diff --git a/send/async_group.go b/send/async_group.go
index 03206e2..7af1433 100644
--- a/send/async_group.go
+++ b/send/async_group.go
@@ -61,21 +61,21 @@ func MakeAsyncGroup(ctx context.Context, bufferSize int, senders ...Sender) Send
 	wg := &s.wg
 	s.closer.Set(func() (err error) {
 		s.doClose.Do(func() {
-			catcher := &erc.Collector{}
-			defer func() { err = catcher.Resolve() }()
+			ec := &erc.Collector{}
+			defer func() { err = ec.Resolve() }()
 			defer s.cancel()
-			catcher.Add(s.senders.Close())
+			ec.Add(s.senders.Close())
 
 			wg.Add(1)
 			go func() {
 				defer wg.Done()
-				catcher.Add(s.senders.Iterator().Observe(ctx, func(sender Sender) {
-					catcher.Add(sender.Close())
-				}))
+				ec.Add(s.senders.Iterator().Observe(func(sender Sender) {
+					ec.Add(sender.Close())
+				}).Run(ctx))
 
 			}()
 
-			catcher.Add(s.senders.Close())
+			ec.Add(s.senders.Close())
 			close(shutdown)
 			wg.Wait(ctx)
 			s.cancel()
@@ -111,24 +111,24 @@ func (s *asyncGroupSender) startSenderWorker(newSender Sender) {
 func (s *asyncGroupSender) SetPriority(p level.Priority) {
 	s.Base.SetPriority(p)
 
-	fun.Invariant.Must(s.senders.Iterator().Observe(s.ctx, func(sender Sender) {
+	fun.Invariant.Must(s.senders.Iterator().Observe(func(sender Sender) {
 		sender.SetPriority(p)
-	}))
+	}).Run(s.ctx))
 }
 
 func (s *asyncGroupSender) SetErrorHandler(erh ErrorHandler) {
 	s.Base.SetErrorHandler(erh)
 
-	fun.Invariant.Must(s.senders.Iterator().Observe(s.ctx, func(sender Sender) {
+	fun.Invariant.Must(s.senders.Iterator().Observe(func(sender Sender) {
 		sender.SetErrorHandler(erh)
-	}))
+	}).Run(s.ctx))
 }
 
 func (s *asyncGroupSender) SetFormatter(fmtr MessageFormatter) {
 	s.Base.SetFormatter(fmtr)
-	fun.Invariant.Must(s.senders.Iterator().Observe(s.ctx, func(sender Sender) {
+	fun.Invariant.Must(s.senders.Iterator().Observe(func(sender Sender) {
 		sender.SetFormatter(fmtr)
-	}))
+	}).Run(s.ctx))
 }
 
 func (s *asyncGroupSender) Send(m message.Composer) {
@@ -141,9 +141,9 @@ func (s *asyncGroupSender) Send(m message.Composer) {
 func (s *asyncGroupSender) Flush(ctx context.Context) error {
 	catcher := &erc.Collector{}
 
-	fun.Invariant.Must(s.senders.Iterator().Observe(s.ctx, func(sender Sender) {
+	fun.Invariant.Must(s.senders.Iterator().Observe(func(sender Sender) {
 		catcher.Add(sender.Flush(ctx))
-	}))
+	}).Run(ctx))
 
 	return catcher.Resolve()
 }
diff --git a/send/base.go b/send/base.go
index 62b4b9e..eeb8a06 100644
--- a/send/base.go
+++ b/send/base.go
@@ -7,7 +7,7 @@ import (
 	"sync/atomic"
 
 	"github.com/tychoish/fun/adt"
-	"github.com/tychoish/fun/erc"
+	"github.com/tychoish/fun/ers"
 	"github.com/tychoish/grip/level"
 	"github.com/tychoish/grip/message"
 )
@@ -43,7 +43,7 @@ var ErrAlreadyClosed = errors.New("sender already closed")
 // an error rooted in ErrAlreadyClosed.
 func (b *Base) Close() error {
 	if swapped := b.closed.CompareAndSwap(false, true); !swapped {
-		return erc.Join(fmt.Errorf("sender %q is already closed: %w", b.Name(), ErrAlreadyClosed), b.doClose())
+		return ers.Join(fmt.Errorf("sender %q is already closed: %w", b.Name(), ErrAlreadyClosed), b.doClose())
 	}
 
 	return b.doClose()
diff --git a/send/error_handler.go b/send/error_handler.go
index f1346d9..6293499 100644
--- a/send/error_handler.go
+++ b/send/error_handler.go
@@ -5,7 +5,6 @@ import (
 	"io"
 	"log"
 
