diff --git a/items_0/Cargo.toml b/items_0/Cargo.toml
index 78cf410..4384537 100644
--- a/items_0/Cargo.toml
+++ b/items_0/Cargo.toml
@@ -13,6 +13,7 @@ erased-serde = "0.3"
 serde_json = "1.0"
 bincode = "1.3.3"
 bytes = "1.2.1"
+futures-util = "0.3.24"
 chrono = { version = "0.4.19", features = ["serde"] }
 netpod = { path = "../netpod" }
 err = { path = "../err" }
diff --git a/items_0/src/items_0.rs b/items_0/src/items_0.rs
index 8699731..407321f 100644
--- a/items_0/src/items_0.rs
+++ b/items_0/src/items_0.rs
@@ -12,6 +12,8 @@ pub mod bincode {
     pub use bincode::*;
 }
 
+pub use futures_util;
+
 use collect_s::Collectable;
 use container::ByteEstimate;
 use netpod::range::evrange::SeriesRange;
diff --git a/items_0/src/transform.rs b/items_0/src/transform.rs
index 970af93..404bc34 100644
--- a/items_0/src/transform.rs
+++ b/items_0/src/transform.rs
@@ -1,4 +1,12 @@
+use crate::collect_s::Collected;
+use crate::streamitem::RangeCompletableItem;
+use crate::streamitem::Sitemty;
+use crate::streamitem::StreamItem;
 use crate::Events;
+use err::Error;
+use futures_util::stream;
+use futures_util::Future;
+use futures_util::Stream;
 use std::pin::Pin;
 
 pub struct TransformProperties {
@@ -6,8 +14,29 @@ pub struct TransformProperties {
     pub needs_value: bool,
 }
 
-pub trait EventTransform {
+pub trait WithTransformProperties {
     fn query_transform_properties(&self) -> TransformProperties;
+}
+
+impl<T> WithTransformProperties for Box<T>
+where
+    T: WithTransformProperties,
+{
+    fn query_transform_properties(&self) -> TransformProperties {
+        self.as_ref().query_transform_properties()
+    }
+}
+
+impl<T> WithTransformProperties for Pin<Box<T>>
+where
+    T: WithTransformProperties,
+{
+    fn query_transform_properties(&self) -> TransformProperties {
+        self.as_ref().query_transform_properties()
+    }
+}
+
+pub trait EventTransform: WithTransformProperties {
     fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events>;
 }
 
@@ -15,12 +44,8 @@ impl<T> EventTransform for Box<T>
 where
     T: EventTransform,
 {
-    fn query_transform_properties(&self) -> TransformProperties {
-        self.as_ref().query_transform_properties()
-    }
-
     fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
-        todo!()
+        self.as_mut().transform(src)
     }
 }
 
@@ -28,10 +53,6 @@ impl<T> EventTransform for Pin<Box<T>>
 where
     T: EventTransform,
 {
-    fn query_transform_properties(&self) -> TransformProperties {
-        self.as_ref().query_transform_properties()
-    }
-
     fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
         todo!()
     }
@@ -45,12 +66,57 @@ impl IdentityTransform {
     }
 }
 
