fix: 修正 conversion 代理路径和错误边界

backend/internal/conversion/anthropic/adapter_test.go

@@ -49,6 +49,28 @@ func TestAdapter_DetectInterfaceType(t *testing.T) {
 	}
 }
 
+func TestAdapter_APIReferenceNativePaths(t *testing.T) {
+	a := NewAdapter()
+
+	// docs/api_reference/anthropic defines messages and models under /v1.
+	tests := []struct {
+		path     string
+		expected conversion.InterfaceType
+	}{
+		{"/v1/messages", conversion.InterfaceTypeChat},
+		{"/v1/models", conversion.InterfaceTypeModels},
+		{"/v1/models/claude-sonnet-4-5", conversion.InterfaceTypeModelInfo},
+		{"/messages", conversion.InterfaceTypePassthrough},
+		{"/models", conversion.InterfaceTypePassthrough},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.path, func(t *testing.T) {
+			assert.Equal(t, tt.expected, a.DetectInterfaceType(tt.path))
+		})
+	}
+}
+
 func TestAdapter_BuildUrl(t *testing.T) {
 	a := NewAdapter()
 

backend/internal/conversion/engine.go

@@ -3,11 +3,13 @@ package conversion
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/google/uuid"
 	"go.uber.org/zap"
 
+	"nex/backend/internal/conversion/canonical"
 	pkglogger "nex/backend/pkg/logger"
 )
 
@@ -71,7 +73,7 @@ func (e *ConversionEngine) IsPassthrough(clientProtocol, providerProtocol string
 
 // ConvertHttpRequest 转换 HTTP 请求
 func (e *ConversionEngine) ConvertHttpRequest(spec HTTPRequestSpec, clientProtocol, providerProtocol string, provider *TargetProvider) (*HTTPRequestSpec, error) {
-	nativePath := spec.URL
+	nativePath, rawQuery := splitRequestPath(spec.URL)
 
 	if e.IsPassthrough(clientProtocol, providerProtocol) {
 		providerAdapter, err := e.registry.Get(providerProtocol)
@@ -96,8 +98,11 @@ func (e *ConversionEngine) ConvertHttpRequest(spec HTTPRequestSpec, clientProtoc
 			}
 		}
 
+		providerURL := providerAdapter.BuildUrl(nativePath, interfaceType)
+		providerURL = appendRawQuery(providerURL, rawQuery)
+
 		return &HTTPRequestSpec{
-			URL:     provider.BaseURL + nativePath,
+			URL:     joinBaseURL(provider.BaseURL, providerURL),
 			Method:  spec.Method,
 			Headers: providerAdapter.BuildHeaders(provider),
 			Body:    rewrittenBody,
@@ -115,6 +120,7 @@ func (e *ConversionEngine) ConvertHttpRequest(spec HTTPRequestSpec, clientProtoc
 
 	interfaceType := clientAdapter.DetectInterfaceType(nativePath)
 	providerURL := providerAdapter.BuildUrl(nativePath, interfaceType)
+	providerURL = appendRawQuery(providerURL, rawQuery)
 	providerHeaders := providerAdapter.BuildHeaders(provider)
 	providerBody, err := e.convertBody(interfaceType, clientAdapter, providerAdapter, provider, spec.Body)
 	if err != nil {
@@ -122,7 +128,7 @@ func (e *ConversionEngine) ConvertHttpRequest(spec HTTPRequestSpec, clientProtoc
 	}
 
 	return &HTTPRequestSpec{
-		URL:     provider.BaseURL + providerURL,
+		URL:     joinBaseURL(provider.BaseURL, providerURL),
 		Method:  spec.Method,
 		Headers: providerHeaders,
 		Body:    providerBody,
@@ -198,7 +204,7 @@ func (e *ConversionEngine) CreateStreamConverter(clientProtocol, providerProtoco
 
 	ctx := ConversionContext{
 		ConversionID:  uuid.New().String(),
-		InterfaceType: InterfaceTypeChat,
+		InterfaceType: interfaceType,
 		Timestamp:     time.Now(),
 	}
 
