diff --git a/libs/pageserver_api/src/key.rs b/libs/pageserver_api/src/key.rs
index 16715bc667..151ed14627 100644
--- a/libs/pageserver_api/src/key.rs
+++ b/libs/pageserver_api/src/key.rs
@@ -144,3 +144,35 @@ impl Key {
 pub fn is_rel_block_key(key: &Key) -> bool {
     key.field1 == 0x00 && key.field4 != 0
 }
+
+impl std::str::FromStr for Key {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        Self::from_hex(s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::str::FromStr;
+
+    use crate::key::Key;
+
+    #[test]
+    fn display_fromstr_bijection() {
+        let mut rng = rand::thread_rng();
+        use rand::Rng;
+
+        let key = Key {
+            field1: rng.gen(),
+            field2: rng.gen(),
+            field3: rng.gen(),
+            field4: rng.gen(),
+            field5: rng.gen(),
+            field6: rng.gen(),
+        };
+
+        assert_eq!(key, Key::from_str(&format!("{key}")).unwrap());
+    }
+}
diff --git a/pageserver/src/client/mgmt_api.rs b/pageserver/src/client/mgmt_api.rs
index 10d39ec9cd..66d7da9d0b 100644
--- a/pageserver/src/client/mgmt_api.rs
+++ b/pageserver/src/client/mgmt_api.rs
@@ -93,6 +93,22 @@ impl Client {
             .map_err(Error::ReceiveBody)
     }
 
+    pub async fn keyspace(
+        &self,
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> Result<crate::http::models::partitioning::Partitioning> {
+        let uri = format!(
+            "{}/v1/tenant/{tenant_id}/timeline/{timeline_id}/keyspace?check_serialization_roundtrip=true",
+            self.mgmt_api_endpoint
+        );
+        self.get(&uri)
+            .await?
+            .json()
+            .await
+            .map_err(Error::ReceiveBody)
+    }
+
     async fn get<U: IntoUrl>(&self, uri: U) -> Result<reqwest::Response> {
         self.request(Method::GET, uri, ()).await
     }
diff --git a/pageserver/src/http/mod.rs b/pageserver/src/http/mod.rs
index 1c083bd382..220fa29b43 100644
--- a/pageserver/src/http/mod.rs
+++ b/pageserver/src/http/mod.rs
@@ -1,4 +1,4 @@
 pub mod routes;
 pub use routes::make_router;
 