-impl EventTransform for IdentityTransform {
-    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
-        src
-    }
-
+impl WithTransformProperties for IdentityTransform {
     fn query_transform_properties(&self) -> TransformProperties {
         todo!()
     }
 }
+
+impl EventTransform for IdentityTransform {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        src
+    }
+}
+
+pub struct TransformEvent(pub Box<dyn EventTransform>);
+
+impl WithTransformProperties for TransformEvent {
+    fn query_transform_properties(&self) -> TransformProperties {
+        self.0.query_transform_properties()
+    }
+}
+
+impl EventTransform for TransformEvent {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        self.0.transform(src)
+    }
+}
+
+pub struct EventStream(pub Pin<Box<dyn Stream<Item = Sitemty<Box<dyn Events>>> + Send>>);
+
+impl<T> From<T> for EventStream
+where
+    T: Events,
+{
+    fn from(value: T) -> Self {
+        let item = Ok(StreamItem::DataItem(RangeCompletableItem::Data(Box::new(value) as _)));
+        let x = stream::iter(vec![item]);
+        EventStream(Box::pin(x))
+    }
+}
+
+// TODO these must return type which can take events as input.
+
+pub struct TransformedCollectedStream(pub Pin<Box<dyn Future<Output = Result<Box<dyn Collected>, Error>>>>);
+
+impl WithTransformProperties for TransformedCollectedStream {
+    fn query_transform_properties(&self) -> TransformProperties {
+        todo!()
+    }
+}
+
+impl EventTransform for TransformedCollectedStream {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        todo!()
+    }
+}
diff --git a/items_2/src/items_2.rs b/items_2/src/items_2.rs
index 8d4dbf7..87c2cb2 100644
--- a/items_2/src/items_2.rs
+++ b/items_2/src/items_2.rs
@@ -15,6 +15,7 @@ pub mod streams;
 #[cfg(test)]
 pub mod test;
 pub mod testgen;
+pub mod transform;
 
 use channelevents::ChannelEvents;
 use chrono::DateTime;
diff --git a/items_2/src/merger.rs b/items_2/src/merger.rs
index 02fb230..7dc8d1f 100644
--- a/items_2/src/merger.rs
+++ b/items_2/src/merger.rs
@@ -9,6 +9,7 @@ use items_0::streamitem::Sitemty;
 use items_0::streamitem::StreamItem;
 use items_0::transform::EventTransform;
 use items_0::transform::TransformProperties;
+use items_0::transform::WithTransformProperties;
 use items_0::MergeError;
 use items_0::WithLen;
 use netpod::log::*;
@@ -444,11 +445,13 @@ where
     }
 }
 
-impl<T> EventTransform for Merger<T> {
+impl<T> WithTransformProperties for Merger<T> {
     fn query_transform_properties(&self) -> TransformProperties {
         todo!()
     }
+}
 
+impl<T> EventTransform for Merger<T> {
     fn transform(&mut self, src: Box<dyn items_0::Events>) -> Box<dyn items_0::Events> {
         todo!()
     }
diff --git a/items_2/src/streams.rs b/items_2/src/streams.rs
index 8f40640..c3db44a 100644
--- a/items_2/src/streams.rs
+++ b/items_2/src/streams.rs
@@ -4,6 +4,7 @@ use futures_util::Stream;
 use futures_util::StreamExt;
 use items_0::transform::EventTransform;
 use items_0::transform::TransformProperties;
+use items_0::transform::WithTransformProperties;
 use std::collections::VecDeque;
 use std::pin::Pin;
 use std::task::Context;
@@ -43,11 +44,19 @@ where
     }
 }
 
-impl<T> EventTransform for Enumerate2<T> {
+impl<T> WithTransformProperties for Enumerate2<T>
+where
+    T: WithTransformProperties,
+{
     fn query_transform_properties(&self) -> TransformProperties {
-        todo!()
+        self.inp.query_transform_properties()
     }
+}
 
+impl<T> EventTransform for Enumerate2<T>
+where
+    T: WithTransformProperties,
+{
     fn transform(&mut self, src: Box<dyn items_0::Events>) -> Box<dyn items_0::Events> {
         todo!()
     }
@@ -64,7 +73,10 @@ where
     T: Stream,
     F: Fn(<T as Stream>::Item) -> Fut,
 {
-    pub fn new(inp: T, f: F) -> Self {
+    pub fn new(inp: T, f: F) -> Self
+    where
+        T: EventTransform,
+    {
         Self {
             inp: Box::pin(inp),
             f: Box::pin(f),
@@ -118,11 +130,19 @@ where
     }
 }
 
-impl<T, F, Fut> EventTransform for Then2<T, F, Fut> {
+impl<T, F, Fut> WithTransformProperties for Then2<T, F, Fut>
+where
+    T: EventTransform,
+{
     fn query_transform_properties(&self) -> TransformProperties {
-        todo!()
+        self.inp.query_transform_properties()
     }
+}
 
