diff --git a/Cargo.lock b/Cargo.lock
index be64bc53..4500b8ba 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3887,7 +3887,6 @@ dependencies = [
 [[package]]
 name = "zenoh"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "ahash",
  "arc-swap",
@@ -3938,7 +3937,6 @@ dependencies = [
 [[package]]
 name = "zenoh-buffers"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "zenoh-collections",
 ]
@@ -3946,7 +3944,6 @@ dependencies = [
 [[package]]
 name = "zenoh-codec"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "tracing",
  "uhlc",
@@ -3958,7 +3955,6 @@ dependencies = [
 [[package]]
 name = "zenoh-collections"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "ahash",
 ]
@@ -3966,7 +3962,6 @@ dependencies = [
 [[package]]
 name = "zenoh-config"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "json5",
  "nonempty-collections",
@@ -3991,7 +3986,6 @@ dependencies = [
 [[package]]
 name = "zenoh-core"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "lazy_static",
  "tokio",
@@ -4002,7 +3996,6 @@ dependencies = [
 [[package]]
 name = "zenoh-crypto"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "aes",
  "hmac",
@@ -4015,7 +4008,6 @@ dependencies = [
 [[package]]
 name = "zenoh-ext"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "bincode",
@@ -4034,7 +4026,6 @@ dependencies = [
 [[package]]
 name = "zenoh-keyexpr"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "getrandom 0.2.17",
  "hashbrown 0.16.1",
@@ -4049,7 +4040,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "zenoh-config",
  "zenoh-link-commons",
@@ -4067,7 +4057,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-commons"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "base64",
@@ -4103,7 +4092,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-quic"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "rustls-webpki",
@@ -4119,7 +4107,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-quic_datagram"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "rustls-webpki",
@@ -4135,7 +4122,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-tcp"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "socket2 0.5.10",
@@ -4152,7 +4138,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-tls"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "base64",
@@ -4181,7 +4166,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-udp"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "libc",
@@ -4203,7 +4187,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-unixsock_stream"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "nix",
@@ -4221,7 +4204,6 @@ dependencies = [
 [[package]]
 name = "zenoh-link-ws"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "futures-util",
@@ -4241,7 +4223,6 @@ dependencies = [
 [[package]]
 name = "zenoh-macros"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -4252,7 +4233,6 @@ dependencies = [
 [[package]]
 name = "zenoh-plugin-trait"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "git-version",
  "libloading",
@@ -4269,7 +4249,6 @@ dependencies = [
 [[package]]
 name = "zenoh-protocol"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "const_format",
  "rand 0.8.5",
@@ -4294,7 +4273,6 @@ dependencies = [
 [[package]]
 name = "zenoh-result"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "anyhow",
 ]
@@ -4302,7 +4280,6 @@ dependencies = [
 [[package]]
 name = "zenoh-runtime"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "lazy_static",
  "ron",
@@ -4316,7 +4293,6 @@ dependencies = [
 [[package]]
 name = "zenoh-shm"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "advisory-lock",
  "async-trait",
@@ -4345,7 +4321,6 @@ dependencies = [
 [[package]]
 name = "zenoh-stats"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "ahash",
  "prometheus-client",
@@ -4358,7 +4333,6 @@ dependencies = [
 [[package]]
 name = "zenoh-sync"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "arc-swap",
  "event-listener",
@@ -4372,7 +4346,6 @@ dependencies = [
 [[package]]
 name = "zenoh-task"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "futures",
  "tokio",
@@ -4385,7 +4358,6 @@ dependencies = [
 [[package]]
 name = "zenoh-transport"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "crossbeam-utils",
@@ -4421,7 +4393,6 @@ dependencies = [
 [[package]]
 name = "zenoh-util"
 version = "1.9.0"
-source = "git+https://github.com/eclipse-zenoh/zenoh.git?branch=main#90c06a28c7e1d396ea1a97b3a63a5e6a38afc6ee"
 dependencies = [
  "async-trait",
  "const_format",
diff --git a/Cargo.toml b/Cargo.toml
index ff161af4..ec312428 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,10 +44,10 @@ maintenance = { status = "actively-developed" }
 [dependencies]
 paste = "1.0.14"
 pyo3 = { version = "0.25.1", features = ["abi3-py39", "extension-module"] }
-zenoh = { version = "1.9.0", git = "https://github.com/eclipse-zenoh/zenoh.git", branch = "main", features = [
