diff --git a/crates/erp-ai/src/knowledge/mod.rs b/crates/erp-ai/src/knowledge/mod.rs
new file mode 100644
index 0000000..1ee1d65
--- /dev/null
+++ b/crates/erp-ai/src/knowledge/mod.rs
@@ -0,0 +1,116 @@
+use async_trait::async_trait;
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::error::AiResult;
+
+/// 知识源 trait — 统一结构化和未来向量检索的知识获取接口
+#[async_trait]
+pub trait KnowledgeSource: Send + Sync {
+    /// 根据查询获取知识上下文
+    async fn get_context(&self, query: &KnowledgeQuery) -> AiResult<KnowledgeContext>;
+
+    /// 知识源类型标识
+    fn source_type(&self) -> &str;
+
+    /// 健康检查
+    async fn health_check(&self) -> AiResult<bool>;
+}
+
+/// 知识查询参数
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct KnowledgeQuery {
+    pub tenant_id: Uuid,
+    pub analysis_type: String,
+    pub patient_context: Option<PatientSummary>,
+    pub query_text: Option<String>,
+}
+
+/// 脱敏患者摘要（不含 PII）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct PatientSummary {
+    pub age: Option<i32>,
+    pub gender: Option<String>,
+    pub tags: Vec<String>,
+}
+
+/// 知识上下文（返回给 Prompt 注入）
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct KnowledgeContext {
+    pub source: String,
+    pub context_text: String,
+    pub references: Vec<Reference>,
+    pub confidence: f32,
+}
+
+/// 参考引用
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Reference {
+    pub title: String,
+    pub source: String,
+    pub relevance_score: f32,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn knowledge_query_construction() {
+        let query = KnowledgeQuery {
+            tenant_id: Uuid::now_v7(),
+            analysis_type: "lab_report".into(),
+            patient_context: Some(PatientSummary {
+                age: Some(65),
+                gender: Some("male".into()),
+                tags: vec!["高血压".into(), "糖尿病".into()],
+            }),
+            query_text: Some("血红蛋白偏低".into()),
+        };
+        assert_eq!(query.analysis_type, "lab_report");
+        assert_eq!(query.patient_context.as_ref().unwrap().tags.len(), 2);
+    }
+
+    #[test]
+    fn knowledge_context_serde_roundtrip() {
+        let ctx = KnowledgeContext {
+            source: "structured".into(),
+            context_text: "【规则】血压 >140 需关注".into(),
+            references: vec![Reference {
+                title: "高血压指南".into(),
+                source: "system".into(),
+                relevance_score: 0.95,
+            }],
+            confidence: 0.9,
+        };
+        let json = serde_json::to_string(&ctx).unwrap();
+        let back: KnowledgeContext = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.source, "structured");
+        assert_eq!(back.references.len(), 1);
+        assert!((back.confidence - 0.9).abs() < 0.01);
+    }
+
+    #[test]
+    fn patient_summary_serde() {
+        let summary = PatientSummary {
+            age: Some(70),
+            gender: Some("female".into()),
+            tags: vec![],
+        };
+        let json = serde_json::to_string(&summary).unwrap();
+        let back: PatientSummary = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.age, Some(70));
+    }
+
+    #[test]
+    fn truncate_context_text() {
+        let long_text: String = "x".repeat(10000);
+        let max_chars = 8000;
+        let truncated = if long_text.len() > max_chars {
+            long_text[..max_chars].to_string()
+        } else {
+            long_text
+        };
+        assert_eq!(truncated.len(), max_chars);
+    }
+}
diff --git a/crates/erp-ai/src/lib.rs b/crates/erp-ai/src/lib.rs
index 7d7b9f8..c0e0dfe 100644
--- a/crates/erp-ai/src/lib.rs
+++ b/crates/erp-ai/src/lib.rs
@@ -3,6 +3,7 @@ pub mod dto;
 pub mod entity;
 pub mod error;
 pub mod handler;
+pub mod knowledge;
 pub mod module;
 pub mod prompt;
 pub mod provider;