+impl<T, F, Fut> EventTransform for Then2<T, F, Fut>
+where
+    T: EventTransform,
+{
     fn transform(&mut self, src: Box<dyn items_0::Events>) -> Box<dyn items_0::Events> {
         todo!()
     }
@@ -186,11 +206,13 @@ where
     }
 }
 
-impl<T> EventTransform for VecStream<T> {
+impl<T> WithTransformProperties for VecStream<T> {
     fn query_transform_properties(&self) -> TransformProperties {
         todo!()
     }
+}
 
+impl<T> EventTransform for VecStream<T> {
     fn transform(&mut self, src: Box<dyn items_0::Events>) -> Box<dyn items_0::Events> {
         todo!()
     }
diff --git a/items_2/src/transform.rs b/items_2/src/transform.rs
new file mode 100644
index 0000000..5edfe5c
--- /dev/null
+++ b/items_2/src/transform.rs
@@ -0,0 +1,97 @@
+//! Helper functions to create transforms which act locally on a batch of events.
+//! Tailored to the usage pattern given by `TransformQuery`.
+
+use crate::channelevents::ChannelEvents;
+use crate::eventsdim0::EventsDim0;
+use items_0::transform::EventStream;
+use items_0::transform::EventTransform;
+use items_0::transform::TransformEvent;
+use items_0::transform::TransformProperties;
+use items_0::transform::WithTransformProperties;
+use items_0::Appendable;
+use items_0::AsAnyMut;
+use items_0::Empty;
+use items_0::Events;
+use items_0::EventsNonObj;
+use netpod::log::*;
+use std::mem;
+
+struct TransformEventIdentity {}
+
+impl WithTransformProperties for TransformEventIdentity {
+    fn query_transform_properties(&self) -> TransformProperties {
+        todo!()
+    }
+}
+
+impl EventTransform for TransformEventIdentity {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        todo!()
+    }
+}
+
+pub fn make_transform_identity() -> TransformEvent {
+    TransformEvent(Box::new(TransformEventIdentity {}))
+}
+
+struct TransformEventMinMaxAvg {}
+
+impl WithTransformProperties for TransformEventMinMaxAvg {
+    fn query_transform_properties(&self) -> TransformProperties {
+        todo!()
+    }
+}
+
+impl EventTransform for TransformEventMinMaxAvg {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        todo!()
+    }
+}
+
+pub fn make_transform_min_max_avg() -> TransformEvent {
+    TransformEvent(Box::new(TransformEventMinMaxAvg {}))
+}
+
+struct TransformEventPulseIdDiff {}
+
+impl WithTransformProperties for TransformEventPulseIdDiff {
+    fn query_transform_properties(&self) -> TransformProperties {
+        todo!()
+    }
+}
+
+impl EventTransform for TransformEventPulseIdDiff {
+    fn transform(&mut self, src: Box<dyn Events>) -> Box<dyn Events> {
+        let mut src = src;
+        if let Some(chevs) = src.as_any_mut().downcast_mut::<ChannelEvents>() {
+            let chevs2 = chevs;
+            let chevs = mem::replace(chevs2, ChannelEvents::Status(None));
+            let mut pulse_last = None;
+            match chevs {
+                ChannelEvents::Events(item) => {
+                    let (tss, pulses) = EventsNonObj::into_tss_pulses(item);
+                    let mut item = EventsDim0::empty();
+                    for (ts, pulse) in tss.into_iter().zip(pulses) {
+                        let value = if let Some(last) = pulse_last {
+                            pulse as i64 - last as i64
+                        } else {
+                            0
+                        };
+                        item.push(ts, pulse, value);
+                        pulse_last = Some(pulse);
+                    }
+                    *chevs2 = ChannelEvents::Events(Box::new(item));
+                }
+                ChannelEvents::Status(_) => {}
+            }
+            src
+        } else {
+            warn!("make_transform_pulse_id_diff item is not ChannelEvents");
+            src
+        }
+    }
+}
+
+pub fn make_transform_pulse_id_diff() -> TransformEvent {
+    TransformEvent(Box::new(TransformEventPulseIdDiff {}))
+}
diff --git a/query/Cargo.toml b/query/Cargo.toml
index f617061..3dca474 100644
--- a/query/Cargo.toml
+++ b/query/Cargo.toml
@@ -14,3 +14,4 @@ humantime-serde = "1.1.1"
 err = { path = "../err" }
 netpod = { path = "../netpod" }
 items_0 = { path = "../items_0" }
+items_2 = { path = "../items_2" }
diff --git a/query/src/transform.rs b/query/src/transform.rs
index efd119c..b9ac9c8 100644
--- a/query/src/transform.rs
+++ b/query/src/transform.rs
@@ -1,4 +1,10 @@
 use err::Error;
+use items_0::transform::EventStream;
+use items_0::transform::TransformEvent;
+use items_0::transform::TransformedCollectedStream;
+use items_2::transform::make_transform_identity;
+use items_2::transform::make_transform_min_max_avg;
+use items_2::transform::make_transform_pulse_id_diff;
 use netpod::get_url_query_pairs;
 use netpod::log::*;
 use netpod::AppendToUrl;
@@ -108,7 +114,31 @@ impl TransformQuery {
         }
     }
 