-pub use pageserver_api::models;
+pub mod models;
diff --git a/pageserver/src/http/models.rs b/pageserver/src/http/models.rs
new file mode 100644
index 0000000000..1d8e76b7a7
--- /dev/null
+++ b/pageserver/src/http/models.rs
@@ -0,0 +1,3 @@
+//! If possible, use `::pageserver_api::models` instead.
+
+pub mod partitioning;
diff --git a/pageserver/src/http/models/partitioning.rs b/pageserver/src/http/models/partitioning.rs
new file mode 100644
index 0000000000..bf0a62f3a7
--- /dev/null
+++ b/pageserver/src/http/models/partitioning.rs
@@ -0,0 +1,112 @@
+use utils::lsn::Lsn;
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct Partitioning {
+    pub keys: crate::keyspace::KeySpace,
+
+    pub at_lsn: Lsn,
+}
+
+impl serde::Serialize for Partitioning {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        pub struct KeySpace<'a>(&'a crate::keyspace::KeySpace);
+
+        impl<'a> serde::Serialize for KeySpace<'a> {
+            fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+            where
+                S: serde::Serializer,
+            {
+                use serde::ser::SerializeSeq;
+                let mut seq = serializer.serialize_seq(Some(self.0.ranges.len()))?;
+                for kr in &self.0.ranges {
+                    seq.serialize_element(&KeyRange(kr))?;
+                }
+                seq.end()
+            }
+        }
+
+        use serde::ser::SerializeMap;
+        let mut map = serializer.serialize_map(Some(2))?;
+        map.serialize_key("keys")?;
+        map.serialize_value(&KeySpace(&self.keys))?;
+        map.serialize_key("at_lsn")?;
+        map.serialize_value(&WithDisplay(&self.at_lsn))?;
+        map.end()
+    }
+}
+
+pub struct WithDisplay<'a, T>(&'a T);
+
+impl<'a, T: std::fmt::Display> serde::Serialize for WithDisplay<'a, T> {
+    fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.collect_str(&self.0)
+    }
+}
+
+pub struct KeyRange<'a>(&'a std::ops::Range<crate::repository::Key>);
+
+impl<'a> serde::Serialize for KeyRange<'a> {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        use serde::ser::SerializeTuple;
+        let mut t = serializer.serialize_tuple(2)?;
+        t.serialize_element(&WithDisplay(&self.0.start))?;
+        t.serialize_element(&WithDisplay(&self.0.end))?;
+        t.end()
+    }
+}
+
+impl<'a> serde::Deserialize<'a> for Partitioning {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'a>,
+    {
+        pub struct KeySpace(crate::keyspace::KeySpace);
+
+        impl<'de> serde::Deserialize<'de> for KeySpace {
+            fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+            where
+                D: serde::Deserializer<'de>,
+            {
+                #[serde_with::serde_as]
+                #[derive(serde::Deserialize)]
+                #[serde(transparent)]
+                struct Key(#[serde_as(as = "serde_with::DisplayFromStr")] crate::repository::Key);
+
+                #[serde_with::serde_as]
+                #[derive(serde::Deserialize)]
+                struct Range(Key, Key);
+
+                let ranges: Vec<Range> = serde::Deserialize::deserialize(deserializer)?;
+                Ok(Self(crate::keyspace::KeySpace {
+                    ranges: ranges
+                        .into_iter()
+                        .map(|Range(start, end)| (start.0..end.0))
+                        .collect(),
+                }))
+            }
+        }
+
+        #[serde_with::serde_as]
+        #[derive(serde::Deserialize)]
+        struct De {
+            keys: KeySpace,
+            #[serde_as(as = "serde_with::DisplayFromStr")]
+            at_lsn: Lsn,
+        }
+
+        let de: De = serde::Deserialize::deserialize(deserializer)?;
+        Ok(Self {
+            at_lsn: de.at_lsn,
+            keys: de.keys.0,
+        })
+    }
+}
diff --git a/pageserver/src/http/routes.rs b/pageserver/src/http/routes.rs
index fee50460a5..d083868599 100644
--- a/pageserver/src/http/routes.rs
+++ b/pageserver/src/http/routes.rs
@@ -28,10 +28,6 @@ use utils::http::endpoint::request_span;
 use utils::http::json::json_request_or_empty_body;
 use utils::http::request::{get_request_param, must_get_query_param, parse_query_param};
 
-use super::models::{
-    StatusResponse, TenantConfigRequest, TenantCreateRequest, TenantCreateResponse, TenantInfo,
-    TimelineCreateRequest, TimelineGcRequest, TimelineInfo,
-};
 use crate::context::{DownloadBehavior, RequestContext};
 use crate::deletion_queue::DeletionQueueClient;
 use crate::metrics::{StorageTimeOperation, STORAGE_TIME_GLOBAL};
@@ -49,6 +45,10 @@ use crate::tenant::timeline::Timeline;
 use crate::tenant::{LogicalSizeCalculationCause, PageReconstructError, TenantSharedResources};
 use crate::{config::PageServerConf, tenant::mgr};
 use crate::{disk_usage_eviction_task, tenant};
+use pageserver_api::models::{
+    StatusResponse, TenantConfigRequest, TenantCreateRequest, TenantCreateResponse, TenantInfo,
+    TimelineCreateRequest, TimelineGcRequest, TimelineInfo,
+};
 use utils::{
     auth::SwappableJwtAuth,
     generation::Generation,
@@ -64,7 +64,7 @@ use utils::{
 };
 
 // Imports only used for testing APIs
-use super::models::ConfigureFailpointsRequest;
+use pageserver_api::models::ConfigureFailpointsRequest;
 
 pub struct State {
     conf: &'static PageServerConf,
@@ -1487,71 +1487,11 @@ async fn timeline_collect_keyspace(
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_shard_id.tenant_id))?;
 
