliciousUrlLevelBar          string
-	ModelHallucinationLevelBar    string
-	CustomLabelLevelBar           string
-	Timeout                       uint32
-	BufferLimit                   int
-	Metrics                       map[string]proxywasm.MetricCounter
-	ConsumerRequestCheckService   []map[string]interface{}
-	ConsumerResponseCheckService  []map[string]interface{}
-	ConsumerRiskLevel             []map[string]interface{}
+	Client                                 wrapper.HttpClient
+	Host                                   string
+	AK                                     string
+	SK                                     string
+	Token                                  string
+	Action                                 string
+	CheckRequest                           bool
+	CheckRequestImage                      bool
+	RequestCheckService                    string
+	RequestImageCheckService               string
+	RequestContentJsonPath                 string
+	CheckResponse                          bool
+	ResponseCheckService                   string
+	ResponseImageCheckService              string
+	ResponseContentJsonPath                string
+	ResponseStreamContentJsonPath          string
+	ResponseContentFallbackJsonPaths       []string
+	ResponseStreamContentFallbackJsonPaths []string
+	DenyCode                               int64
+	DenyMessage                            string
+	ProtocolOriginal                       bool
+	RiskLevelBar                           string
+	ContentModerationLevelBar              string
+	PromptAttackLevelBar                   string
+	SensitiveDataLevelBar                  string
+	MaliciousUrlLevelBar                   string
+	ModelHallucinationLevelBar             string
+	CustomLabelLevelBar                    string
+	Timeout                                uint32
+	BufferLimit                            int
+	Metrics                                map[string]proxywasm.MetricCounter
+	ConsumerRequestCheckService            []map[string]interface{}
+	ConsumerResponseCheckService           []map[string]interface{}
+	ConsumerRiskLevel                      []map[string]interface{}
 	// text_generation, image_generation, etc.
 	ApiType string
 	// openai, qwen, comfyui, etc.
@@ -287,6 +309,16 @@ func (config *AISecurityConfig) Parse(json gjson.Result) error {
 	if obj := json.Get("responseStreamContentJsonPath"); obj.Exists() {
 		config.ResponseStreamContentJsonPath = obj.String()
 	}
+	if paths, exists, err := parseOptionalStringArrayConfig(json, "responseContentFallbackJsonPaths"); err != nil {
+		return err
+	} else if exists {
+		config.ResponseContentFallbackJsonPaths = paths
+	}
+	if paths, exists, err := parseOptionalStringArrayConfig(json, "responseStreamContentFallbackJsonPaths"); err != nil {
+		return err
+	} else if exists {
+		config.ResponseStreamContentFallbackJsonPaths = paths
+	}
 	if obj := json.Get("contentModerationLevelBar"); obj.Exists() {
 		config.ContentModerationLevelBar = obj.String()
 		if LevelToInt(config.ContentModerationLevelBar) <= 0 {
@@ -448,6 +480,29 @@ func parseDimensionAction(json gjson.Result, fieldName string) (string, error) {
 	return "", nil
 }
 
+func parseOptionalStringArrayConfig(json gjson.Result, fieldName string) ([]string, bool, error) {
+	obj := json.Get(fieldName)
+	if !obj.Exists() {
+		return nil, false, nil
+	}
+	if !obj.IsArray() {
+		return nil, true, fmt.Errorf("invalid %s, value must be an array of non-empty strings", fieldName)
+	}
+	items := obj.Array()
+	paths := make([]string, 0, len(items))
+	for _, item := range items {
+		if item.Type != gjson.String {
+			return nil, true, fmt.Errorf("invalid %s, value must be an array of non-empty strings", fieldName)
+		}
+		path := strings.TrimSpace(item.String())
+		if path == "" {
+			return nil, true, fmt.Errorf("invalid %s, value must be an array of non-empty strings", fieldName)
+		}
+		paths = append(paths, path)
+	}
+	return paths, true, nil
+}
+
 func (config *AISecurityConfig) SetDefaultValues() {
 	switch config.Action {
 	case TextModerationPlus:
@@ -463,6 +518,8 @@ func (config *AISecurityConfig) SetDefaultValues() {
 	config.RequestContentJsonPath = DefaultRequestJsonPath
 	config.ResponseContentJsonPath = DefaultResponseJsonPath
 	config.ResponseStreamContentJsonPath = DefaultStreamingResponseJsonPath
+	config.ResponseContentFallbackJsonPaths = DefaultResponseFallbackJsonPaths()
+	config.ResponseStreamContentFallbackJsonPaths = DefaultStreamingResponseFallbackJsonPaths()
 	config.ContentModerationLevelBar = MaxRisk
 	config.PromptAttackLevelBar = MaxRisk
 	config.SensitiveDataLevelBar = S4Sensitive