fix(openai): strip residual input namespaces before HTTP forwarding

backend/internal/service/openai_gateway_forward.go

@@ -71,6 +71,14 @@ func (s *OpenAIGatewayService) Forward(ctx context.Context, c *gin.Context, acco
 			}})
 			return nil, err
 		}
+		body, err = stripOpenAIResponsesInputNamespaces(body)
+		if err != nil {
+			setOpsUpstreamError(c, http.StatusBadRequest, err.Error(), "")
+			c.JSON(http.StatusBadRequest, gin.H{"error": gin.H{
+				"type": "invalid_request_error", "message": err.Error(), "param": "input",
+			}})
+			return nil, err
+		}
 	}
 
 	originalBody := body

backend/internal/service/openai_oauth_passthrough_test.go

@@ -450,7 +450,10 @@ func TestOpenAIGatewayService_OAuthPassthrough_NamespaceRequestAndStreamResponse
 			{"type":"namespace","name":"collaboration","tools":[{"type":"function","name":"spawn_agent","description":"spawn","parameters":{"type":"object"}}]}
 		],
 		"tool_choice":{"type":"function","name":"spawn_agent","namespace":"collaboration"},
-		"input":[{"type":"function_call","call_id":"call_old","name":"spawn_agent","namespace":"collaboration","arguments":"{}"}]
+		"input":[
+			{"type":"function_call","call_id":"call_old","name":"spawn_agent","namespace":"collaboration","arguments":"{}"},
+			{"type":"message","role":"user","namespace":"residual","content":[{"type":"input_text","text":"keep","namespace":"nested"}]}
+		]
 	}`)
 
 	upstreamSSE := strings.Join([]string{
@@ -488,6 +491,9 @@ func TestOpenAIGatewayService_OAuthPassthrough_NamespaceRequestAndStreamResponse
 	require.False(t, gjson.GetBytes(upstream.lastBody, "tool_choice.namespace").Exists())
 	require.Equal(t, "collaboration__spawn_agent", gjson.GetBytes(upstream.lastBody, "input.0.name").String())
 	require.False(t, gjson.GetBytes(upstream.lastBody, "input.0.namespace").Exists())
+	require.False(t, gjson.GetBytes(upstream.lastBody, "input.1.namespace").Exists())
+	require.Equal(t, "nested", gjson.GetBytes(upstream.lastBody, "input.1.content.0.namespace").String())
+	require.Len(t, upstream.bodies, 1)
 
 	downstream := rec.Body.String()
 	require.NotContains(t, downstream, "collaboration__spawn_agent")

backend/internal/service/openai_responses_namespace.go

@@ -7,6 +7,8 @@ import (
 
 	"github.com/Wei-Shaw/sub2api/internal/pkg/apicompat"
 	"github.com/gin-gonic/gin"
+	"github.com/tidwall/gjson"
+	"github.com/tidwall/sjson"
 )
 
 const openAIResponsesNamespaceNamesContextKey = "openai_responses_namespace_names"
@@ -49,6 +51,55 @@ func flattenOpenAIResponsesNamespaces(c *gin.Context, body []byte) ([]byte, erro
 	return rebuilt, nil
 }
 
+// stripOpenAIResponsesInputNamespaces removes namespace only from direct input
+// array items. Namespace declarations and nested namespace fields are left
+// untouched. Rebuilding the input array once keeps this linear for long
+// histories and avoids decoding JSON numbers through float64.
+func stripOpenAIResponsesInputNamespaces(body []byte) ([]byte, error) {
+	if !bytes.Contains(body, []byte(`"namespace"`)) {
+		return body, nil
+	}
+	input := gjson.GetBytes(body, "input")
+	if !input.IsArray() {
+		return body, nil
+	}
+
+	var rebuilt bytes.Buffer
+	rebuilt.Grow(len(input.Raw))
+	rebuilt.WriteByte('[')
+	changed := false
+	first := true
+	var stripErr error
+	input.ForEach(func(_, item gjson.Result) bool {
+		if !first {
+			rebuilt.WriteByte(',')
+		}
+		first = false
+		itemBody := []byte(item.Raw)
+		if item.IsObject() && item.Get("namespace").Exists() {
+			itemBody, stripErr = sjson.DeleteBytes(itemBody, "namespace")
+			if stripErr != nil {
+				return false
+			}
+			changed = true
+		}
+		rebuilt.Write(itemBody)
+		return true
+	})
+	if stripErr != nil {
+		return body, fmt.Errorf("delete OpenAI input namespace: %w", stripErr)
+	}
+	if !changed {
+		return body, nil
+	}
+	rebuilt.WriteByte(']')
+	stripped, err := sjson.SetRawBytes(body, "input", rebuilt.Bytes())
+	if err != nil {
+		return body, fmt.Errorf("replace OpenAI input after namespace deletion: %w", err)
+	}
+	return stripped, nil
+}
+
 func setOpenAIResponsesNamespaceNames(c *gin.Context, names map[string]apicompat.ResponsesNamespaceName) {
 	if c != nil && len(names) > 0 {
 		c.Set(openAIResponsesNamespaceNamesContextKey, names)