-	"github.com/tychoish/fun/erc"
 	"github.com/tychoish/fun/ers"
 	"github.com/tychoish/grip/level"
 	"github.com/tychoish/grip/message"
@@ -22,7 +21,7 @@ func WrapError(err error, m message.Composer) error {
 		return nil
 	}
 
-	return erc.Join(ErrGripMessageSendError, err, ers.Error(m.String()))
+	return ers.Join(ErrGripMessageSendError, err, ers.Error(m.String()))
 }
 
 func ErrorHandlerWriter(writer io.Writer) ErrorHandler {
diff --git a/series/collector.go b/series/collector.go
index 17629eb..b983ce5 100644
--- a/series/collector.go
+++ b/series/collector.go
@@ -303,8 +303,7 @@ func (c *Collector) spawnBackground(dur time.Duration, tr *tracked) {
 					case <-ctx.Done():
 						return
 					case <-ticker.C:
-						if err := pipe.Iterator().Observe(ctx, func(tr *tracked) {
-
+						if err := pipe.Iterator().Observe(func(tr *tracked) {
 							c.broker.Publish(c.ctx, func(wr io.Writer, r Renderer) error {
 								buf := c.pool.Get()
 								defer c.pool.Put(buf)
@@ -313,7 +312,7 @@ func (c *Collector) spawnBackground(dur time.Duration, tr *tracked) {
 
 								return ft.IgnoreFirst(wr.Write(buf.Bytes()))
 							})
-						}); err != nil {
+						}).Run(ctx); err != nil {
 							return
 						}
 					}
diff --git a/series/persistance.go b/series/persistance.go
index 3c8d244..f6d174b 100644
--- a/series/persistance.go
+++ b/series/persistance.go
@@ -139,7 +139,7 @@ func LoggerBackend(sender send.Sender, r Renderer) CollectorBackend {
 		for iter.Next(ctx) {
 			op := iter.Value()
 			if err := op(wr, r); err != nil {
-				return erc.Join(err, wr.Close())
+				return ers.Join(err, wr.Close())
 			}
 			count++
 		}
@@ -417,7 +417,7 @@ func SocketBackend(opts ...CollectorBakendSocketOptionProvider) (CollectorBacken
 						connCacheSize.Add(1)
 						return
 					}
-					err = erc.Join(err, ft.IgnoreFirst(conf.handleMessageError(ec.Add, conn.conn.Close())))
+					err = ers.Join(err, ft.IgnoreFirst(conf.handleMessageError(ec.Add, conn.conn.Close())))
 				}()
 
 				timer := time.NewTimer(0)
diff --git a/x/metrics/go.mod b/x/metrics/go.mod
index a4ac746..e2b9c5f 100644
--- a/x/metrics/go.mod
+++ b/x/metrics/go.mod
@@ -5,7 +5,7 @@ go 1.20
 require (
 	github.com/shirou/gopsutil v3.21.11+incompatible
 	github.com/tychoish/birch v0.2.3-0.20230815160103-70c52db1b271
-	github.com/tychoish/birch/x/ftdc v0.0.0-20230815160103-70c52db1b271
+	github.com/tychoish/birch/x/ftdc v0.0.0-20230824231239-7522c174b74b
 	github.com/tychoish/fun v0.10.4
 	github.com/tychoish/grip v0.3.5
 )
diff --git a/x/metrics/go.sum b/x/metrics/go.sum
index 70cfa56..72d8ae6 100644
--- a/x/metrics/go.sum
+++ b/x/metrics/go.sum
@@ -15,7 +15,10 @@ github.com/tychoish/birch v0.2.3-0.20230815160103-70c52db1b271 h1:4BBpigJOisXsnT
 github.com/tychoish/birch v0.2.3-0.20230815160103-70c52db1b271/go.mod h1:6VXjKviYBKvDKj5pADE1Ecw79+4AQMQ2PJTkfLXd3Vg=
 github.com/tychoish/birch/x/ftdc v0.0.0-20230815160103-70c52db1b271 h1:atNiog1swK3hIgzPTzdMU20a+rexlCDlbCndAzkzjAo=
 github.com/tychoish/birch/x/ftdc v0.0.0-20230815160103-70c52db1b271/go.mod h1:eAkHGxL73BATG+UC2yeIO9vnyitSjfNbImsN4k+Cx/o=
+github.com/tychoish/birch/x/ftdc v0.0.0-20230824231239-7522c174b74b h1:iIB16kwCNPVRlz6T5Nv5wwzut5acOCTFTMqCIcduVHE=
+github.com/tychoish/birch/x/ftdc v0.0.0-20230824231239-7522c174b74b/go.mod h1:r89lWK437DDM2fS4JO3kYKaYRSTCmrVeSeH6tKvNXos=
 github.com/tychoish/fun v0.10.4 h1:ZV//9hmGCKt5QDdEhEYLVWWjkjJkzhpIwXiHeTjUAOo=
+github.com/tychoish/fun v0.10.4/go.mod h1:ZZfrwtsnHHV81ecZCBPp57DjjYY9Io39JH2QSXNpKn4=
 github.com/tychoish/grip v0.3.5 h1:HPJTW9xaO+kFubhSNCPGBiIBsXWCvGmX8kCtawX0NOA=
 github.com/tychoish/grip v0.3.5/go.mod h1:yUxPpU6c/Z40pyHGlmdUXQyOIW9QooUsw9qB3y0NmBA=
 github.com/yusufpapurcu/wmi v1.2.2 h1:KBNDSne4vP5mbSWnJbO+51IMOXJB67QiYCSBrubbPRg=
diff --git a/x/metrics/series.go b/x/metrics/series.go
index b50225b..e3a6c98 100644
--- a/x/metrics/series.go
+++ b/x/metrics/series.go
@@ -13,28 +13,19 @@ import (
 	"github.com/tychoish/grip/series"
 )
 