+zenoh = { version = "1.9.0", git = "https://github.com/YuanYuYuan/zenoh.git", branch = "feat/routing-timestamps", features = [
   "internal",
   "unstable",
 ], default-features = false }
-zenoh-ext = { version = "1.9.0", git = "https://github.com/eclipse-zenoh/zenoh.git", branch = "main", features = [
+zenoh-ext = { version = "1.9.0", git = "https://github.com/YuanYuYuan/zenoh.git", branch = "feat/routing-timestamps", features = [
   "internal",
 ], optional = true }
diff --git a/examples/z_timestamp_instrumentation.py b/examples/z_timestamp_instrumentation.py
new file mode 100644
index 00000000..d4c0ab65
--- /dev/null
+++ b/examples/z_timestamp_instrumentation.py
@@ -0,0 +1,114 @@
+#
+# Copyright (c) 2026 ZettaScale Technology
+#
+# This program and the accompanying materials are made available under the
+# terms of the Eclipse Public License 2.0 which is available at
+# http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+# which is available at https://www.apache.org/licenses/LICENSE-2.0.
+#
+# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+#
+# Contributors:
+#   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+#
+# Demonstrates opt-in end-to-end latency instrumentation.
+#
+# Run this example to see Send/Route/Receive timestamps on each message.
+# The custom_callback variant shows how to inject your own clock bytes.
+#
+import time
+
+import zenoh
+from zenoh import InterceptionPoint, TimestampInstrumentation
+
+
+def print_stack(stack):
+    if stack is None:
+        print("  (no timestamp stack)")
+        return
+    for rec in stack.records:
+        ts = rec.as_timestamp()
+        if ts is not None:
+            print(f"  {rec.point.name:8s}  hlc={ts}  custom={rec.is_custom}")
+        else:
+            print(
+                f"  {rec.point.name:8s}  raw={rec.timestamp().hex()}  custom={rec.is_custom}"
+            )
+
+
+def example_put_subscribe(session):
+    print("\n── put/subscribe with send+receive instrumentation ─────────────────")
+    instr = TimestampInstrumentation(send=True, receive=True)
+    received = []
+    with session.declare_subscriber("demo/ts/**", lambda s: received.append(s)):
+        time.sleep(0.05)
+        session.put("demo/ts/hello", b"world", timestamp_instrumentation=instr)
+        time.sleep(0.2)
+    if received:
+        print(f"Received sample on '{received[0].key_expr}':")
+        print_stack(received[0].timestamp_stack)
+
+
+def example_publisher_default(session):
+    print("\n── publisher with default instrumentation ───────────────────────────")
+    instr = TimestampInstrumentation(send=True, receive=True)
+    received = []
+    with session.declare_publisher(
+        "demo/ts/pub", timestamp_instrumentation=instr
+    ) as pub:
+        with session.declare_subscriber("demo/ts/pub", lambda s: received.append(s)):
+            time.sleep(0.05)
+            pub.put(b"message-1")
+            pub.put(
+                b"message-2",
+                timestamp_instrumentation=TimestampInstrumentation(send=True),
+            )
+            time.sleep(0.2)
+    for s in received:
+        print(f"Received '{s.payload.to_string()}':")
+        print_stack(s.timestamp_stack)
+
+
+def example_custom_callback():
+    print("\n── session with custom timestamp callback ───────────────────────────")
+    import struct
+    import time as _t
+
+    def my_clock(ctx):
+        # Return a simple 8-byte little-endian nanosecond timestamp.
+        ns = int(_t.time_ns())
+        return struct.pack("<Q", ns)
+
+    instr = TimestampInstrumentation(send=True, receive=True)
+    received = []
+    with zenoh.open(zenoh.Config(), timestamp_callback=my_clock) as session:
+        with session.declare_subscriber("demo/ts/custom", lambda s: received.append(s)):
+            time.sleep(0.05)
+            session.put("demo/ts/custom", b"data", timestamp_instrumentation=instr)
+            time.sleep(0.2)
+    if received:
+        print("Received sample with custom timestamps:")
+        print_stack(received[0].timestamp_stack)
+
+
+def main(conf: zenoh.Config):
+    zenoh.init_log_from_env_or("error")
+    print("Opening session...")
+    with zenoh.open(conf) as session:
+        example_put_subscribe(session)
+        example_publisher_default(session)
+    example_custom_callback()
+    print("\nDone.")
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description="Zenoh timestamp instrumentation example"
+    )
+    parser.add_argument("--config", "-c", type=str, help="Path to zenoh config file")
+    args = parser.parse_args()
+
+    conf = zenoh.Config.from_file(args.config) if args.config else zenoh.Config()
+    main(conf)
diff --git a/src/lib.rs b/src/lib.rs
index 09235cce..72db2f4a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -32,6 +32,7 @@ mod session;
 #[cfg(feature = "shared-memory")]
 mod shm;
 mod time;
+mod timestamp_stack;
 mod utils;
 
