Refactor Activity Page (#710)

- inference handles to store an activity record for all inference endpoints
- add path, status code, and content type to Activities page
- toggle on/off columns no Activities page 
- add configurable capture level for inference endpoints so large binary blobs are not stored in memory
- store captures in compressed binary format

proxy/cache/cache.go

@@ -0,0 +1,102 @@
+package cache
+
+import (
+	"errors"
+	"sync"
+)
+
+var (
+	ErrExceedsMaxSize = errors.New("item exceeds maximum cache size")
+	ErrNotFound       = errors.New("item not found")
+)
+
+type Cache struct {
+	mu      sync.Mutex
+	items   map[int][]byte
+	order   []int
+	size    int
+	maxSize int
+}
+
+func New(maxBytes int) *Cache {
+	return &Cache{
+		items:   make(map[int][]byte),
+		order:   make([]int, 0),
+		maxSize: maxBytes,
+	}
+}
+
+func (c *Cache) Add(id int, data []byte) error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	dataSize := len(data)
+	if dataSize > c.maxSize {
+		return ErrExceedsMaxSize
+	}
+
+	// If key already exists, remove old entry from size and order
+	if old, exists := c.items[id]; exists {
+		c.size -= len(old)
+		c.removeOrder(id)
+	}
+
+	// Evict oldest (FIFO) until room available
+	for c.size+dataSize > c.maxSize && len(c.order) > 0 {
+		oldestID := c.order[0]
+		c.order = c.order[1:]
+		if evicted, exists := c.items[oldestID]; exists {
+			c.size -= len(evicted)
+			delete(c.items, oldestID)
+		}
+	}
+
+	c.items[id] = data
+	c.order = append(c.order, id)
+	c.size += dataSize
+	return nil
+}
+
+func (c *Cache) removeOrder(id int) {
+	for i, v := range c.order {
+		if v == id {
+			c.order = append(c.order[:i], c.order[i+1:]...)
+			return
+		}
+	}
+}
+
+func (c *Cache) Get(id int) ([]byte, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	data, exists := c.items[id]
+	if !exists {
+		return nil, ErrNotFound
+	}
+	return data, nil
+}
+
+func (c *Cache) Has(id int) bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	_, exists := c.items[id]
+	return exists
+}
+
+func (c *Cache) Size() int {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	return c.size
+}
+
+func (c *Cache) Clear() {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.items = make(map[int][]byte)
+	c.order = c.order[:0]
+	c.size = 0
+}

proxy/cache/cache_test.go

@@ -0,0 +1,130 @@
+package cache
+
+import (
+	"sync"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCache_Add(t *testing.T) {
+	t.Run("adds and retrieves item", func(t *testing.T) {
+		c := New(1024)
+		data := []byte("hello")
+		require.NoError(t, c.Add(1, data))
+
+		got, err := c.Get(1)
+		require.NoError(t, err)
+		assert.Equal(t, data, got)
+	})
+
+	t.Run("returns error for oversized item", func(t *testing.T) {
+		c := New(10)
+		err := c.Add(1, make([]byte, 20))
+		assert.ErrorIs(t, err, ErrExceedsMaxSize)
+	})
+
+	t.Run("evicts oldest items to make room", func(t *testing.T) {
+		c := New(100)
+
+		require.NoError(t, c.Add(1, make([]byte, 40)))
+		require.NoError(t, c.Add(2, make([]byte, 40)))
+		// Adding item 3 should evict item 1
+		require.NoError(t, c.Add(3, make([]byte, 40)))
+
+		assert.False(t, c.Has(1))
+		assert.True(t, c.Has(2))
+		assert.True(t, c.Has(3))
+	})
+
+	t.Run("overwrites existing key", func(t *testing.T) {
+		c := New(100)
+		require.NoError(t, c.Add(1, []byte("old")))
+		require.NoError(t, c.Add(1, []byte("new")))
+
+		got, err := c.Get(1)
+		require.NoError(t, err)
+		assert.Equal(t, []byte("new"), got)
+		assert.Equal(t, 3, c.Size())
+	})
+}
+
+func TestCache_Get(t *testing.T) {
+	t.Run("returns ErrNotFound for missing key", func(t *testing.T) {
+		c := New(100)
+		_, err := c.Get(99)
+		assert.ErrorIs(t, err, ErrNotFound)
+	})
+}
+
+func TestCache_Has(t *testing.T) {
+	t.Run("returns true for existing key", func(t *testing.T) {
+		c := New(100)
+		require.NoError(t, c.Add(1, []byte("data")))
+		assert.True(t, c.Has(1))
+	})
+
+	t.Run("returns false for missing key", func(t *testing.T) {
+		c := New(100)
+		assert.False(t, c.Has(1))
+	})
+}
+
+func TestCache_Size(t *testing.T) {
+	t.Run("tracks byte usage", func(t *testing.T) {
+		c := New(1000)
+		assert.Equal(t, 0, c.Size())
+
+		require.NoError(t, c.Add(1, make([]byte, 100)))
+		assert.Equal(t, 100, c.Size())
+
+		require.NoError(t, c.Add(2, make([]byte, 200)))
+		assert.Equal(t, 300, c.Size())
+	})
+
+	t.Run("updates on eviction", func(t *testing.T) {
+		c := New(150)
+		require.NoError(t, c.Add(1, make([]byte, 100)))
+		require.NoError(t, c.Add(2, make([]byte, 100)))
+
+		// Item 1 should be evicted, size = 100
+		assert.Equal(t, 100, c.Size())
+	})
+}
+
+func TestCache_Clear(t *testing.T) {
+	t.Run("removes all items and resets size", func(t *testing.T) {
+		c := New(1000)
+		require.NoError(t, c.Add(1, []byte("a")))
+		require.NoError(t, c.Add(2, []byte("b")))
+
+		c.Clear()
+
+		assert.Equal(t, 0, c.Size())
+		assert.False(t, c.Has(1))
+		assert.False(t, c.Has(2))
+	})
+}
+
+func TestCache_Concurrent(t *testing.T) {
+	t.Run("concurrent operations are safe", func(t *testing.T) {
+		c := New(10000)
+
+		var wg sync.WaitGroup
+		for i := 0; i < 10; i++ {
+			wg.Add(1)
+			go func(id int) {
+				defer wg.Done()
+				for j := 0; j < 100; j++ {
+					key := id*100 + j
+					_ = c.Add(key, []byte("data"))
+					_, _ = c.Get(key)
+					_ = c.Has(key)
+					_ = c.Size()
+				}
+			}(i)
+		}
+		wg.Wait()
+	})
+}

proxy/events.go

@@ -6,7 +6,7 @@ const ProcessStateChangeEventID = 0x01
 const ChatCompletionStatsEventID = 0x02
 const ConfigFileChangedEventID = 0x03
 const LogDataEventID = 0x04
-const TokenMetricsEventID = 0x05
+const ActivityLogEventID = 0x05
 const ModelPreloadedEventID = 0x06
 const InFlightRequestsEventID = 0x07
 

proxy/metrics_monitor.go

@@ -12,9 +12,11 @@ import (
 	"sync"
 	"time"
 
+	"github.com/fxamacker/cbor/v2"
 	"github.com/gin-gonic/gin"
 	"github.com/klauspost/compress/zstd"
 	"github.com/mostlygeek/llama-swap/event"
+	"github.com/mostlygeek/llama-swap/proxy/cache"
 	"github.com/tidwall/gjson"
 )
 
@@ -42,37 +44,53 @@ var zstdDecPool = &sync.Pool{
 	},
 }
 
-// compressCapture marshals a ReqRespCapture to JSON and compresses it with zstd.
-// Returns compressed bytes and the original JSON byte count for logging.
+// compressCapture marshals a ReqRespCapture to CBOR and compresses it with zstd.
+// Returns compressed bytes and the original CBOR byte count for logging.
 func compressCapture(c *ReqRespCapture) ([]byte, int, error) {
-	jsonBytes, err := json.Marshal(c)
+	cborBytes, err := cbor.Marshal(c)
 	if err != nil {
 		return nil, 0, fmt.Errorf("marshal capture: %w", err)
 	}
-	enc := zstdEncPool.Get().(*zstd.Encoder)
-	defer zstdEncPool.Put(enc)
-	return enc.EncodeAll(jsonBytes, nil), len(jsonBytes), nil
+	zenc := zstdEncPool.Get().(*zstd.Encoder)
+	defer zstdEncPool.Put(zenc)
+	return zenc.EncodeAll(cborBytes, nil), len(cborBytes), nil
 }
 
-// decompressCapture decompresses zstd-compressed JSON and returns it.
-func decompressCapture(data []byte) ([]byte, error) {
+// decompressCapture decompresses zstd-compressed CBOR and unmarshals it into a ReqRespCapture.
+func decompressCapture(data []byte) (*ReqRespCapture, error) {
 	dec := zstdDecPool.Get().(*zstd.Decoder)
 	defer zstdDecPool.Put(dec)
-	return dec.DecodeAll(data, nil)
+	cborBytes, err := dec.DecodeAll(data, nil)
+	if err != nil {
+		return nil, fmt.Errorf("decompress capture: %w", err)
+	}
+	var capture ReqRespCapture
+	if err := cbor.Unmarshal(cborBytes, &capture); err != nil {
+		return nil, fmt.Errorf("unmarshal capture: %w", err)
+	}
+	return &capture, nil
 }
 
-// TokenMetrics represents parsed token statistics from llama-server logs
+// TokenMetrics holds token usage and performance metrics
 type TokenMetrics struct {
-	ID              int       `json:"id"`
-	Timestamp       time.Time `json:"timestamp"`
-	Model           string    `json:"model"`
-	CachedTokens    int       `json:"cache_tokens"`
-	InputTokens     int       `json:"input_tokens"`
-	OutputTokens    int       `json:"output_tokens"`
-	PromptPerSecond float64   `json:"prompt_per_second"`
-	TokensPerSecond float64   `json:"tokens_per_second"`
-	DurationMs      int       `json:"duration_ms"`
-	HasCapture      bool      `json:"has_capture"`
+	CachedTokens    int     `json:"cache_tokens"`
+	InputTokens     int     `json:"input_tokens"`
+	OutputTokens    int     `json:"output_tokens"`
+	PromptPerSecond float64 `json:"prompt_per_second"`
+	TokensPerSecond float64 `json:"tokens_per_second"`
+}
+
+// ActivityLogEntry represents parsed token statistics from llama-server logs
+type ActivityLogEntry struct {
+	ID              int          `json:"id"`
+	Timestamp       time.Time    `json:"timestamp"`
+	Model           string       `json:"model"`
+	ReqPath         string       `json:"req_path"`
+	RespContentType string       `json:"resp_content_type"`
+	RespStatusCode  int          `json:"resp_status_code"`
+	Tokens          TokenMetrics `json:"tokens"`
+	DurationMs      int          `json:"duration_ms"`
+	HasCapture      bool         `json:"has_capture"`
 }
 
 type ReqRespCapture struct {
@@ -84,48 +102,45 @@ type ReqRespCapture struct {
 	RespBody    []byte            `json:"resp_body"`
 }
 