-func CollectorConfOutputBSON() series.CollectorOptionProvider {
-	return func(conf *series.CollectorConf) error {
-		conf.LabelRenderer = RenderLabelsBSON
-		conf.MetricRenderer = RenderMetricBSON
-		conf.DefaultHistogramRender = RenderHistogramBSON
-		return nil
+func SeriesRendererBSON() series.Renderer {
+	return series.Renderer{
+		Metric:    RenderMetricBSON,
+		Histogram: RenderHistogramBSON,
 	}
 }
 
-func RenderLabelsBSON(output *bytes.Buffer, labels []dt.Pair[string, string], extra ...dt.Pair[string, string]) {
-	doc := birch.DC.Make(len(labels))
-	dt.Sliceify(append(labels, extra...)).Observe(func(label dt.Pair[string, string]) {
-		doc.Append(birch.EC.String(label.Key, label.Value))
-	})
-
-	fun.Invariant.Must(ft.IgnoreFirst(doc.WriteTo(output)))
-}
-
-func RenderMetricBSON(buf *bytes.Buffer, key string, labels fun.Future[[]byte], value int64, ts time.Time) {
+func RenderMetricBSON(buf *bytes.Buffer, key string, labels fun.Future[*dt.Pairs[string, string]], value int64, ts time.Time) {
 	doc := birch.DC.Elements(birch.EC.String("metric", key))
 	if tags := labels(); tags != nil {
-		doc.Append(birch.EC.SubDocumentFromReader("labels", birch.Reader(tags)))
+		tagdoc := birch.DC.Make(tags.Len())
+		tags.Observe(func(kv dt.Pair[string, string]) { tagdoc.Append(birch.EC.String(kv.Key, kv.Value)) })
+		doc.Append(birch.EC.SubDocument("labels", tagdoc))
 	}
 	doc.Append(
 		birch.EC.Time("ts", ts),
@@ -46,15 +37,18 @@ func RenderMetricBSON(buf *bytes.Buffer, key string, labels fun.Future[[]byte],
 func RenderHistogramBSON(
 	wr *bytes.Buffer,
 	key string,
-	labels fun.Future[[]byte],
+	labels fun.Future[*dt.Pairs[string, string]],
 	sample *dt.Pairs[float64, int64],
 	ts time.Time,
 ) {
 	doc := birch.DC.Elements(birch.EC.String("metric", key))
 
 	if tags := labels(); tags != nil {
-		doc.Append(birch.EC.SubDocumentFromReader("labels", birch.Reader(tags)))
+		tagdoc := birch.DC.Make(tags.Len())
+		tags.Observe(func(kv dt.Pair[string, string]) { tagdoc.Append(birch.EC.String(kv.Key, kv.Value)) })
+		doc.Append(birch.EC.SubDocument("labels", tagdoc))
 	}
+
 	doc.Append(birch.EC.Time("ts", ts))
 	quants := birch.DC.Make(sample.Len())
 	risky.Observe(sample.Iterator(), func(pair dt.Pair[float64, int64]) {