diff --git a/src/get.rs b/src/get.rs
index 6fa5b510b..45b7d8882 100644
--- a/src/get.rs
+++ b/src/get.rs
@@ -156,26 +156,20 @@ pub unsafe extern "C" fn z_get(
     let key_expr = key_expr.transmute_ref();
     let mut get = session.get(Selector::new(key_expr, p));
     if let Some(options) = options {
-        if let Some(payload) = options.payload.as_mut() {
+        if let Some(payload) = unsafe { options.payload.as_mut() } {
             let payload = payload.transmute_mut().extract();
             get = get.payload(payload);
         }
-        if let Some(encoding) = options.encoding.as_mut() {
+        if let Some(encoding) = unsafe { options.encoding.as_mut() } {
             let encoding = encoding.transmute_mut().extract();
             get = get.encoding(encoding);
         }
-        if !options.source_info.is_null() {
-            let source_info = unsafe { options.source_info.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(source_info) = unsafe { options.source_info.as_mut() } {
+            let source_info = source_info.transmute_mut().extract();
             get = get.source_info(source_info);
         }
-        if !options.attachment.is_null() {
-            let attachment = unsafe { options.attachment.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(attachment) = unsafe { options.attachment.as_mut() } {
+            let attachment = attachment.transmute_mut().extract();
             get = get.attachment(attachment);
         }
 
diff --git a/src/publication_cache.rs b/src/publication_cache.rs
index 0c95c0a0f..92b006364 100644
--- a/src/publication_cache.rs
+++ b/src/publication_cache.rs
@@ -95,10 +95,8 @@ pub extern "C" fn ze_declare_publication_cache(
         if options.resources_limit != 0 {
             p = p.resources_limit(options.resources_limit)
         }
-        if !options.queryable_prefix.is_null() {
-            let queryable_prefix = unsafe { options.queryable_prefix.as_ref() }
-                .unwrap()
-                .transmute_ref();
+        if let Some(queryable_prefix) = unsafe { options.queryable_prefix.as_ref() } {
+            let queryable_prefix = queryable_prefix.transmute_ref();
             p = p.queryable_prefix(queryable_prefix.clone());
         }
     }
diff --git a/src/publisher.rs b/src/publisher.rs
index e2035807d..f9e05037c 100644
--- a/src/publisher.rs
+++ b/src/publisher.rs
@@ -177,25 +177,16 @@ pub unsafe extern "C" fn z_publisher_put(
 
     let mut put = publisher.put(payload);
     if let Some(options) = options {
-        if !options.encoding.is_null() {
-            let encoding = unsafe { options.encoding.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(encoding) = unsafe { options.encoding.as_mut() } {
+            let encoding = encoding.transmute_mut().extract();
             put = put.encoding(encoding);
         };
-        if !options.source_info.is_null() {
-            let source_info = unsafe { options.source_info.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(source_info) = unsafe { options.source_info.as_mut() } {
+            let source_info = source_info.transmute_mut().extract();
             put = put.source_info(source_info);
-        }
-        if !options.attachment.is_null() {
-            let attachment = unsafe { options.attachment.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        };
+        if let Some(attachment) = unsafe { options.attachment.as_mut() } {
+            let attachment = attachment.transmute_mut().extract();
             put = put.attachment(attachment);
         }
     }
diff --git a/src/pull_subscriber.rs b/src/pull_subscriber.rs
deleted file mode 100644
index 7c7b11868..000000000
--- a/src/pull_subscriber.rs
+++ /dev/null
@@ -1,220 +0,0 @@
-//
-// Copyright (c) 2017, 2022 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 crate::commons::*;
-use crate::impl_guarded_transmute;
-use crate::keyexpr::*;
-use crate::session::*;
-use crate::z_closure_sample_call;
-use crate::z_owned_closure_sample_t;
-use crate::z_reliability_t;
-use crate::LOG_INVALID_SESSION;
-use zenoh::prelude::sync::SyncResolve;
-use zenoh::prelude::SessionDeclarations;
-use zenoh_protocol::core::SubInfo;
-use zenoh_util::core::zresult::ErrNo;
-
-/**************************************/
-/*            DECLARATION             */
-/**************************************/
-type PullSubscriber = Option<Box<zenoh::subscriber::PullSubscriber<'static, ()>>>;
-
-/// An owned zenoh pull subscriber. Destroying the subscriber cancels the subscription.
-///
-/// Like most `z_owned_X_t` types, you may obtain an instance of `z_X_t` by loaning it using `z_X_loan(&val)`.  