-// TokenMetricsEvent represents a token metrics event
-type TokenMetricsEvent struct {
-	Metrics TokenMetrics
+// ActivityLogEvent represents a token metrics event
+type ActivityLogEvent struct {
+	Metrics ActivityLogEntry
 }
 
-func (e TokenMetricsEvent) Type() uint32 {
-	return TokenMetricsEventID // defined in events.go
+func (e ActivityLogEvent) Type() uint32 {
+	return ActivityLogEventID // defined in events.go
 }
 
 // metricsMonitor parses llama-server output for token statistics
 type metricsMonitor struct {
 	mu         sync.RWMutex
-	metrics    []TokenMetrics
+	metrics    []ActivityLogEntry
 	maxMetrics int
 	nextID     int
 	logger     *LogMonitor
 
 	// capture fields
 	enableCaptures bool
-	captures       map[int][]byte // zstd-compressed JSON of ReqRespCapture
-	captureOrder   []int          // track insertion order for FIFO eviction
-	captureSize    int            // current total compressed size in bytes
-	maxCaptureSize int            // max bytes for captures (uncompressed)
+	captureCache   *cache.Cache // zstd-compressed CBOR of ReqRespCapture
 }
 
 // newMetricsMonitor creates a new metricsMonitor. captureBufferMB is the
 // capture buffer size in megabytes; 0 disables captures.
 func newMetricsMonitor(logger *LogMonitor, maxMetrics int, captureBufferMB int) *metricsMonitor {
-	return &metricsMonitor{
+	mm := &metricsMonitor{
 		logger:         logger,
 		maxMetrics:     maxMetrics,
 		enableCaptures: captureBufferMB > 0,
-		captures:       make(map[int][]byte),
-		captureOrder:   make([]int, 0),
-		captureSize:    0,
-		maxCaptureSize: captureBufferMB * 1024 * 1024,
 	}
+	if captureBufferMB > 0 {
+		mm.captureCache = cache.New(captureBufferMB * 1024 * 1024)
+	}
+	return mm
 }
 
-// addMetrics adds a new metric to the collection and publishes an event.
-// Returns the assigned metric ID.
-func (mp *metricsMonitor) addMetrics(metric TokenMetrics) int {
+// queueMetrics adds a new metric to the collection without emitting an event.
+// Returns the assigned metric ID. Call emitMetric after capture setup.
+func (mp *metricsMonitor) queueMetrics(metric ActivityLogEntry) int {
 	mp.mu.Lock()
 	defer mp.mu.Unlock()
 
@@ -135,93 +150,75 @@ func (mp *metricsMonitor) addMetrics(metric TokenMetrics) int {
 	if len(mp.metrics) > mp.maxMetrics {
 		mp.metrics = mp.metrics[len(mp.metrics)-mp.maxMetrics:]
 	}
-	event.Emit(TokenMetricsEvent{Metrics: metric})
 	return metric.ID
 }
 
-// addCapture adds a new capture to the buffer with size-based eviction.
-// Captures are skipped if enableCaptures is false or if compressed data exceeds maxCaptureSize.
-func (mp *metricsMonitor) addCapture(capture ReqRespCapture) {
+// emitMetric publishes an ActivityLogEvent for the given metric.
+func (mp *metricsMonitor) emitMetric(metric ActivityLogEntry) {
+	event.Emit(ActivityLogEvent{Metrics: metric})
+}
+
+// addCapture compresses and stores a capture in the cache.
+// Returns true if the capture was stored, false otherwise.
+func (mp *metricsMonitor) addCapture(capture ReqRespCapture) bool {
 	if !mp.enableCaptures {
-		return
+		return false
 	}
 
 	compressed, uncompressedBytes, err := compressCapture(&capture)
 	if err != nil {
 		mp.logger.Warnf("failed to compress capture: %v, skipping", err)
-		return
+		return false
 	}
 
-	captureSize := len(compressed)
-	if captureSize > mp.maxCaptureSize {
-		mp.logger.Warnf("compressed capture size %d exceeds max %d, skipping", captureSize, mp.maxCaptureSize)
-		return
+	if err := mp.captureCache.Add(capture.ID, compressed); err != nil {
+		mp.logger.Warnf("capture %d too large (%d bytes), skipping: %v", capture.ID, len(compressed), err)
+		return false
 	}
 
-	compressionRatio := (1 - float64(captureSize)/float64(uncompressedBytes)) * 100
-
-	mp.mu.Lock()
-	defer mp.mu.Unlock()
-
-	// Evict oldest (FIFO) until room available for the compressed data
-	for mp.captureSize+captureSize > mp.maxCaptureSize && len(mp.captureOrder) > 0 {
-		oldestID := mp.captureOrder[0]
-		mp.captureOrder = mp.captureOrder[1:]
-		if evicted, exists := mp.captures[oldestID]; exists {
-			l := len(evicted)
-			mp.captureSize -= l
-			delete(mp.captures, oldestID)
-			mp.logger.Debugf("Capture %d evicted to make space: %d bytes", oldestID, l)
-		}
-	}
-
-	mp.captures[capture.ID] = compressed
-	mp.captureOrder = append(mp.captureOrder, capture.ID)
-	mp.captureSize += captureSize
-
+	compressionRatio := (1 - float64(len(compressed))/float64(uncompressedBytes)) * 100
 	mp.logger.Debugf("Capture %d compressed and saved: %d bytes -> %d bytes (%.1f%% compression)", capture.ID, uncompressedBytes, len(compressed), compressionRatio)
+	return true
 }
 
 // getCompressedBytes returns the raw compressed bytes for a capture by ID.
 func (mp *metricsMonitor) getCompressedBytes(id int) ([]byte, bool) {
-	mp.mu.RLock()
-	defer mp.mu.RUnlock()
-
-	data, exists := mp.captures[id]
-	return data, exists
+	if mp.captureCache == nil {
+		return nil, false
+	}
+	data, err := mp.captureCache.Get(id)
+	if err != nil {
+		return nil, false
+	}
+	return data, true
 }
 
-// getCaptureByID returns decompressed capture bytes if found and decompress=true.
-// If decompress=false, returns the raw zstd-compressed bytes.
-// Returns nil if the capture is not found.
-func (mp *metricsMonitor) getCaptureByID(id int, decompress bool) []byte {
-	mp.mu.RLock()
-	defer mp.mu.RUnlock()
-
-	data, exists := mp.captures[id]
+// getCaptureByID decompresses and unmarshals a capture by ID.
+// Returns nil if the capture is not found or decompression fails.
+func (mp *metricsMonitor) getCaptureByID(id int) *ReqRespCapture {
+	if mp.captureCache == nil {
+		return nil
+	}
+	data, exists := mp.getCompressedBytes(id)
 	if !exists {
 		return nil
 	}
 
-	if !decompress {
-		return data
-	}
-
-	decompressed, err := decompressCapture(data)
+	capture, err := decompressCapture(data)
 	if err != nil {
 		mp.logger.Warnf("failed to decompress capture %d: %v", id, err)
 		return nil
 	}
 
-	return decompressed
+	return capture
 }
 
 // getMetrics returns a copy of the current metrics
-func (mp *metricsMonitor) getMetrics() []TokenMetrics {
+func (mp *metricsMonitor) getMetrics() []ActivityLogEntry {
 	mp.mu.RLock()
 	defer mp.mu.RUnlock()
 
-	result := make([]TokenMetrics, len(mp.metrics))
+	result := make([]ActivityLogEntry, len(mp.metrics))
 	copy(result, mp.metrics)
 	return result
 }
@@ -230,22 +227,52 @@ func (mp *metricsMonitor) getMetrics() []TokenMetrics {
 func (mp *metricsMonitor) getMetricsJSON() ([]byte, error) {
 	mp.mu.RLock()
 	defer mp.mu.RUnlock()
-	return json.Marshal(mp.metrics)
+
+	if mp.captureCache == nil {
+		return json.Marshal(mp.metrics)
+	}
+
+	// Make a copy with up-to-date has_capture from cache
+	result := make([]ActivityLogEntry, len(mp.metrics))
+	for i, m := range mp.metrics {
+		m.HasCapture = mp.captureCache.Has(m.ID)
+		result[i] = m
+	}
+	return json.Marshal(result)
 }
 
-// wrapHandler wraps the proxy handler to extract token metrics
+// Capture field flags for controlling what is saved in ReqRespCapture.
+type captureFields uint
+
+const (
+	captureNone captureFields = 1 << iota
+	captureReqHeaders
+	captureReqBody
+	captureRespHeaders
+	captureRespBody
+)
+
+const (
+	captureReqAll  = captureReqHeaders | captureReqBody
+	captureRespAll = captureRespHeaders | captureRespBody
+	captureAll     = captureReqAll | captureRespAll
+)
+
+// wrapHandler wraps the proxy handler to extract token metrics.
+// captureFields controls what is saved in the ReqRespCapture using bitwise flags.
 // if wrapHandler returns an error it is safe to assume that no
 // data was sent to the client
 func (mp *metricsMonitor) wrapHandler(
 	modelID string,
 	writer gin.ResponseWriter,
 	request *http.Request,
+	captureFields captureFields,
 	next func(modelID string, w http.ResponseWriter, r *http.Request) error,
 ) error {
 	// Capture request body and headers if captures enabled
 	var reqBody []byte
 	var reqHeaders map[string]string
-	if mp.enableCaptures {
+	if mp.enableCaptures && (captureFields&captureReqBody) != 0 {
 		if request.Body != nil {
 			var err error
 			reqBody, err = io.ReadAll(request.Body)
@@ -255,6 +282,8 @@ func (mp *metricsMonitor) wrapHandler(
 			request.Body.Close()
 			request.Body = io.NopCloser(bytes.NewBuffer(reqBody))
 		}
+	}
+	if mp.enableCaptures && (captureFields&captureReqHeaders) != 0 {
 		reqHeaders = make(map[string]string)
 		for key, values := range request.Header {
 			if len(values) > 0 {
@@ -278,22 +307,28 @@ func (mp *metricsMonitor) wrapHandler(
 	// after this point we have to assume that data was sent to the client
 	// and we can only log errors but not send them to clients
 
