feat(runtime): track upstream response headers in logging and usage reporting

- Added APIs to store, retrieve, and clone upstream response headers in context for detailed logging.
- Updated `RecordAPIResponseMetadata`, `RecordAPIWebsocketHandshake`, and related methods to capture response headers.
- Extended `UsageReporter` to include response headers in published usage records.
- Enhanced payload tests to validate response headers' integrity and persistence.
- Refactored `usage.Record` to support optional `ResponseHeaders` field.

internal/logging/requestmeta.go

@@ -2,16 +2,24 @@ package logging
 
 import (
 	"context"
+	"net/http"
+	"sync"
 	"sync/atomic"
 )
 
 type endpointKey struct{}
 type responseStatusKey struct{}
+type responseHeadersKey struct{}
 
 type responseStatusHolder struct {
 	status atomic.Int32
 }
 
+type responseHeadersHolder struct {
+	mu      sync.RWMutex
+	headers http.Header
+}
+
 func WithEndpoint(ctx context.Context, endpoint string) context.Context {
 	if ctx == nil {
 		ctx = context.Background()
@@ -39,6 +47,16 @@ func WithResponseStatusHolder(ctx context.Context) context.Context {
 	return context.WithValue(ctx, responseStatusKey{}, &responseStatusHolder{})
 }
 
+func WithResponseHeadersHolder(ctx context.Context) context.Context {
+	if ctx == nil {
+		ctx = context.Background()
+	}
+	if holder, ok := ctx.Value(responseHeadersKey{}).(*responseHeadersHolder); ok && holder != nil {
+		return ctx
+	}
+	return context.WithValue(ctx, responseHeadersKey{}, &responseHeadersHolder{})
+}
+
 func SetResponseStatus(ctx context.Context, status int) {
 	if ctx == nil || status <= 0 {
 		return
@@ -50,6 +68,19 @@ func SetResponseStatus(ctx context.Context, status int) {
 	holder.status.Store(int32(status))
 }
 
+func SetResponseHeaders(ctx context.Context, headers http.Header) {
+	if ctx == nil {
+		return
+	}
+	holder, ok := ctx.Value(responseHeadersKey{}).(*responseHeadersHolder)
+	if !ok || holder == nil {
+		return
+	}
+	holder.mu.Lock()
+	defer holder.mu.Unlock()
+	holder.headers = cloneHTTPHeader(headers)
+}
+
 func GetResponseStatus(ctx context.Context) int {
 	if ctx == nil {
 		return 0
@@ -60,3 +91,27 @@ func GetResponseStatus(ctx context.Context) int {
 	}
 	return int(holder.status.Load())
 }
+
+func GetResponseHeaders(ctx context.Context) http.Header {
+	if ctx == nil {
+		return nil
+	}
+	holder, ok := ctx.Value(responseHeadersKey{}).(*responseHeadersHolder)
+	if !ok || holder == nil {
+		return nil
+	}
+	holder.mu.RLock()
+	defer holder.mu.RUnlock()
+	return cloneHTTPHeader(holder.headers)
+}
+
+func cloneHTTPHeader(src http.Header) http.Header {
+	if len(src) == 0 {
+		return nil
+	}
+	dst := make(http.Header, len(src))
+	for key, values := range src {
+		dst[key] = append([]string(nil), values...)
+	}
+	return dst
+}

internal/redisqueue/plugin.go

@@ -3,6 +3,7 @@ package redisqueue
 import (
 	"context"
 	"encoding/json"
+	"net/http"
 	"strings"
 	"time"
 
@@ -78,6 +79,7 @@ func (p *usageQueuePlugin) HandleUsage(ctx context.Context, record coreusage.Rec
 		Tokens:          tokens,
 		Failed:          failed,
 		Fail:            fail,
+		ResponseHeaders: record.ResponseHeaders,
 	}
 
 	payload, err := json.Marshal(queuedUsageDetail{
@@ -115,6 +117,7 @@ type requestDetail struct {
 	Tokens          tokenStats  `json:"tokens"`
 	Failed          bool        `json:"failed"`
 	Fail            failDetail  `json:"fail"`
+	ResponseHeaders http.Header `json:"response_headers,omitempty"`
 }
 
 type tokenStats struct {

internal/redisqueue/plugin_test.go

@@ -19,6 +19,9 @@ func TestUsageQueuePluginPayloadIncludesStableFieldsAndSuccess(t *testing.T) {
 		ctx = internallogging.WithEndpoint(ctx, "POST /v1/chat/completions")
 		ctx = internallogging.WithResponseStatusHolder(ctx)
 		internallogging.SetResponseStatus(ctx, http.StatusOK)
+		responseHeaders := http.Header{}
+		responseHeaders.Add("X-Upstream-Request-Id", "upstream-req-1")
+		responseHeaders.Add("Retry-After", "30")
 
