diff --git a/crates/ruma-client-api/src/profile.rs b/crates/ruma-client-api/src/profile.rs
index 2c5293c6..ebf71129 100644
--- a/crates/ruma-client-api/src/profile.rs
+++ b/crates/ruma-client-api/src/profile.rs
@@ -1,10 +1,13 @@
 //! Endpoints for user profiles.
 
+pub mod delete_profile_key;
+pub mod delete_timezone_key;
 pub mod get_avatar_url;
 pub mod get_display_name;
 pub mod get_profile;
+pub mod get_profile_key;
 pub mod get_timezone_key;
 pub mod set_avatar_url;
 pub mod set_display_name;
+pub mod set_profile_key;
 pub mod set_timezone_key;
-pub mod delete_timezone_key;
diff --git a/crates/ruma-client-api/src/profile/delete_profile_key.rs b/crates/ruma-client-api/src/profile/delete_profile_key.rs
new file mode 100644
index 00000000..d6bc4dc8
--- /dev/null
+++ b/crates/ruma-client-api/src/profile/delete_profile_key.rs
@@ -0,0 +1,59 @@
+//! `DELETE /_matrix/client/*/profile/{user_id}/{key_name}`
+//!
+//! Deletes a custom profile key from the user
+
+pub mod unstable {
+    //! `msc4133` ([MSC])
+    //!
+    //! [MSC]: https://github.com/tcpipuk/matrix-spec-proposals/blob/main/proposals/4133-extended-profiles.md
+
+    use std::collections::BTreeMap;
+
+    use ruma_common::{
+        api::{request, response, Metadata},
+        metadata, OwnedUserId,
+    };
+    use serde_json::Value as JsonValue;
+
+    const METADATA: Metadata = metadata! {
+        method: DELETE,
+        rate_limited: true,
+        authentication: AccessToken,
+        history: {
+            unstable => "/_matrix/client/unstable/uk.tcpip.msc4133/profile/:user_id/:key_name",
+            // 1.12 => "/_matrix/client/v3/profile/:user_id/:key_name",
+        }
+    };
+
+    #[request(error = crate::Error)]
+    pub struct Request {
+        #[ruma_api(path)]
+        pub user_id: OwnedUserId,
+
+        #[ruma_api(path)]
+        pub key: String,
+
+        #[serde(flatten)]
+        pub kv_pair: BTreeMap<String, JsonValue>,
+    }
+
+    #[response(error = crate::Error)]
+    #[derive(Default)]
+    pub struct Response {}
+
+    impl Request {
+        pub fn new(
+            user_id: OwnedUserId,
+            key: String,
+            kv_pair: BTreeMap<String, JsonValue>,
+        ) -> Self {
+            Self { user_id, key, kv_pair }
+        }
+    }
+
+    impl Response {
+        pub fn new() -> Self {
+            Self {}
+        }
+    }
+}
diff --git a/crates/ruma-client-api/src/profile/get_profile.rs b/crates/ruma-client-api/src/profile/get_profile.rs
index 80715170..d069820d 100644
--- a/crates/ruma-client-api/src/profile/get_profile.rs
+++ b/crates/ruma-client-api/src/profile/get_profile.rs
@@ -1,8 +1,6 @@
 //! `GET /_matrix/client/*/profile/{userId}`
 //!
 //! Get all profile information of an user.
-//!
-//! TODO: implement the "generic-ness" of MSC4133
 
 pub mod v3 {
     //! `/v3/` ([spec])
@@ -13,10 +11,13 @@ pub mod v3 {
     //!
     //! [MSC]: https://github.com/tcpipuk/matrix-spec-proposals/blob/main/proposals/4133-extended-profiles.md
 
+    use std::collections::BTreeMap;
+
     use ruma_common::{
         api::{request, response, Metadata},
         metadata, OwnedMxcUri, OwnedUserId,
     };
+    use serde_json::Value as JsonValue;
 
     const METADATA: Metadata = metadata! {
         method: GET,
@@ -71,6 +72,11 @@ pub mod v3 {
         /// TODO: strong type this to be a valid IANA timezone?
         #[serde(rename = "us.cloke.msc4175.tz", skip_serializing_if = "Option::is_none")]
         pub tz: Option<String>,
+
+        /// Custom arbitrary profile fields as part of MSC4133 that are not reserved such as
+        /// MSC4175
+        #[serde(flatten, skip_serializing_if = "BTreeMap::is_empty")]
+        pub custom_profile_fields: BTreeMap<String, JsonValue>,
     }
 
