diff --git a/kinds.test.ts b/kinds.test.ts
index 51bf55d..9f64914 100644
--- a/kinds.test.ts
+++ b/kinds.test.ts
@@ -1,5 +1,6 @@
-import { test, expect } from 'bun:test'
-import { classifyKind } from './kinds.ts'
+import { expect, test } from 'bun:test'
+import { classifyKind, isKind, Repost, ShortTextNote } from './kinds.ts'
+import { finalizeEvent, generateSecretKey } from './pure.ts'
 
 test('kind classification', () => {
   expect(classifyKind(1)).toBe('regular')
@@ -19,3 +20,22 @@ test('kind classification', () => {
   expect(classifyKind(40000)).toBe('unknown')
   expect(classifyKind(255)).toBe('unknown')
 })
+
+test('kind type guard', () => {
+  const privateKey = generateSecretKey()
+  const repostedEvent = finalizeEvent(
+    {
+      kind: ShortTextNote,
+      tags: [
+        ['e', 'replied event id'],
+        ['p', 'replied event pubkey'],
+      ],
+      content: 'Replied to a post',
+      created_at: 1617932115,
+    },
+    privateKey,
+  )
+
+  expect(isKind(repostedEvent, ShortTextNote)).toBeTrue()
+  expect(isKind(repostedEvent, Repost)).toBeFalse()
+})
diff --git a/kinds.ts b/kinds.ts
index ad5ab63..c9fafd1 100644
--- a/kinds.ts
+++ b/kinds.ts
@@ -1,3 +1,5 @@
+import { NostrEvent, validateEvent } from './pure.ts'
+
 /** Events are **regular**, which means they're all expected to be stored by relays. */
 export function isRegularKind(kind: number): boolean {
   return (1000 <= kind && kind < 10000) || [1, 2, 4, 5, 6, 7, 8, 16, 40, 41, 42, 43, 44].includes(kind)
@@ -30,80 +32,162 @@ export function classifyKind(kind: number): KindClassification {
   return 'unknown'
 }
 
+export function isKind<T extends number>(event: unknown, kind: T | Array<T>): event is NostrEvent & { kind: T } {
+  const kindAsArray: number[] = kind instanceof Array ? kind : [kind]
+  return (validateEvent(event) && kindAsArray.includes(event.kind)) || false
+}
+
 export const Metadata = 0
+export type Metadata = typeof Metadata
 export const ShortTextNote = 1
+export type ShortTextNote = typeof ShortTextNote
 export const RecommendRelay = 2
+export type RecommendRelay = typeof RecommendRelay
 export const Contacts = 3
+export type Contacts = typeof Contacts
 export const EncryptedDirectMessage = 4
+export type EncryptedDirectMessage = typeof EncryptedDirectMessage
 export const EventDeletion = 5
+export type EventDeletion = typeof EventDeletion
 export const Repost = 6
+export type Repost = typeof Repost
 export const Reaction = 7
+export type Reaction = typeof Reaction
 export const BadgeAward = 8
+export type BadgeAward = typeof BadgeAward
 export const Seal = 13
+export type Seal = typeof Seal
 export const PrivateDirectMessage = 14
+export type PrivateDirectMessage = typeof PrivateDirectMessage
 export const GenericRepost = 16
+export type GenericRepost = typeof GenericRepost
 export const ChannelCreation = 40
+export type ChannelCreation = typeof ChannelCreation
 export const ChannelMetadata = 41
+export type ChannelMetadata = typeof ChannelMetadata
 export const ChannelMessage = 42
+export type ChannelMessage = typeof ChannelMessage
 export const ChannelHideMessage = 43
+export type ChannelHideMessage = typeof ChannelHideMessage
 export const ChannelMuteUser = 44
+export type ChannelMuteUser = typeof ChannelMuteUser
 export const OpenTimestamps = 1040
+export type OpenTimestamps = typeof OpenTimestamps
 export const GiftWrap = 1059
+export type GiftWrap = typeof GiftWrap
 export const FileMetadata = 1063
+export type FileMetadata = typeof FileMetadata
 export const LiveChatMessage = 1311
+export type LiveChatMessage = typeof LiveChatMessage
 export const ProblemTracker = 1971
+export type ProblemTracker = typeof ProblemTracker
 export const Report = 1984
+export type Report = typeof Report
 export const Reporting = 1984
+export type Reporting = typeof Reporting
 export const Label = 1985
+export type Label = typeof Label
 export const CommunityPostApproval = 4550
+export type CommunityPostApproval = typeof CommunityPostApproval
 export const JobRequest = 5999
+export type JobRequest = typeof JobRequest
 export const JobResult = 6999
+export type JobResult = typeof JobResult
 export const JobFeedback = 7000
