diff --git a/cfgsync/adapter/src/artifacts.rs b/cfgsync/adapter/src/artifacts.rs
index 2418ade..1afe2e6 100644
--- a/cfgsync/adapter/src/artifacts.rs
+++ b/cfgsync/adapter/src/artifacts.rs
@@ -19,21 +19,29 @@ pub struct ArtifactSet {
 }
 
 impl ArtifactSet {
+    /// Creates one logical artifact group.
+    ///
+    /// The same type is used for:
+    /// - node-local files that belong to one node only
+    /// - shared files that should be delivered alongside every node
     #[must_use]
     pub fn new(files: Vec<ArtifactFile>) -> Self {
         Self { files }
     }
 
+    /// Returns the files carried by this artifact group.
     #[must_use]
     pub fn files(&self) -> &[ArtifactFile] {
         &self.files
     }
 
+    /// Returns `true` when the group contains no files.
     #[must_use]
     pub fn is_empty(&self) -> bool {
         self.files.is_empty()
     }
 
+    /// Consumes the group and returns its files.
     #[must_use]
     pub fn into_files(self) -> Vec<ArtifactFile> {
         self.files
@@ -49,21 +57,25 @@ pub struct ResolvedNodeArtifacts {
 }
 
 impl ResolvedNodeArtifacts {
+    /// Creates the resolved file set for one node.
     #[must_use]
     pub fn new(node: ArtifactSet, shared: ArtifactSet) -> Self {
         Self { node, shared }
     }
 
+    /// Returns the node-local files.
     #[must_use]
     pub fn node(&self) -> &ArtifactSet {
         &self.node
     }
 
+    /// Returns the shared files delivered alongside every node.
     #[must_use]
     pub fn shared(&self) -> &ArtifactSet {
         &self.shared
     }
 
+    /// Returns the full file list that should be written for this node.
     #[must_use]
     pub fn files(&self) -> Vec<ArtifactFile> {
         let mut files = self.node.files().to_vec();
@@ -79,6 +91,7 @@ pub struct NodeArtifactsCatalog {
 }
 
 impl NodeArtifactsCatalog {
+    /// Creates a catalog indexed by stable node identifier.
     #[must_use]
     pub fn new(nodes: Vec<NodeArtifacts>) -> Self {
         let nodes = nodes
@@ -89,21 +102,25 @@ impl NodeArtifactsCatalog {
         Self { nodes }
     }
 
+    /// Resolves one node's local artifacts by identifier.
     #[must_use]
     pub fn resolve(&self, identifier: &str) -> Option<&NodeArtifacts> {
         self.nodes.get(identifier)
     }
 
+    /// Returns the number of nodes in the catalog.
     #[must_use]
     pub fn len(&self) -> usize {
         self.nodes.len()
     }
 
+    /// Returns `true` when the catalog is empty.
     #[must_use]
     pub fn is_empty(&self) -> bool {
         self.nodes.is_empty()
     }
 
+    /// Consumes the catalog and returns its node entries.
     #[must_use]
     pub fn into_nodes(self) -> Vec<NodeArtifacts> {
         self.nodes.into_values().collect()
@@ -118,26 +135,34 @@ pub struct MaterializedArtifacts {
 }
 
 impl MaterializedArtifacts {
+    /// Creates a fully materialized cfgsync result.
+    ///
+    /// `nodes` contains node-specific files.
+    /// `shared` contains files that should accompany every node.
     #[must_use]
     pub fn new(nodes: NodeArtifactsCatalog, shared: ArtifactSet) -> Self {
         Self { nodes, shared }
     }
 
+    /// Creates a materialized result without any shared files.
     #[must_use]
     pub fn from_catalog(nodes: NodeArtifactsCatalog) -> Self {
         Self::new(nodes, ArtifactSet::default())
     }
 
+    /// Returns the node-specific artifact catalog.
     #[must_use]
     pub fn nodes(&self) -> &NodeArtifactsCatalog {
         &self.nodes
     }
 
+    /// Returns the shared artifact set.
     #[must_use]
     pub fn shared(&self) -> &ArtifactSet {
         &self.shared
     }
 
+    /// Resolves the full file set for one node.
     #[must_use]
     pub fn resolve(&self, identifier: &str) -> Option<ResolvedNodeArtifacts> {
         self.nodes.resolve(identifier).map(|node| {
diff --git a/cfgsync/adapter/src/materializer.rs b/cfgsync/adapter/src/materializer.rs
index b2d18de..8e00b96 100644
--- a/cfgsync/adapter/src/materializer.rs
+++ b/cfgsync/adapter/src/materializer.rs
@@ -10,6 +10,10 @@ pub type DynCfgsyncError = Box<dyn Error + Send + Sync + 'static>;
 