@@ -268,7 +274,7 @@ func (e *ConversionEngine) convertResponseBody(interfaceType InterfaceType, clie
 func (e *ConversionEngine) convertChatBody(clientAdapter, providerAdapter ProtocolAdapter, provider *TargetProvider, body []byte) ([]byte, error) {
 	canonicalReq, err := clientAdapter.DecodeRequest(body)
 	if err != nil {
-		return nil, NewConversionError(ErrorCodeJSONParseError, "解码请求失败").WithCause(err)
+		return nil, NewRequestJSONParseError("解码请求失败", err)
 	}
 
 	ctx := NewConversionContext(InterfaceTypeChat)
@@ -276,6 +282,9 @@ func (e *ConversionEngine) convertChatBody(clientAdapter, providerAdapter Protoc
 	if err != nil {
 		return nil, err
 	}
+	if containsUnsupportedMultimodal(canonicalReq) {
+		return nil, NewConversionError(ErrorCodeUnsupportedMultimodal, "跨协议暂不支持多模态内容")
+	}
 
 	encoded, err := providerAdapter.EncodeRequest(canonicalReq, provider)
 	if err != nil {
@@ -287,7 +296,7 @@ func (e *ConversionEngine) convertChatBody(clientAdapter, providerAdapter Protoc
 func (e *ConversionEngine) convertChatResponseBody(clientAdapter, providerAdapter ProtocolAdapter, body []byte, modelOverride string) ([]byte, error) {
 	canonicalResp, err := providerAdapter.DecodeResponse(body)
 	if err != nil {
-		return nil, NewConversionError(ErrorCodeJSONParseError, "解码响应失败").WithCause(err)
+		return nil, NewResponseJSONParseError("解码响应失败", err)
 	}
 	if modelOverride != "" {
 		canonicalResp.Model = modelOverride
@@ -375,6 +384,7 @@ func (e *ConversionEngine) DetectInterfaceType(nativePath, clientProtocol string
 	if err != nil {
 		return InterfaceTypePassthrough, err
 	}
+	nativePath, _ = splitRequestPath(nativePath)
 	return adapter.DetectInterfaceType(nativePath), nil
 }
 
@@ -398,3 +408,46 @@ func (e *ConversionEngine) EncodeError(err *ConversionError, clientProtocol stri
 	body, statusCode := adapter.EncodeError(err)
 	return body, statusCode, nil
 }
+
+func splitRequestPath(rawPath string) (string, string) {
+	path, query, found := strings.Cut(rawPath, "?")
+	if !found {
+		return rawPath, ""
+	}
+	return path, query
+}
+
+func appendRawQuery(path, rawQuery string) string {
+	if rawQuery == "" {
+		return path
+	}
+	if strings.Contains(path, "?") {
+		return path + "&" + rawQuery
+	}
+	return path + "?" + rawQuery
+}
+
+func joinBaseURL(baseURL, path string) string {
+	if baseURL == "" {
+		return path
+	}
+	if path == "" {
+		return baseURL
+	}
+	return strings.TrimRight(baseURL, "/") + "/" + strings.TrimLeft(path, "/")
+}
+
+func containsUnsupportedMultimodal(req *canonical.CanonicalRequest) bool {
+	if req == nil {
+		return false
+	}
+	for _, msg := range req.Messages {
+		for _, block := range msg.Content {
+			switch block.Type {
+			case "image", "audio", "video", "file":
+				return true
+			}
+		}
+	}
+	return false
+}