-	if recorder.Status() != http.StatusOK {
-		mp.logger.Warnf("metrics skipped, HTTP status=%d, path=%s", recorder.Status(), request.URL.Path)
-		return nil
+	// Initialize default metrics - recorded for every request
+	tm := ActivityLogEntry{
+		Timestamp:       time.Now(),
+		Model:           modelID,
+		ReqPath:         request.URL.Path,
+		RespContentType: recorder.Header().Get("Content-Type"),
+		RespStatusCode:  recorder.Status(),
+		DurationMs:      int(time.Since(recorder.StartTime()).Milliseconds()),
 	}
 
-	// Initialize default metrics - these will always be recorded
-	tm := TokenMetrics{
-		Timestamp:  time.Now(),
-		Model:      modelID,
-		DurationMs: int(time.Since(recorder.StartTime()).Milliseconds()),
+	if recorder.Status() != http.StatusOK {
+		mp.logger.Warnf("non-200 response, recording partial metrics: status=%d, path=%s", recorder.Status(), request.URL.Path)
+		tm.ID = mp.queueMetrics(tm)
+		mp.emitMetric(tm)
+		return nil
 	}
 
 	body := recorder.body.Bytes()
 	if len(body) == 0 {
 		mp.logger.Warn("metrics: empty body, recording minimal metrics")
-		mp.addMetrics(tm)
+		tm.ID = mp.queueMetrics(tm)
+		mp.emitMetric(tm)
 		return nil
 	}
 
@@ -303,7 +338,8 @@ func (mp *metricsMonitor) wrapHandler(
 		body, err = decompressBody(body, encoding)
 		if err != nil {
 			mp.logger.Warnf("metrics: decompression failed: %v, path=%s, recording minimal metrics", err, request.URL.Path)
-			mp.addMetrics(tm)
+			tm.ID = mp.queueMetrics(tm)
+			mp.emitMetric(tm)
 			return nil
 		}
 	}
@@ -311,7 +347,8 @@ func (mp *metricsMonitor) wrapHandler(
 		if parsed, err := processStreamingResponse(modelID, recorder.StartTime(), body); err != nil {
 			mp.logger.Warnf("error processing streaming response: %v, path=%s, recording minimal metrics", err, request.URL.Path)
 		} else {
-			tm = parsed
+			tm.Tokens = parsed.Tokens
+			tm.DurationMs = parsed.DurationMs
 		}
 	} else {
 		if gjson.ValidBytes(body) {
@@ -331,7 +368,8 @@ func (mp *metricsMonitor) wrapHandler(
 				if parsedMetrics, err := parseMetrics(modelID, recorder.StartTime(), usage, timings); err != nil {
 					mp.logger.Warnf("error parsing metrics: %v, path=%s, recording minimal metrics", err, request.URL.Path)
 				} else {
-					tm = parsedMetrics
+					tm.Tokens = parsedMetrics.Tokens
+					tm.DurationMs = parsedMetrics.DurationMs
 				}
 			}
 		} else {
@@ -342,39 +380,50 @@ func (mp *metricsMonitor) wrapHandler(
 	// Build capture if enabled and determine if it will be stored
 	var capture *ReqRespCapture
 	if mp.enableCaptures {
-		respHeaders := make(map[string]string)
-		for key, values := range recorder.Header() {
-			if len(values) > 0 {
-				respHeaders[key] = values[0]
+		var respHeaders map[string]string
+		var respBody []byte
+		if (captureFields & captureRespHeaders) != 0 {
+			respHeaders = make(map[string]string)
+			for key, values := range recorder.Header() {
+				if len(values) > 0 {
+					respHeaders[key] = values[0]
+				}
 			}
+			redactHeaders(respHeaders)
+			delete(respHeaders, "Content-Encoding")
+		}
+		if (captureFields & captureRespBody) != 0 {
+			respBody = body
 		}
-		redactHeaders(respHeaders)
-		delete(respHeaders, "Content-Encoding")
 		capture = &ReqRespCapture{
 			ReqPath:     request.URL.Path,
 			ReqHeaders:  reqHeaders,
 			ReqBody:     reqBody,
 			RespHeaders: respHeaders,
-			RespBody:    body,
-		}
-		compressed, _, err := compressCapture(capture)
-		if err == nil && len(compressed) <= mp.maxCaptureSize {
-			tm.HasCapture = true
+			RespBody:    respBody,
 		}
 	}
 
-	metricID := mp.addMetrics(tm)
+	metricID := mp.queueMetrics(tm)
+	tm.ID = metricID
 
 	// Store capture if enabled
 	if capture != nil {
 		capture.ID = metricID
-		mp.addCapture(*capture)
+		if mp.addCapture(*capture) {
+			tm.HasCapture = true
+			mp.mu.Lock()
+			mp.metrics[len(mp.metrics)-1].HasCapture = true
+			mp.mu.Unlock()
+		}
 	}
 
+	mp.emitMetric(tm)
+
 	return nil
 }
 
-func processStreamingResponse(modelID string, start time.Time, body []byte) (TokenMetrics, error) {
+func processStreamingResponse(modelID string, start time.Time, body []byte) (ActivityLogEntry, error) {
 	// Iterate **backwards** through the body looking for the data payload with
 	// usage data. This avoids allocating a slice of all lines via bytes.Split.
 
@@ -428,10 +477,10 @@ func processStreamingResponse(modelID string, start time.Time, body []byte) (Tok
 		}
 	}
 
-	return TokenMetrics{}, fmt.Errorf("no valid JSON data found in stream")
+	return ActivityLogEntry{}, fmt.Errorf("no valid JSON data found in stream")
 }
 
-func parseMetrics(modelID string, start time.Time, usage, timings gjson.Result) (TokenMetrics, error) {
+func parseMetrics(modelID string, start time.Time, usage, timings gjson.Result) (ActivityLogEntry, error) {
 	wallDurationMs := int(time.Since(start).Milliseconds())
 
 	// default values
@@ -481,15 +530,17 @@ func parseMetrics(modelID string, start time.Time, usage, timings gjson.Result)
 		}
 	}
 
-	return TokenMetrics{
-		Timestamp:       time.Now(),
-		Model:           modelID,
-		CachedTokens:    cachedTokens,
-		InputTokens:     inputTokens,
-		OutputTokens:    outputTokens,
-		PromptPerSecond: promptPerSecond,
-		TokensPerSecond: tokensPerSecond,
-		DurationMs:      durationMs,
+	return ActivityLogEntry{
+		Timestamp: time.Now(),
+		Model:     modelID,
+		Tokens: TokenMetrics{
+			CachedTokens:    cachedTokens,
+			InputTokens:     inputTokens,
+			OutputTokens:    outputTokens,
+			PromptPerSecond: promptPerSecond,
+			TokensPerSecond: tokensPerSecond,
+		},
+		DurationMs: durationMs,
 	}, nil
 }
 

proxy/metrics_monitor_test.go

@@ -12,8 +12,10 @@ import (
 	"testing"
 	"time"
 
+	"github.com/fxamacker/cbor/v2"
 	"github.com/gin-gonic/gin"
 	"github.com/mostlygeek/llama-swap/event"
+	"github.com/mostlygeek/llama-swap/proxy/cache"
 	"github.com/stretchr/testify/assert"
 	"github.com/tidwall/gjson"
 )
@@ -22,27 +24,29 @@ func TestMetricsMonitor_AddMetrics(t *testing.T) {
 	t.Run("adds metrics and assigns ID", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
 
-		metric := TokenMetrics{
-			Model:        "test-model",
-			InputTokens:  100,
-			OutputTokens: 50,
+		metric := ActivityLogEntry{
+			Model: "test-model",
+			Tokens: TokenMetrics{
+				InputTokens:  100,
+				OutputTokens: 50,
+			},
 		}
 
-		mm.addMetrics(metric)
+		mm.queueMetrics(metric)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, 0, metrics[0].ID)
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("increments ID for each metric", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
 
 		for i := 0; i < 5; i++ {
-			mm.addMetrics(TokenMetrics{Model: "model"})
+			mm.queueMetrics(ActivityLogEntry{Model: "model"})
 		}
 
 		metrics := mm.getMetrics()
@@ -57,9 +61,11 @@ func TestMetricsMonitor_AddMetrics(t *testing.T) {
 
 		// Add 5 metrics
 		for i := 0; i < 5; i++ {
-			mm.addMetrics(TokenMetrics{
-				Model:       "model",
-				InputTokens: i,
+			mm.queueMetrics(ActivityLogEntry{
+				Model: "model",
+				Tokens: TokenMetrics{
+					InputTokens: i,
+				},
 			})
 		}
 
@@ -72,29 +78,32 @@ func TestMetricsMonitor_AddMetrics(t *testing.T) {
 		assert.Equal(t, 4, metrics[2].ID)
 	})
 
-	t.Run("emits TokenMetricsEvent", func(t *testing.T) {
+	t.Run("emits ActivityLogEvent", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
 
-		receivedEvent := make(chan TokenMetricsEvent, 1)
-		cancel := event.On(func(e TokenMetricsEvent) {
+		receivedEvent := make(chan ActivityLogEvent, 1)
+		cancel := event.On(func(e ActivityLogEvent) {
 			receivedEvent <- e
 		})
 		defer cancel()
 
-		metric := TokenMetrics{
-			Model:        "test-model",
-			InputTokens:  100,
-			OutputTokens: 50,
+		metric := ActivityLogEntry{
+			Model: "test-model",
+			Tokens: TokenMetrics{
+				InputTokens:  100,
+				OutputTokens: 50,
+			},
 		}
 
-		mm.addMetrics(metric)
+		mm.queueMetrics(metric)
+		mm.emitMetric(metric)
 
 		select {
 		case evt := <-receivedEvent:
 			assert.Equal(t, 0, evt.Metrics.ID)
 			assert.Equal(t, "test-model", evt.Metrics.Model)
-			assert.Equal(t, 100, evt.Metrics.InputTokens)
-			assert.Equal(t, 50, evt.Metrics.OutputTokens)
+			assert.Equal(t, 100, evt.Metrics.Tokens.InputTokens)
+			assert.Equal(t, 50, evt.Metrics.Tokens.OutputTokens)
 		case <-time.After(1 * time.Second):
 			t.Fatal("timeout waiting for event")
 		}
@@ -111,8 +120,8 @@ func TestMetricsMonitor_GetMetrics(t *testing.T) {
 
 	t.Run("returns copy of metrics", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
-		mm.addMetrics(TokenMetrics{Model: "model1"})
-		mm.addMetrics(TokenMetrics{Model: "model2"})
+		mm.queueMetrics(ActivityLogEntry{Model: "model1"})
+		mm.queueMetrics(ActivityLogEntry{Model: "model2"})
 
 		metrics1 := mm.getMetrics()
 		metrics2 := mm.getMetrics()
@@ -135,7 +144,7 @@ func TestMetricsMonitor_GetMetricsJSON(t *testing.T) {
 		assert.NoError(t, err)
 		assert.NotNil(t, jsonData)
 
