diff --git a/src/lib.rs b/src/lib.rs
index 3b7e3c6..70edb06 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -62,11 +62,13 @@ pub use master_playlist::MasterPlaylist;
 pub use media_playlist::MediaPlaylist;
 pub use media_segment::MediaSegment;
 
+/// Builder structs
 pub mod builder {
     pub use crate::master_playlist::MasterPlaylistBuilder;
     pub use crate::media_playlist::MediaPlaylistBuilder;
     pub use crate::media_segment::MediaSegmentBuilder;
 
+    /// Builder structs for tags
     pub mod tags {
         // master playlist
         pub use crate::tags::master_playlist::media::ExtXMediaBuilder;
@@ -78,6 +80,7 @@ pub mod builder {
         // media playlist
     }
 
+    /// Builder structs for types
     pub mod types {
         pub use crate::types::decryption_key::DecryptionKeyBuilder;
         pub use crate::types::stream_data::StreamDataBuilder;
diff --git a/src/media_playlist.rs b/src/media_playlist.rs
index 855aea8..9fb4aad 100644
--- a/src/media_playlist.rs
+++ b/src/media_playlist.rs
@@ -262,6 +262,11 @@ impl MediaPlaylistBuilder {
         self
     }
 
+    /// Builds a new `MediaPlaylist`.
+    ///
+    /// # Errors
+    ///
+    /// If a required field has not been initialized.
     pub fn build(&self) -> Result<MediaPlaylist, String> {
         // validate builder
         self.validate()?;
diff --git a/src/types/decryption_key.rs b/src/types/decryption_key.rs
index 0caf17a..53bff38 100644
--- a/src/types/decryption_key.rs
+++ b/src/types/decryption_key.rs
@@ -81,6 +81,17 @@ pub struct DecryptionKey {
 }
 
 impl DecryptionKey {
+    /// Creates a new `DecryptionKey` from an uri pointing to the key data and
+    /// an `EncryptionMethod`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use hls_m3u8::types::DecryptionKey;
+    /// use hls_m3u8::types::EncryptionMethod;
+    ///
+    /// let key = DecryptionKey::new(EncryptionMethod::Aes128, "https://www.example.uri/key");
+    /// ```
     #[must_use]
     #[inline]
     pub fn new<I: Into<String>>(method: EncryptionMethod, uri: I) -> Self {
@@ -93,6 +104,25 @@ impl DecryptionKey {
         }
     }
 
+    /// Returns a builder for a `DecryptionKey`.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use hls_m3u8::types::DecryptionKey;
+    /// use hls_m3u8::types::{EncryptionMethod, KeyFormat};
+    ///
+    /// let key = DecryptionKey::builder()
+    ///     .method(EncryptionMethod::Aes128)
+    ///     .uri("https://www.example.com/")
+    ///     .iv([
+    ///         16, 239, 143, 117, 140, 165, 85, 17, 85, 132, 187, 91, 60, 104, 127, 82,
+    ///     ])
+    ///     .format(KeyFormat::Identity)
+    ///     .versions(&[1, 2, 3, 4, 5])
+    ///     .build()?;
+    /// # Ok::<(), String>(())
+    /// ```
     #[must_use]
     #[inline]
     pub fn builder() -> DecryptionKeyBuilder { DecryptionKeyBuilder::default() }