backend/internal/conversion/engine_adapter_test.go

@@ -0,0 +1,63 @@
+package conversion_test
+
+import (
+	"testing"
+
+	"nex/backend/internal/conversion"
+	"nex/backend/internal/conversion/anthropic"
+	"nex/backend/internal/conversion/openai"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+)
+
+func TestConvertHttpRequest_SameProtocolUsesAdapterBuildURL(t *testing.T) {
+	tests := []struct {
+		name             string
+		adapter          conversion.ProtocolAdapter
+		clientProtocol   string
+		providerProtocol string
+		baseURL          string
+		nativePath       string
+		expectedURL      string
+		body             []byte
+	}{
+		{
+			name:             "openai base url includes version path",
+			adapter:          openai.NewAdapter(),
+			clientProtocol:   "openai",
+			providerProtocol: "openai",
+			baseURL:          "http://example.com/v1",
+			nativePath:       "/chat/completions",
+			expectedURL:      "http://example.com/v1/chat/completions",
+			body:             []byte(`{"model":"gpt-4","messages":[]}`),
+		},
+		{
+			name:             "anthropic native path keeps v1",
+			adapter:          anthropic.NewAdapter(),
+			clientProtocol:   "anthropic",
+			providerProtocol: "anthropic",
+			baseURL:          "http://example.com",
+			nativePath:       "/v1/messages",
+			expectedURL:      "http://example.com/v1/messages",
+			body:             []byte(`{"model":"claude","messages":[]}`),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			registry := conversion.NewMemoryRegistry()
+			engine := conversion.NewConversionEngine(registry, zap.NewNop())
+			require.NoError(t, registry.Register(tt.adapter))
+
+			out, err := engine.ConvertHttpRequest(conversion.HTTPRequestSpec{
+				URL:    tt.nativePath,
+				Method: "POST",
+				Body:   tt.body,
+			}, tt.clientProtocol, tt.providerProtocol, conversion.NewTargetProvider(tt.baseURL, "key", "upstream-model"))
+			require.NoError(t, err)
+			assert.Equal(t, tt.expectedURL, out.URL)
+		})
+	}
+}

backend/internal/conversion/engine_test.go

@@ -2,6 +2,7 @@ package conversion
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 
 	"nex/backend/internal/conversion/canonical"
@@ -498,12 +499,13 @@ func TestCreateStreamConverter_ModelOverride_SmartPassthrough(t *testing.T) {
 	_, ok := converter.(*SmartPassthroughStreamConverter)
 	assert.True(t, ok)
 
-	// 验证 chunk 改写
-	chunks := converter.ProcessChunk([]byte(`{"model":"gpt-4","choices":[]}`))
+	// 验证 SSE frame 中的 data JSON 被改写
+	chunks := converter.ProcessChunk([]byte(`data: {"model":"gpt-4","choices":[]}` + "\n\n"))
 	require.Len(t, chunks, 1)
 
 	var resp map[string]interface{}
-	require.NoError(t, json.Unmarshal(chunks[0], &resp))
+	payload := strings.TrimPrefix(strings.TrimSpace(string(chunks[0])), "data: ")
+	require.NoError(t, json.Unmarshal([]byte(payload), &resp))
 	assert.Equal(t, "openai/gpt-4", resp["model"])
 }
 

backend/internal/conversion/errors.go

@@ -17,6 +17,13 @@ const (
 	ErrorCodeProtocolConstraint    ErrorCode = "PROTOCOL_CONSTRAINT_VIOLATION"
 	ErrorCodeEncodingFailure       ErrorCode = "ENCODING_FAILURE"
 	ErrorCodeInterfaceNotSupported ErrorCode = "INTERFACE_NOT_SUPPORTED"
+	ErrorCodeUnsupportedMultimodal ErrorCode = "UNSUPPORTED_MULTIMODAL"
+)
+
+const (
+	ErrorDetailPhase   = "phase"
+	ErrorPhaseRequest  = "request"
+	ErrorPhaseResponse = "response"
 )
 
 // ConversionError 协议转换错误
@@ -39,6 +46,20 @@ func NewConversionError(code ErrorCode, message string) *ConversionError {
 	}
 }
 