-		var metrics []TokenMetrics
+		var metrics []ActivityLogEntry
 		err = json.Unmarshal(jsonData, &metrics)
 		assert.NoError(t, err)
 		assert.Equal(t, 0, len(metrics))
@@ -143,23 +152,27 @@ func TestMetricsMonitor_GetMetricsJSON(t *testing.T) {
 
 	t.Run("returns valid JSON with metrics", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
-		mm.addMetrics(TokenMetrics{
-			Model:           "model1",
-			InputTokens:     100,
-			OutputTokens:    50,
-			TokensPerSecond: 25.5,
+		mm.queueMetrics(ActivityLogEntry{
+			Model: "model1",
+			Tokens: TokenMetrics{
+				InputTokens:     100,
+				OutputTokens:    50,
+				TokensPerSecond: 25.5,
+			},
 		})
-		mm.addMetrics(TokenMetrics{
-			Model:           "model2",
-			InputTokens:     200,
-			OutputTokens:    100,
-			TokensPerSecond: 30.0,
+		mm.queueMetrics(ActivityLogEntry{
+			Model: "model2",
+			Tokens: TokenMetrics{
+				InputTokens:     200,
+				OutputTokens:    100,
+				TokensPerSecond: 30.0,
+			},
 		})
 
 		jsonData, err := mm.getMetricsJSON()
 		assert.NoError(t, err)
 
-		var metrics []TokenMetrics
+		var metrics []ActivityLogEntry
 		err = json.Unmarshal(jsonData, &metrics)
 		assert.NoError(t, err)
 		assert.Equal(t, 2, len(metrics))
@@ -190,14 +203,14 @@ func TestMetricsMonitor_WrapHandler(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("successful request with timings data", func(t *testing.T) {
@@ -226,17 +239,17 @@ func TestMetricsMonitor_WrapHandler(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
-		assert.Equal(t, 20, metrics[0].CachedTokens)
-		assert.Equal(t, 150.5, metrics[0].PromptPerSecond)
-		assert.Equal(t, 25.5, metrics[0].TokensPerSecond)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
+		assert.Equal(t, 20, metrics[0].Tokens.CachedTokens)
+		assert.Equal(t, 150.5, metrics[0].Tokens.PromptPerSecond)
+		assert.Equal(t, 25.5, metrics[0].Tokens.TokensPerSecond)
 		assert.Equal(t, 2000, metrics[0].DurationMs) // 500 + 1500
 	})
 
@@ -265,18 +278,18 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
 		// When timings data is present, it takes precedence
-		assert.Equal(t, 10, metrics[0].InputTokens)
-		assert.Equal(t, 20, metrics[0].OutputTokens)
+		assert.Equal(t, 10, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 20, metrics[0].Tokens.OutputTokens)
 	})
 
-	t.Run("non-OK status code does not record metrics", func(t *testing.T) {
+	t.Run("non-OK status code records partial metrics", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 0)
 
 		nextHandler := func(modelID string, w http.ResponseWriter, r *http.Request) error {
@@ -289,11 +302,16 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
-		assert.Equal(t, 0, len(metrics))
+		assert.Equal(t, 1, len(metrics))
+		assert.Equal(t, "test-model", metrics[0].Model)
+		assert.Equal(t, "/test", metrics[0].ReqPath)
+		assert.Equal(t, http.StatusBadRequest, metrics[0].RespStatusCode)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("empty response body records minimal metrics", func(t *testing.T) {
@@ -308,14 +326,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("invalid JSON records minimal metrics", func(t *testing.T) {
@@ -332,14 +350,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err) // Errors after response is sent are logged, not returned
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("next handler error is propagated", func(t *testing.T) {
@@ -354,7 +372,7 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.Equal(t, expectedErr, err)
 
 		metrics := mm.getMetrics()
@@ -377,14 +395,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("infill request extracts timings from last array element", func(t *testing.T) {
@@ -416,17 +434,17 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 150, metrics[0].InputTokens)
-		assert.Equal(t, 75, metrics[0].OutputTokens)
-		assert.Equal(t, 30, metrics[0].CachedTokens)
-		assert.Equal(t, 200.5, metrics[0].PromptPerSecond)
-		assert.Equal(t, 35.5, metrics[0].TokensPerSecond)
+		assert.Equal(t, 150, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 75, metrics[0].Tokens.OutputTokens)
+		assert.Equal(t, 30, metrics[0].Tokens.CachedTokens)
+		assert.Equal(t, 200.5, metrics[0].Tokens.PromptPerSecond)
+		assert.Equal(t, 35.5, metrics[0].Tokens.TokensPerSecond)
 		assert.Equal(t, 2400, metrics[0].DurationMs) // 600 + 1800
 	})
 
@@ -446,14 +464,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 }
 
@@ -507,7 +525,7 @@ func TestMetricsMonitor_ResponseBodyCopier(t *testing.T) {
 }
 
 func TestMetricsMonitor_Concurrent(t *testing.T) {
-	t.Run("concurrent addMetrics is safe", func(t *testing.T) {
+	t.Run("concurrent queueMetrics is safe", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 1000, 0)
 
 		var wg sync.WaitGroup
@@ -519,10 +537,12 @@ func TestMetricsMonitor_Concurrent(t *testing.T) {
 			go func(id int) {
 				defer wg.Done()
 				for j := 0; j < metricsPerGoroutine; j++ {
-					mm.addMetrics(TokenMetrics{
-						Model:        "test-model",
-						InputTokens:  id*1000 + j,
-						OutputTokens: j,
+					mm.queueMetrics(ActivityLogEntry{
+						Model: "test-model",
+						Tokens: TokenMetrics{
+							InputTokens:  id*1000 + j,
+							OutputTokens: j,
+						},
 					})
 				}
 			}(i)
@@ -542,7 +562,7 @@ func TestMetricsMonitor_Concurrent(t *testing.T) {
 		// Writer goroutine
 		go func() {
 			for i := 0; i < 50; i++ {
-				mm.addMetrics(TokenMetrics{Model: "test-model"})
+				mm.queueMetrics(ActivityLogEntry{Model: "test-model"})
 				time.Sleep(1 * time.Millisecond)
 			}
 			done <- true
@@ -586,10 +606,10 @@ func TestMetricsMonitor_ParseMetrics(t *testing.T) {
 
 		metrics, err := parseMetrics("test-model", start, usage, timings)
 		assert.NoError(t, err)
-		assert.Equal(t, 5, metrics.InputTokens)
-		assert.Equal(t, 1, metrics.OutputTokens)
-		assert.Equal(t, 10.0, metrics.PromptPerSecond)
-		assert.Equal(t, 2.0, metrics.TokensPerSecond)
+		assert.Equal(t, 5, metrics.Tokens.InputTokens)
+		assert.Equal(t, 1, metrics.Tokens.OutputTokens)
+		assert.Equal(t, 10.0, metrics.Tokens.PromptPerSecond)
+		assert.Equal(t, 2.0, metrics.Tokens.TokensPerSecond)
 		assert.GreaterOrEqual(t, metrics.DurationMs, 5000)
 	})
 
@@ -623,14 +643,14 @@ func TestMetricsMonitor_ParseMetrics(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		// Should use timings values, not usage values
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("handles missing cache_n in timings", func(t *testing.T) {
@@ -658,12 +678,12 @@ func TestMetricsMonitor_ParseMetrics(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
-		assert.Equal(t, -1, metrics[0].CachedTokens) // Default value when not present
+		assert.Equal(t, -1, metrics[0].Tokens.CachedTokens) // Default value when not present
 	})
 }
 
@@ -693,13 +713,13 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("handles streaming with no valid JSON records minimal metrics", func(t *testing.T) {
@@ -722,14 +742,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("v1/responses format with nested response.usage", func(t *testing.T) {
@@ -751,14 +771,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 17, metrics[0].InputTokens)
-		assert.Equal(t, 23, metrics[0].OutputTokens)
+		assert.Equal(t, 17, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 23, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("handles empty streaming response records minimal metrics", func(t *testing.T) {
@@ -777,14 +797,14 @@ data: [DONE]
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 }
 
@@ -792,20 +812,22 @@ data: [DONE]
 func BenchmarkMetricsMonitor_AddMetrics(b *testing.B) {
 	mm := newMetricsMonitor(testLogger, 1000, 0)
 
-	metric := TokenMetrics{
-		Model:           "test-model",
-		CachedTokens:    100,
-		InputTokens:     500,
-		OutputTokens:    250,
-		PromptPerSecond: 1200.5,
-		TokensPerSecond: 45.8,
-		DurationMs:      5000,
-		Timestamp:       time.Now(),
+	metric := ActivityLogEntry{
+		Model: "test-model",
+		Tokens: TokenMetrics{
+			CachedTokens:    100,
+			InputTokens:     500,
+			OutputTokens:    250,
+			PromptPerSecond: 1200.5,
+			TokensPerSecond: 45.8,
+		},
+		DurationMs: 5000,
+		Timestamp:  time.Now(),
 	}
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		mm.addMetrics(metric)
+		mm.queueMetrics(metric)
 	}
 }
 
@@ -813,20 +835,22 @@ func BenchmarkMetricsMonitor_AddMetrics_SmallBuffer(b *testing.B) {
 	// Test performance with a smaller buffer where wrapping occurs more frequently
 	mm := newMetricsMonitor(testLogger, 100, 0)
 
-	metric := TokenMetrics{
-		Model:           "test-model",
-		CachedTokens:    100,
-		InputTokens:     500,
-		OutputTokens:    250,
-		PromptPerSecond: 1200.5,
-		TokensPerSecond: 45.8,
-		DurationMs:      5000,
-		Timestamp:       time.Now(),
+	metric := ActivityLogEntry{
+		Model: "test-model",
+		Tokens: TokenMetrics{
+			CachedTokens:    100,
+			InputTokens:     500,
+			OutputTokens:    250,
+			PromptPerSecond: 1200.5,
+			TokensPerSecond: 45.8,
+		},
+		DurationMs: 5000,
+		Timestamp:  time.Now(),
 	}
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		mm.addMetrics(metric)
+		mm.queueMetrics(metric)
 	}
 }
 