-/// The `z_loan(val)` macro, available if your compiler supports C11's `_Generic`, is equivalent to writing `z_X_loan(&val)`.  
-///
-/// Like all `z_owned_X_t`, an instance will be destroyed by any function which takes a mutable pointer to said instance, as this implies the instance's inners were moved.  
-/// To make this fact more obvious when reading your code, consider using `z_move(val)` instead of `&val` as the argument.  
-/// After a move, `val` will still exist, but will no longer be valid. The destructors are double-drop-safe, but other functions will still trust that your `val` is valid.  
-///
-/// To check if `val` is still valid, you may use `z_X_check(&val)` or `z_check(val)` if your compiler supports `_Generic`, which will return `true` if `val` is valid.
-#[cfg(not(target_arch = "arm"))]
-#[repr(C, align(8))]
-pub struct z_owned_pull_subscriber_t([u64; 1]);
-
-#[cfg(target_arch = "arm")]
-#[repr(C, align(4))]
-pub struct z_owned_pull_subscriber_t([u32; 1]);
-
-impl_guarded_transmute!(PullSubscriber, z_owned_pull_subscriber_t);
-
-#[repr(C)]
-#[allow(non_camel_case_types)]
-pub struct z_pull_subscriber_t<'a>(&'a z_owned_pull_subscriber_t);
-
-impl<'a> AsRef<PullSubscriber> for z_pull_subscriber_t<'a> {
-    fn as_ref(&self) -> &PullSubscriber {
-        self.0
-    }
-}
-
-impl AsMut<PullSubscriber> for z_owned_pull_subscriber_t {
-    fn as_mut(&mut self) -> &mut PullSubscriber {
-        unsafe { std::mem::transmute(self) }
-    }
-}
-
-impl z_owned_pull_subscriber_t {
-    pub fn new(sub: zenoh::subscriber::PullSubscriber<'static, ()>) -> Self {
-        Some(Box::new(sub)).into()
-    }
-    pub fn null() -> Self {
-        None.into()
-    }
-}
-
-/// Constructs a null safe-to-drop value of 'z_owned_pull_subscriber_t' type
-#[no_mangle]
-#[allow(clippy::missing_safety_doc)]
-pub extern "C" fn z_pull_subscriber_null() -> z_owned_pull_subscriber_t {
-    z_owned_pull_subscriber_t::null()
-}
-
-/// Represents the set of options that can be applied to a pull subscriber,
-/// upon its declaration via `z_declare_pull_subscriber`.
-///
-/// Members:
-///   z_reliability_t reliability: The subscription reliability.
-#[repr(C)]
-#[allow(non_camel_case_types)]
-pub struct z_pull_subscriber_options_t {
-    reliability: z_reliability_t,
-}
-
-/// Constructs the default value for `z_pull_subscriber_options_t`.
-#[no_mangle]
-pub extern "C" fn z_pull_subscriber_options_default() -> z_pull_subscriber_options_t {
-    let info = SubInfo::default();
-    z_pull_subscriber_options_t {
-        reliability: info.reliability.into(),
-    }
-}
-
-/// Declares a pull subscriber for a given key expression.
-///
-/// Parameters:
-///     session: The zenoh session.
-///     keyexpr: The key expression to subscribe.
-///     callback: The callback function that will be called each time a data matching the subscribed expression is received.
-///     opts: Additional options for the pull subscriber.
-///
-/// Returns:
-///    A `z_owned_subscriber_t`.
-///
-///    To check if the subscription succeeded and if the pull subscriber is still valid,
-///    you may use `z_pull_subscriber_check(&val)` or `z_check(val)` if your compiler supports `_Generic`, which will return `true` if `val` is valid.
-///
-///    Like all `z_owned_X_t`, an instance will be destroyed by any function which takes a mutable pointer to said instance, as this implies the instance's inners were moved.  
-///    To make this fact more obvious when reading your code, consider using `z_move(val)` instead of `&val` as the argument.  
-///    After a move, `val` will still exist, but will no longer be valid. The destructors are double-drop-safe, but other functions will still trust that your `val` is valid.