+// NewRequestJSONParseError 创建请求 JSON 解析错误。
+func NewRequestJSONParseError(message string, cause error) *ConversionError {
+	return NewConversionError(ErrorCodeJSONParseError, message).
+		WithDetail(ErrorDetailPhase, ErrorPhaseRequest).
+		WithCause(cause)
+}
+
+// NewResponseJSONParseError 创建响应 JSON 解析错误。
+func NewResponseJSONParseError(message string, cause error) *ConversionError {
+	return NewConversionError(ErrorCodeJSONParseError, message).
+		WithDetail(ErrorDetailPhase, ErrorPhaseResponse).
+		WithCause(cause)
+}
+
 // WithClientProtocol 设置客户端协议
 func (e *ConversionError) WithClientProtocol(protocol string) *ConversionError {
 	e.ClientProtocol = protocol

backend/internal/conversion/openai/adapter_test.go

@@ -44,6 +44,29 @@ func TestAdapter_DetectInterfaceType(t *testing.T) {
 	}
 }
 
+func TestAdapter_APIReferenceNativePaths(t *testing.T) {
+	a := NewAdapter()
+
+	// docs/api_reference/openai, excluding responses, defines paths without /v1.
+	tests := []struct {
+		path     string
+		expected conversion.InterfaceType
+	}{
+		{"/chat/completions", conversion.InterfaceTypeChat},
+		{"/models", conversion.InterfaceTypeModels},
+		{"/models/gpt-4.1", conversion.InterfaceTypeModelInfo},
+		{"/embeddings", conversion.InterfaceTypeEmbeddings},
+		{"/rerank", conversion.InterfaceTypeRerank},
+		{"/v1/chat/completions", conversion.InterfaceTypePassthrough},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.path, func(t *testing.T) {
+			assert.Equal(t, tt.expected, a.DetectInterfaceType(tt.path))
+		})
+	}
+}
+
 func TestAdapter_BuildUrl(t *testing.T) {
 	a := NewAdapter()
 

backend/internal/conversion/stream.go

@@ -1,6 +1,11 @@
 package conversion
 
-import "nex/backend/internal/conversion/canonical"
+import (
+	"bytes"
+	"strings"
+
+	"nex/backend/internal/conversion/canonical"
+)
 
 // StreamDecoder 流式解码器接口
 type StreamDecoder interface {
@@ -39,11 +44,12 @@ func (c *PassthroughStreamConverter) Flush() [][]byte {
 }
 
 // SmartPassthroughStreamConverter 同协议 Smart Passthrough 流式转换器
-// 逐 chunk 改写 model 字段
+// 按 SSE frame 改写 data JSON 中的 model 字段
 type SmartPassthroughStreamConverter struct {
 	adapter       ProtocolAdapter
 	modelOverride string
 	interfaceType InterfaceType
+	buffer        []byte
 }
 
 // NewSmartPassthroughStreamConverter 创建 Smart Passthrough 流式转换器
@@ -55,24 +61,45 @@ func NewSmartPassthroughStreamConverter(adapter ProtocolAdapter, modelOverride s
 	}
 }
 
-// ProcessChunk 改写 chunk 中的 model 字段
+// ProcessChunk 按 SSE frame 改写 data JSON 中的 model 字段
 func (c *SmartPassthroughStreamConverter) ProcessChunk(rawChunk []byte) [][]byte {
 	if len(rawChunk) == 0 {
 		return nil
 	}
 
-	rewrittenChunk, err := c.adapter.RewriteResponseModelName(rawChunk, c.modelOverride, c.interfaceType)
-	if err != nil {
-		// 改写失败，返回原始 chunk
-		return [][]byte{rawChunk}
-	}
+	c.buffer = append(c.buffer, rawChunk...)
+	frames, rest := splitSSEFrames(c.buffer)
+	c.buffer = rest
 
-	return [][]byte{rewrittenChunk}
+	result := make([][]byte, 0, len(frames))
+	for _, frame := range frames {
+		result = append(result, c.rewriteFrame(frame))
+	}
+	return result
 }
 
