v2: add embedding tests, multilingual embedding support

Sources/MarkBaseServer/SimpleServerApp.swift

@@ -23,6 +23,7 @@ struct SimpleServerApp {
         let model = try E4BModel(modelDir: modelPath, engine: engine, maxContextLength: 512)
         let tokenizer = try TokenizerFactory.load(modelDir: modelPath)
         let generator = StreamingGenerator(model: model, tokenizer: tokenizer, engine: engine)
+        let embeddingModel = try TextEmbeddingModel(modelDir: modelPath, engine: engine, config: TextEmbeddingConfig())
 
         print("✓ E4B loaded (\(model.numHiddenLayers) layers)")
 
@@ -168,14 +169,15 @@ struct SimpleServerApp {
                 "deployment": "docs/DEPLOYMENT.md",
                 "performance": "docs/PERFORMANCE.md"
               },
-              "notes": [
+                "notes": [
                 "All responses are in JSON format",
                 "Text generation only (multimodal not yet supported via API)",
                 "E4B model with 42 layers, ~4B parameters",
                 "For multimodal (vision/audio) support, use the MarkBase Swift library directly",
                 "Streaming support is planned but not yet implemented",
                 "Function calling uses native Gemma 4 special tokens",
-                "Messages can include tool_calls (assistant) and tool responses (tool role) for multi-turn function calling"
+                "Messages can include tool_calls (assistant) and tool responses (tool role) for multi-turn function calling",
+                "Text embeddings available via /v1/embeddings endpoint (OpenAI-compatible)"
               ]
             }
             """
@@ -287,6 +289,73 @@ struct SimpleServerApp {
             }
         }
 
+        router.post("/v1/embeddings") { request, _ in
+            let buffer = try await request.body.collect(upTo: .max)
+            let data = Data(buffer: buffer)
+
+            guard let json = try JSONSerialization.jsonObject(with: data) as? [String: Any],
+                  let input = json["input"] else {
+                return "{\"error\":\"invalid request\",\"type\":\"invalid_request_error\",\"code\":400,\"message\":\"missing 'input' field\"}"
+            }
+
+            let modelId = (json["model"] as? String) ?? "e4b"
+            let encodingFormat = (json["encoding_format"] as? String) ?? "float"
+
+            let inputs: [String]
+            if let str = input as? String {
+                inputs = [str]
+            } else if let arr = input as? [String] {
+                inputs = arr
+            } else {
+                return "{\"error\":\"invalid request\",\"type\":\"invalid_request_error\",\"code\":400,\"message\":\"'input' must be string or array of strings\"}"
+            }
+
+            var embeddings: [[String: Any]] = []
+            for (i, text) in inputs.enumerated() {
+                let t0 = Date()
+                let embedding = try embeddingModel.embed(text: text)
+                let duration = Date().timeIntervalSince(t0)
+
+                let embeddingData: [String: Any]
+                if encodingFormat == "base64" {
+                    let base64 = embedding.withUnsafeBytes { Data($0).base64EncodedString() }
+                    embeddingData = [
+                        "object": "embedding",
+                        "index": i,
+                        "embedding": base64,
+                        "usage_ms": Int(duration * 1000)
+                    ]
+                } else {
+                    embeddingData = [
+                        "object": "embedding",
+                        "index": i,
+                        "embedding": embedding,
+                        "usage_ms": Int(duration * 1000)
+                    ]
+                }
+                embeddings.append(embeddingData)
+            }
+
+            let id = UUID().uuidString
+            let ts = Int(Date().timeIntervalSince1970)
+            let totalTokens = inputs.reduce(0) { $0 + tokenizer.encode(text: $1).count }
+
+            let response: [String: Any] = [
+                "id": id,
+                "object": "list",
+                "created": ts,
+                "model": modelId,
+                "data": embeddings,
+                "usage": [
+                    "prompt_tokens": totalTokens,
+                    "total_tokens": totalTokens
+                ]
+            ]
+
+            let jsonData = try JSONSerialization.data(withJSONObject: response)
+            return String(data: jsonData, encoding: .utf8) ?? "{}"
+        }
+
         let app = Application(
             router: router,
             configuration: .init(address: .hostname("0.0.0.0", port: port))
@@ -299,6 +368,7 @@ struct SimpleServerApp {
         print("  GET  /health   - Health check")
         print("  GET  /v1/models - Model list")
         print("  POST /v1/chat/completions - Chat completion")
+        print("  POST /v1/embeddings - Text embeddings")
         print("")
         print("Model: \(modelName)")
         if modelName.contains("E4B") {