fix(opencode): rewrite mapped model onto all three upstream protocols

Apply account model_mapping to the request body before OpenCode
protocol routing so /v1/responses, /v1/chat/completions, and
/v1/messages all send the mapped ID as the real upstream model.

backend/internal/service/openai_gateway_chat_completions.go

@@ -117,7 +117,12 @@ func (s *OpenAIGatewayService) forwardAsChatCompletions(
 	// OpenCode Go：按模型原生协议分流（与 inbound 协议正交）。
 	// 规则未命中一律兜底 Chat Completions，只有显式 Responses 才走下方转换链。
 	if account.IsOpenCodeGo() {
-		proto := openCodeGoNativeProtocol(account, resolveOpenCodeGoMappedModel(account, body, defaultMappedModel))
+		mapped, rewritten, rewriteErr := rewriteOpenCodeGoRequestModel(account, body, defaultMappedModel)
+		if rewriteErr != nil {
+			return nil, rewriteErr
+		}
+		body = rewritten
+		proto := openCodeGoNativeProtocol(account, mapped)
 		if proto != APIProtocolResponses {
 			if isResponsesShape {
 				if proto == APIProtocolAnthropic {

backend/internal/service/openai_gateway_forward.go

@@ -156,10 +156,20 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 	}
 
 	if account.IsOpenCodeGo() {
-		mapped := normalizeOpenAIModelForUpstream(account, resolveOpenAIForwardModel(account, originalModel, ""))
+		mapped, rewritten, rewriteErr := rewriteOpenCodeGoRequestModel(account, body, "")
+		if rewriteErr != nil {
+			return nil, rewriteErr
+		}
+		if mapped != originalModel {
+			body = rewritten
+			originalBody = rewritten
+			requestView = newOpenAIRequestView(body)
+			reqModel, reqStream, promptCacheKey = requestView.Model, requestView.Stream, requestView.PromptCacheKey
+			originalModel = reqModel
+		}
 		switch openCodeGoNativeProtocol(account, mapped) {
 		case APIProtocolAnthropic:
-			return s.forwardResponsesViaNativeAnthropic(ctx, c, account, body, reqModel)
+			return s.forwardResponsesViaNativeAnthropic(ctx, c, account, body, mapped)
 		case APIProtocolResponses:
 			break
 		default:

backend/internal/service/openai_gateway_messages.go

@@ -46,13 +46,18 @@ func (s *OpenAIGatewayService) ForwardAsAnthropic(
 
 	// OpenCode Go：按模型原生协议分流。规则未命中兜底 Chat Completions。
 	if account.IsOpenCodeGo() {
-		switch openCodeGoNativeProtocol(account, resolveOpenCodeGoMappedModel(account, body, defaultMappedModel)) {
+		mapped, rewritten, rewriteErr := rewriteOpenCodeGoRequestModel(account, body, defaultMappedModel)
+		if rewriteErr != nil {
+			return nil, rewriteErr
+		}
+		body = rewritten
+		switch openCodeGoNativeProtocol(account, mapped) {
 		case APIProtocolAnthropic:
-			return s.forwardAnthropicViaNativeAnthropicEndpoint(ctx, c, account, body, defaultMappedModel)
+			return s.forwardAnthropicViaNativeAnthropicEndpoint(ctx, c, account, body, mapped)
 		case APIProtocolResponses:
 			break
 		default:
-			return s.forwardAnthropicViaRawChatCompletions(ctx, c, account, body, defaultMappedModel)
+			return s.forwardAnthropicViaRawChatCompletions(ctx, c, account, body, mapped)
 		}
 	} else if account.IsAnthropicProtocol() || account.IsAdaptiveAPIProtocol() {
 		// 入口分流（国产供应商 Anthropic 协议）：上游为供应商原生 Anthropic 端点时，

backend/internal/service/openai_gateway_messages_anthropic_native.go

@@ -146,6 +146,25 @@ func resolveOpenCodeGoMappedModel(account *Account, body []byte, defaultMappedMo
 	return normalizeOpenAIModelForUpstream(account, billing)
 }
 
+// rewriteOpenCodeGoRequestModel applies account model_mapping to the request
+// body so every OpenCode protocol path (Responses / Chat Completions /
+// Anthropic Messages) sends the mapped ID as the real upstream model.
+func rewriteOpenCodeGoRequestModel(account *Account, body []byte, defaultMappedModel string) (string, []byte, error) {
+	mapped := resolveOpenCodeGoMappedModel(account, body, defaultMappedModel)
+	original := strings.TrimSpace(gjson.GetBytes(body, "model").String())
+	if mapped == "" {
+		mapped = original
+	}
+	if mapped == "" || mapped == original || len(body) == 0 {
+		return mapped, body, nil
+	}
+	rewritten, err := sjson.SetBytes(body, "model", mapped)
+	if err != nil {
+		return mapped, body, fmt.Errorf("rewrite OpenCode mapped model: %w", err)
+	}
+	return mapped, rewritten, nil
+}
+
 func (s *OpenAIGatewayService) buildNativeAnthropicUpstreamRequest(
 	ctx context.Context,
 	c *gin.Context,

