feat: implement managed-account rotation on 429 empty-output completion retries

internal/auth/auth_edge_test.go

@@ -241,6 +241,36 @@ func TestSwitchAccountSkipsLoginFailureAndContinues(t *testing.T) {
 	}
 }
 
+func TestSwitchAccountRespectsPinnedTargetAccount(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"acc1@test.com","token":"t1"},
+			{"email":"acc2@test.com","token":"t2"}
+		]
+	}`)
+	store := config.LoadStore()
+	pool := account.NewPool(store)
+	r := NewResolver(store, pool, func(_ context.Context, _ config.Account) (string, error) {
+		return "new-token", nil
+	})
+
+	req, _ := http.NewRequest("POST", "/", nil)
+	req.Header.Set("Authorization", "Bearer managed-key")
+	req.Header.Set("X-Ds2-Target-Account", "acc1@test.com")
+	a, err := r.Determine(req)
+	if err != nil {
+		t.Fatalf("determine failed: %v", err)
+	}
+	defer r.Release(a)
+	if r.SwitchAccount(context.Background(), a) {
+		t.Fatal("expected switch to be disabled for pinned target account")
+	}
+	if a.AccountID != "acc1@test.com" {
+		t.Fatalf("expected pinned account to remain selected, got %q", a.AccountID)
+	}
+}
+
 // ─── Release edge cases ─────────────────────────────────────────────
 
 func TestReleaseNilAuth(t *testing.T) {

internal/auth/request.go

@@ -28,6 +28,7 @@ type RequestAuth struct {
 	DeepSeekToken  string
 	CallerID       string
 	AccountID      string
+	TargetAccount  string
 	Account        config.Account
 	TriedAccounts  map[string]bool
 	resolver       *Resolver
@@ -99,6 +100,7 @@ func (r *Resolver) acquireManagedRequestAuth(ctx context.Context, callerID, targ
 			UseConfigToken: true,
 			CallerID:       callerID,
 			AccountID:      acc.Identifier(),
+			TargetAccount:  target,
 			Account:        acc,
 			TriedAccounts:  tried,
 			resolver:       r,
@@ -185,6 +187,9 @@ func (r *Resolver) SwitchAccount(ctx context.Context, a *RequestAuth) bool {
 	if !a.UseConfigToken {
 		return false
 	}
+	if strings.TrimSpace(a.TargetAccount) != "" {
+		return false
+	}
 	if a.TriedAccounts == nil {
 		a.TriedAccounts = map[string]bool{}
 	}
@@ -208,6 +213,13 @@ func (r *Resolver) SwitchAccount(ctx context.Context, a *RequestAuth) bool {
 	}
 }
 
+func (a *RequestAuth) SwitchAccount(ctx context.Context) bool {
+	if a == nil || a.resolver == nil {
+		return false
+	}
+	return a.resolver.SwitchAccount(ctx, a)
+}
+
 func (r *Resolver) Release(a *RequestAuth) {
 	if a == nil || !a.UseConfigToken || a.AccountID == "" {
 		return

internal/completionruntime/nonstream.go

@@ -104,6 +104,7 @@ func ExecuteNonStreamStartedWithRetry(ctx context.Context, ds DeepSeekCaller, a
 	pow := start.Pow
 