 use pyo3::prelude::*;
@@ -77,6 +78,10 @@ pub(crate) mod zenoh {
             Transport, TransportEvent, TransportEventsListener,
         },
         time::{Timestamp, TimestampId, NTP64},
+        timestamp_stack::{
+            InterceptionPoint, TimestampInstrumentation, TimestampStack, TimestampStackRecord,
+            TsStackContext,
+        },
         ZError,
     };
 
diff --git a/src/pubsub.rs b/src/pubsub.rs
index f5c46ef0..357904ac 100644
--- a/src/pubsub.rs
+++ b/src/pubsub.rs
@@ -27,6 +27,7 @@ use crate::{
     sample::{Sample, SourceInfo},
     session::EntityGlobalId,
     time::Timestamp,
+    timestamp_stack::TimestampInstrumentation,
     utils::{generic, wait},
 };
 
@@ -84,7 +85,8 @@ impl Publisher {
         Ok(wait(py, self.get_ref()?.matching_status())?.into())
     }
 
-    #[pyo3(signature = (payload, *, encoding = None, attachment = None, timestamp = None, source_info = None))]
+    #[allow(clippy::too_many_arguments)]
+    #[pyo3(signature = (payload, *, encoding = None, attachment = None, timestamp = None, source_info = None, timestamp_instrumentation = None))]
     fn put(
         &self,
         py: Python,
@@ -93,15 +95,19 @@ impl Publisher {
         #[pyo3(from_py_with = ZBytes::from_py_opt)] attachment: Option<ZBytes>,
         timestamp: Option<Timestamp>,
         source_info: Option<SourceInfo>,
+        timestamp_instrumentation: Option<TimestampInstrumentation>,
     ) -> PyResult<()> {
         let this = self.get_ref()?;
-        let builder = build!(
+        let mut builder = build!(
             this.put(payload),
             encoding,
             attachment,
             timestamp,
             source_info
         );
+        if let Some(instr) = timestamp_instrumentation {
+            builder = builder.timestamp_instrumentation(Some(instr.0));
+        }
         wait(py, builder)
     }
 
diff --git a/src/query.rs b/src/query.rs
index 17d5e674..ccd785c7 100644
--- a/src/query.rs
+++ b/src/query.rs
@@ -30,6 +30,7 @@ use crate::{
     sample::SourceInfo,
     session::EntityGlobalId,
     time::Timestamp,
+    timestamp_stack::TimestampStack,
     utils::{generic, wait, IntoPyResult, IntoPython, IntoRust, MapInto},
 };
 
@@ -276,6 +277,14 @@ impl Reply {
         self.0.replier_id().map_into()
     }
 
+    #[getter]
+    fn timestamp_stack(&self) -> Option<TimestampStack> {
+        match self.0.result() {
+            Ok(sample) => sample.timestamp_stack().cloned().map(TimestampStack),
+            Err(err) => err.timestamp_stack().cloned().map(TimestampStack),
+        }
+    }
+
     fn __repr__(&self) -> String {
         format!("{:?}", self.0)
     }
@@ -295,6 +304,11 @@ impl ReplyError {
         self.0.encoding().clone().into()
     }
 
+    #[getter]
+    fn timestamp_stack(&self) -> Option<TimestampStack> {
+        self.0.timestamp_stack().cloned().map(TimestampStack)
+    }
+
     fn __repr__(&self) -> String {
         format!("{:?}", self.0)
     }
diff --git a/src/sample.rs b/src/sample.rs
index dce32cf6..07aaea53 100644
--- a/src/sample.rs
+++ b/src/sample.rs
@@ -21,6 +21,7 @@ use crate::{
     qos::{CongestionControl, Priority},
     session::EntityGlobalId,
     time::Timestamp,
+    timestamp_stack::TimestampStack,
     utils::MapInto,
 };
 
@@ -95,6 +96,11 @@ impl Sample {
         self.0.source_info().cloned().map_into()
     }
 