backend/internal/service/openai_gateway_opencode_mapping_test.go

@@ -0,0 +1,124 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+func openCodeMappedTestAccount() *Account {
+	return &Account{
+		ID:          801,
+		Name:        "oc",
+		Platform:    PlatformOpenCodeGo,
+		Type:        AccountTypeAPIKey,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"api_key":      "sk-opencode",
+			"account_mode": AccountModeZen,
+			"api_protocol": APIProtocolAdaptive,
+			"base_url":     "https://opencode.ai/zen/v1",
+			"api_base_urls": map[string]any{
+				APIProtocolChatCompletions: "https://opencode.ai/zen/v1",
+				APIProtocolAnthropic:       "https://opencode.ai/zen",
+				APIProtocolResponses:       "https://opencode.ai/zen/v1",
+			},
+			"model_mapping": map[string]any{
+				"opencode/muse-spark-1.3-contributior-free": "muse-spark-1.3-contributior-free",
+				"opencode/claude-sonnet-4":                  "claude-sonnet-4",
+				"opencode/glm-5.3":                          "glm-5.3",
+			},
+		},
+	}
+}
+
+func TestOpenCodeGatewayAppliesMappedModelOnAllIngresses(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+
+	tests := []struct {
+		name         string
+		path         string
+		body         string
+		wantURL      string
+		wantModel    string
+		wantNotModel string
+		forward      func(*OpenAIGatewayService, *gin.Context, *Account, []byte) error
+		upstream     *http.Response
+	}{
+		{
+			name:         "responses muse-spark",
+			path:         "/v1/responses",
+			body:         `{"model":"opencode/muse-spark-1.3-contributior-free","stream":false,"input":"hi"}`,
+			wantURL:      "https://opencode.ai/zen/v1/responses",
+			wantModel:    "muse-spark-1.3-contributior-free",
+			wantNotModel: "opencode/muse-spark-1.3-contributior-free",
+			upstream: &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     http.Header{"Content-Type": []string{"application/json"}, "x-request-id": []string{"rid-oc-responses"}},
+				Body: io.NopCloser(strings.NewReader(
+					`{"id":"resp_oc","object":"response","model":"muse-spark-1.3-contributior-free","status":"completed","output":[{"type":"message","role":"assistant","content":[{"type":"output_text","text":"ok"}]}],"usage":{"input_tokens":2,"output_tokens":1,"total_tokens":3}}`,
+				)),
+			},
+			forward: func(svc *OpenAIGatewayService, c *gin.Context, account *Account, body []byte) error {
+				SetOpenAIClientTransport(c, OpenAIClientTransportHTTP)
+				_, err := svc.Forward(context.Background(), c, account, body)
+				return err
+			},
+		},
+		{
+			name:         "chat completions glm",
+			path:         "/v1/chat/completions",
+			body:         `{"model":"opencode/glm-5.3","stream":false,"messages":[{"role":"user","content":"hi"}]}`,
+			wantURL:      "https://opencode.ai/zen/v1/chat/completions",
+			wantModel:    "glm-5.3",
+			wantNotModel: "opencode/glm-5.3",
+			upstream: &http.Response{
+				StatusCode: http.StatusOK,
+				Header:     http.Header{"Content-Type": []string{"application/json"}, "x-request-id": []string{"rid-oc-cc"}},
+				Body: io.NopCloser(strings.NewReader(
+					`{"id":"chatcmpl_oc","object":"chat.completion","model":"glm-5.3","choices":[{"index":0,"message":{"role":"assistant","content":"ok"},"finish_reason":"stop"}],"usage":{"prompt_tokens":2,"completion_tokens":1,"total_tokens":3}}`,
+				)),
+			},
+			forward: func(svc *OpenAIGatewayService, c *gin.Context, account *Account, body []byte) error {
+				_, err := svc.ForwardAsChatCompletions(context.Background(), c, account, body, "", "")
+				return err
+			},
+		},
+		{
+			name:         "messages claude",
+			path:         "/v1/messages",
+			body:         `{"model":"opencode/claude-sonnet-4","max_tokens":32,"stream":false,"messages":[{"role":"user","content":"hi"}]}`,
+			wantURL:      "https://opencode.ai/zen/v1/messages",
+			wantModel:    "claude-sonnet-4",
+			wantNotModel: "opencode/claude-sonnet-4",
+			upstream:     nativeAnthropicBufferedResponse(),
+			forward: func(svc *OpenAIGatewayService, c *gin.Context, account *Account, body []byte) error {
+				_, err := svc.ForwardAsAnthropic(context.Background(), c, account, body, "", "")
+				return err
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			upstream := &httpUpstreamRecorder{resp: tt.upstream}
+			svc := &OpenAIGatewayService{cfg: rawChatCompletionsTestConfig(), httpUpstream: upstream}
+			c := adaptiveProtocolTestContext(tt.path, []byte(tt.body))
+
+			err := tt.forward(svc, c, openCodeMappedTestAccount(), []byte(tt.body))
+			require.NoError(t, err)
+			require.NotNil(t, upstream.lastReq)
+			require.Equal(t, tt.wantURL, upstream.lastReq.URL.String())
+			require.Equal(t, tt.wantModel, gjson.GetBytes(upstream.lastBody, "model").String())
+			require.NotContains(t, string(upstream.lastBody), tt.wantNotModel)
+		})
+	}
+}