diff --git a/entities/src/filter.rs b/entities/src/filter.rs
index 5d4c470..751e45c 100644
--- a/entities/src/filter.rs
+++ b/entities/src/filter.rs
@@ -1,11 +1,159 @@
-use serde::{Deserialize, Serialize};
+use serde::{de::Visitor, Deserialize, Deserializer, Serialize};
+use time::{serde::iso8601, OffsetDateTime};
+
+/// Represents a user-defined filter for determining which statuses should not
+/// be shown to the user.
+///
+/// ## Example
+/// ```rust
+/// use mastodon_async::entities::filter::Filter;
+/// let subject = r#"{
+///     "id": "19972",
+///     "title": "Test filter",
+///     "context": [
+///         "home"
+///     ],
+///     "expires_at": "2022-09-20T17:27:39.296Z",
+///     "filter_action": "warn",
+///     "keywords": [
+///         {
+///             "id": "1197",
+///             "keyword": "bad word",
+///             "whole_word": false
+///         }
+///     ],
+///     "statuses": [
+///         {
+///             "id": "1",
+///             "status_id": "109031743575371913"
+///         }
+///     ]
+/// }"#;
+/// let subject: Filter = serde_json::from_str(subject).expect("deserialize");
+/// assert_eq!(subject.id, "19972");
+/// ```
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Filter {
+    /// The ID of the Filter in the database.
+    pub id: String,
+    /// A title given by the user to name the filter.
+    pub title: String,
+    /// The contexts in which the filter should be applied.
+    pub context: Vec<FilterContext>,
+    /// When the filter should no longer be applied.
+    #[serde(with = "iso8601::option")]
+    pub expires_at: Option<OffsetDateTime>,
+    /// The action to be taken when a status matches this filter.
+    pub filter_action: Action,
+    /// The keywords grouped under this filter.
+    pub keywords: Vec<Keyword>,
+    /// The statuses grouped under this filter.
+    pub statuses: Vec<Status>,
+}
+
+/// Represents the various types of Filter contexts
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "lowercase")]
+pub enum FilterContext {
+    /// Represents the "home" context
+    Home,
+    /// Represents the "notifications" context
+    Notifications,
+    /// Represents the "public" context
+    Public,
+    /// Represents the "thread" context
+    Thread,
+    /// Represents the "account" context
+    Account,
+}
+
+/// The action the filter should take
+///
+/// Please note that the spec requests that any unknown value be interpreted
+/// as "warn".
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize)]
+#[serde(rename_all = "lowercase")]
+pub enum Action {
+    /// Indicates filtered toots should show up, but with a warning
+    Warn,
+    /// Indicates filtered toots should be hidden.
+    Hide,
+}
+
+impl<'de> Deserialize<'de> for Action {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        struct FilterActionDeserializer;
+
+        impl<'v> Visitor<'v> for FilterActionDeserializer {
+            type Value = Action;
+
+            fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+                formatter.write_str(r#""warn" or "hide" (or really any string; any string other than "hide" will deserialize to "warn")"#)
+            }
+
+            fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+            where
+                E: serde::de::Error,
+            {
+                Ok(if v == "hide" {
+                    Action::Hide
+                } else {
+                    Action::Warn
+                })
+            }
+        }
+
+        deserializer.deserialize_str(FilterActionDeserializer)
+    }
+}
+
+/// Represents a keyword that, if matched, should cause the filter action to be taken.
+///
+/// ## Example
+/// ```json
+/// {
+///     "id": "1197",
+///     "keyword": "bad word",
+///     "whole_word": false
+/// }
+/// ```
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Keyword {
+    /// The ID of the FilterKeyword in the database.
+    id: String,
+    /// The phrase to be matched against.
+    keyword: String,
+    /// Should the filter consider word boundaries? See [implementation guidelines
+    /// for filters](https://docs.joinmastodon.org/api/guidelines/#filters).
+    whole_word: bool,
+}
+
+/// Represents a status ID that, if matched, should cause the filter action to be taken.
+///
+/// ## Example
+/// ```json
+/// {
+///     "id": "1",
+///     "status_id": "109031743575371913"
+/// }
+/// ```
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Status {
+    /// The ID of the FilterStatus in the database.
+    id: String,
+    /// The ID of the filtered Status in the database.
+    status_id: String,
+}
 
 mod v1 {
     pub use super::FilterContext;
     use serde::{Deserialize, Serialize};
     use time::{serde::iso8601, OffsetDateTime};
 
-    /// Represents a single Filter
+    /// Represents a single v1 Filter
     #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
     pub struct Filter {
         /// The ID of the Filter in the database.
@@ -26,19 +174,37 @@ mod v1 {
     }
 }
 
-/// Represents the various types of Filter contexts
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
-pub enum FilterContext {
-    /// Represents the "home" context
-    #[serde(rename = "home")]
-    Home,
-    /// Represents the "notifications" context
-    #[serde(rename = "notifications")]
-    Notifications,
-    /// Represents the "public" context
-    #[serde(rename = "public")]
-    Public,
-    /// Represents the "thread" context
-    #[serde(rename = "thread")]
-    Thread,
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_filter_action_serialize_and_deserialize() {
+        use Action::*;
+        let hide = r#""hide""#;
+        let warn = r#""warn""#;
+        let subject = serde_json::to_string(&Hide).expect("serialize hide");
+        assert_eq!(subject, hide);
+        let subject = serde_json::to_string(&Warn).expect("serialize warn");
+        assert_eq!(subject, warn);
+        let subject: Action = serde_json::from_str(hide).expect("deserialize hide");
+        assert_eq!(subject, Hide);
+        let subject: Action = serde_json::from_str(warn).expect("deserialize warn");
+        assert_eq!(subject, Warn);
+        let subject: Action =
+            serde_json::from_str(r#""something else""#).expect("deserialize something else");
+        assert_eq!(subject, Warn);
+        // This 👆 further implies...
+        let subject: Action = serde_json::from_str(r#""Hide""#).expect("deserialize Hide");
+        assert_eq!(subject, Warn /* 👈 !             capital H */);
+        // This behavior is specified by the spec https://docs.joinmastodon.org/entities/Filter/#filter_action
+
+        // improper value
+        let subject: Result<Action, _> = serde_json::from_str("[1, 2, 3]");
+        let subject = subject.expect_err("value was not expected to be valid");
+        assert_eq!(
+            subject.to_string(),
+            r#"invalid type: sequence, expected "warn" or "hide" (or really any string; any string other than "hide" will deserialize to "warn") at line 1 column 0"#
+        );
+    }
 }