@@ -855,14 +879,14 @@ func TestMetricsMonitor_WrapHandler_Compression(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 100, metrics[0].InputTokens)
-		assert.Equal(t, 50, metrics[0].OutputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 50, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("deflate encoded response", func(t *testing.T) {
@@ -889,14 +913,14 @@ func TestMetricsMonitor_WrapHandler_Compression(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 200, metrics[0].InputTokens)
-		assert.Equal(t, 75, metrics[0].OutputTokens)
+		assert.Equal(t, 200, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 75, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("invalid gzip data records minimal metrics", func(t *testing.T) {
@@ -917,14 +941,14 @@ func TestMetricsMonitor_WrapHandler_Compression(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err) // Should not return error, just log warning
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
 		assert.Equal(t, "test-model", metrics[0].Model)
-		assert.Equal(t, 0, metrics[0].InputTokens)
-		assert.Equal(t, 0, metrics[0].OutputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 0, metrics[0].Tokens.OutputTokens)
 	})
 
 	t.Run("unknown encoding treated as uncompressed", func(t *testing.T) {
@@ -944,13 +968,13 @@ func TestMetricsMonitor_WrapHandler_Compression(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		metrics := mm.getMetrics()
 		assert.Equal(t, 1, len(metrics))
-		assert.Equal(t, 300, metrics[0].InputTokens)
-		assert.Equal(t, 100, metrics[0].OutputTokens)
+		assert.Equal(t, 300, metrics[0].Tokens.InputTokens)
+		assert.Equal(t, 100, metrics[0].Tokens.OutputTokens)
 	})
 }
 
@@ -989,7 +1013,7 @@ func TestMetricsMonitor_AddCapture(t *testing.T) {
 		mm.addCapture(capture)
 
 		// Should not store capture
-		assert.Nil(t, mm.getCaptureByID(0, false))
+		assert.Nil(t, mm.getCaptureByID(0))
 	})
 
 	t.Run("adds capture when enabled", func(t *testing.T) {
@@ -1002,22 +1026,18 @@ func TestMetricsMonitor_AddCapture(t *testing.T) {
 		}
 		mm.addCapture(capture)
 
-		retrieved := mm.getCaptureByID(0, true)
-		assert.NotNil(t, retrieved)
-
-		var decoded ReqRespCapture
-		err := json.Unmarshal(retrieved, &decoded)
-		assert.NoError(t, err)
-		assert.Equal(t, 0, decoded.ID)
-		assert.Equal(t, []byte("test request"), decoded.ReqBody)
-		assert.Equal(t, []byte("test response"), decoded.RespBody)
+		captured := mm.getCaptureByID(0)
+		assert.NotNil(t, captured)
+		assert.Equal(t, 0, captured.ID)
+		assert.Equal(t, []byte("test request"), captured.ReqBody)
+		assert.Equal(t, []byte("test response"), captured.RespBody)
 	})
 
 	t.Run("evicts oldest when exceeding max size", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 5)
 		// Each full ReqRespCapture with 80 bytes random data compresses to ~185 bytes.
 		// 2 captures = ~370 bytes, 3 captures = ~555 bytes. Set limit so only 2 fit.
-		mm.maxCaptureSize = 450
+		mm.captureCache = cache.New(450)
 
 		// Use random-looking data that doesn't compress well with zstd
 		rng := rand.New(rand.NewSource(42))
@@ -1033,16 +1053,14 @@ func TestMetricsMonitor_AddCapture(t *testing.T) {
 		// Adding capture3 should evict capture1
 		mm.addCapture(capture3)
 
-		assert.Nil(t, mm.getCaptureByID(0, true), "capture 0 should be evicted")
-		retrieved := mm.getCaptureByID(1, true)
-		assert.NotNil(t, retrieved, "capture 1 should exist")
-		retrieved = mm.getCaptureByID(2, true)
-		assert.NotNil(t, retrieved, "capture 2 should exist")
+		assert.Nil(t, mm.getCaptureByID(0), "capture 0 should be evicted")
+		assert.NotNil(t, mm.getCaptureByID(1), "capture 1 should exist")
+		assert.NotNil(t, mm.getCaptureByID(2), "capture 2 should exist")
 	})
 
 	t.Run("skips capture larger than max size", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 5)
-		mm.maxCaptureSize = 100
+		mm.captureCache = cache.New(100)
 
 		// Use random data that doesn't compress well to create an oversized capture
 		rng := rand.New(rand.NewSource(99))
@@ -1050,7 +1068,7 @@ func TestMetricsMonitor_AddCapture(t *testing.T) {
 		rng.Read(largeCapture.ReqBody)
 		mm.addCapture(largeCapture)
 
-		assert.Nil(t, mm.getCaptureByID(0, false), "oversized capture should not be stored")
+		assert.Nil(t, mm.getCaptureByID(0), "oversized capture should not be stored")
 	})
 }
 
@@ -1058,7 +1076,7 @@ func TestMetricsMonitor_GetCaptureByID(t *testing.T) {
 	t.Run("returns nil for non-existent ID", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 5)
 
-		assert.Nil(t, mm.getCaptureByID(999, false))
+		assert.Nil(t, mm.getCaptureByID(999))
 	})
 
 	t.Run("returns decompressed capture by ID", func(t *testing.T) {
@@ -1071,18 +1089,14 @@ func TestMetricsMonitor_GetCaptureByID(t *testing.T) {
 		}
 		mm.addCapture(capture)
 
-		retrieved := mm.getCaptureByID(42, true)
-		assert.NotNil(t, retrieved)
-
-		var decoded ReqRespCapture
-		err := json.Unmarshal(retrieved, &decoded)
-		assert.NoError(t, err)
-		assert.Equal(t, 42, decoded.ID)
-		assert.Equal(t, []byte("test request"), decoded.ReqBody)
-		assert.Equal(t, []byte("test response"), decoded.RespBody)
+		captured := mm.getCaptureByID(42)
+		assert.NotNil(t, captured)
+		assert.Equal(t, 42, captured.ID)
+		assert.Equal(t, []byte("test request"), captured.ReqBody)
+		assert.Equal(t, []byte("test response"), captured.RespBody)
 	})
 
-	t.Run("returns compressed bytes when decompress=false", func(t *testing.T) {
+	t.Run("stores data as compressed bytes", func(t *testing.T) {
 		mm := newMetricsMonitor(testLogger, 10, 5)
 
 		capture := ReqRespCapture{
@@ -1092,10 +1106,12 @@ func TestMetricsMonitor_GetCaptureByID(t *testing.T) {
 		}
 		mm.addCapture(capture)
 
-		compressed := mm.getCaptureByID(42, false)
+		compressed, exists := mm.getCompressedBytes(42)
+		assert.True(t, exists)
 		assert.NotNil(t, compressed)
-		// Compressed data should not be valid JSON (it's zstd-compressed)
-		assert.False(t, gjson.ValidBytes(compressed))
+		// Compressed data should not be valid CBOR (it's zstd-compressed)
+		var decoded ReqRespCapture
+		assert.Error(t, cbor.Unmarshal(compressed, &decoded))
 	})
 }
 
@@ -1164,7 +1180,7 @@ func TestMetricsMonitor_WrapHandler_Capture(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		// Check metric was recorded
@@ -1173,12 +1189,8 @@ func TestMetricsMonitor_WrapHandler_Capture(t *testing.T) {
 		metricID := metrics[0].ID
 
 		// Check capture was stored with same ID (decompressed)
-		captureData := mm.getCaptureByID(metricID, true)
-		assert.NotNil(t, captureData)
-
-		var capture ReqRespCapture
-		err = json.Unmarshal(captureData, &capture)
-		assert.NoError(t, err)
+		capture := mm.getCaptureByID(metricID)
+		assert.NotNil(t, capture)
 		assert.Equal(t, metricID, capture.ID)
 		assert.Equal(t, []byte(requestBody), capture.ReqBody)
 		assert.Equal(t, []byte(responseBody), capture.RespBody)
@@ -1206,7 +1218,7 @@ func TestMetricsMonitor_WrapHandler_Capture(t *testing.T) {
 		rec := httptest.NewRecorder()
 		ginCtx, _ := gin.CreateTestContext(rec)
 
-		err := mm.wrapHandler("test-model", ginCtx.Writer, req, nextHandler)
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureAll, nextHandler)
 		assert.NoError(t, err)
 
 		// Metrics should still be recorded
@@ -1214,7 +1226,168 @@ func TestMetricsMonitor_WrapHandler_Capture(t *testing.T) {
 		assert.Equal(t, 1, len(metrics))
 
 		// But no capture
-		capture := mm.getCaptureByID(metrics[0].ID, false)
-		assert.Nil(t, capture)
+		assert.Nil(t, mm.getCaptureByID(metrics[0].ID))
+	})
+}
+
+func TestMetricsMonitor_WrapHandler_PartialCaptures(t *testing.T) {
+	requestBody := `{"model": "test"}`
+	responseBody := `{"usage": {"prompt_tokens": 100, "completion_tokens": 50}}`
+
+	nextHandler := func(modelID string, w http.ResponseWriter, r *http.Request) error {
+		w.Header().Set("Content-Type", "application/json")
+		w.Header().Set("X-Custom", "header-value")
+		w.WriteHeader(http.StatusOK)
+		w.Write([]byte(responseBody))
+		return nil
+	}
+
+	t.Run("only request headers", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("Authorization", "Bearer secret")
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureReqHeaders, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Equal(t, "application/json", capture.ReqHeaders["Content-Type"])
+		assert.Equal(t, "[REDACTED]", capture.ReqHeaders["Authorization"])
+		assert.Nil(t, capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Nil(t, capture.RespBody)
+	})
+
+	t.Run("only request body", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureReqBody, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Nil(t, capture.ReqHeaders)
+		assert.Equal(t, []byte(requestBody), capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Nil(t, capture.RespBody)
+	})
+
+	t.Run("only response headers", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureRespHeaders, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Nil(t, capture.ReqHeaders)
+		assert.Nil(t, capture.ReqBody)
+		assert.Equal(t, "application/json", capture.RespHeaders["Content-Type"])
+		assert.Equal(t, "header-value", capture.RespHeaders["X-Custom"])
+		assert.Nil(t, capture.RespBody)
+	})
+
+	t.Run("only response body", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureRespBody, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Nil(t, capture.ReqHeaders)
+		assert.Nil(t, capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Equal(t, []byte(responseBody), capture.RespBody)
+	})
+
+	t.Run("captureReqAll", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("Authorization", "Bearer secret")
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureReqAll, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Equal(t, "application/json", capture.ReqHeaders["Content-Type"])
+		assert.Equal(t, "[REDACTED]", capture.ReqHeaders["Authorization"])
+		assert.Equal(t, []byte(requestBody), capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Nil(t, capture.RespBody)
+	})
+
+	t.Run("captureRespAll", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureRespAll, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Nil(t, capture.ReqHeaders)
+		assert.Nil(t, capture.ReqBody)
+		assert.Equal(t, "application/json", capture.RespHeaders["Content-Type"])
+		assert.Equal(t, "header-value", capture.RespHeaders["X-Custom"])
+		assert.Equal(t, []byte(responseBody), capture.RespBody)
+	})
+
+	t.Run("no flags", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		req.Header.Set("Content-Type", "application/json")
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureFields(0), nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Nil(t, capture.ReqHeaders)
+		assert.Nil(t, capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Nil(t, capture.RespBody)
+	})
+
+	t.Run("mixed flags req headers and resp body", func(t *testing.T) {
+		mm := newMetricsMonitor(testLogger, 10, 100)
+		req := httptest.NewRequest("POST", "/test", bytes.NewBufferString(requestBody))
+		req.Header.Set("Content-Type", "application/json")
+		req.Header.Set("Authorization", "Bearer secret")
+		rec := httptest.NewRecorder()
+		ginCtx, _ := gin.CreateTestContext(rec)
+
+		err := mm.wrapHandler("test-model", ginCtx.Writer, req, captureReqHeaders|captureRespBody, nextHandler)
+		assert.NoError(t, err)
+
+		capture := mm.getCaptureByID(mm.getMetrics()[0].ID)
+		assert.NotNil(t, capture)
+		assert.Equal(t, "application/json", capture.ReqHeaders["Content-Type"])
+		assert.Equal(t, "[REDACTED]", capture.ReqHeaders["Authorization"])
+		assert.Nil(t, capture.ReqBody)
+		assert.Nil(t, capture.RespHeaders)
+		assert.Equal(t, []byte(responseBody), capture.RespBody)
 	})
 }