-///
-/// Example:
-///    Declaring a subscriber passing ``NULL`` for the options:
-///
-///    .. code-block:: C
-///
-///       z_owned_subscriber_t sub = z_declare_pull_subscriber(z_loan(s), z_keyexpr(expr), callback, NULL);
-///
-///    is equivalent to initializing and passing the default subscriber options:
-///
-///    .. code-block:: C
-///
-///       z_subscriber_options_t options = z_subscriber_options_default();
-///       z_owned_subscriber_t sub = z_declare_pull_subscriber(z_loan(s), z_keyexpr(expr), callback, &opts);
-#[no_mangle]
-#[allow(clippy::missing_safety_doc)]
-pub extern "C" fn z_declare_pull_subscriber(
-    session: z_loaned_session_t,
-    keyexpr: z_loaned_keyexpr_t,
-    callback: &mut z_owned_closure_sample_t,
-    options: Option<&z_pull_subscriber_options_t>,
-) -> z_owned_pull_subscriber_t {
-    let mut closure = z_owned_closure_sample_t::empty();
-    std::mem::swap(callback, &mut closure);
-
-    match session.upgrade() {
-        Some(s) => {
-            let mut res = s
-                .declare_subscriber(keyexpr)
-                .callback(move |sample| {
-                    let sample = z_loaned_sample_t::new(&sample);
-                    z_closure_sample_call(&closure, &sample)
-                })
-                .pull_mode();
-            if let Some(opts) = opts {
-                res = res.reliability(opts.reliability.into())
-            }
-            match res.res() {
-                Ok(sub) => z_owned_pull_subscriber_t::new(sub),
-                Err(e) => {
-                    log::debug!("{}", e);
-                    z_owned_pull_subscriber_t::null()
-                }
-            }
-        }
-        None => {
-            log::debug!("{}", LOG_INVALID_SESSION);
-            z_owned_pull_subscriber_t::null()
-        }
-    }
-}
-
-/// Undeclares the given `z_owned_pull_subscriber_t`, droping it and invalidating it for double-drop safety.
-#[allow(clippy::missing_safety_doc)]
-#[no_mangle]
-pub extern "C" fn z_undeclare_pull_subscriber(sub: &mut z_owned_pull_subscriber_t) -> i8 {
-    if let Some(s) = sub.as_mut().take() {
-        if let Err(e) = s.undeclare().res_sync() {
-            log::warn!("{}", e);
-            return e.errno().get();
-        }
-    }
-    0
-}
-
-/// Returns ``true`` if `sub` is valid.
-#[allow(clippy::missing_safety_doc)]
-#[no_mangle]
-pub extern "C" fn z_pull_subscriber_check(sub: &z_owned_pull_subscriber_t) -> bool {
-    sub.as_ref().is_some()
-}
-
-/// Returns ``true`` if `sub` is valid.
-#[allow(clippy::missing_safety_doc)]
-#[no_mangle]
-pub extern "C" fn z_pull_subscriber_loan(sub: &z_owned_pull_subscriber_t) -> z_pull_subscriber_t {
-    z_pull_subscriber_t(sub)
-}
-
-/// Pull data for `z_owned_pull_subscriber_t`. The pulled data will be provided
-/// by calling the **callback** function provided to the `z_declare_subscriber` function.
-///
-/// Parameters:
-///     sub: The `z_owned_pull_subscriber_t` to pull from.
-#[allow(clippy::missing_safety_doc)]
-#[no_mangle]
-pub extern "C" fn z_subscriber_pull(sub: z_pull_subscriber_t) -> i8 {
-    match sub.0.as_ref() {
-        Some(tx) => {
-            if let Err(e) = tx.pull().res_sync() {
-                log::error!("{}", e);
-                e.errno().get()
-            } else {
-                0
-            }
-        }
-        None => i8::MIN,
-    }
-}
diff --git a/src/put.rs b/src/put.rs
index 7eae86dd3..073b9880e 100644
--- a/src/put.rs
+++ b/src/put.rs
@@ -82,25 +82,16 @@ pub extern "C" fn z_put(
 
     let mut put = session.put(key_expr, payload);
     if let Some(options) = options {
-        if !options.encoding.is_null() {
-            let encoding = unsafe { options.encoding.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(encoding) = unsafe { options.encoding.as_mut() } {
+            let encoding = encoding.transmute_mut().extract();
             put = put.encoding(encoding);
         };
-        if !options.source_info.is_null() {
-            let source_info = unsafe { options.source_info.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(source_info) = unsafe { options.source_info.as_mut() } {
+            let source_info = source_info.transmute_mut().extract();
             put = put.source_info(source_info);
         };
-        if !options.attachment.is_null() {
-            let attachment = unsafe { options.attachment.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(attachment) = unsafe { options.attachment.as_mut() } {
+            let attachment = attachment.transmute_mut().extract();
             put = put.attachment(attachment);
         }
         put = put.priority(options.priority.into());
diff --git a/src/queryable.rs b/src/queryable.rs
index 8efe0c849..a26f54b90 100644
--- a/src/queryable.rs
+++ b/src/queryable.rs
@@ -232,7 +232,7 @@ pub extern "C" fn z_queryable_check(this: &z_owned_queryable_t) -> bool {
 /// @return 0 in case of success, negative error code otherwise.