-    pub fn build_event_transform(&self) -> () {}
+    pub fn build_event_transform(&self, inp: EventStream) -> Result<TransformEvent, Error> {
+        match &self.event {
+            EventTransformQuery::ValueFull => Ok(make_transform_identity()),
+            EventTransformQuery::MinMaxAvgDev => Ok(make_transform_min_max_avg()),
+            EventTransformQuery::ArrayPick(..) => Err(Error::with_msg_no_trace(format!(
+                "build_event_transform don't know what to do {self:?}"
+            ))),
+            EventTransformQuery::PulseIdDiff => Ok(make_transform_pulse_id_diff()),
+            EventTransformQuery::EventBlobsVerbatim => Err(Error::with_msg_no_trace(format!(
+                "build_event_transform don't know what to do {self:?}"
+            ))),
+            EventTransformQuery::EventBlobsUncompressed => Err(Error::with_msg_no_trace(format!(
+                "build_event_transform don't know what to do {self:?}"
+            ))),
+        }
+    }
+
+    pub fn build_full_transform_collected(&self, inp: EventStream) -> Result<TransformedCollectedStream, Error> {
+        let evs = self.build_event_transform(inp)?;
+        match &self.time_binning {
+            TimeBinningTransformQuery::None => todo!(),
+            TimeBinningTransformQuery::TimeWeighted => todo!(),
+            TimeBinningTransformQuery::Unweighted => todo!(),
+        }
+    }
 }
 
 impl FromUrl for TransformQuery {
diff --git a/streams/src/boxed.rs b/streams/src/boxed.rs
new file mode 100644
index 0000000..2abfaa4
--- /dev/null
+++ b/streams/src/boxed.rs
@@ -0,0 +1,20 @@
+use futures_util::stream::StreamExt;
+use futures_util::Stream;
+use items_0::on_sitemty_data;
+use items_0::streamitem::Sitemty;
+use items_0::transform::EventStream;
+use items_0::Events;
+
+pub fn boxed_event_stream<T, S>(inp: S) -> EventStream
+where
+    T: Events,
+    S: Stream<Item = Sitemty<T>> + Send + 'static,
+{
+    let stream = inp.map(|x| {
+        let x = on_sitemty_data!(x, |x| Ok(StreamItem::DataItem(RangeCompletableItem::Data(
+            Box::new(x) as Box<dyn Events>
+        ))));
+        x
+    });
+    EventStream(Box::pin(stream))
+}
diff --git a/streams/src/generators.rs b/streams/src/generators.rs
index ea1bbe1..cc9d583 100644
--- a/streams/src/generators.rs
+++ b/streams/src/generators.rs
@@ -3,7 +3,9 @@ use futures_util::FutureExt;
 use futures_util::Stream;
 use items_0::container::ByteEstimate;
 use items_0::streamitem::sitem_data;
+use items_0::streamitem::RangeCompletableItem;
 use items_0::streamitem::Sitemty;
+use items_0::streamitem::StreamItem;
 use items_0::Appendable;
 use items_0::Empty;
 use items_2::channelevents::ChannelEvents;
@@ -21,6 +23,8 @@ pub struct GenerateI32 {
     #[allow(unused)]
     c1: u64,
     timeout: Option<Pin<Box<dyn Future<Output = ()> + Send>>>,
+    done: bool,
+    done_range_final: bool,
 }
 