+    #[getter]
+    fn timestamp_stack(&self) -> Option<TimestampStack> {
+        self.0.timestamp_stack().cloned().map(TimestampStack)
+    }
+
     fn __repr__(&self) -> String {
         format!("{:?}", self.0)
     }
diff --git a/src/session.rs b/src/session.rs
index 92ae591e..686fc964 100644
--- a/src/session.rs
+++ b/src/session.rs
@@ -33,6 +33,7 @@ use crate::{
     query::{Querier, QueryConsolidation, QueryTarget, Queryable, Reply, ReplyKeyExpr, Selector},
     sample::{Locality, SampleKind, SourceInfo},
     time::Timestamp,
+    timestamp_stack::{py_to_session_ts_callback, TimestampInstrumentation},
     utils::{duration, wait, IntoPython, MapInto},
 };
 
@@ -94,7 +95,7 @@ impl Session {
     }
 
     #[allow(clippy::too_many_arguments)]
-    #[pyo3(signature = (key_expr, payload, *, encoding = None, congestion_control = None, priority = None, express = None, attachment = None, timestamp = None, allowed_destination = None, source_info = None))]
+    #[pyo3(signature = (key_expr, payload, *, encoding = None, congestion_control = None, priority = None, express = None, attachment = None, timestamp = None, allowed_destination = None, source_info = None, timestamp_instrumentation = None))]
     fn put(
         &self,
         py: Python,
@@ -108,8 +109,9 @@ impl Session {
         timestamp: Option<Timestamp>,
         allowed_destination: Option<Locality>,
         source_info: Option<SourceInfo>,
+        timestamp_instrumentation: Option<TimestampInstrumentation>,
     ) -> PyResult<()> {
-        let build = build!(
+        let mut build = build!(
             self.0.put(key_expr, payload),
             encoding,
             congestion_control,
@@ -120,6 +122,9 @@ impl Session {
             allowed_destination,
             source_info,
         );
+        if let Some(instr) = timestamp_instrumentation {
+            build = build.timestamp_instrumentation(Some(instr.0));
+        }
         wait(py, build)
     }
 
@@ -151,7 +156,7 @@ impl Session {
     }
 
     #[allow(clippy::too_many_arguments)]
-    #[pyo3(signature = (selector, handler = None, *, target = None, consolidation = None, accept_replies = None, timeout = None, congestion_control = None, priority = None, express = None, payload = None, encoding = None, attachment = None, allowed_destination = None, source_info = None, cancellation_token = None))]
+    #[pyo3(signature = (selector, handler = None, *, target = None, consolidation = None, accept_replies = None, timeout = None, congestion_control = None, priority = None, express = None, payload = None, encoding = None, attachment = None, allowed_destination = None, source_info = None, cancellation_token = None, timestamp_instrumentation = None))]
     fn get(
         &self,
         py: Python,
@@ -172,9 +177,10 @@ impl Session {
         allowed_destination: Option<Locality>,
         source_info: Option<SourceInfo>,
         cancellation_token: Option<CancellationToken>,
+        timestamp_instrumentation: Option<TimestampInstrumentation>,
     ) -> PyResult<HandlerImpl<Reply>> {
         let (handler, _) = into_handler(py, handler, cancellation_token.as_ref())?;
-        let builder = build!(
+        let mut builder = build!(
             self.0.get(selector),
             target,
             consolidation,
@@ -190,7 +196,9 @@ impl Session {
             source_info,
             cancellation_token
         );
-
+        if let Some(instr) = timestamp_instrumentation {
+            builder = builder.timestamp_instrumentation(Some(instr.0));
+        }
         wait(py, builder.with(handler)).map_into()
     }
 
@@ -235,7 +243,7 @@ impl Session {
     }
 
     #[allow(clippy::too_many_arguments)]
-    #[pyo3(signature = (key_expr, *, encoding = None, congestion_control = None, priority = None, express = None, reliability = None, allowed_destination = None))]
+    #[pyo3(signature = (key_expr, *, encoding = None, congestion_control = None, priority = None, express = None, reliability = None, allowed_destination = None, timestamp_instrumentation = None))]
     fn declare_publisher(
         &self,
         py: Python,
@@ -246,8 +254,9 @@ impl Session {
         express: Option<bool>,
         reliability: Option<Reliability>,
         allowed_destination: Option<Locality>,
+        timestamp_instrumentation: Option<TimestampInstrumentation>,
     ) -> PyResult<Publisher> {
-        let builder = build!(
+        let mut builder = build!(
             self.0.declare_publisher(key_expr),
             encoding,
             congestion_control,
@@ -256,6 +265,9 @@ impl Session {
             reliability,
             allowed_destination,
         );
+        if let Some(instr) = timestamp_instrumentation {
+            builder = builder.timestamp_instrumentation(Some(instr.0));
+        }
         wait(py, builder).map_into()
     }
 