proxy/proxymanager.go

@@ -332,41 +332,77 @@ func (pm *ProxyManager) setupGinEngine() {
 
 	// Set up routes using the Gin engine
 	// Protected routes use pm.apiKeyAuth() middleware
-	pm.ginEngine.POST("/v1/chat/completions", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/v1/responses", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	llmHandler := pm.mkProxyJSONHandler(captureAll)
+	pm.ginEngine.POST("/v1/chat/completions", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
+	pm.ginEngine.POST("/v1/responses", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 	// Support legacy /v1/completions api, see issue #12
-	pm.ginEngine.POST("/v1/completions", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/v1/completions", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 	// Support anthropic /v1/messages (added https://github.com/ggml-org/llama.cpp/pull/17570)
-	pm.ginEngine.POST("/v1/messages", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/v1/messages", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 	// Support anthropic count_tokens API (Also added in the above PR)
-	pm.ginEngine.POST("/v1/messages/count_tokens", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/v1/messages/count_tokens", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 
 	// Support embeddings and reranking
-	pm.ginEngine.POST("/v1/embeddings", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/v1/embeddings", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 
 	// llama-server's /reranking endpoint + aliases
-	pm.ginEngine.POST("/reranking", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/rerank", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/v1/rerank", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/v1/reranking", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/reranking", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
+	pm.ginEngine.POST("/rerank", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
+	pm.ginEngine.POST("/v1/rerank", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
+	pm.ginEngine.POST("/v1/reranking", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 
 	// llama-server's /infill endpoint for code infilling
-	pm.ginEngine.POST("/infill", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/infill", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 
 	// llama-server's /completion endpoint
-	pm.ginEngine.POST("/completion", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/completion", pm.apiKeyAuth(), pm.trackInflight(), llmHandler)
 
 	// Support audio/speech endpoint
-	pm.ginEngine.POST("/v1/audio/speech", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/v1/audio/voices", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST(
+		"/v1/audio/speech",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkProxyJSONHandler(captureReqAll|captureRespHeaders),
+	)
+	pm.ginEngine.POST(
+		"/v1/audio/voices",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkProxyJSONHandler(captureReqHeaders|captureRespAll),
+	)
 	pm.ginEngine.GET("/v1/audio/voices", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyGETModelHandler)
-	pm.ginEngine.POST("/v1/audio/transcriptions", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyOAIPostFormHandler)
-	pm.ginEngine.POST("/v1/images/generations", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/v1/images/edits", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyOAIPostFormHandler)
+
+	pm.ginEngine.POST(
+		"/v1/audio/transcriptions",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkPostFormHandler(captureReqHeaders|captureRespHeaders|captureRespBody),
+	)
+	pm.ginEngine.POST(
+		"/v1/images/generations",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkProxyJSONHandler(captureReqAll|captureRespHeaders),
+	)
+
+	pm.ginEngine.POST(
+		"/v1/images/edits",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkPostFormHandler(captureReqHeaders|captureRespHeaders),
+	)
 
 	// sd.cpp /sdapi/v1 endpoints
-	pm.ginEngine.POST("/sdapi/v1/txt2img", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
-	pm.ginEngine.POST("/sdapi/v1/img2img", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyInferenceHandler)
+	pm.ginEngine.POST("/sdapi/v1/txt2img",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkProxyJSONHandler(captureReqAll|captureRespHeaders),
+	)
+	pm.ginEngine.POST("/sdapi/v1/img2img",
+		pm.apiKeyAuth(),
+		pm.trackInflight(),
+		pm.mkProxyJSONHandler(captureReqHeaders|captureRespHeaders),
+	)
 	pm.ginEngine.GET("/sdapi/v1/loras", pm.apiKeyAuth(), pm.trackInflight(), pm.proxyGETModelHandler)
 
 	pm.ginEngine.GET("/v1/models", pm.apiKeyAuth(), pm.listModelsHandler)
@@ -686,7 +722,7 @@ func (pm *ProxyManager) proxyToUpstream(c *gin.Context) {
 
 	// attempt to record metrics if it is a POST request
 	if pm.metricsMonitor != nil && c.Request.Method == "POST" {
-		if err := pm.metricsMonitor.wrapHandler(modelID, c.Writer, c.Request, handler); err != nil {
+		if err := pm.metricsMonitor.wrapHandler(modelID, c.Writer, c.Request, captureNone, handler); err != nil {
 			pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying metrics wrapped request: %s", err.Error()))
 			pm.proxyLogger.Errorf("Error proxying wrapped upstream request for model %s, path=%s", modelID, originalPath)
 			return
@@ -700,280 +736,294 @@ func (pm *ProxyManager) proxyToUpstream(c *gin.Context) {
 	}
 }
 
-func (pm *ProxyManager) proxyInferenceHandler(c *gin.Context) {
-	bodyBytes, err := io.ReadAll(c.Request.Body)
-	if err != nil {
-		pm.sendErrorResponse(c, http.StatusBadRequest, "could not ready request body")
-		return
-	}
-
-	requestedModel := gjson.GetBytes(bodyBytes, "model").String()
-	if requestedModel == "" {
-		pm.sendErrorResponse(c, http.StatusBadRequest, "missing or invalid 'model' key")
-		return
-	}
-
-	// Look for a matching local model first
-	var nextHandler func(modelID string, w http.ResponseWriter, r *http.Request) error
-
-	modelID, found := pm.config.RealModelName(requestedModel)
-	if found {
-		var localHandler func(string, http.ResponseWriter, *http.Request) error
-		if pm.matrix != nil {
-			localHandler = pm.matrix.ProxyRequest
-		} else {
-			processGroup, err := pm.swapProcessGroup(modelID)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error swapping process group: %s", err.Error()))
-				return
-			}
-			localHandler = processGroup.ProxyRequest
+func (pm *ProxyManager) mkProxyJSONHandler(cf captureFields) func(*gin.Context) {
+	return func(c *gin.Context) {
+		bodyBytes, err := io.ReadAll(c.Request.Body)
+		if err != nil {
+			pm.sendErrorResponse(c, http.StatusBadRequest, "could not ready request body")
+			return
 		}
 
-		// issue #69 allow custom model names to be sent to upstream
-		useModelName := pm.config.Models[modelID].UseModelName
-		if useModelName != "" {
-			bodyBytes, err = sjson.SetBytes(bodyBytes, "model", useModelName)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error rewriting model name in JSON: %s", err.Error()))
-				return
-			}
+		requestedModel := gjson.GetBytes(bodyBytes, "model").String()
+		if requestedModel == "" {
+			pm.sendErrorResponse(c, http.StatusBadRequest, "missing or invalid 'model' key")
+			return
 		}
 