 	attempts := 0
+	accountSwitchAttempted := false
 	currentResp := start.Response
 	usagePrompt := stdReq.PromptTokenText
 	accumulatedThinking := ""
@@ -112,6 +113,24 @@ func ExecuteNonStreamStartedWithRetry(ctx context.Context, ds DeepSeekCaller, a
 	for {
 		turn, outErr := collectAttempt(currentResp, stdReq, usagePrompt, opts)
 		if outErr != nil {
+			if canRetryOnAlternateAccount(ctx, a, outErr, opts.RetryEnabled, &accountSwitchAttempted) {
+				switched, switchErr := startStandardCompletionOnAlternateAccount(ctx, ds, a, stdReq, maxAttempts)
+				if switchErr != nil {
+					return NonStreamResult{SessionID: sessionID, Payload: payload, Attempts: attempts}, switchErr
+				}
+				if switched.Response != nil {
+					config.Logger.Info("[completion_runtime_account_switch_retry] retrying after 429", "surface", stdReq.Surface, "stream", false, "account", a.AccountID)
+					sessionID = switched.SessionID
+					payload = switched.Payload
+					pow = switched.Pow
+					currentResp = switched.Response
+					usagePrompt = stdReq.PromptTokenText
+					accumulatedThinking = ""
+					accumulatedRawThinking = ""
+					accumulatedToolDetectionThinking = ""
+					continue
+				}
+			}
 			return NonStreamResult{SessionID: sessionID, Payload: payload, Attempts: attempts}, outErr
 		}
 		accumulatedThinking += sse.TrimContinuationOverlap(accumulatedThinking, turn.Thinking)
@@ -134,6 +153,24 @@ func ExecuteNonStreamStartedWithRetry(ctx context.Context, ds DeepSeekCaller, a
 			retryMax = shared.EmptyOutputRetryMaxAttempts()
 		}
 		if !opts.RetryEnabled || !assistantturn.ShouldRetryEmptyOutput(turn, attempts, retryMax) {
+			if canRetryOnAlternateAccount(ctx, a, turn.Error, opts.RetryEnabled, &accountSwitchAttempted) {
+				switched, switchErr := startStandardCompletionOnAlternateAccount(ctx, ds, a, stdReq, maxAttempts)
+				if switchErr != nil {
+					return NonStreamResult{SessionID: sessionID, Payload: payload, Turn: turn, Attempts: attempts}, switchErr
+				}
+				if switched.Response != nil {
+					config.Logger.Info("[completion_runtime_account_switch_retry] retrying after 429", "surface", stdReq.Surface, "stream", false, "account", a.AccountID)
+					sessionID = switched.SessionID
+					payload = switched.Payload
+					pow = switched.Pow
+					currentResp = switched.Response
+					usagePrompt = stdReq.PromptTokenText
+					accumulatedThinking = ""
+					accumulatedRawThinking = ""
+					accumulatedToolDetectionThinking = ""
+					continue
+				}
+			}
 			return NonStreamResult{SessionID: sessionID, Payload: payload, Turn: turn, Attempts: attempts}, turn.Error
 		}
 
@@ -154,6 +191,37 @@ func ExecuteNonStreamStartedWithRetry(ctx context.Context, ds DeepSeekCaller, a
 	}
 }
 
+func canRetryOnAlternateAccount(ctx context.Context, a *auth.RequestAuth, outErr *assistantturn.OutputError, retryEnabled bool, attempted *bool) bool {
+	if outErr == nil || outErr.Status != http.StatusTooManyRequests {
+		return false
+	}
+	if !retryEnabled || attempted == nil || *attempted {
+		return false
+	}
+	if a == nil || !a.UseConfigToken {
+		return false
+	}
+	*attempted = true
+	return a.SwitchAccount(ctx)
+}
+
+func startStandardCompletionOnAlternateAccount(ctx context.Context, ds DeepSeekCaller, a *auth.RequestAuth, stdReq promptcompat.StandardRequest, maxAttempts int) (StartResult, *assistantturn.OutputError) {
+	sessionID, err := ds.CreateSession(ctx, a, maxAttempts)
+	if err != nil {
+		return StartResult{}, authOutputError(a)
+	}
+	pow, err := ds.GetPow(ctx, a, maxAttempts)
+	if err != nil {
+		return StartResult{SessionID: sessionID}, &assistantturn.OutputError{Status: http.StatusUnauthorized, Message: "Failed to get PoW (invalid token or unknown error).", Code: "error"}
+	}
+	payload := stdReq.CompletionPayload(sessionID)
+	resp, err := ds.CallCompletion(ctx, a, payload, pow, maxAttempts)
+	if err != nil {
+		return StartResult{SessionID: sessionID, Payload: payload, Pow: pow}, &assistantturn.OutputError{Status: http.StatusInternalServerError, Message: "Failed to get completion.", Code: "error"}
+	}
+	return StartResult{SessionID: sessionID, Payload: payload, Pow: pow, Response: resp, Request: stdReq}, nil
+}
+
 func collectAttempt(resp *http.Response, stdReq promptcompat.StandardRequest, usagePrompt string, opts Options) (assistantturn.Turn, *assistantturn.OutputError) {
 	defer func() {
 		if err := resp.Body.Close(); err != nil {