@@ -306,8 +318,17 @@ impl Drop for Session {
 }
 
 #[pyfunction]
-pub(crate) fn open(py: Python, config: Config) -> PyResult<Session> {
-    wait(py, zenoh::open(config)).map(Session)
+#[pyo3(signature = (config, *, timestamp_callback = None))]
+pub(crate) fn open(
+    py: Python,
+    config: Config,
+    timestamp_callback: Option<PyObject>,
+) -> PyResult<Session> {
+    let mut builder = zenoh::open(config);
+    if let Some(cb) = timestamp_callback {
+        builder = builder.with_timestamp_callback(py_to_session_ts_callback(cb));
+    }
+    wait(py, builder).map(Session)
 }
 
 wrapper!(zenoh::session::SessionInfo);
diff --git a/src/timestamp_stack.rs b/src/timestamp_stack.rs
new file mode 100644
index 00000000..e0c13300
--- /dev/null
+++ b/src/timestamp_stack.rs
@@ -0,0 +1,182 @@
+//
+// Copyright (c) 2026 ZettaScale Technology
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License 2.0 which is available at
+// http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+//
+// Contributors:
+//   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+//
+use std::sync::Arc;
+
+use pyo3::{prelude::*, types::PyBytes};
+use zenoh::timestamp_stack::{
+    InterceptionPoint as RustInterceptionPoint, SessionTimestampCallback,
+    TimestampInstrumentation as RustTimestampInstrumentation, TsStackContext as RustTsStackContext,
+};
+
+use crate::{
+    config::{WhatAmI, ZenohId},
+    macros::wrapper,
+    time::Timestamp,
+    utils::IntoPyResult,
+};
+
+// InterceptionPoint is #[non_exhaustive] so we can't use enum_mapper! (it generates exhaustive
+// From impls). Define it manually with a repr u8 for Python comparison, and a fallback variant.
+#[pyo3::pyclass(eq)]
+#[repr(u8)]
+#[derive(Copy, Clone, PartialEq, Eq)]
+pub enum InterceptionPoint {
+    #[pyo3(name = "SEND")]
+    Send = 0,
+    #[pyo3(name = "ROUTE")]
+    Route = 1,
+    #[pyo3(name = "RECEIVE")]
+    Receive = 2,
+    /// Catch-all for future variants added by the Rust core.
+    #[pyo3(name = "UNKNOWN")]
+    Unknown = 255,
+}
+
+impl From<RustInterceptionPoint> for InterceptionPoint {
+    fn from(v: RustInterceptionPoint) -> Self {
+        match v {
+            RustInterceptionPoint::Send => Self::Send,
+            RustInterceptionPoint::Route => Self::Route,
+            RustInterceptionPoint::Receive => Self::Receive,
+            _ => Self::Unknown,
+        }
+    }
+}
+
+impl From<InterceptionPoint> for RustInterceptionPoint {
+    fn from(v: InterceptionPoint) -> Self {
+        match v {
+            InterceptionPoint::Send => RustInterceptionPoint::Send,
+            InterceptionPoint::Route => RustInterceptionPoint::Route,
+            InterceptionPoint::Receive | InterceptionPoint::Unknown => {
+                RustInterceptionPoint::Receive
+            }
+        }
+    }
+}
+
+wrapper!(zenoh::timestamp_stack::TsStackContext: Clone);
+
+#[pymethods]
+impl TsStackContext {
+    #[getter]
+    fn zid(&self) -> ZenohId {
+        self.0.zid.into()
+    }
+
+    #[getter]
+    fn whatami(&self) -> WhatAmI {
+        self.0.whatami.into()
+    }
+
+    #[getter]
+    fn interception_point(&self) -> InterceptionPoint {
+        self.0.interception_point.into()
+    }
+
+    fn __repr__(&self) -> String {
+        format!("{:?}", self.0)
+    }
+}
+
+wrapper!(zenoh::timestamp_stack::TimestampInstrumentation: Clone, Copy);
+
+#[pymethods]
+impl TimestampInstrumentation {
+    #[new]
+    #[pyo3(signature = (*, send = false, route = false, receive = false))]
+    fn new(send: bool, route: bool, receive: bool) -> PyResult<Self> {
+        RustTimestampInstrumentation::new(send, route, receive)
+            .map(Self)
+            .into_pyres()
+    }
+
+    fn is_instrumented(&self, point: InterceptionPoint) -> bool {
+        self.0.is_instrumented(point.into())
+    }
+
+    fn __repr__(&self) -> String {
+        format!("{:?}", self.0)
+    }
+}
+
+wrapper!(zenoh::timestamp_stack::TimestampStackRecord: Clone);
+
+#[pymethods]
+impl TimestampStackRecord {
+    #[getter]
+    fn point(&self) -> InterceptionPoint {
+        self.0.point().into()
+    }
+
+    #[getter]
+    fn is_custom(&self) -> bool {
+        self.0.is_custom()
+    }
+
+    fn timestamp<'py>(&self, py: Python<'py>) -> Bound<'py, PyBytes> {
+        PyBytes::new(py, self.0.timestamp())
+    }
+
+    fn as_timestamp(&self) -> Option<Timestamp> {
+        self.0.as_timestamp().map(Timestamp)
+    }
+
+    fn __repr__(&self) -> String {
+        format!("{:?}", self.0)
+    }
+}
+
+wrapper!(zenoh::timestamp_stack::TimestampStack: Clone);
+
+#[pymethods]
+impl TimestampStack {
+    #[getter]
+    fn instrumentation(&self) -> TimestampInstrumentation {
+        TimestampInstrumentation(self.0.instrumentation())
+    }
+
+    #[getter]
+    fn records(&self) -> Vec<TimestampStackRecord> {