-		// issue #174 strip parameters from the JSON body
-		stripParams, err := pm.config.Models[modelID].Filters.SanitizedStripParams()
-		if err != nil { // just log it and continue
-			pm.proxyLogger.Errorf("Error sanitizing strip params string: %s, %s", pm.config.Models[modelID].Filters.StripParams, err.Error())
-		} else {
+		// Look for a matching local model first
+		var nextHandler func(modelID string, w http.ResponseWriter, r *http.Request) error
+
+		modelID, found := pm.config.RealModelName(requestedModel)
+		if found {
+			var localHandler func(string, http.ResponseWriter, *http.Request) error
+			if pm.matrix != nil {
+				localHandler = pm.matrix.ProxyRequest
+			} else {
+				processGroup, err := pm.swapProcessGroup(modelID)
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error swapping process group: %s", err.Error()))
+					return
+				}
+				localHandler = processGroup.ProxyRequest
+			}
+
+			// issue #69 allow custom model names to be sent to upstream
+			useModelName := pm.config.Models[modelID].UseModelName
+			if useModelName != "" {
+				bodyBytes, err = sjson.SetBytes(bodyBytes, "model", useModelName)
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error rewriting model name in JSON: %s", err.Error()))
+					return
+				}
+			}
+
+			// issue #174 strip parameters from the JSON body
+			stripParams, err := pm.config.Models[modelID].Filters.SanitizedStripParams()
+			if err != nil { // just log it and continue
+				pm.proxyLogger.Errorf("Error sanitizing strip params string: %s, %s", pm.config.Models[modelID].Filters.StripParams, err.Error())
+			} else {
+				for _, param := range stripParams {
+					pm.proxyLogger.Debugf("<%s> stripping param: %s", modelID, param)
+					bodyBytes, err = sjson.DeleteBytes(bodyBytes, param)
+					if err != nil {
+						pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error deleting parameter %s from request", param))
+						return
+					}
+				}
+			}
+
+			// issue #453 set/override parameters in the JSON body
+			setParams, setParamKeys := pm.config.Models[modelID].Filters.SanitizedSetParams()
+			for _, key := range setParamKeys {
+				pm.proxyLogger.Debugf("<%s> setting param: %s", modelID, key)
+				bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParams[key])
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
+					return
+				}
+			}
+
+			// setParamsByID: set params based on the requested model ID (runs after setParams, can override it)
+			setParamsByIDParams, setParamsByIDKeys := pm.config.Models[modelID].Filters.SanitizedSetParamsByID(requestedModel)
+			for _, key := range setParamsByIDKeys {
+				pm.proxyLogger.Debugf("<%s> setting param by id: %s", requestedModel, key)
+				bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParamsByIDParams[key])
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
+					return
+				}
+			}
+
+			pm.proxyLogger.Debugf("ProxyManager using local Process for model: %s", requestedModel)
+			nextHandler = localHandler
+		} else if pm.peerProxy != nil && pm.peerProxy.HasPeerModel(requestedModel) {
+			pm.proxyLogger.Debugf("ProxyManager using ProxyPeer for model: %s", requestedModel)
+			modelID = requestedModel
+
+			// issue #453 apply filters for peer requests
+			peerFilters := pm.peerProxy.GetPeerFilters(requestedModel)
+
+			// Apply stripParams - remove specified parameters from request
+			stripParams := peerFilters.SanitizedStripParams()
 			for _, param := range stripParams {
-				pm.proxyLogger.Debugf("<%s> stripping param: %s", modelID, param)
+				pm.proxyLogger.Debugf("<%s> stripping param: %s", requestedModel, param)
 				bodyBytes, err = sjson.DeleteBytes(bodyBytes, param)
 				if err != nil {
-					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error deleting parameter %s from request", param))
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error stripping parameter %s from request", param))
+					return
+				}
+			}
+
+			// Apply setParams - set/override specified parameters in request
+			setParams, setParamKeys := peerFilters.SanitizedSetParams()
+			for _, key := range setParamKeys {
+				pm.proxyLogger.Debugf("<%s> setting param: %s", requestedModel, key)
+				bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParams[key])
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
+					return
+				}
+			}
+
+			nextHandler = pm.peerProxy.ProxyRequest
+		}
+
+		if nextHandler == nil {
+			pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("could not find suitable inference handler for %s", requestedModel))
+			return
+		}
+
+		c.Request.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
+
+		// dechunk it as we already have all the body bytes see issue #11
+		c.Request.Header.Del("transfer-encoding")
+		c.Request.Header.Set("content-length", strconv.Itoa(len(bodyBytes)))
+		c.Request.ContentLength = int64(len(bodyBytes))
+
+		// issue #366 extract values that downstream handlers may need
+		isStreaming := gjson.GetBytes(bodyBytes, "stream").Bool()
+		ctx := context.WithValue(c.Request.Context(), proxyCtxKey("streaming"), isStreaming)
+		ctx = context.WithValue(ctx, proxyCtxKey("model"), modelID)
+		c.Request = c.Request.WithContext(ctx)
+
+		if pm.metricsMonitor != nil && c.Request.Method == "POST" {
+			if err := pm.metricsMonitor.wrapHandler(modelID, c.Writer, c.Request, cf, nextHandler); err != nil {
+				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying metrics wrapped request: %s", err.Error()))
+				pm.proxyLogger.Errorf("Error Proxying Metrics Wrapped Request model %s", modelID)
+				return
+			}
+		} else {
+			if err := nextHandler(modelID, c.Writer, c.Request); err != nil {
+				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error()))
+				pm.proxyLogger.Errorf("Error Proxying Request for model %s", modelID)
+				return
+			}
+		}
+	}
+}
+
+// mkPostFormHandler creates a POST form handler for inference backends
+// with a custom captureFields to filter out large binary requests or responses.
+func (pm *ProxyManager) mkPostFormHandler(cf captureFields) func(*gin.Context) {
+	return func(c *gin.Context) {
+		// Parse multipart form
+		if err := c.Request.ParseMultipartForm(32 << 20); err != nil { // 32MB max memory, larger files go to tmp disk
+			pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("error parsing multipart form: %s", err.Error()))
+			return
+		}
+
+		// Get model parameter from the form
+		requestedModel := c.Request.FormValue("model")
+		if requestedModel == "" {
+			pm.sendErrorResponse(c, http.StatusBadRequest, "missing or invalid 'model' parameter in form data")
+			return
+		}
+
+		// Look for a matching local model first, then check peers
+		var nextHandler func(modelID string, w http.ResponseWriter, r *http.Request) error
+		var useModelName string
+
+		modelID, found := pm.config.RealModelName(requestedModel)
+		if found {
+			if pm.matrix != nil {
+				nextHandler = pm.matrix.ProxyRequest
+			} else {
+				processGroup, err := pm.swapProcessGroup(modelID)
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error swapping process group: %s", err.Error()))
+					return
+				}
+				nextHandler = processGroup.ProxyRequest
+			}
+
+			useModelName = pm.config.Models[modelID].UseModelName
+			pm.proxyLogger.Debugf("ProxyManager using local Process for model: %s", requestedModel)
+		} else if pm.peerProxy != nil && pm.peerProxy.HasPeerModel(requestedModel) {
+			pm.proxyLogger.Debugf("ProxyManager using ProxyPeer for model: %s", requestedModel)
+			modelID = requestedModel
+			nextHandler = pm.peerProxy.ProxyRequest
+		}
+
+		if nextHandler == nil {
+			pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("could not find suitable handler for %s", requestedModel))
+			return
+		}
+
+		// We need to reconstruct the multipart form in any case since the body is consumed
+		// Create a new buffer for the reconstructed request
+		var requestBuffer bytes.Buffer
+		multipartWriter := multipart.NewWriter(&requestBuffer)
+
+		// Copy all form values
+		for key, values := range c.Request.MultipartForm.Value {
+			for _, value := range values {
+				fieldValue := value
+				// If this is the model field and we have a profile, use just the model name
+				if key == "model" {
+					// # issue #69 allow custom model names to be sent to upstream
+					if useModelName != "" {
+						fieldValue = useModelName
+					} else {
+						fieldValue = requestedModel
+					}
+				}
+				field, err := multipartWriter.CreateFormField(key)
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, "error recreating form field")
+					return
+				}
+				if _, err = field.Write([]byte(fieldValue)); err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, "error writing form field")
 					return
 				}
 			}
 		}
 
-		// issue #453 set/override parameters in the JSON body
-		setParams, setParamKeys := pm.config.Models[modelID].Filters.SanitizedSetParams()
-		for _, key := range setParamKeys {
-			pm.proxyLogger.Debugf("<%s> setting param: %s", modelID, key)
-			bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParams[key])
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
-				return
-			}
-		}
-
-		// setParamsByID: set params based on the requested model ID (runs after setParams, can override it)
-		setParamsByIDParams, setParamsByIDKeys := pm.config.Models[modelID].Filters.SanitizedSetParamsByID(requestedModel)
-		for _, key := range setParamsByIDKeys {
-			pm.proxyLogger.Debugf("<%s> setting param by id: %s", requestedModel, key)
-			bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParamsByIDParams[key])
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
-				return
-			}
-		}
-
-		pm.proxyLogger.Debugf("ProxyManager using local Process for model: %s", requestedModel)
-		nextHandler = localHandler
-	} else if pm.peerProxy != nil && pm.peerProxy.HasPeerModel(requestedModel) {
-		pm.proxyLogger.Debugf("ProxyManager using ProxyPeer for model: %s", requestedModel)
-		modelID = requestedModel
-
-		// issue #453 apply filters for peer requests
-		peerFilters := pm.peerProxy.GetPeerFilters(requestedModel)
-
-		// Apply stripParams - remove specified parameters from request
-		stripParams := peerFilters.SanitizedStripParams()
-		for _, param := range stripParams {
-			pm.proxyLogger.Debugf("<%s> stripping param: %s", requestedModel, param)
-			bodyBytes, err = sjson.DeleteBytes(bodyBytes, param)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error stripping parameter %s from request", param))
-				return
-			}
-		}
-
-		// Apply setParams - set/override specified parameters in request
-		setParams, setParamKeys := peerFilters.SanitizedSetParams()
-		for _, key := range setParamKeys {
-			pm.proxyLogger.Debugf("<%s> setting param: %s", requestedModel, key)
-			bodyBytes, err = sjson.SetBytes(bodyBytes, key, setParams[key])
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error setting parameter %s in request", key))
-				return
-			}
-		}
-
-		nextHandler = pm.peerProxy.ProxyRequest
-	}
-
-	if nextHandler == nil {
-		pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("could not find suitable inference handler for %s", requestedModel))
-		return
-	}
-
-	c.Request.Body = io.NopCloser(bytes.NewBuffer(bodyBytes))
-
-	// dechunk it as we already have all the body bytes see issue #11
-	c.Request.Header.Del("transfer-encoding")
-	c.Request.Header.Set("content-length", strconv.Itoa(len(bodyBytes)))
-	c.Request.ContentLength = int64(len(bodyBytes))
-
-	// issue #366 extract values that downstream handlers may need
-	isStreaming := gjson.GetBytes(bodyBytes, "stream").Bool()
-	ctx := context.WithValue(c.Request.Context(), proxyCtxKey("streaming"), isStreaming)
-	ctx = context.WithValue(ctx, proxyCtxKey("model"), modelID)
-	c.Request = c.Request.WithContext(ctx)
-
-	if pm.metricsMonitor != nil && c.Request.Method == "POST" {
-		if err := pm.metricsMonitor.wrapHandler(modelID, c.Writer, c.Request, nextHandler); err != nil {
-			pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying metrics wrapped request: %s", err.Error()))
-			pm.proxyLogger.Errorf("Error Proxying Metrics Wrapped Request model %s", modelID)
-			return
-		}
-	} else {
-		if err := nextHandler(modelID, c.Writer, c.Request); err != nil {
-			pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error()))
-			pm.proxyLogger.Errorf("Error Proxying Request for model %s", modelID)
-			return
-		}
-	}
-}
-
-func (pm *ProxyManager) proxyOAIPostFormHandler(c *gin.Context) {
-	// Parse multipart form
-	if err := c.Request.ParseMultipartForm(32 << 20); err != nil { // 32MB max memory, larger files go to tmp disk
-		pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("error parsing multipart form: %s", err.Error()))
-		return
-	}
-
-	// Get model parameter from the form
-	requestedModel := c.Request.FormValue("model")
-	if requestedModel == "" {
-		pm.sendErrorResponse(c, http.StatusBadRequest, "missing or invalid 'model' parameter in form data")
-		return
-	}
-
-	// Look for a matching local model first, then check peers
-	var nextHandler func(modelID string, w http.ResponseWriter, r *http.Request) error
-	var useModelName string
-
-	modelID, found := pm.config.RealModelName(requestedModel)
-	if found {
-		if pm.matrix != nil {
-			nextHandler = pm.matrix.ProxyRequest
-		} else {
-			processGroup, err := pm.swapProcessGroup(modelID)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error swapping process group: %s", err.Error()))
-				return
-			}
-			nextHandler = processGroup.ProxyRequest
-		}
-
-		useModelName = pm.config.Models[modelID].UseModelName
-		pm.proxyLogger.Debugf("ProxyManager using local Process for model: %s", requestedModel)
-	} else if pm.peerProxy != nil && pm.peerProxy.HasPeerModel(requestedModel) {
-		pm.proxyLogger.Debugf("ProxyManager using ProxyPeer for model: %s", requestedModel)
-		modelID = requestedModel
-		nextHandler = pm.peerProxy.ProxyRequest
-	}
-
-	if nextHandler == nil {
-		pm.sendErrorResponse(c, http.StatusBadRequest, fmt.Sprintf("could not find suitable handler for %s", requestedModel))
-		return
-	}
-
-	// We need to reconstruct the multipart form in any case since the body is consumed
-	// Create a new buffer for the reconstructed request
-	var requestBuffer bytes.Buffer
-	multipartWriter := multipart.NewWriter(&requestBuffer)
-
-	// Copy all form values
-	for key, values := range c.Request.MultipartForm.Value {
-		for _, value := range values {
-			fieldValue := value
-			// If this is the model field and we have a profile, use just the model name
-			if key == "model" {
-				// # issue #69 allow custom model names to be sent to upstream
-				if useModelName != "" {
-					fieldValue = useModelName
-				} else {
-					fieldValue = requestedModel
+		// Copy all files from the original request
+		for key, fileHeaders := range c.Request.MultipartForm.File {
+			for _, fileHeader := range fileHeaders {
+				formFile, err := multipartWriter.CreateFormFile(key, fileHeader.Filename)
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, "error recreating form file")
+					return
 				}
-			}
-			field, err := multipartWriter.CreateFormField(key)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, "error recreating form field")
-				return
-			}
-			if _, err = field.Write([]byte(fieldValue)); err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, "error writing form field")
-				return
-			}
-		}
-	}
 