 /// Adapter-side materialization contract for a single registered node.
 pub trait NodeArtifactsMaterializer: Send + Sync {
+    /// Resolves one node from the current registration set.
+    ///
+    /// Returning `Ok(None)` means the node is known but its artifacts are not
+    /// ready yet.
     fn materialize(
         &self,
         registration: &NodeRegistration,
@@ -20,6 +24,13 @@ pub trait NodeArtifactsMaterializer: Send + Sync {
 /// Adapter contract for materializing a whole registration snapshot into
 /// per-node cfgsync artifacts.
 pub trait RegistrationSnapshotMaterializer: Send + Sync {
+    /// Materializes the current registration set.
+    ///
+    /// This is the main registration-driven integration point for cfgsync.
+    /// Implementations decide:
+    /// - when the current snapshot is ready to serve
+    /// - which per-node artifacts should be produced
+    /// - which shared artifacts should accompany every node
     fn materialize_snapshot(
         &self,
         registrations: &RegistrationSnapshot,
@@ -28,6 +39,7 @@ pub trait RegistrationSnapshotMaterializer: Send + Sync {
 
 /// Optional hook for persisting or publishing materialized cfgsync artifacts.
 pub trait MaterializedArtifactsSink: Send + Sync {
+    /// Persists or publishes a ready materialization result.
     fn persist(&self, artifacts: &MaterializedArtifacts) -> Result<(), DynCfgsyncError>;
 }
 
@@ -40,11 +52,13 @@ pub enum MaterializationResult {
 }
 
 impl MaterializationResult {
+    /// Creates a ready materialization result.
     #[must_use]
     pub fn ready(nodes: MaterializedArtifacts) -> Self {
         Self::Ready(nodes)
     }
 
+    /// Returns the ready artifacts when materialization succeeded.
     #[must_use]
     pub fn artifacts(&self) -> Option<&MaterializedArtifacts> {
         match self {
@@ -66,6 +80,8 @@ struct CachedSnapshot {
 }
 
 impl<M> CachedSnapshotMaterializer<M> {
+    /// Wraps a snapshot materializer with deterministic snapshot-result
+    /// caching.
     #[must_use]
     pub fn new(inner: M) -> Self {
         Self {
@@ -126,6 +142,8 @@ pub struct PersistingSnapshotMaterializer<M, S> {
 }
 
 impl<M, S> PersistingSnapshotMaterializer<M, S> {
+    /// Wraps a snapshot materializer with one-time persistence for each
+    /// distinct registration snapshot.
     #[must_use]
     pub fn new(inner: M, sink: S) -> Self {
         Self {
diff --git a/cfgsync/core/src/protocol.rs b/cfgsync/core/src/protocol.rs
index ca8f205..f794fd1 100644
--- a/cfgsync/core/src/protocol.rs
+++ b/cfgsync/core/src/protocol.rs
@@ -28,16 +28,19 @@ pub struct RegistrationPayload {
 }
 
 impl RegistrationPayload {
+    /// Creates an empty adapter-owned payload.
     #[must_use]
     pub fn new() -> Self {
         Self::default()
     }
 
+    /// Returns `true` when no adapter-owned payload was attached.
     #[must_use]
     pub fn is_empty(&self) -> bool {
         self.raw_json.is_none()
     }
 
+    /// Stores one typed adapter payload as opaque JSON.
     pub fn from_serializable<T>(value: &T) -> Result<Self, serde_json::Error>
     where
         T: Serialize,
@@ -47,6 +50,7 @@ impl RegistrationPayload {
         })
     }
 
+    /// Stores a raw JSON payload after validating that it parses.
     pub fn from_json_str(raw_json: &str) -> Result<Self, serde_json::Error> {
         let value: Value = serde_json::from_str(raw_json)?;
 
@@ -55,6 +59,7 @@ impl RegistrationPayload {
         })
     }
 
+    /// Deserializes the adapter-owned payload into the requested type.
     pub fn deserialize<T>(&self) -> Result<Option<T>, serde_json::Error>
     where
         T: DeserializeOwned,
@@ -65,6 +70,7 @@ impl RegistrationPayload {
             .transpose()
     }
 
+    /// Returns the validated JSON representation stored in this payload.
     #[must_use]
     pub fn raw_json(&self) -> Option<&str> {
         self.raw_json.as_deref()
@@ -111,6 +117,7 @@ pub struct NodeRegistration {
 }
 
 impl NodeRegistration {
+    /// Creates a registration with the generic node identity fields only.
     #[must_use]
     pub fn new(identifier: impl Into<String>, ip: Ipv4Addr) -> Self {
         Self {
@@ -120,6 +127,7 @@ impl NodeRegistration {
         }
     }
 