internal/completionruntime/nonstream_test.go

@@ -7,15 +7,19 @@ import (
 	"strings"
 	"testing"
 
+	"ds2api/internal/account"
 	"ds2api/internal/auth"
+	"ds2api/internal/config"
 	dsclient "ds2api/internal/deepseek/client"
 	"ds2api/internal/promptcompat"
 )
 
 type fakeDeepSeekCaller struct {
-	responses []*http.Response
-	payloads  []map[string]any
-	uploads   []dsclient.UploadFileRequest
+	responses          []*http.Response
+	payloads           []map[string]any
+	uploads            []dsclient.UploadFileRequest
+	completionAccounts []string
+	sessionByAccount   bool
 }
 
 type currentInputRuntimeConfig struct{}
@@ -23,7 +27,10 @@ type currentInputRuntimeConfig struct{}
 func (currentInputRuntimeConfig) CurrentInputFileEnabled() bool { return true }
 func (currentInputRuntimeConfig) CurrentInputFileMinChars() int { return 0 }
 
-func (f *fakeDeepSeekCaller) CreateSession(context.Context, *auth.RequestAuth, int) (string, error) {
+func (f *fakeDeepSeekCaller) CreateSession(_ context.Context, a *auth.RequestAuth, _ int) (string, error) {
+	if f.sessionByAccount && a != nil && a.AccountID != "" {
+		return "session-" + a.AccountID, nil
+	}
 	return "session-1", nil
 }
 
@@ -36,8 +43,11 @@ func (f *fakeDeepSeekCaller) UploadFile(_ context.Context, _ *auth.RequestAuth,
 	return &dsclient.UploadFileResult{ID: "file-runtime-1"}, nil
 }
 
-func (f *fakeDeepSeekCaller) CallCompletion(_ context.Context, _ *auth.RequestAuth, payload map[string]any, _ string, _ int) (*http.Response, error) {
+func (f *fakeDeepSeekCaller) CallCompletion(_ context.Context, a *auth.RequestAuth, payload map[string]any, _ string, _ int) (*http.Response, error) {
 	f.payloads = append(f.payloads, payload)
+	if a != nil {
+		f.completionAccounts = append(f.completionAccounts, a.AccountID)
+	}
 	if len(f.responses) == 0 {
 		return sseHTTPResponse(http.StatusOK, `data: {"p":"response/content","v":"fallback"}`), nil
 	}
@@ -89,6 +99,69 @@ func TestExecuteNonStreamWithRetryBuildsCanonicalTurn(t *testing.T) {
 	}
 }
 
