diff --git a/.gitignore b/.gitignore
index 06ab5e5..7540984 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,7 @@ node_modules/*
 *.log
 *~
 package-lock.json
+*.d.ts
+*.js.map
+*.js
+!test/*.js
diff --git a/.npmignore b/.npmignore
new file mode 100644
index 0000000..a09524a
--- /dev/null
+++ b/.npmignore
@@ -0,0 +1,3 @@
+**/*
+!*.d.ts
+!*.js.map
diff --git a/mongodb-queue.js b/mongodb-queue.ts
similarity index 55%
rename from mongodb-queue.js
rename to mongodb-queue.ts
index fb781d7..71ad175 100644
--- a/mongodb-queue.js
+++ b/mongodb-queue.ts
@@ -10,32 +10,74 @@
  *
  **/
 
-const crypto = require('crypto')
+import {randomBytes} from 'crypto';
+import {Collection, Db, Filter, FindOneAndUpdateOptions, Sort, UpdateFilter, WithId} from 'mongodb';
 
-function id() {
-  return crypto.randomBytes(16).toString('hex')
+function id(): string {
+  return randomBytes(16).toString('hex')
 }
 
-function now() {
+function now(): string {
   return (new Date()).toISOString()
 }
 
-function nowPlusSecs(secs) {
+function nowPlusSecs(secs: number): string {
   return (new Date(Date.now() + secs * 1000)).toISOString()
 }
 
-module.exports = class Queue {
-  constructor(db, name, opts) {
+export type QueueOptions = {
+  visibility?: number;
+  delay?: number;
+  deadQueue?: Queue;
+  maxRetries?: number;
+}
+
+export type AddOptions = {
+  delay?: number;
+}
+
+export type GetOptions = {
+  visibility?: number;
+}
+
+export type PingOptions = {
+  visibility?: number;
+  resetTries?: boolean;
+}
+
+export type BaseMessage<T extends any = any> = {
+  payload: T;
+  visible: string;
+}
+
+export type Message<T extends any = any> = BaseMessage<T> & {
+  ack: string;
+  tries: number;
+  deleted?: string;
+}
+
+export type ExternalMessage<T extends any = any> = {
+  id: string;
+  ack: string;
+  payload: T;
+  tries: number;
+}
+
+export default class Queue<T extends any = any> {
+  private readonly col: Collection<Partial<Message<T>>>;
+  private readonly visibility: number;
+  private readonly delay: number;
+  private readonly maxRetries: number;
+  private readonly deadQueue: Queue;
+
+  constructor(db: Db, name: string, opts: QueueOptions = {}) {
     if (!db) {
       throw new Error("mongodb-queue: provide a mongodb.MongoClient.db")
     }
     if (!name) {
       throw new Error("mongodb-queue: provide a queue name")
     }
-    opts = opts || {}
 
-    this.db = db
-    this.name = name
     this.col = db.collection(name)
     this.visibility = opts.visibility || 30
     this.delay = opts.delay || 0
@@ -46,7 +88,7 @@ module.exports = class Queue {
     }
   }
 
-  async createIndexes() {
+  async createIndexes(): Promise<void> {
     await Promise.all([
       this.col.createIndex({deleted: 1, visible: 1}),
       this.col.createIndex({ack: 1}, {unique: true, sparse: true}),
@@ -54,11 +96,11 @@ module.exports = class Queue {
     ])
   }
 
-  async add(payload, opts = {}) {
+  async add(payload: T | T[], opts: AddOptions = {}): Promise<string> {
     const delay = opts.delay || this.delay
     const visible = delay ? nowPlusSecs(delay) : now()
 
-    const msgs = []
+    const msgs: BaseMessage<T>[] = []
     if (payload instanceof Array) {
       if (payload.length === 0) {
         throw new Error('Queue.add(): Array payload length must be greater than 0')
@@ -81,33 +123,33 @@ module.exports = class Queue {
     return '' + results.insertedIds[0]
   }
 
-  async get(opts = {}) {
+  async get(opts: GetOptions = {}): Promise<ExternalMessage<T> | null> {
     const visibility = opts.visibility || this.visibility
-    const query = {
-      deleted: null,
+    const query: Filter<Partial<Message<T>>> = {
+      deleted: {$exists: false},
       visible: {$lte: now()},
     }
-    const sort = {
+    const sort: Sort = {
       _id: 1
     }
-    const update = {
+    const update: UpdateFilter<Message<T>> = {
       $inc: {tries: 1},
       $set: {
         ack: id(),
         visible: nowPlusSecs(visibility),
       }
     }
-    const options = {
+    const options: FindOneAndUpdateOptions = {
       sort: sort,
       returnDocument: 'after'
     }
 
     const result = await this.col.findOneAndUpdate(query, update, options)
-    let msg = result.value
-    if (!msg) return
+    const msg = result.value as WithId<Message<T>>;
+    if (!msg) return null
 
     // convert to an external representation
-    msg = {
+    const externalMessage: ExternalMessage<T> = {
       // convert '_id' to an 'id' string
       id: '' + msg._id,
       ack: msg.ack,
@@ -121,32 +163,35 @@ module.exports = class Queue {
       // 1) add this message to the deadQueue
       // 2) ack this message from the regular queue
       // 3) call ourself to return a new message (if exists)
-      await this.deadQueue.add(msg)
+      await this.deadQueue.add(externalMessage)
       await this.ack(msg.ack)
       return this.get()
     }
 