+        self.0
+            .records()
+            .iter()
+            .cloned()
+            .map(TimestampStackRecord)
+            .collect()
+    }
+
+    fn __repr__(&self) -> String {
+        format!("{:?}", self.0)
+    }
+}
+
+/// Build a `SessionTimestampCallback` Arc from a Python callable.
+pub(crate) fn py_to_session_ts_callback(py_cb: PyObject) -> SessionTimestampCallback {
+    Arc::new(move |ctx: RustTsStackContext| {
+        Python::with_gil(|py| {
+            let py_ctx = match Py::new(py, TsStackContext(ctx)) {
+                Ok(obj) => obj,
+                Err(_) => return Vec::new(),
+            };
+            match py_cb.call1(py, (py_ctx,)) {
+                Ok(result) => result.extract::<Vec<u8>>(py).unwrap_or_default(),
+                Err(e) => {
+                    e.print(py);
+                    Vec::new()
+                }
+            }
+        })
+    })
+}
diff --git a/tests/test_timestamp_stack.py b/tests/test_timestamp_stack.py
new file mode 100644
index 00000000..d5814f72
--- /dev/null
+++ b/tests/test_timestamp_stack.py
@@ -0,0 +1,239 @@
+#
+# Copyright (c) 2026 ZettaScale Technology
+#
+# This program and the accompanying materials are made available under the
+# terms of the Eclipse Public License 2.0 which is available at
+# http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+# which is available at https://www.apache.org/licenses/LICENSE-2.0.
+#
+# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+#
+# Contributors:
+#   ZettaScale Zenoh Team, <zenoh@zettascale.tech>
+#
+import time
+from typing import List, Optional
+
+import pytest
+
+import zenoh
+from zenoh import InterceptionPoint, TimestampInstrumentation, TimestampStack
+
+SLEEP = 0.2
+
+
+def peer_config() -> zenoh.Config:
+    cfg = zenoh.Config()
+    cfg.insert_json5("scouting/multicast/enabled", "false")
+    return cfg
+
+
+# ── helpers ───────────────────────────────────────────────────────────────────
+
+
+def collect_one(key: str, action, timeout: float = SLEEP) -> Optional[zenoh.Sample]:
+    received: List[zenoh.Sample] = []
+    with zenoh.open(peer_config()) as session:
+        with session.declare_subscriber(key, lambda s: received.append(s)):
+            time.sleep(0.05)
+            action(session)
+            time.sleep(timeout)
+    return received[0] if received else None
+
+
+# ── test_no_instrumentation ───────────────────────────────────────────────────
+
+
+def test_no_instrumentation():
+    """Without instrumentation the stack should be None."""
+
+    def put(session):
+        session.put("test/ts/none", b"hello")
+
+    sample = collect_one("test/ts/none", put)
+    assert sample is not None
+    assert sample.timestamp_stack is None
+
+
+# ── test_put_subscribe_send_receive ──────────────────────────────────────────
+
+
+def test_put_subscribe_send_receive():
+    """A put with send+receive instrumentation produces SEND and RECEIVE records."""
+    instr = TimestampInstrumentation(send=True, receive=True)
+
+    def put(session):
+        session.put("test/ts/put", b"hello", timestamp_instrumentation=instr)
+
+    sample = collect_one("test/ts/put", put)
+    assert sample is not None
+    stack = sample.timestamp_stack
+    assert stack is not None
+    points = [r.point for r in stack.records]
+    assert InterceptionPoint.SEND in points
+    assert InterceptionPoint.RECEIVE in points
+
+
+# ── test_send_only ────────────────────────────────────────────────────────────
+
+
+def test_send_only():
+    """send=True, receive=False → only SEND record."""
+    instr = TimestampInstrumentation(send=True, receive=False)
+
+    def put(session):
+        session.put("test/ts/send_only", b"x", timestamp_instrumentation=instr)
+
+    sample = collect_one("test/ts/send_only", put)
+    assert sample is not None
+    stack = sample.timestamp_stack
+    assert stack is not None
+    points = [r.point for r in stack.records]
+    assert InterceptionPoint.SEND in points
+    assert InterceptionPoint.RECEIVE not in points
+
+
+# ── test_receive_only ─────────────────────────────────────────────────────────
+
+
+def test_receive_only():
+    """receive=True, send=False → only RECEIVE record."""
+    instr = TimestampInstrumentation(send=False, receive=True)
+
+    def put(session):
+        session.put("test/ts/recv_only", b"x", timestamp_instrumentation=instr)
+
+    sample = collect_one("test/ts/recv_only", put)
+    assert sample is not None
+    stack = sample.timestamp_stack
+    assert stack is not None
+    points = [r.point for r in stack.records]
+    assert InterceptionPoint.RECEIVE in points
+    assert InterceptionPoint.SEND not in points
+
+
+# ── test_publisher_default ────────────────────────────────────────────────────
+
+
+def test_publisher_default():