 		plugin := &usageQueuePlugin{}
 		plugin.HandleUsage(ctx, coreusage.Record{
@@ -36,7 +39,9 @@ func TestUsageQueuePluginPayloadIncludesStableFieldsAndSuccess(t *testing.T) {
 				OutputTokens: 20,
 				TotalTokens:  30,
 			},
+			ResponseHeaders: responseHeaders.Clone(),
 		})
+		responseHeaders.Set("Retry-After", "999")
 
 		payload := popSinglePayload(t)
 		requireStringField(t, payload, "provider", "openai")
@@ -46,11 +51,57 @@ func TestUsageQueuePluginPayloadIncludesStableFieldsAndSuccess(t *testing.T) {
 		requireStringField(t, payload, "auth_type", "apikey")
 		requireMissingField(t, payload, "user_api_key")
 		requireStringField(t, payload, "request_id", "ctx-request-id")
+		requireHeaderField(t, payload, "response_headers", "X-Upstream-Request-Id", []string{"upstream-req-1"})
+		requireHeaderField(t, payload, "response_headers", "Retry-After", []string{"30"})
 		requireBoolField(t, payload, "failed", false)
 		requireFailField(t, payload, http.StatusOK, "")
 	})
 }
 
+func TestUsageQueuePluginAsyncUsesRecordResponseHeaders(t *testing.T) {
+	withEnabledQueue(t, func() {
+		ctx := internallogging.WithRequestID(context.Background(), "ctx-request-id")
+		ctx = internallogging.WithEndpoint(ctx, "POST /v1/chat/completions")
+		ctx = internallogging.WithResponseStatusHolder(ctx)
+		ctx = internallogging.WithResponseHeadersHolder(ctx)
+		internallogging.SetResponseStatus(ctx, http.StatusOK)
+		initialHeaders := http.Header{}
+		initialHeaders.Set("X-Upstream-Request-Id", "upstream-req-1")
+		internallogging.SetResponseHeaders(ctx, initialHeaders)
+
+		mgr := coreusage.NewManager(16)
+		defer mgr.Stop()
+
+		mgr.Register(pluginFunc(func(ctx context.Context, _ coreusage.Record) {
+			nextHeaders := http.Header{}
+			nextHeaders.Set("X-Upstream-Request-Id", "upstream-req-2")
+			internallogging.SetResponseHeaders(ctx, nextHeaders)
+		}))
+		mgr.Register(&usageQueuePlugin{})
+
+		mgr.Publish(ctx, coreusage.Record{
+			Provider:    "openai",
+			Model:       "gpt-5.4",
+			Alias:       "client-gpt",
+			APIKey:      "test-key",
+			AuthIndex:   "0",
+			AuthType:    "apikey",
+			Source:      "user@example.com",
+			RequestedAt: time.Date(2026, 4, 25, 0, 0, 0, 0, time.UTC),
+			Latency:     1500 * time.Millisecond,
+			Detail: coreusage.Detail{
+				InputTokens:  10,
+				OutputTokens: 20,
+				TotalTokens:  30,
+			},
+			ResponseHeaders: internallogging.GetResponseHeaders(ctx),
+		})
+
+		payload := waitForSinglePayload(t, 2*time.Second)
+		requireHeaderField(t, payload, "response_headers", "X-Upstream-Request-Id", []string{"upstream-req-1"})
+	})
+}
+
 func TestUsageQueuePluginPayloadIncludesStableFieldsAndFailureAndGinRequestID(t *testing.T) {
 	withEnabledQueue(t, func() {
 		ctx := internallogging.WithRequestID(context.Background(), "gin-request-id")
@@ -276,3 +327,28 @@ func requireFailField(t *testing.T, payload map[string]json.RawMessage, wantStat
 		t.Fatalf("fail = {status_code:%d body:%q}, want {status_code:%d body:%q}", got.StatusCode, got.Body, wantStatus, wantBody)
 	}
 }
+
+func requireHeaderField(t *testing.T, payload map[string]json.RawMessage, field, key string, want []string) {
+	t.Helper()
+
+	raw, ok := payload[field]
+	if !ok {
+		t.Fatalf("payload missing %q", field)
+	}
+	var headers map[string][]string
+	if err := json.Unmarshal(raw, &headers); err != nil {
+		t.Fatalf("unmarshal %q: %v", field, err)
+	}
+	got, ok := headers[key]
+	if !ok {
+		t.Fatalf("%s missing header %q", field, key)
+	}
+	if len(got) != len(want) {
+		t.Fatalf("%s[%q] = %v, want %v", field, key, got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("%s[%q] = %v, want %v", field, key, got, want)
+		}
+	}
+}

internal/runtime/executor/helps/logging_helpers.go

@@ -102,6 +102,7 @@ func RecordAPIRequest(ctx context.Context, cfg *config.Config, info UpstreamRequ
 
 // RecordAPIResponseMetadata captures upstream response status/header information for the latest attempt.
 func RecordAPIResponseMetadata(ctx context.Context, cfg *config.Config, status int, headers http.Header) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}
@@ -227,6 +228,7 @@ func RecordAPIWebsocketRequest(ctx context.Context, cfg *config.Config, info Ups
 