-    struct Partitioning {
-        keys: crate::keyspace::KeySpace,
-
-        at_lsn: Lsn,
-    }
-
-    impl serde::Serialize for Partitioning {
-        fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-        where
-            S: serde::Serializer,
-        {
-            use serde::ser::SerializeMap;
-            let mut map = serializer.serialize_map(Some(2))?;
-            map.serialize_key("keys")?;
-            map.serialize_value(&KeySpace(&self.keys))?;
-            map.serialize_key("at_lsn")?;
-            map.serialize_value(&WithDisplay(&self.at_lsn))?;
-            map.end()
-        }
-    }
-
-    struct WithDisplay<'a, T>(&'a T);
-
-    impl<'a, T: std::fmt::Display> serde::Serialize for WithDisplay<'a, T> {
-        fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-        where
-            S: serde::Serializer,
-        {
-            serializer.collect_str(&self.0)
-        }
-    }
-
-    struct KeySpace<'a>(&'a crate::keyspace::KeySpace);
-
-    impl<'a> serde::Serialize for KeySpace<'a> {
-        fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
-        where
-            S: serde::Serializer,
-        {
-            use serde::ser::SerializeSeq;
-            let mut seq = serializer.serialize_seq(Some(self.0.ranges.len()))?;
-            for kr in &self.0.ranges {
-                seq.serialize_element(&KeyRange(kr))?;
-            }
-            seq.end()
-        }
-    }
-
-    struct KeyRange<'a>(&'a std::ops::Range<crate::repository::Key>);
-
-    impl<'a> serde::Serialize for KeyRange<'a> {
-        fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-        where
-            S: serde::Serializer,
-        {
-            use serde::ser::SerializeTuple;
-            let mut t = serializer.serialize_tuple(2)?;
-            t.serialize_element(&WithDisplay(&self.0.start))?;
-            t.serialize_element(&WithDisplay(&self.0.end))?;
-            t.end()
-        }
-    }
-
     let at_lsn: Option<Lsn> = parse_query_param(&request, "at_lsn")?;
 
+    let check_serialization_roundtrip: bool =
+        parse_query_param(&request, "check_serialization_roundtrip")?.unwrap_or(false);
+
     async {
         let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
         let timeline = active_timeline_of_active_tenant(tenant_shard_id, timeline_id).await?;
@@ -1561,7 +1501,20 @@ async fn timeline_collect_keyspace(
             .await
             .map_err(|e| ApiError::InternalServerError(e.into()))?;
 
-        json_response(StatusCode::OK, Partitioning { keys, at_lsn })
+        let res = crate::http::models::partitioning::Partitioning { keys, at_lsn };
+        if check_serialization_roundtrip {
+            (|| {
+                let ser = serde_json::ser::to_vec(&res).context("serialize")?;
+                let de: crate::http::models::partitioning::Partitioning =
+                    serde_json::from_slice(&ser).context("deserialize")?;
+                anyhow::ensure!(de == res, "not equal");
+                info!("passed serialization rountrip check");
+                Ok(())
+            })()
+            .context("serialization rountrip")
+            .map_err(ApiError::InternalServerError)?;
+        }
+        json_response(StatusCode::OK, res)
     }
     .instrument(info_span!("timeline_collect_keyspace", tenant_id = %tenant_shard_id.tenant_id, shard_id = %tenant_shard_id.shard_slug(), %timeline_id))
     .await
diff --git a/pageserver/src/keyspace.rs b/pageserver/src/keyspace.rs
index 20e6df9c7b..970c96589e 100644
--- a/pageserver/src/keyspace.rs
+++ b/pageserver/src/keyspace.rs
@@ -5,7 +5,7 @@ use std::ops::Range;
 ///
 /// Represents a set of Keys, in a compact form.
 ///
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct KeySpace {
     /// Contiguous ranges of keys that belong to the key space. In key order,
     /// and with no overlap.