+    /// Attaches one typed adapter-owned payload to this registration.
     pub fn with_metadata<T>(mut self, metadata: &T) -> Result<Self, serde_json::Error>
     where
         T: Serialize,
@@ -128,6 +136,7 @@ impl NodeRegistration {
         Ok(self)
     }
 
+    /// Attaches a prebuilt registration payload to this registration.
     #[must_use]
     pub fn with_payload(mut self, payload: RegistrationPayload) -> Self {
         self.metadata = payload;
@@ -136,6 +145,7 @@ impl NodeRegistration {
 }
 
 impl NodeArtifactsPayload {
+    /// Creates a payload from the files that should be written for one node.
     #[must_use]
     pub fn from_files(files: Vec<NodeArtifactFile>) -> Self {
         Self {
@@ -144,11 +154,13 @@ impl NodeArtifactsPayload {
         }
     }
 
+    /// Returns the files carried by this payload.
     #[must_use]
     pub fn files(&self) -> &[NodeArtifactFile] {
         &self.files
     }
 
+    /// Returns `true` when the payload carries no files.
     #[must_use]
     pub fn is_empty(&self) -> bool {
         self.files.is_empty()
@@ -172,6 +184,7 @@ pub struct CfgsyncErrorResponse {
 }
 
 impl CfgsyncErrorResponse {
+    /// Builds a missing-config error for one identifier.
     #[must_use]
     pub fn missing_config(identifier: &str) -> Self {
         Self {
@@ -180,6 +193,7 @@ impl CfgsyncErrorResponse {
         }
     }
 
+    /// Builds a not-ready error for one identifier.
     #[must_use]
     pub fn not_ready(identifier: &str) -> Self {
         Self {
@@ -188,6 +202,7 @@ impl CfgsyncErrorResponse {
         }
     }
 
+    /// Builds an internal cfgsync error.
     #[must_use]
     pub fn internal(message: impl Into<String>) -> Self {
         Self {
diff --git a/cfgsync/runtime/src/server.rs b/cfgsync/runtime/src/server.rs
index cfefd78..0e00628 100644
--- a/cfgsync/runtime/src/server.rs
+++ b/cfgsync/runtime/src/server.rs
@@ -17,9 +17,17 @@ use thiserror::Error;
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct CfgsyncServerConfig {
     pub port: u16,
+    /// Source used by the runtime-managed cfgsync server.
     pub source: CfgsyncServerSource,
 }
 
+/// Runtime cfgsync source loaded from config.
+///
+/// This type is intentionally runtime-oriented:
+/// - `Bundle` serves a static precomputed bundle directly
+/// - `RegistrationBundle` serves a precomputed bundle through the registration
+///   protocol, which is useful when the consumer wants clients to register
+///   before receiving already-materialized artifacts
 #[derive(Debug, Clone, Deserialize, PartialEq, Eq)]
 #[serde(tag = "kind", rename_all = "snake_case")]
 pub enum CfgsyncServerSource {
@@ -189,6 +197,13 @@ pub async fn serve_cfgsync_from_config(config_path: &Path) -> anyhow::Result<()>
 
 /// Builds a registration-backed cfgsync router directly from a snapshot
 /// materializer.
+///
+/// This is the main code-driven entrypoint for apps that want cfgsync to own:
+/// - node registration
+/// - readiness polling
+/// - artifact serving
+///
+/// while the app owns only snapshot materialization logic.
 pub fn build_snapshot_cfgsync_router<M>(materializer: M) -> Router
 where
     M: RegistrationSnapshotMaterializer + 'static,
@@ -199,6 +214,9 @@ where
 
 /// Builds a registration-backed cfgsync router with a persistence hook for
 /// ready materialization results.
+///
+/// Use this when the application wants cfgsync to persist or publish shared
+/// artifacts after a snapshot becomes ready.
 pub fn build_persisted_snapshot_cfgsync_router<M, S>(materializer: M, sink: S) -> Router
 where
     M: RegistrationSnapshotMaterializer + 'static,
@@ -213,6 +231,9 @@ where
 
 /// Runs a registration-backed cfgsync server directly from a snapshot
 /// materializer.
+///
+/// This is the simplest runtime entrypoint when the application already has a
+/// materializer value and does not need to compose extra routes.
 pub async fn serve_snapshot_cfgsync<M>(port: u16, materializer: M) -> Result<(), RunCfgsyncError>
 where
     M: RegistrationSnapshotMaterializer + 'static,
@@ -223,6 +244,9 @@ where
 
 /// Runs a registration-backed cfgsync server with a persistence hook for ready
 /// materialization results.
+///
+/// This is the direct serving counterpart to
+/// [`build_persisted_snapshot_cfgsync_router`].
 pub async fn serve_persisted_snapshot_cfgsync<M, S>(
     port: u16,
     materializer: M,