backend/internal/service/openai_responses_namespace_test.go

@@ -1,9 +1,11 @@
 package service
 
 import (
+	"strconv"
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
 )
 
 func TestShouldFlattenOpenAIResponsesNamespaces(t *testing.T) {
@@ -34,3 +36,48 @@ func TestShouldFlattenOpenAIResponsesNamespaces(t *testing.T) {
 		})
 	}
 }
+
+func TestStripOpenAIResponsesInputNamespaces(t *testing.T) {
+	body := []byte(`{
+		"meta":9007199254740993,
+		"scientific":1.25e+42,
+		"escaped":"line\\n\\u003ctag\\u003e",
+		"tools":[{"type":"function","name":"keep","namespace":"tool-namespace"}],
+		"input":[
+			{"type":"function_call","namespace":"n0","name":"one","content":{"namespace":"nested"},"large":9007199254740993},
+			{"type":"message","namespace":"n1","content":[{"type":"input_text","text":"hello","namespace":"nested-content"}]},
+			{"type":"custom_tool_call","namespace":"n2","input":"{}"},
+			{"type":"function_call_output","namespace":"n3","output":"ok"},
+			{"type":"item","namespace":"n4"},
+			{"type":"item","namespace":"n5"},
+			{"type":"item","namespace":"n6"},
+			{"type":"item","namespace":"n7"}
+		]
+	}`)
+
+	stripped, err := stripOpenAIResponsesInputNamespaces(body)
+	require.NoError(t, err)
+	for index := 0; index < 8; index++ {
+		require.False(t, gjson.GetBytes(stripped, "input."+strconv.Itoa(index)+".namespace").Exists())
+	}
+	require.Equal(t, "nested", gjson.GetBytes(stripped, "input.0.content.namespace").String())
+	require.Equal(t, "nested-content", gjson.GetBytes(stripped, "input.1.content.0.namespace").String())
+	require.Equal(t, "tool-namespace", gjson.GetBytes(stripped, "tools.0.namespace").String())
+	require.Equal(t, gjson.GetBytes(body, "meta").Raw, gjson.GetBytes(stripped, "meta").Raw)
+	require.Equal(t, gjson.GetBytes(body, "scientific").Raw, gjson.GetBytes(stripped, "scientific").Raw)
+	require.Equal(t, gjson.GetBytes(body, "escaped").Raw, gjson.GetBytes(stripped, "escaped").Raw)
+	require.Equal(t, gjson.GetBytes(body, "input.0.large").Raw, gjson.GetBytes(stripped, "input.0.large").Raw)
+}
+
+func TestStripOpenAIResponsesInputNamespacesLeavesOtherShapesByteExact(t *testing.T) {
+	tests := [][]byte{
+		[]byte(`{"input":"text","namespace":"top-level"}`),
+		[]byte(`{"input":{"namespace":"single-object"}}`),
+		[]byte(`{"input":[{"content":{"namespace":"nested-only"}}],"tools":[{"namespace":"keep"}]}`),
+	}
+	for _, body := range tests {
+		stripped, err := stripOpenAIResponsesInputNamespaces(body)
+		require.NoError(t, err)
+		require.Equal(t, body, stripped)
+	}
+}

backend/internal/service/openai_responses_rejected_field_retry_test.go

@@ -135,6 +135,32 @@ func TestOpenAIGatewayService_RetriesRejectedIndexedNamespaceField(t *testing.T)
 	require.False(t, gjson.GetBytes(upstream.bodies[1], "input.1.namespace").Exists())
 }
 
