diff --git a/src/pipeline.ts b/src/pipeline.ts
index 7297844..3c5d1dc 100644
--- a/src/pipeline.ts
+++ b/src/pipeline.ts
@@ -1,15 +1,20 @@
 import { InputMessage, OutputMessage, Policy } from './types.ts';
 
+/** A policy function with opts to run it with. Used by the pipeline. */
 type PolicyTuple<Opts = unknown> = [policy: Policy<Opts>, opts?: Opts];
 
+/** Helper type for proper type inference of PolicyTuples in the pipeline. */
 // https://stackoverflow.com/a/75806165
 // https://stackoverflow.com/a/54608401
 type PolicyTuplesRest<T extends PolicyTuple[]> = {
-  [K in keyof T]: PolicyTuple<T[K]> | Policy<T[K]>
-}
+  [K in keyof T]: PolicyTuple<T[K]> | Policy<T[K]>;
+};
 
 /** Processes messages through multiple policies, bailing early on rejection. */
-async function pipeline<P extends any[]>(msg: InputMessage, policies: [...PolicyTuplesRest<P>]): Promise<OutputMessage> {
+async function pipeline<P extends any[]>(
+  msg: InputMessage,
+  policies: [...PolicyTuplesRest<P>],
+): Promise<OutputMessage> {
   for (const item of policies) {
     const [policy, opts] = toTuple(item);
     const result = await policy(msg, opts);
diff --git a/src/types.ts b/src/types.ts
index 6243eaa..f5e45c5 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,17 +1,37 @@
+/**
+ * strfry input message from stdin.
+ * https://github.com/hoytech/strfry/blob/master/docs/plugins.md#input-messages
+ */
 interface InputMessage {
+  /** Either `new` or `lookback`. */
   type: 'new' | 'lookback';
+  /** The event posted by the client, with all the required fields such as `id`, `pubkey`, etc. */
   event: Event;
+  /** Unix timestamp of when this event was received by the relay. */
   receivedAt: number;
+  /** Where this event came from. Typically will be `IP4` or `IP6`, but in lookback can also be `Import`, `Stream`, or `Sync`. */
   sourceType: 'IP4' | 'IP6' | 'Import' | 'Stream' | 'Sync';
+  /** Specifics of the event's source. Either an IP address or a relay URL (for stream/sync). */
   sourceInfo: string;
 }
 
+/**
+ * strfry output message to be printed as JSONL (minified JSON followed by a newline) to stdout.
+ * https://github.com/hoytech/strfry/blob/master/docs/plugins.md#output-messages
+ */
 interface OutputMessage {
+  /** The event ID taken from the `event.id` field of the input message. */
   id: string;
+  /** Either `accept`, `reject`, or `shadowReject`. */
   action: 'accept' | 'reject' | 'shadowReject';
+  /** The NIP-20 response message to be sent to the client. Only used for `reject`. */
   msg: string;
 }
 
+/**
+ * Nostr event.
+ * https://github.com/nostr-protocol/nips/blob/master/01.md
+ */
 interface Event<K extends number = number> {
   id: string;
   sig: string;
@@ -22,6 +42,10 @@ interface Event<K extends number = number> {
   created_at: number;
 }
 
+/**
+ * A policy function in this library.
+ * It accepts an input message, opts, and returns an output message.
+ */
 type Policy<Opts = unknown> = (msg: InputMessage, opts?: Opts) => Promise<OutputMessage> | OutputMessage;
 
 export type { Event, InputMessage, OutputMessage, Policy };