+    """Publisher-level default instrumentation applies to all puts."""
+    instr = TimestampInstrumentation(send=True, receive=True)
+    received: List[zenoh.Sample] = []
+
+    with zenoh.open(peer_config()) as session:
+        with session.declare_subscriber(
+            "test/ts/pub_default", lambda s: received.append(s)
+        ):
+            with session.declare_publisher(
+                "test/ts/pub_default", timestamp_instrumentation=instr
+            ) as pub:
+                time.sleep(0.05)
+                pub.put(b"data")
+                time.sleep(SLEEP)
+
+    assert len(received) == 1
+    stack = received[0].timestamp_stack
+    assert stack is not None
+    points = [r.point for r in stack.records]
+    assert InterceptionPoint.SEND in points
+    assert InterceptionPoint.RECEIVE in points
+
+
+# ── test_publisher_per_put_override ──────────────────────────────────────────
+
+
+def test_publisher_per_put_override():
+    """Per-put override takes precedence over publisher default."""
+    default_instr = TimestampInstrumentation(send=True, receive=True)
+    override_instr = TimestampInstrumentation(send=True, receive=False)
+    received: List[zenoh.Sample] = []
+
+    with zenoh.open(peer_config()) as session:
+        with session.declare_subscriber(
+            "test/ts/pub_override", lambda s: received.append(s)
+        ):
+            with session.declare_publisher(
+                "test/ts/pub_override", timestamp_instrumentation=default_instr
+            ) as pub:
+                time.sleep(0.05)
+                pub.put(b"data", timestamp_instrumentation=override_instr)
+                time.sleep(SLEEP)
+
+    assert len(received) == 1
+    points = [r.point for r in received[0].timestamp_stack.records]
+    assert InterceptionPoint.SEND in points
+    assert InterceptionPoint.RECEIVE not in points
+
+
+# ── test_as_timestamp ─────────────────────────────────────────────────────────
+
+
+def test_as_timestamp():
+    """Standard HLC records decode via as_timestamp(); returns a Timestamp object."""
+    instr = TimestampInstrumentation(send=True, receive=True)
+
+    def put(session):
+        session.put("test/ts/as_ts", b"t", timestamp_instrumentation=instr)
+
+    sample = collect_one("test/ts/as_ts", put)
+    assert sample is not None
+    for r in sample.timestamp_stack.records:
+        if not r.is_custom:
+            ts = r.as_timestamp()
+            assert ts is not None
+
+
+# ── test_is_custom_false ──────────────────────────────────────────────────────
+
+
+def test_is_custom_false():
+    """Standard (non-callback) records have is_custom == False."""
+    instr = TimestampInstrumentation(send=True, receive=True)
+
+    def put(session):
+        session.put("test/ts/not_custom", b"x", timestamp_instrumentation=instr)
+
+    sample = collect_one("test/ts/not_custom", put)
+    assert sample is not None
+    for r in sample.timestamp_stack.records:
+        assert not r.is_custom
+
+
+# ── test_custom_callback ──────────────────────────────────────────────────────
+
+
+def test_custom_callback():
+    """A session-level timestamp callback produces custom records with the returned bytes."""
+    MARKER = b"custom-ts-bytes"
+
+    def my_callback(ctx):
+        return MARKER
+
+    instr = TimestampInstrumentation(send=True, receive=True)
+    received: List[zenoh.Sample] = []
+
+    with zenoh.open(peer_config(), timestamp_callback=my_callback) as session:
+        with session.declare_subscriber(
+            "test/ts/custom_cb", lambda s: received.append(s)
+        ):
+            time.sleep(0.05)
+            session.put("test/ts/custom_cb", b"x", timestamp_instrumentation=instr)
+            time.sleep(SLEEP)
+
+    assert len(received) == 1
+    stack = received[0].timestamp_stack
+    assert stack is not None
+    custom_records = [r for r in stack.records if r.is_custom]
+    assert len(custom_records) > 0
+    for r in custom_records:
+        assert r.timestamp() == MARKER
+        assert r.as_timestamp() is None  # custom bytes don't decode as UHLC
+
+
+# ── test_invalid_instrumentation ─────────────────────────────────────────────
+
+
+def test_invalid_instrumentation():
+    """All-false instrumentation should raise (at least one point required)."""
+    with pytest.raises(Exception):
+        TimestampInstrumentation(send=False, route=False, receive=False)
diff --git a/zenoh/__init__.pyi b/zenoh/__init__.pyi
index 5fe200e5..2f723603 100644
--- a/zenoh/__init__.pyi
+++ b/zenoh/__init__.pyi
@@ -742,6 +742,7 @@ class Publisher:
         attachment: _IntoZBytes | None = None,
         timestamp: Timestamp | None = None,
         source_info: SourceInfo | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ):
         """Publish data to :class:`Subscriber` instances matching this publisher's key expression.
 