+func TestExecuteNonStreamWithRetrySwitchesManagedAccountBeforeFinal429(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"acc1@test.com","password":"pwd"},
+			{"email":"acc2@test.com","password":"pwd"}
+		]
+	}`)
+	store := config.LoadStore()
+	resolver := auth.NewResolver(store, account.NewPool(store), func(_ context.Context, acc config.Account) (string, error) {
+		return "token-" + acc.Identifier(), nil
+	})
+	req, _ := http.NewRequest(http.MethodPost, "/", nil)
+	req.Header.Set("Authorization", "Bearer managed-key")
+	a, err := resolver.Determine(req)
+	if err != nil {
+		t.Fatalf("determine failed: %v", err)
+	}
+	defer resolver.Release(a)
+
+	ds := &fakeDeepSeekCaller{
+		sessionByAccount: true,
+		responses: []*http.Response{
+			sseHTTPResponse(http.StatusOK, `data: {"response_message_id":11,"p":"response/thinking_content","v":"first empty"}`),
+			sseHTTPResponse(http.StatusOK, `data: {"response_message_id":12,"p":"response/thinking_content","v":"retry empty"}`),
+			sseHTTPResponse(http.StatusOK, `data: {"response_message_id":21,"p":"response/content","v":"ok from second account"}`),
+		},
+	}
+	stdReq := promptcompat.StandardRequest{
+		Surface:         "test",
+		ResponseModel:   "deepseek-v4-flash",
+		PromptTokenText: "prompt",
+		FinalPrompt:     "final prompt",
+		Thinking:        true,
+	}
+
+	result, outErr := ExecuteNonStreamWithRetry(context.Background(), ds, a, stdReq, Options{RetryEnabled: true})
+	if outErr != nil {
+		t.Fatalf("unexpected output error after account switch retry: %#v", outErr)
+	}
+	if result.Turn.Text != "ok from second account" {
+		t.Fatalf("text mismatch after switch retry: %q", result.Turn.Text)
+	}
+	if result.SessionID != "session-acc2@test.com" {
+		t.Fatalf("expected switched account session, got %q", result.SessionID)
+	}
+	wantAccounts := []string{"acc1@test.com", "acc1@test.com", "acc2@test.com"}
+	if len(ds.completionAccounts) != len(wantAccounts) {
+		t.Fatalf("completion account count mismatch: got %v want %v", ds.completionAccounts, wantAccounts)
+	}
+	for i, want := range wantAccounts {
+		if ds.completionAccounts[i] != want {
+			t.Fatalf("completion account %d = %q want %q (all=%v)", i, ds.completionAccounts[i], want, ds.completionAccounts)
+		}
+	}
+	if got := ds.payloads[2]["chat_session_id"]; got != "session-acc2@test.com" {
+		t.Fatalf("switched payload session mismatch: %#v", got)
+	}
+	if prompt, _ := ds.payloads[2]["prompt"].(string); strings.Contains(prompt, "Previous reply had no visible output") {
+		t.Fatalf("expected fresh switched-account prompt without empty-output suffix, got %q", prompt)
+	}
+}
+
 func TestExecuteNonStreamWithRetryUsesParentMessageForEmptyRetry(t *testing.T) {
 	ds := &fakeDeepSeekCaller{responses: []*http.Response{
 		sseHTTPResponse(http.StatusOK, `data: {"response_message_id":77,"p":"response/thinking_content","v":"plan"}`),

internal/completionruntime/stream_retry.go

@@ -6,6 +6,7 @@ import (
 	"net/http"
 	"strings"
 
+	"ds2api/internal/assistantturn"
 	"ds2api/internal/auth"
 	"ds2api/internal/config"
 	"ds2api/internal/httpapi/openai/shared"
@@ -27,6 +28,7 @@ type StreamRetryHooks struct {
 	OnRetry         func(attempts int)
 	OnRetryPrompt   func(prompt string)
 	OnRetryFailure  func(status int, message, code string)
+	OnAccountSwitch func(sessionID string)
 	OnTerminal      func(attempts int)
 }
 
@@ -48,16 +50,48 @@ func ExecuteStreamWithRetry(ctx context.Context, ds DeepSeekCaller, a *auth.Requ
 	}
 