 impl GenerateI32 {
@@ -38,6 +42,8 @@ impl GenerateI32 {
             tsend,
             c1: 0,
             timeout: None,
+            done: false,
+            done_range_final: false,
         }
     }
 
@@ -67,8 +73,12 @@ impl Stream for GenerateI32 {
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
         use Poll::*;
         loop {
-            break if self.ts >= self.tsend {
+            break if self.done_range_final {
                 Ready(None)
+            } else if self.ts >= self.tsend {
+                self.done = true;
+                self.done_range_final = true;
+                Ready(Some(Ok(StreamItem::DataItem(RangeCompletableItem::RangeComplete))))
             } else if false {
                 // To use the generator without throttling, use this scope
                 Ready(Some(self.make_batch()))
diff --git a/streams/src/lib.rs b/streams/src/lib.rs
index 1be5a74..0095b59 100644
--- a/streams/src/lib.rs
+++ b/streams/src/lib.rs
@@ -1,3 +1,4 @@
+pub mod boxed;
 pub mod collect;
 pub mod dtflags;
 pub mod filechunkread;
diff --git a/streams/src/test/timebin.rs b/streams/src/test/timebin.rs
index faae2bf..493e975 100644
--- a/streams/src/test/timebin.rs
+++ b/streams/src/test/timebin.rs
@@ -16,12 +16,14 @@ use items_2::binsdim0::BinsDim0;
 use items_2::channelevents::ChannelEvents;
 use items_2::channelevents::ConnStatus;
 use items_2::channelevents::ConnStatusEvent;
+use items_2::eventsdim0::EventsDim0;
 use items_2::testgen::make_some_boxed_d0_f32;
 use netpod::range::evrange::NanoRange;
 use netpod::range::evrange::SeriesRange;
 use netpod::timeunits::MS;
 use netpod::timeunits::SEC;
 use netpod::BinnedRangeEnum;
+use query::transform::TransformQuery;
 use serde_json::Value as JsValue;
 use std::collections::VecDeque;
 use std::time::Duration;
@@ -209,6 +211,10 @@ fn time_bin_02() -> Result<(), Error> {
             let s = String::from_utf8_lossy(&d);
             eprintln!("{s}");
             let jsval: JsValue = serde_json::from_slice(&d)?;
+            {
+                let ts_anchor = jsval.get("tsAnchor").unwrap().as_u64().unwrap();
+                assert_eq!(ts_anchor, 1200);
+            }
             {
                 let counts = jsval.get("counts").unwrap().as_array().unwrap();
                 assert_eq!(counts.len(), expected_bin_count);
@@ -232,6 +238,10 @@ fn time_bin_02() -> Result<(), Error> {
                     assert_eq!((40 + ts1ms.as_u64().unwrap() / 100) % 1000, max.as_u64().unwrap());
                 }
             }
+            {
+                let range_final = jsval.get("rangeFinal").unwrap().as_bool().unwrap();
+                assert_eq!(range_final, true);
+            }
         }
         Ok(())
     };
@@ -239,3 +249,12 @@ fn time_bin_02() -> Result<(), Error> {
 }
 
 // TODO add test case to observe RangeComplete after binning.
+
+#[test]
+fn transform_chain_correctness_01() -> Result<(), Error> {
+    type STY = f32;
+    let tq = TransformQuery::default_time_binned();
+    let empty = EventsDim0::<STY>::empty();
+    tq.build_event_transform(empty.into())?;
+    Ok(())
+}