-// Flush 无缓冲数据
+func (c *SmartPassthroughStreamConverter) rewriteFrame(frame []byte) []byte {
+	payload, ok := sseFrameDataPayload(frame)
+	if !ok || strings.TrimSpace(payload) == "[DONE]" {
+		return frame
+	}
+
+	rewrittenPayload, err := c.adapter.RewriteResponseModelName([]byte(payload), c.modelOverride, c.interfaceType)
+	if err != nil {
+		return frame
+	}
+
+	return rebuildSSEFrameWithData(frame, string(rewrittenPayload))
+}
+
+// Flush 输出未形成完整 frame 的剩余数据
 func (c *SmartPassthroughStreamConverter) Flush() [][]byte {
-	return nil
+	if len(c.buffer) == 0 {
+		return nil
+	}
+	frame := append([]byte(nil), c.buffer...)
+	c.buffer = nil
+	return [][]byte{c.rewriteFrame(frame)}
 }
 
 // CanonicalStreamConverter 跨协议规范流式转换器
@@ -153,3 +180,86 @@ func (c *CanonicalStreamConverter) applyModelOverride(event *canonical.Canonical
 		event.Message.Model = c.modelOverride
 	}
 }
+
+func splitSSEFrames(data []byte) ([][]byte, []byte) {
+	var frames [][]byte
+	for len(data) > 0 {
+		idx, sepLen := findSSEFrameSeparator(data)
+		if idx < 0 {
+			break
+		}
+		end := idx + sepLen
+		frames = append(frames, append([]byte(nil), data[:end]...))
+		data = data[end:]
+	}
+	return frames, data
+}
+
+func findSSEFrameSeparator(data []byte) (int, int) {
+	lf := bytes.Index(data, []byte("\n\n"))
+	crlf := bytes.Index(data, []byte("\r\n\r\n"))
+	switch {
+	case lf < 0 && crlf < 0:
+		return -1, 0
+	case lf < 0:
+		return crlf, 4
+	case crlf < 0:
+		return lf, 2
+	case crlf <= lf:
+		return crlf, 4
+	default:
+		return lf, 2
+	}
+}
+
+func sseFrameDataPayload(frame []byte) (string, bool) {
+	text := strings.TrimRight(string(frame), "\r\n")
+	lines := strings.Split(text, "\n")
+	var dataLines []string
+	for _, line := range lines {
+		line = strings.TrimRight(line, "\r")
+		if strings.HasPrefix(line, "data:") {
+			value := strings.TrimPrefix(line, "data:")
+			if strings.HasPrefix(value, " ") {
+				value = value[1:]
+			}
+			dataLines = append(dataLines, value)
+		}
+	}
+	if len(dataLines) == 0 {
+		return "", false
+	}
+	return strings.Join(dataLines, "\n"), true
+}
+
+func rebuildSSEFrameWithData(frame []byte, data string) []byte {
+	lineEnding, separator := sseLineEnding(frame)
+	text := strings.TrimRight(string(frame), "\r\n")
+	lines := strings.Split(text, "\n")
+	out := make([]string, 0, len(lines)+1)
+	dataWritten := false
+	for _, line := range lines {
+		line = strings.TrimRight(line, "\r")
+		if strings.HasPrefix(line, "data:") {
+			if !dataWritten {
+				for _, dataLine := range strings.Split(data, "\n") {
+					out = append(out, "data: "+dataLine)
+				}
+				dataWritten = true
+			}
+			continue
+		}
+		out = append(out, line)
+	}
+	if !dataWritten {
+		out = append(out, "data: "+data)
+	}
+	return []byte(strings.Join(out, lineEnding) + separator)
+}
+
+func sseLineEnding(frame []byte) (string, string) {
+	if bytes.Contains(frame, []byte("\r\n")) {
+		return "\r\n", "\r\n\r\n"
+	}
+	return "\n", "\n\n"
+}