 	attempts := 0
+	accountSwitchAttempted := false
 	currentResp := initialResp
+	currentPayload := clonePayload(payload)
 	for {
-		terminalWritten, retryable := hooks.ConsumeAttempt(currentResp, opts.RetryEnabled && attempts < retryMax)
+		allowAccountSwitch := opts.RetryEnabled && attempts >= retryMax && !accountSwitchAttempted && a != nil && a.UseConfigToken
+		terminalWritten, retryable := hooks.ConsumeAttempt(currentResp, opts.RetryEnabled && (attempts < retryMax || allowAccountSwitch))
 		if terminalWritten {
 			if hooks.OnTerminal != nil {
 				hooks.OnTerminal(attempts)
 			}
 			return
 		}
-		if !retryable || !opts.RetryEnabled || attempts >= retryMax {
+		if !retryable || !opts.RetryEnabled {
+			if hooks.Finalize != nil {
+				hooks.Finalize(attempts)
+			}
+			return
+		}
+
+		if attempts >= retryMax {
+			if canRetryOnAlternateAccount(ctx, a, &assistantturn.OutputError{Status: http.StatusTooManyRequests}, opts.RetryEnabled, &accountSwitchAttempted) {
+				switched, switchErr := startPayloadCompletionOnAlternateAccount(ctx, ds, a, payload, maxAttempts)
+				if switchErr != nil {
+					if hooks.OnRetryFailure != nil {
+						hooks.OnRetryFailure(switchErr.Status, switchErr.Message, switchErr.Code)
+					}
+					return
+				}
+				if switched.Response != nil {
+					config.Logger.Info("[completion_runtime_account_switch_retry] retrying after 429", "surface", surface, "stream", opts.Stream, "account", a.AccountID)
+					currentResp = switched.Response
+					currentPayload = switched.Payload
+					pow = switched.Pow
+					if hooks.OnAccountSwitch != nil {
+						hooks.OnAccountSwitch(switched.SessionID)
+					}
+					if hooks.OnRetryPrompt != nil {
+						hooks.OnRetryPrompt(opts.UsagePrompt)
+					}
+					continue
+				}
+			}
 			if hooks.Finalize != nil {
 				hooks.Finalize(attempts)
 			}
@@ -75,7 +109,7 @@ func ExecuteStreamWithRetry(ctx context.Context, ds DeepSeekCaller, a *auth.Requ
 			config.Logger.Warn("[completion_runtime_empty_retry] retry PoW fetch failed, falling back to original PoW", "surface", surface, "stream", opts.Stream, "retry_attempt", attempts, "error", powErr)
 			retryPow = pow
 		}
-		nextResp, err := ds.CallCompletion(ctx, a, shared.ClonePayloadForEmptyOutputRetry(payload, parentMessageID), retryPow, maxAttempts)
+		nextResp, err := ds.CallCompletion(ctx, a, shared.ClonePayloadForEmptyOutputRetry(currentPayload, parentMessageID), retryPow, maxAttempts)
 		if err != nil {
 			if hooks.OnRetryFailure != nil {
 				hooks.OnRetryFailure(http.StatusInternalServerError, "Failed to get completion.", "error")
@@ -108,6 +142,33 @@ func ExecuteStreamWithRetry(ctx context.Context, ds DeepSeekCaller, a *auth.Requ
 	}
 }
 
+func startPayloadCompletionOnAlternateAccount(ctx context.Context, ds DeepSeekCaller, a *auth.RequestAuth, payload map[string]any, maxAttempts int) (StartResult, *assistantturn.OutputError) {
+	sessionID, err := ds.CreateSession(ctx, a, maxAttempts)
+	if err != nil {
+		return StartResult{}, authOutputError(a)
+	}
+	pow, err := ds.GetPow(ctx, a, maxAttempts)
+	if err != nil {
+		return StartResult{SessionID: sessionID}, &assistantturn.OutputError{Status: http.StatusUnauthorized, Message: "Failed to get PoW (invalid token or unknown error).", Code: "error"}
+	}
+	nextPayload := clonePayload(payload)
+	nextPayload["chat_session_id"] = sessionID
+	delete(nextPayload, "parent_message_id")
+	resp, err := ds.CallCompletion(ctx, a, nextPayload, pow, maxAttempts)
+	if err != nil {
+		return StartResult{SessionID: sessionID, Payload: nextPayload, Pow: pow}, &assistantturn.OutputError{Status: http.StatusInternalServerError, Message: "Failed to get completion.", Code: "error"}
+	}
+	return StartResult{SessionID: sessionID, Payload: nextPayload, Pow: pow, Response: resp}, nil
+}
+
+func clonePayload(payload map[string]any) map[string]any {
+	clone := make(map[string]any, len(payload))
+	for k, v := range payload {
+		clone[k] = v
+	}
+	return clone
+}
+
 func closeRetryBody(surface string, body io.Closer) {
 	if body == nil {
 		return

internal/completionruntime/stream_retry_test.go

@@ -7,7 +7,9 @@ import (
 	"strings"
 	"testing"
 
