diff --git a/Cargo.lock b/Cargo.lock
index c373b81..8a6fffb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,7 +4,7 @@ version = 3
 
 [[package]]
 name = "activitypub_federation"
-version = "0.4.0-rc1"
+version = "0.4.0-rc2"
 dependencies = [
  "activitystreams-kinds",
  "actix-rt",
diff --git a/src/activity_queue.rs b/src/activity_queue.rs
index c2e8cbc..fbc8a42 100644
--- a/src/activity_queue.rs
+++ b/src/activity_queue.rs
@@ -7,7 +7,7 @@ use crate::{
     error::Error,
     http_signatures::sign_request,
     reqwest_shim::ResponseExt,
-    traits::ActivityHandler,
+    traits::{ActivityHandler, Actor},
     APUB_JSON_CONTENT_TYPE,
 };
 use anyhow::anyhow;
@@ -40,9 +40,9 @@ use url::Url;
 ///                  signature. Generated with [crate::http_signatures::generate_actor_keypair].
 /// - `inboxes`: List of actor inboxes that should receive the activity. Should be built by calling
 ///              [crate::traits::Actor::shared_inbox_or_inbox] for each target actor.
-pub async fn send_activity<Activity, Datatype>(
+pub async fn send_activity<Activity, Datatype, ActorType>(
     activity: Activity,
-    private_key: String,
+    actor: ActorType,
     inboxes: Vec<Url>,
     data: &RequestData<Datatype>,
 ) -> Result<(), <Activity as ActivityHandler>::Error>
@@ -50,11 +50,14 @@ where
     Activity: ActivityHandler + Serialize,
     <Activity as ActivityHandler>::Error: From<anyhow::Error> + From<serde_json::Error>,
     Datatype: Clone,
+    ActorType: Actor,
+    for<'de2> ActorType::ApubType: Deserialize<'de2>,
 {
     let config = &data.config;
     let actor_id = activity.actor();
     let activity_id = activity.id();
     let activity_serialized = serde_json::to_string_pretty(&activity)?;
+    let private_key = actor.private_key_pem().unwrap();
     let inboxes: Vec<Url> = inboxes
         .into_iter()
         .unique()
diff --git a/src/actix_web/inbox.rs b/src/actix_web/inbox.rs
index fdcce81..04184fd 100644
--- a/src/actix_web/inbox.rs
+++ b/src/actix_web/inbox.rs
@@ -112,8 +112,8 @@ mod test {
         let request_builder =
             ClientWithMiddleware::from(Client::default()).post("https://example.com/inbox");
         let activity = Follow {
-            actor: ObjectId::new("http://localhost:123").unwrap(),
-            object: ObjectId::new("http://localhost:124").unwrap(),
+            actor: ObjectId::parse("http://localhost:123").unwrap(),
+            object: ObjectId::parse("http://localhost:124").unwrap(),
             kind: Default::default(),
             id: "http://localhost:123/1".try_into().unwrap(),
         };
diff --git a/src/fetch/object_id.rs b/src/fetch/object_id.rs
index af9b4fa..d803086 100644
--- a/src/fetch/object_id.rs
+++ b/src/fetch/object_id.rs
@@ -5,9 +5,21 @@ use serde::{Deserialize, Serialize};
 use std::{
     fmt::{Debug, Display, Formatter},
     marker::PhantomData,
+    str::FromStr,
 };
 use url::Url;
 
+impl<T> FromStr for ObjectId<T>
+where
+    T: ApubObject + Send + 'static,
+    for<'de2> <T as ApubObject>::ApubType: Deserialize<'de2>,
+{
+    type Err = url::ParseError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        ObjectId::parse(s)
+    }
+}
 /// Typed wrapper for Activitypub Object ID which helps with dereferencing and caching.
 ///
 /// It provides convenient methods for fetching the object from remote server or local database.
@@ -32,7 +44,7 @@ use url::Url;
 ///     .app_data(db_connection)
 ///     .build()?;
 /// let request_data = config.to_request_data();
-/// let object_id = ObjectId::<DbUser>::new("https://lemmy.ml/u/nutomic")?;
+/// let object_id = ObjectId::<DbUser>::parse("https://lemmy.ml/u/nutomic")?;
 /// // Attempt to fetch object from local database or fall back to remote server
 /// let user = object_id.dereference(&request_data).await;
 /// assert!(user.is_ok());
@@ -55,7 +67,7 @@ where
     for<'de2> <Kind as ApubObject>::ApubType: serde::Deserialize<'de2>,
 {
     /// Construct a new objectid instance
-    pub fn new<T>(url: T) -> Result<Self, url::ParseError>
+    pub fn parse<T>(url: T) -> Result<Self, url::ParseError>
     where
         T: TryInto<Url>,
         url::ParseError: From<<T as TryInto<Url>>::Error>,
@@ -238,7 +250,7 @@ pub mod tests {
 
     #[test]
     fn test_deserialize() {
-        let id = ObjectId::<DbUser>::new("http://test.com/").unwrap();
+        let id = ObjectId::<DbUser>::parse("http://test.com/").unwrap();
 
         let string = serde_json::to_string(&id).unwrap();
         assert_eq!("\"http://test.com/\"", string);
diff --git a/src/protocol/public_key.rs b/src/protocol/public_key.rs
index 27dd550..ecfcd3c 100644
--- a/src/protocol/public_key.rs
+++ b/src/protocol/public_key.rs
@@ -21,7 +21,7 @@ impl PublicKey {
     /// Create a new [PublicKey] struct for the `owner` with `public_key_pem`.
     ///
     /// It uses an standard key id of `{actor_id}#main-key`
-    pub fn new(owner: Url, public_key_pem: String) -> Self {
+    pub(crate) fn new(owner: Url, public_key_pem: String) -> Self {
         let id = main_key_id(&owner);
         PublicKey {
             id,
diff --git a/src/traits.rs b/src/traits.rs
index 4744632..4dd71b1 100644
--- a/src/traits.rs
+++ b/src/traits.rs
@@ -227,7 +227,7 @@ pub trait ActivityHandler {
 }
 
 /// Trait to allow retrieving common Actor data.
-pub trait Actor: ApubObject {
+pub trait Actor: ApubObject + Send + 'static {
     /// `id` field of the actor
     fn id(&self) -> &Url;
 
@@ -237,6 +237,12 @@ pub trait Actor: ApubObject {
     /// actor keypair.
     fn public_key_pem(&self) -> &str;
 
+    /// The actor's private key for signing outgoing activities.
+    ///
+    /// Use [generate_actor_keypair](crate::http_signatures::generate_actor_keypair) to create the
+    /// actor keypair.
+    fn private_key_pem(&self) -> Option<String>;
+
     /// The inbox where activities for this user should be sent to
     fn inbox(&self) -> Url;
 
@@ -412,6 +418,10 @@ pub mod tests {
             &self.public_key
         }
 
+        fn private_key_pem(&self) -> Option<String> {
+            self.private_key.clone()
+        }
+
         fn inbox(&self) -> Url {
             self.inbox.clone()
         }