Merge pull request #7827 from Achordchan/fix/anthropic-tool-change-betas

fix(anthropic): preserve requested tool change beta headers

backend/internal/pkg/claude/constants.go

@@ -20,6 +20,9 @@ const (
 	BetaFastMode                 = "fast-mode-2026-02-01"
 	// Legacy structured output compatibility; forwarded only when explicitly requested.
 	BetaStructuredOutputs = "structured-outputs-2025-11-13"
+	// Tool-change compatibility tokens; never enabled without an explicit client request.
+	BetaMidConversationToolChanges = "mid-conversation-tool-changes-2026-07-01"
+	BetaInlineTools                = "inline-tools-2026-09-15"
 
 	// 新增（对齐官方 CLI 2.1.9x 以来的流量）
 	BetaPromptCachingScope          = "prompt-caching-scope-2026-01-05"

backend/internal/service/gateway_tool_changes_beta_test.go

@@ -0,0 +1,63 @@
+//go:build unit
+
+package service
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/Wei-Shaw/sub2api/internal/config"
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+	"github.com/tidwall/gjson"
+)
+
+func TestBuildUpstreamRequestToolChangeBetas(t *testing.T) {
+	const mid = "mid-conversation-tool-changes-2026-07-01"
+	const inline = "inline-tools-2026-09-15"
+	for _, tc := range []struct {
+		name, header        string
+		drop                map[string]struct{}
+		wantMid, wantInline bool
+	}{
+		{"both", mid + "," + inline, nil, true, true},
+		{"mid only", mid, nil, true, false},
+		{"inline only", inline, nil, false, true},
+		{"absent", "", nil, false, false},
+		{"unknown", inline + "-other", nil, false, false},
+		{"duplicate", inline + ", " + inline + "," + mid, nil, true, true},
+		{"filter inline", mid + "," + inline, map[string]struct{}{inline: {}}, true, false},
+		{"filter mid", mid + "," + inline, map[string]struct{}{mid: {}}, false, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			gin.SetMode(gin.TestMode)
+			c, _ := gin.CreateTestContext(httptest.NewRecorder())
+			c.Request = httptest.NewRequest(http.MethodPost, "/v1/messages", nil)
+			c.Request.Header.Set("anthropic-beta", tc.header+",unrelated-beta")
+			if tc.drop != nil {
+				c.Set(betaPolicyFilterSetKey, tc.drop)
+			}
+			account := &Account{ID: 701, Platform: PlatformAnthropic, Type: AccountTypeOAuth,
+				Credentials: map[string]any{"access_token": "test-token"}, Status: StatusActive, Schedulable: true}
+			body := []byte(`{"model":"claude-opus-5-5","max_tokens":1024,"messages":[{"role":"user","content":[{"type":"tool_addition","tool":{"type":"tool_reference","tool_name":"lookup"}},{"type":"text","text":"Use lookup"}]}]}`)
+			svc := &GatewayService{cfg: &config.Config{}}
+			req, _, err := svc.buildUpstreamRequest(context.Background(), c, account, body,
+				"test-token", "oauth", "claude-opus-5-5", false, true)
+			require.NoError(t, err)
+			out := readUpstreamBodyForTest(t, req)
+			require.JSONEq(t, gjson.GetBytes(body, "messages").Raw, gjson.GetBytes(out, "messages").Raw)
+			header := getHeaderRaw(req.Header, "anthropic-beta")
+			require.Equal(t, tc.wantMid, containsBetaToken(header, mid))
+			require.Equal(t, tc.wantInline, containsBetaToken(header, inline))
+			require.False(t, containsBetaToken(header, "unrelated-beta"))
+			require.False(t, containsBetaToken(header, inline+"-other"))
+			require.True(t, containsBetaToken(header, "oauth-2025-04-20"))
+			if tc.wantInline {
+				require.Equal(t, 1, strings.Count(header, inline))
+			}
+		})
+	}
+}

backend/internal/service/gateway_upstream_request.go

@@ -545,14 +545,20 @@ func (s *GatewayService) computeFinalAnthropicBeta(
 
 	if tokenType == "oauth" {
 		if mimicClaudeCode {
-			// Keep the default beta set, with a narrow opt-in for legacy structured
-			// output requests. Unknown client betas remain excluded and policy drops
-			// still take precedence over this compatibility token.
-			incomingBeta := ""
-			if containsBetaToken(clientBeta, claude.BetaStructuredOutputs) {
-				incomingBeta = claude.BetaStructuredOutputs
+			// Preserve explicitly requested compatibility tokens so the forwarded
+			// body and headers agree. Unknown betas remain excluded; policy drops
+			// still take precedence. Missing companion tokens are not inferred.
+			var incomingBetas []string
+			for _, token := range []string{
+				claude.BetaStructuredOutputs,
+				claude.BetaMidConversationToolChanges,
+				claude.BetaInlineTools,
+			} {
+				if containsBetaToken(clientBeta, token) {
+					incomingBetas = append(incomingBetas, token)
+				}
 			}
-			return mergeAnthropicBetaDropping(claude.FullClaudeCodeMimicryBetas(), incomingBeta, effectiveDropSet), true
+			return mergeAnthropicBetaDropping(claude.FullClaudeCodeMimicryBetas(), strings.Join(incomingBetas, ","), effectiveDropSet), true
 		}
 		// 真 Claude Code 客户端透传路径
 		return stripBetaTokensWithSet(s.getBetaHeader(modelID, clientBeta), effectiveDropSet), true