+	"ds2api/internal/account"
 	"ds2api/internal/auth"
+	"ds2api/internal/config"
 	"ds2api/internal/httpapi/openai/shared"
 )
 
@@ -60,3 +62,89 @@ func TestExecuteStreamWithRetryUsesSharedRetryPayloadAndUsagePrompt(t *testing.T
 		t.Fatalf("expected retry suffix in usage prompt, got %q", retryPrompt)
 	}
 }
+
+func TestExecuteStreamWithRetrySwitchesManagedAccountBeforeFinal429(t *testing.T) {
+	t.Setenv("DS2API_CONFIG_JSON", `{
+		"keys":["managed-key"],
+		"accounts":[
+			{"email":"acc1@test.com","password":"pwd"},
+			{"email":"acc2@test.com","password":"pwd"}
+		]
+	}`)
+	store := config.LoadStore()
+	resolver := auth.NewResolver(store, account.NewPool(store), func(_ context.Context, acc config.Account) (string, error) {
+		return "token-" + acc.Identifier(), nil
+	})
+	req, _ := http.NewRequest(http.MethodPost, "/", nil)
+	req.Header.Set("Authorization", "Bearer managed-key")
+	a, err := resolver.Determine(req)
+	if err != nil {
+		t.Fatalf("determine failed: %v", err)
+	}
+	defer resolver.Release(a)
+
+	ds := &fakeDeepSeekCaller{
+		sessionByAccount: true,
+		responses: []*http.Response{
+			sseHTTPResponse(http.StatusOK, `data: {"response_message_id":12,"p":"response/thinking_content","v":"retry empty"}`),
+			sseHTTPResponse(http.StatusOK, `data: {"response_message_id":21,"p":"response/content","v":"ok from second account"}`),
+		},
+	}
+	initial := sseHTTPResponse(http.StatusOK, `data: {"response_message_id":11,"p":"response/thinking_content","v":"first empty"}`)
+	payload := map[string]any{"prompt": "original prompt", "chat_session_id": "session-acc1@test.com"}
+	attemptsSeen := 0
+	switchedSession := ""
+
+	ExecuteStreamWithRetry(context.Background(), ds, a, initial, payload, "pow", StreamRetryOptions{
+		Surface:          "test.stream",
+		Stream:           true,
+		RetryEnabled:     true,
+		RetryMaxAttempts: 1,
+		UsagePrompt:      "original prompt",
+	}, StreamRetryHooks{
+		ConsumeAttempt: func(resp *http.Response, allowDeferEmpty bool) (bool, bool) {
+			defer func() {
+				if err := resp.Body.Close(); err != nil {
+					t.Fatalf("close failed: %v", err)
+				}
+			}()
+			body, _ := io.ReadAll(resp.Body)
+			attemptsSeen++
+			if strings.Contains(string(body), "ok from second account") {
+				return true, false
+			}
+			if !allowDeferEmpty {
+				t.Fatalf("expected empty attempt %d to be deferred before final 429", attemptsSeen)
+			}
+			return false, true
+		},
+		ParentMessageID: func() int {
+			return 11 + attemptsSeen
+		},
+		OnAccountSwitch: func(sessionID string) {
+			switchedSession = sessionID
+		},
+	})
+
+	if attemptsSeen != 3 {
+		t.Fatalf("expected three stream attempts, got %d", attemptsSeen)
+	}
+	if switchedSession != "session-acc2@test.com" {
+		t.Fatalf("expected switched session id, got %q", switchedSession)
+	}
+	wantAccounts := []string{"acc1@test.com", "acc2@test.com"}
+	if len(ds.completionAccounts) != len(wantAccounts) {
+		t.Fatalf("completion accounts mismatch: got %v want %v", ds.completionAccounts, wantAccounts)
+	}
+	for i, want := range wantAccounts {
+		if ds.completionAccounts[i] != want {
+			t.Fatalf("completion account %d = %q want %q (all=%v)", i, ds.completionAccounts[i], want, ds.completionAccounts)
+		}
+	}
+	if got := ds.payloads[1]["chat_session_id"]; got != "session-acc2@test.com" {
+		t.Fatalf("switched payload session mismatch: %#v", got)
+	}
+	if prompt, _ := ds.payloads[1]["prompt"].(string); strings.Contains(prompt, shared.EmptyOutputRetrySuffix) {
+		t.Fatalf("expected switched-account prompt without empty-output suffix, got %q", prompt)
+	}
+}