@@ -1440,6 +1441,7 @@ class Session:
         timestamp: Timestamp | None = None,
         allowed_destination: Locality | None = None,
         source_info: SourceInfo | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ):
         """Publish data directly from the session.
 
@@ -1482,6 +1484,7 @@ class Session:
         allowed_destination: Locality | None = None,
         source_info: SourceInfo | None = None,
         cancellation_token: CancellationToken | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ) -> Handler[Reply]:
         """Query data from the matching queryables in the system.
 
@@ -1507,6 +1510,7 @@ class Session:
         allowed_destination: Locality | None = None,
         source_info: SourceInfo | None = None,
         cancellation_token: CancellationToken | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ) -> _H:
         """Query data from the matching queryables in the system.
 
@@ -1532,6 +1536,7 @@ class Session:
         allowed_destination: Locality | None = None,
         source_info: SourceInfo | None = None,
         cancellation_token: CancellationToken | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ) -> None:
         """Query data from the matching queryables in the system.
 
@@ -1611,6 +1616,7 @@ class Session:
         express: bool | None = None,
         reliability: Reliability | None = None,
         allowed_destination: Locality | None = None,
+        timestamp_instrumentation: TimestampInstrumentation | None = None,
     ) -> Publisher:
         """Create a :class:`Publisher` for the given key expression."""
 
@@ -2260,7 +2266,9 @@ def init_log_from_env_or(level: str):
     For example, `RUST_LOG=debug` will set the log level to DEBUG.
     If `RUST_LOG` is not set, then logging is set to the provided level."""
 
-def open(config: Config) -> Session:
+def open(
+    config: Config, *, timestamp_callback: SessionTimestampCallback | None = None
+) -> Session:
     """Open a zenoh :class:`zenoh.Session`.
 
     For more information about sessions and configuration, see :ref:`session-and-config`.