 // RecordAPIWebsocketHandshake stores the upstream websocket handshake response metadata.
 func RecordAPIWebsocketHandshake(ctx context.Context, cfg *config.Config, status int, headers http.Header) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}
@@ -250,6 +252,7 @@ func RecordAPIWebsocketHandshake(ctx context.Context, cfg *config.Config, status
 
 // RecordAPIWebsocketUpgradeRejection stores a rejected websocket upgrade as an HTTP attempt.
 func RecordAPIWebsocketUpgradeRejection(ctx context.Context, cfg *config.Config, info UpstreamRequestLog, status int, headers http.Header, body []byte) {
+	logging.SetResponseHeaders(ctx, headers)
 	if cfg == nil || !cfg.RequestLog {
 		return
 	}

internal/runtime/executor/helps/logging_helpers_test.go

@@ -0,0 +1,24 @@
+package helps
+
+import (
+	"context"
+	"net/http"
+	"testing"
+
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/config"
+	"github.com/router-for-me/CLIProxyAPI/v7/internal/logging"
+)
+
+func TestRecordAPIResponseMetadataStoresHeadersWhenRequestLogDisabled(t *testing.T) {
+	ctx := logging.WithResponseHeadersHolder(context.Background())
+	headers := http.Header{}
+	headers.Add("X-Upstream-Request-Id", "upstream-req-1")
+
+	RecordAPIResponseMetadata(ctx, &config.Config{}, http.StatusOK, headers)
+	headers.Set("X-Upstream-Request-Id", "mutated")
+
+	got := logging.GetResponseHeaders(ctx)
+	if got.Get("X-Upstream-Request-Id") != "upstream-req-1" {
+		t.Fatalf("response header = %q, want %q", got.Get("X-Upstream-Request-Id"), "upstream-req-1")
+	}
+}

internal/runtime/executor/helps/usage_helpers.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gin-gonic/gin"
+	internallogging "github.com/router-for-me/CLIProxyAPI/v7/internal/logging"
 	cliproxyauth "github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/auth"
 	"github.com/router-for-me/CLIProxyAPI/v7/sdk/cliproxy/usage"
 	"github.com/tidwall/gjson"
@@ -60,7 +61,7 @@ func (r *UsageReporter) PublishAdditionalModel(ctx context.Context, model string
 	if !ok {
 		return
 	}
-	usage.PublishRecord(ctx, record)
+	r.publishRecord(ctx, record)
 }
 
 func (r *UsageReporter) buildAdditionalModelRecord(model string, detail usage.Detail) (usage.Record, bool) {
@@ -97,7 +98,7 @@ func (r *UsageReporter) publishWithOutcome(ctx context.Context, detail usage.Det
 	}
 	detail = normalizeUsageDetailTotal(detail)
 	r.once.Do(func() {
-		usage.PublishRecord(ctx, r.buildRecord(detail, failed, fail))
+		r.publishRecord(ctx, r.buildRecord(detail, failed, fail))
 	})
 }
 
@@ -130,10 +131,15 @@ func (r *UsageReporter) EnsurePublished(ctx context.Context) {
 		return
 	}
 	r.once.Do(func() {
-		usage.PublishRecord(ctx, r.buildRecord(usage.Detail{}, false, usage.Failure{}))
+		r.publishRecord(ctx, r.buildRecord(usage.Detail{}, false, usage.Failure{}))
 	})
 }
 
+func (r *UsageReporter) publishRecord(ctx context.Context, record usage.Record) {
+	record.ResponseHeaders = internallogging.GetResponseHeaders(ctx)
+	usage.PublishRecord(ctx, record)
+}
+
 func (r *UsageReporter) buildRecord(detail usage.Detail, failed bool, failures ...usage.Failure) usage.Record {
 	var fail usage.Failure
 	if len(failures) > 0 {

sdk/api/handlers/handlers.go

@@ -400,6 +400,7 @@ func (h *BaseAPIHandler) GetContextWithCancel(handler interfaces.APIHandler, c *
 		newCtx = logging.WithEndpoint(newCtx, endpoint)
 	}
 	newCtx = logging.WithResponseStatusHolder(newCtx)
+	newCtx = logging.WithResponseHeadersHolder(newCtx)
 
 	cancelCtx := newCtx
 	if requestCtx != nil && requestCtx != parentCtx {

sdk/cliproxy/usage/manager.go

@@ -2,6 +2,7 @@ package usage
 
 import (
 	"context"
+	"net/http"
 	"strings"
 	"sync"
 	"time"
@@ -24,6 +25,8 @@ type Record struct {
 	Failed      bool
 	Fail        Failure
 	Detail      Detail
+	// ResponseHeaders stores a snapshot of upstream response headers for usage sinks.
+	ResponseHeaders http.Header
 }
 
 // Failure holds HTTP failure metadata for an upstream request attempt.