internal/httpapi/openai/chat/empty_retry_runtime.go

@@ -66,7 +66,7 @@ func (h *Handler) handleNonStreamWithRetry(w http.ResponseWriter, ctx context.Co
 	writeJSON(w, http.StatusOK, respBody)
 }
 
-func (h *Handler) handleStreamWithRetry(w http.ResponseWriter, r *http.Request, a *auth.RequestAuth, resp *http.Response, payload map[string]any, pow, completionID, model, finalPrompt string, refFileTokens int, thinkingEnabled, searchEnabled bool, toolNames []string, toolsRaw any, toolChoice promptcompat.ToolChoicePolicy, historySession *chatHistorySession) {
+func (h *Handler) handleStreamWithRetry(w http.ResponseWriter, r *http.Request, a *auth.RequestAuth, resp *http.Response, payload map[string]any, pow, completionID string, sessionIDRef *string, model, finalPrompt string, refFileTokens int, thinkingEnabled, searchEnabled bool, toolNames []string, toolsRaw any, toolChoice promptcompat.ToolChoicePolicy, historySession *chatHistorySession) {
 	streamRuntime, initialType, ok := h.prepareChatStreamRuntime(w, resp, completionID, model, finalPrompt, refFileTokens, thinkingEnabled, searchEnabled, toolNames, toolsRaw, toolChoice, historySession)
 	if !ok {
 		return
@@ -96,6 +96,11 @@ func (h *Handler) handleStreamWithRetry(w http.ResponseWriter, r *http.Request,
 		OnRetryFailure: func(status int, message, code string) {
 			failChatStreamRetry(streamRuntime, historySession, status, message, code)
 		},
+		OnAccountSwitch: func(sessionID string) {
+			if sessionIDRef != nil {
+				*sessionIDRef = sessionID
+			}
+		},
 		OnTerminal: func(attempts int) {
 			logChatStreamTerminal(streamRuntime, attempts)
 		},

internal/httpapi/openai/chat/handler_chat.go

@@ -114,7 +114,7 @@ func (h *Handler) ChatCompletions(w http.ResponseWriter, r *http.Request) {
 	}
 	streamReq := start.Request
 	refFileTokens := streamReq.RefFileTokens
-	h.handleStreamWithRetry(w, r, a, start.Response, start.Payload, start.Pow, sessionID, streamReq.ResponseModel, streamReq.PromptTokenText, refFileTokens, streamReq.Thinking, streamReq.Search, streamReq.ToolNames, streamReq.ToolsRaw, streamReq.ToolChoice, historySession)
+	h.handleStreamWithRetry(w, r, a, start.Response, start.Payload, start.Pow, sessionID, &sessionID, streamReq.ResponseModel, streamReq.PromptTokenText, refFileTokens, streamReq.Thinking, streamReq.Search, streamReq.ToolNames, streamReq.ToolsRaw, streamReq.ToolChoice, historySession)
 }
 
 func (h *Handler) autoDeleteRemoteSession(ctx context.Context, a *auth.RequestAuth, sessionID string) {