-	// Copy all files from the original request
-	for key, fileHeaders := range c.Request.MultipartForm.File {
-		for _, fileHeader := range fileHeaders {
-			formFile, err := multipartWriter.CreateFormFile(key, fileHeader.Filename)
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, "error recreating form file")
-				return
-			}
+				file, err := fileHeader.Open()
+				if err != nil {
+					pm.sendErrorResponse(c, http.StatusInternalServerError, "error opening uploaded file")
+					return
+				}
 
-			file, err := fileHeader.Open()
-			if err != nil {
-				pm.sendErrorResponse(c, http.StatusInternalServerError, "error opening uploaded file")
-				return
-			}
-
-			if _, err = io.Copy(formFile, file); err != nil {
+				if _, err = io.Copy(formFile, file); err != nil {
+					file.Close()
+					pm.sendErrorResponse(c, http.StatusInternalServerError, "error copying file data")
+					return
+				}
 				file.Close()
-				pm.sendErrorResponse(c, http.StatusInternalServerError, "error copying file data")
+			}
+		}
+
+		// Close the multipart writer to finalize the form
+		if err := multipartWriter.Close(); err != nil {
+			pm.sendErrorResponse(c, http.StatusInternalServerError, "error finalizing multipart form")
+			return
+		}
+
+		// Create a new request with the reconstructed form data
+		modifiedReq, err := http.NewRequestWithContext(
+			c.Request.Context(),
+			c.Request.Method,
+			c.Request.URL.String(),
+			&requestBuffer,
+		)
+		if err != nil {
+			pm.sendErrorResponse(c, http.StatusInternalServerError, "error creating modified request")
+			return
+		}
+
+		// Copy the headers from the original request
+		modifiedReq.Header = c.Request.Header.Clone()
+		modifiedReq.Header.Set("Content-Type", multipartWriter.FormDataContentType())
+
+		// set the content length of the body
+		modifiedReq.Header.Set("Content-Length", strconv.Itoa(requestBuffer.Len()))
+		modifiedReq.ContentLength = int64(requestBuffer.Len())
+
+		// Use the modified request for proxying
+		if pm.metricsMonitor != nil {
+			if err := pm.metricsMonitor.wrapHandler(modelID, c.Writer, modifiedReq, cf, nextHandler); err != nil {
+				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error()))
+				pm.proxyLogger.Errorf("Error Proxying Request for model %s", modelID)
+				return
+			}
+		} else {
+			if err := nextHandler(modelID, c.Writer, modifiedReq); err != nil {
+				pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error()))
+				pm.proxyLogger.Errorf("Error Proxying Request for model %s", modelID)
 				return
 			}
-			file.Close()
 		}
 	}
-
-	// Close the multipart writer to finalize the form
-	if err := multipartWriter.Close(); err != nil {
-		pm.sendErrorResponse(c, http.StatusInternalServerError, "error finalizing multipart form")
-		return
-	}
-
-	// Create a new request with the reconstructed form data
-	modifiedReq, err := http.NewRequestWithContext(
-		c.Request.Context(),
-		c.Request.Method,
-		c.Request.URL.String(),
-		&requestBuffer,
-	)
-	if err != nil {
-		pm.sendErrorResponse(c, http.StatusInternalServerError, "error creating modified request")
-		return
-	}
-
-	// Copy the headers from the original request
-	modifiedReq.Header = c.Request.Header.Clone()
-	modifiedReq.Header.Set("Content-Type", multipartWriter.FormDataContentType())
-
-	// set the content length of the body
-	modifiedReq.Header.Set("Content-Length", strconv.Itoa(requestBuffer.Len()))
-	modifiedReq.ContentLength = int64(requestBuffer.Len())
-
-	// Use the modified request for proxying
-	if err := nextHandler(modelID, c.Writer, modifiedReq); err != nil {
-		pm.sendErrorResponse(c, http.StatusInternalServerError, fmt.Sprintf("error proxying request: %s", err.Error()))
-		pm.proxyLogger.Errorf("Error Proxying Request for model %s", modelID)
-		return
-	}
 }
 
 func (pm *ProxyManager) proxyGETModelHandler(c *gin.Context) {

proxy/proxymanager_api.go

@@ -158,7 +158,7 @@ func (pm *ProxyManager) apiSendEvents(c *gin.Context) {
 		}
 	}
 
-	sendMetrics := func(metrics []TokenMetrics) {
+	sendMetrics := func(metrics []ActivityLogEntry) {
 		jsonData, err := json.Marshal(metrics)
 		if err == nil {
 			select {
@@ -205,8 +205,8 @@ func (pm *ProxyManager) apiSendEvents(c *gin.Context) {
 	/**
 	 * Send Metrics data
 	 */
-	defer event.On(func(e TokenMetricsEvent) {
-		sendMetrics([]TokenMetrics{e.Metrics})
+	defer event.On(func(e ActivityLogEvent) {
+		sendMetrics([]ActivityLogEntry{e.Metrics})
 	})()
 
 	/**
@@ -290,26 +290,16 @@ func (pm *ProxyManager) apiGetCapture(c *gin.Context) {
 		return
 	}
 
-	data, exists := pm.metricsMonitor.getCompressedBytes(id)
-	if !exists {
+	capture := pm.metricsMonitor.getCaptureByID(id)
+	if capture == nil {
 		c.JSON(http.StatusNotFound, gin.H{"error": "capture not found"})
 		return
 	}
 
-	c.Header("Vary", "Accept-Encoding")
-
-	// ¯\_(ツ)_/¯ quality weights are too fancy for us anyway
-	hasZstd := strings.Contains(c.GetHeader("Accept-Encoding"), "zstd")
-
-	if hasZstd {
-		c.Header("Content-Encoding", "zstd")
-		c.Data(http.StatusOK, "application/json", data)
-	} else {
-		decompressed, err := decompressCapture(data)
-		if err != nil {
-			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to decompress capture"})
-			return
-		}
-		c.Data(http.StatusOK, "application/json", decompressed)
+	jsonBytes, err := json.Marshal(capture)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to marshal capture"})
+		return
 	}
+	c.Data(http.StatusOK, "application/json", jsonBytes)
 }

proxy/proxymanager_test.go

@@ -1721,3 +1721,61 @@ models:
 		assert.Contains(t, w.Body.String(), "could not find suitable handler")
 	})
 }
+
+func TestProxyManager_AudioTranscriptionCapture(t *testing.T) {
+	cfg := testConfigFromYAML(t, `
+healthCheckTimeout: 15
+logLevel: error
+captureBuffer: 5
+models:
+  TheExpectedModel:
+    cmd: {{RESPONDER}} --port ${PORT} --silent --respond TheExpectedModel
+`)
+
+	proxy := New(cfg)
+	defer proxy.StopProcesses(StopWaitForInflightRequest)
+	injectTestHandlers(proxy, nil)
+
+	var b bytes.Buffer
+	w := multipart.NewWriter(&b)
+
+	fw, err := w.CreateFormField("model")
+	assert.NoError(t, err)
+	_, err = fw.Write([]byte("TheExpectedModel"))
+	assert.NoError(t, err)
+
+	fw, err = w.CreateFormFile("file", "test.mp3")
+	assert.NoError(t, err)
+	_, err = fw.Write([]byte("test audio content"))
+	assert.NoError(t, err)
+	w.Close()
+
+	req := httptest.NewRequest("POST", "/v1/audio/transcriptions", &b)
+	req.Header.Set("Content-Type", w.FormDataContentType())
+	req.Header.Set("Authorization", "Bearer mysecret")
+	req.Header.Set("X-Custom-Req", "req-value")
+	rec := CreateTestResponseRecorder()
+	proxy.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+
+	// Verify capture exists
+	metrics := proxy.metricsMonitor.getMetrics()
+	assert.Equal(t, 1, len(metrics))
+	assert.True(t, metrics[0].HasCapture)
+
+	capture := proxy.metricsMonitor.getCaptureByID(metrics[0].ID)
+	assert.NotNil(t, capture)
+
+	// Should capture request headers (sensitive ones redacted)
+	assert.NotEmpty(t, capture.ReqHeaders)
+	assert.Equal(t, "[REDACTED]", capture.ReqHeaders["Authorization"])
+	assert.Equal(t, "req-value", capture.ReqHeaders["X-Custom-Req"])
+
+	// Should capture response headers
+	assert.NotNil(t, capture.RespHeaders)
+
+	// Should NOT capture request bodies but get response bodies (text
+	assert.Nil(t, capture.ReqBody)
+	assert.NotNil(t, capture.RespBody)
+}