+func TestOpenAIGatewayService_OAuthHTTPStripsInputNamespacesBeforeFirstForward(t *testing.T) {
+	for _, path := range []string{"/v1/responses", "/v1/responses/compact"} {
+		t.Run(path, func(t *testing.T) {
+			body := []byte(`{"model":"gpt-5.5","stream":false,"instructions":"test","input":[{"type":"message","role":"user","namespace":"remove","content":[{"type":"input_text","text":"hello","namespace":"nested-keep"}]}]}`)
+			upstream := &httpUpstreamRecorder{responses: []*http.Response{
+				newOpenAIRejectedFieldTestResponse(http.StatusOK, `{"id":"resp_namespace_ok","output":[],"usage":{"input_tokens":1,"output_tokens":1,"input_tokens_details":{"cached_tokens":0}}}`),
+			}}
+			c := newOpenAIRejectedFieldTestContext(body)
+			c.Request.URL.Path = path
+
+			result, err := newOpenAIRejectedFieldTestService(upstream).Forward(
+				context.Background(),
+				c,
+				newOpenAIOAuthNamespaceTestAccount(),
+				body,
+			)
+
+			require.NoError(t, err)
+			require.NotNil(t, result)
+			require.Len(t, upstream.bodies, 1, "namespace must be removed before the first upstream request")
+			require.False(t, gjson.GetBytes(upstream.bodies[0], "input.0.namespace").Exists())
+			require.Equal(t, "nested-keep", gjson.GetBytes(upstream.bodies[0], "input.0.content.0.namespace").String())
+		})
+	}
+}
+
 func TestOpenAIGatewayService_RetriesExplicitMaxOutputTokensRejection(t *testing.T) {
 	body := []byte(`{"model":"gpt-5.5","stream":false,"max_output_tokens":4096,"input":[{"type":"message","role":"user","content":{"max_output_tokens":"keep"}}]}`)
 	upstream := &httpUpstreamRecorder{responses: []*http.Response{
@@ -221,6 +247,22 @@ func newOpenAIRejectedFieldTestAccount() *Account {
 	}
 }
 
+func newOpenAIOAuthNamespaceTestAccount() *Account {
+	return &Account{
+		ID:          5108,
+		Name:        "openai-oauth-namespace",
+		Platform:    PlatformOpenAI,
+		Type:        AccountTypeOAuth,
+		Concurrency: 1,
+		Credentials: map[string]any{
+			"access_token":       "oauth-token",
+			"chatgpt_account_id": "chatgpt-account",
+		},
+		Status:      StatusActive,
+		Schedulable: true,
+	}
+}
+
 func newOpenAIRejectedFieldTestResponse(status int, body string) *http.Response {
 	return &http.Response{
 		StatusCode: status,

backend/internal/service/openai_ws_forwarder_success_test.go

@@ -733,7 +733,7 @@ func TestOpenAIGatewayService_Forward_WSv2_OAuthStoreFalseByDefault(t *testing.T
 		},
 	}
 
-	body := []byte(`{"model":"gpt-5.1","stream":false,"store":true,"input":[{"type":"input_text","text":"hello"}]}`)
+	body := []byte(`{"model":"gpt-5.1","stream":false,"store":true,"input":[{"type":"input_text","text":"hello","namespace":"native-wsv2"}]}`)
 	result, err := svc.Forward(context.Background(), c, account, body)
 	require.NoError(t, err)
 	require.NotNil(t, result)
@@ -745,6 +745,7 @@ func TestOpenAIGatewayService_Forward_WSv2_OAuthStoreFalseByDefault(t *testing.T
 	require.False(t, gjson.Get(requestJSON, "store").Bool(), "默认策略应将 OAuth store 置为 false")
 	require.True(t, gjson.Get(requestJSON, "stream").Exists(), "WSv2 payload 应保留 stream 字段")
 	require.True(t, gjson.Get(requestJSON, "stream").Bool(), "OAuth Codex 规范化后应强制 stream=true")
+	require.Equal(t, "native-wsv2", gjson.Get(requestJSON, "input.0.namespace").String(), "OAuth WSv2 应保留原生 namespace")
 	require.Equal(t, openAIWSBetaV2Value, captureDialer.lastHeaders.Get("OpenAI-Beta"))
 	require.Equal(t, "remote_compaction_v2", captureDialer.lastHeaders.Get("x-codex-beta-features"))
 	// OAuth 账号的 session_id/conversation_id 应被 isolateOpenAISessionID 隔离，