 #[allow(clippy::missing_safety_doc)]
 #[no_mangle]
-pub unsafe extern "C" fn z_query_reply(
+pub extern "C" fn z_query_reply(
     this: &z_loaned_query_t,
     key_expr: &z_loaned_keyexpr_t,
     payload: &mut z_owned_bytes_t,
@@ -244,25 +244,16 @@ pub unsafe extern "C" fn z_query_reply(
 
     let mut reply = query.reply(key_expr, payload);
     if let Some(options) = options {
-        if !options.encoding.is_null() {
-            let encoding = unsafe { options.encoding.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(encoding) = unsafe { options.encoding.as_mut() } {
+            let encoding = encoding.transmute_mut().extract();
             reply = reply.encoding(encoding);
         };
-        if !options.source_info.is_null() {
-            let source_info = unsafe { options.source_info.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(source_info) = unsafe { options.source_info.as_mut() } {
+            let source_info = source_info.transmute_mut().extract();
             reply = reply.source_info(source_info);
         };
-        if !options.attachment.is_null() {
-            let attachment = unsafe { options.attachment.as_mut() }
-                .unwrap()
-                .transmute_mut()
-                .extract();
+        if let Some(attachment) = unsafe { options.attachment.as_mut() } {
+            let attachment = attachment.transmute_mut().extract();
             reply = reply.attachment(attachment);
         }
     }
diff --git a/src/querying_subscriber.rs b/src/querying_subscriber.rs
index 7e3dddbc4..72182a264 100644
--- a/src/querying_subscriber.rs
+++ b/src/querying_subscriber.rs
@@ -35,6 +35,8 @@ use crate::{
 use crate::{zcu_locality_default, zcu_locality_t};
 use zenoh::core::Wait;
 use zenoh::prelude::SessionDeclarations;
+use zenoh::sample::SampleBuilderTrait;
+use zenoh::sample::ValueBuilderTrait;
 use zenoh::session::Session;
 use zenoh::subscriber::Reliability;
 use zenoh_ext::*;
@@ -140,12 +142,9 @@ pub unsafe extern "C" fn ze_declare_querying_subscriber(
         {
             sub = sub.allowed_origin(options.allowed_origin.into());
         }
-        if !options.query_selector.is_null() {
-            let query_selector = unsafe { options.query_selector.as_ref() }
-                .unwrap()
-                .transmute_ref()
-                .clone();
-            sub = sub.query_selector(query_selector)
+        if let Some(query_selector) = unsafe { options.query_selector.as_ref() } {
+            let query_selector = query_selector.transmute_ref().clone();
+            sub = sub.query_selector(query_selector);
         }
         if options.query_timeout_ms != 0 {
             sub = sub.query_timeout(std::time::Duration::from_millis(options.query_timeout_ms));
@@ -185,15 +184,37 @@ pub unsafe extern "C" fn ze_querying_subscriber_get(
     if let Err(e) = sub
         .0
         .fetch({
-            move |cb| match options {
-                Some(options) => session
-                    .get(selector)
-                    .target(options.target.into())
-                    .consolidation(options.consolidation)
-                    .timeout(std::time::Duration::from_millis(options.timeout_ms))
-                    .callback(cb)
-                    .wait(),
-                None => session.get(selector).callback(cb).wait(),
+            move |cb| {
+                let mut get = session.get(selector).callback(cb);
+
+                if let Some(options) = options {
+                    if let Some(payload) = unsafe { options.payload.as_mut() } {
+                        let payload = payload.transmute_mut().extract();
+                        get = get.payload(payload);
+                    }
+                    if let Some(encoding) = unsafe { options.encoding.as_mut() } {
+                        let encoding = encoding.transmute_mut().extract();
+                        get = get.encoding(encoding);
+                    }
+                    if let Some(source_info) = unsafe { options.source_info.as_mut() } {
+                        let source_info = source_info.transmute_mut().extract();
+                        get = get.source_info(source_info);
+                    }
+                    if let Some(attachment) = unsafe { options.attachment.as_mut() } {
+                        let attachment = attachment.transmute_mut().extract();
+                        get = get.attachment(attachment);
+                    }
+
+                    get = get
+                        .consolidation(options.consolidation)
+                        .target(options.target.into());
+
+                    if options.timeout_ms != 0 {
+                        get = get.timeout(std::time::Duration::from_millis(options.timeout_ms));
+                    }
+                }
+
+                get.wait()
             }
         })
         .wait()