     impl Request {
@@ -89,6 +95,7 @@ pub mod v3 {
                 #[cfg(feature = "unstable-msc2448")]
                 blurhash: None,
                 tz: None,
+                custom_profile_fields: BTreeMap::new(),
             }
         }
     }
diff --git a/crates/ruma-client-api/src/profile/get_profile_key.rs b/crates/ruma-client-api/src/profile/get_profile_key.rs
new file mode 100644
index 00000000..24cf921e
--- /dev/null
+++ b/crates/ruma-client-api/src/profile/get_profile_key.rs
@@ -0,0 +1,55 @@
+//! `GET /_matrix/client/*/profile/{user_id}/{key_name}`
+//!
+//! Gets a custom profile key from the user
+
+pub mod unstable {
+    //! `msc4133` ([MSC])
+    //!
+    //! [MSC]: https://github.com/tcpipuk/matrix-spec-proposals/blob/main/proposals/4133-extended-profiles.md
+
+    use std::collections::BTreeMap;
+
+    use ruma_common::{
+        api::{request, response, Metadata},
+        metadata, OwnedUserId,
+    };
+    use serde_json::Value as JsonValue;
+
+    const METADATA: Metadata = metadata! {
+        method: GET,
+        rate_limited: false,
+        authentication: None,
+        history: {
+            unstable => "/_matrix/client/unstable/uk.tcpip.msc4133/profile/:user_id/:key_name",
+            // 1.12 => "/_matrix/client/v3/profile/:user_id/:key_name",
+        }
+    };
+
+    #[request(error = crate::Error)]
+    pub struct Request {
+        #[ruma_api(path)]
+        pub user_id: OwnedUserId,
+
+        #[ruma_api(path)]
+        pub key: String,
+    }
+
+    #[response(error = crate::Error)]
+    #[derive(Default)]
+    pub struct Response {
+        #[serde(flatten)]
+        pub value: BTreeMap<String, JsonValue>,
+    }
+
+    impl Request {
+        pub fn new(user_id: OwnedUserId, key: String) -> Self {
+            Self { user_id, key }
+        }
+    }
+
+    impl Response {
+        pub fn new(value: BTreeMap<String, JsonValue>) -> Self {
+            Self { value }
+        }
+    }
+}
diff --git a/crates/ruma-client-api/src/profile/set_profile_key.rs b/crates/ruma-client-api/src/profile/set_profile_key.rs
new file mode 100644
index 00000000..f0bf07d9
--- /dev/null
+++ b/crates/ruma-client-api/src/profile/set_profile_key.rs
@@ -0,0 +1,59 @@
+//! `PUT /_matrix/client/*/profile/{user_id}/{key_name}`
+//!
+//! Sets a custom profile key from the user
+
+pub mod unstable {
+    //! `msc4133` ([MSC])
+    //!
+    //! [MSC]: https://github.com/tcpipuk/matrix-spec-proposals/blob/main/proposals/4133-extended-profiles.md
+
+    use std::collections::BTreeMap;
+
+    use ruma_common::{
+        api::{request, response, Metadata},
+        metadata, OwnedUserId,
+    };
+    use serde_json::Value as JsonValue;
+
+    const METADATA: Metadata = metadata! {
+        method: PUT,
+        rate_limited: true,
+        authentication: AccessToken,
+        history: {
+            unstable => "/_matrix/client/unstable/uk.tcpip.msc4133/profile/:user_id/:key_name",
+            // 1.12 => "/_matrix/client/v3/profile/:user_id/:key_name",
+        }
+    };
+
+    #[request(error = crate::Error)]
+    pub struct Request {
+        #[ruma_api(path)]
+        pub user_id: OwnedUserId,
+
+        #[ruma_api(path)]
+        pub key: String,
+
+        #[serde(flatten)]
+        pub kv_pair: BTreeMap<String, JsonValue>,
+    }
+
+    #[response(error = crate::Error)]
+    #[derive(Default)]
+    pub struct Response {}
+
+    impl Request {
+        pub fn new(
+            user_id: OwnedUserId,
+            key: String,
+            kv_pair: BTreeMap<String, JsonValue>,
+        ) -> Self {
+            Self { user_id, key, kv_pair }
+        }
+    }
+
+    impl Response {
+        pub fn new() -> Self {
+            Self {}
+        }
+    }
+}
diff --git a/crates/ruma-federation-api/src/query/get_profile_information.rs b/crates/ruma-federation-api/src/query/get_profile_information.rs
index 2dc37b79..db6ced3f 100644
--- a/crates/ruma-federation-api/src/query/get_profile_information.rs
+++ b/crates/ruma-federation-api/src/query/get_profile_information.rs
@@ -7,12 +7,15 @@ pub mod v1 {
     //!
     //! [spec]: https://spec.matrix.org/latest/server-server-api/#get_matrixfederationv1queryprofile
 
+    use std::collections::BTreeMap;
+
     use ruma_common::{
         api::{request, response, Metadata},
         metadata,
         serde::StringEnum,
         OwnedMxcUri, OwnedUserId,
     };
+    use serde_json::Value as JsonValue;
 
     use crate::PrivOwnedStr;
 
@@ -72,6 +75,11 @@ pub mod v1 {
         /// TODO: strong type this to be a valid IANA timezone?
         #[serde(rename = "us.cloke.msc4175.tz", skip_serializing_if = "Option::is_none")]
         pub tz: Option<String>,
+
+        /// Custom arbitrary profile fields as part of MSC4133 that are not reserved such as
+        /// MSC4175
+        #[serde(flatten, skip_serializing_if = "BTreeMap::is_empty")]
+        pub custom_profile_fields: BTreeMap<String, JsonValue>,
     }
 
     impl Request {