+export type JobFeedback = typeof JobFeedback
 export const ZapGoal = 9041
+export type ZapGoal = typeof ZapGoal
 export const ZapRequest = 9734
+export type ZapRequest = typeof ZapRequest
 export const Zap = 9735
+export type Zap = typeof Zap
 export const Highlights = 9802
+export type Highlights = typeof Highlights
 export const Mutelist = 10000
+export type Mutelist = typeof Mutelist
 export const Pinlist = 10001
+export type Pinlist = typeof Pinlist
 export const RelayList = 10002
+export type RelayList = typeof RelayList
 export const BookmarkList = 10003
+export type BookmarkList = typeof BookmarkList
 export const CommunitiesList = 10004
+export type CommunitiesList = typeof CommunitiesList
 export const PublicChatsList = 10005
+export type PublicChatsList = typeof PublicChatsList
 export const BlockedRelaysList = 10006
+export type BlockedRelaysList = typeof BlockedRelaysList
 export const SearchRelaysList = 10007
+export type SearchRelaysList = typeof SearchRelaysList
 export const InterestsList = 10015
+export type InterestsList = typeof InterestsList
 export const UserEmojiList = 10030
+export type UserEmojiList = typeof UserEmojiList
 export const DirectMessageRelaysList = 10050
+export type DirectMessageRelaysList = typeof DirectMessageRelaysList
 export const FileServerPreference = 10096
+export type FileServerPreference = typeof FileServerPreference
 export const NWCWalletInfo = 13194
+export type NWCWalletInfo = typeof NWCWalletInfo
 export const LightningPubRPC = 21000
+export type LightningPubRPC = typeof LightningPubRPC
 export const ClientAuth = 22242
+export type ClientAuth = typeof ClientAuth
 export const NWCWalletRequest = 23194
+export type NWCWalletRequest = typeof NWCWalletRequest
 export const NWCWalletResponse = 23195
+export type NWCWalletResponse = typeof NWCWalletResponse
 export const NostrConnect = 24133
+export type NostrConnect = typeof NostrConnect
 export const HTTPAuth = 27235
+export type HTTPAuth = typeof HTTPAuth
 export const Followsets = 30000
+export type Followsets = typeof Followsets
 export const Genericlists = 30001
+export type Genericlists = typeof Genericlists
 export const Relaysets = 30002
+export type Relaysets = typeof Relaysets
 export const Bookmarksets = 30003
+export type Bookmarksets = typeof Bookmarksets
 export const Curationsets = 30004
+export type Curationsets = typeof Curationsets
 export const ProfileBadges = 30008
+export type ProfileBadges = typeof ProfileBadges
 export const BadgeDefinition = 30009
+export type BadgeDefinition = typeof BadgeDefinition
 export const Interestsets = 30015
+export type Interestsets = typeof Interestsets
 export const CreateOrUpdateStall = 30017
+export type CreateOrUpdateStall = typeof CreateOrUpdateStall
 export const CreateOrUpdateProduct = 30018
+export type CreateOrUpdateProduct = typeof CreateOrUpdateProduct
 export const LongFormArticle = 30023
+export type LongFormArticle = typeof LongFormArticle
 export const DraftLong = 30024
+export type DraftLong = typeof DraftLong
 export const Emojisets = 30030
+export type Emojisets = typeof Emojisets
 export const Application = 30078
+export type Application = typeof Application
 export const LiveEvent = 30311
+export type LiveEvent = typeof LiveEvent
 export const UserStatuses = 30315
+export type UserStatuses = typeof UserStatuses
 export const ClassifiedListing = 30402
+export type ClassifiedListing = typeof ClassifiedListing
 export const DraftClassifiedListing = 30403
+export type DraftClassifiedListing = typeof DraftClassifiedListing
 export const Date = 31922
+export type Date = typeof Date
 export const Time = 31923
+export type Time = typeof Time
 export const Calendar = 31924
+export type Calendar = typeof Calendar
 export const CalendarEventRSVP = 31925
+export type CalendarEventRSVP = typeof CalendarEventRSVP
 export const Handlerrecommendation = 31989
+export type Handlerrecommendation = typeof Handlerrecommendation
 export const Handlerinformation = 31990
+export type Handlerinformation = typeof Handlerinformation
 export const CommunityDefinition = 34550
+export type CommunityDefinition = typeof CommunityDefinition