-    return msg
+    return externalMessage
   }
 
-  async ping(ack, opts = {}) {
+  async ping(ack: string, opts: PingOptions = {}): Promise<string> {
     const visibility = opts.visibility || this.visibility
-    const query = {
+    const query: Filter<Partial<Message<T>>> = {
       ack: ack,
       visible: {$gt: now()},
-      deleted: null,
+      deleted: {$exists: false},
     }
-    const update = {
+    const update: UpdateFilter<Message<T>> = {
       $set: {
         visible: nowPlusSecs(visibility)
       }
     }
-    const options = {
+    const options: FindOneAndUpdateOptions = {
       returnDocument: 'after'
     }
 
     if (opts.resetTries) {
-      update.$set.tries = 0
+      update.$set = {
+        ...update.$set,
+        tries: 0,
+      }
     }
 
     const msg = await this.col.findOneAndUpdate(query, update, options)
@@ -156,18 +201,18 @@ module.exports = class Queue {
     return '' + msg.value._id
   }
 
-  async ack(ack) {
-    const query = {
+  async ack(ack: string): Promise<string> {
+    const query: Filter<Partial<Message<T>>> = {
       ack: ack,
       visible: {$gt: now()},
-      deleted: null,
+      deleted: {$exists: false},
     }
-    const update = {
+    const update: UpdateFilter<Message<T>> = {
       $set: {
         deleted: now(),
       }
     }
-    const options = {
+    const options: FindOneAndUpdateOptions = {
       returnDocument: 'after'
     }
     const msg = await this.col.findOneAndUpdate(query, update, options)
@@ -177,42 +222,36 @@ module.exports = class Queue {
     return '' + msg.value._id
   }
 
-  async clean() {
+  async clean(): Promise<void> {
     const query = {
       deleted: {$exists: true},
     }
 
-    return this.col.deleteMany(query)
+    await this.col.deleteMany(query)
   }
 
-  async total() {
+  async total(): Promise<number> {
     return this.col.countDocuments()
   }
 
-  async size() {
-    const query = {
-      deleted: null,
+  async size(): Promise<number> {
+    return this.col.countDocuments({
+      deleted: {$exists: false},
       visible: {$lte: now()},
-    }
-
-    return this.col.countDocuments(query)
+    })
   }
 
-  async inFlight() {
-    const query = {
+  async inFlight(): Promise<number> {
+    return this.col.countDocuments({
       ack: {$exists: true},
       visible: {$gt: now()},
-      deleted: null,
-    }
-
-    return this.col.countDocuments(query)
+      deleted: {$exists: false},
+    })
   }
 
-  async done() {
-    const query = {
+  async done(): Promise<number> {
+    return this.col.countDocuments({
       deleted: {$exists: true},
-    }
-
-    return this.col.countDocuments(query)
+    })
   }
 }
diff --git a/package.json b/package.json
index a0cd8a7..db139d9 100644
--- a/package.json
+++ b/package.json
@@ -1,15 +1,18 @@
 {
   "name": "@reedsy/mongodb-queue",
-  "version": "4.0.0-reedsy-3.0.0",
+  "version": "5.0.0",
   "description": "Message queues which uses MongoDB.",
   "main": "mongodb-queue.js",
   "scripts": {
+    "build": "tsc --pretty",
+    "prepublish": "npm run build",
+    "pretest": "npm run build",
     "test": "set -e; for FILE in test/*.js; do echo --- $FILE ---; node $FILE; done"
   },
-  "dependencies": {},
   "devDependencies": {
     "mongodb": "^5.0.0",
-    "tape": "^4.10.1"
+    "tape": "^4.10.1",
+    "typescript": "^4.9.5"
   },
   "peerDependencies": {
     "mongodb": "^4.0.0 || ^5.0.0"
diff --git a/tag.sh b/tag.sh
index eee381f..9f544d5 100755
--- a/tag.sh
+++ b/tag.sh
@@ -16,11 +16,5 @@ else
   echo "Deploying version $VERSION"
 fi
 
-echo '!/dist' >> .gitignore
-
-git checkout -b release-$VERSION
-git add .gitignore
-git add --all dist/
-git commit --message "Release version $VERSION"
 git tag $VERSION
 git push origin refs/tags/$VERSION
diff --git a/test/clean.js b/test/clean.js
index 1624e65..5be1523 100644
--- a/test/clean.js
+++ b/test/clean.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/dead-queue.js b/test/dead-queue.js
index 13286c4..e49097c 100644
--- a/test/dead-queue.js
+++ b/test/dead-queue.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/default.js b/test/default.js
index 67a8d37..8d1b6ee 100644
--- a/test/default.js
+++ b/test/default.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/delay.js b/test/delay.js
index 61a4efa..582b20d 100644
--- a/test/delay.js
+++ b/test/delay.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 const {timeout} = require('./_timeout.js')
 
 setup().then(({client, db}) => {
diff --git a/test/indexes.js b/test/indexes.js
index e250b7c..fddaaa8 100644
--- a/test/indexes.js
+++ b/test/indexes.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/many.js b/test/many.js
index 39c7659..6fc79b8 100644
--- a/test/many.js
+++ b/test/many.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 const total = 250
 
diff --git a/test/multi.js b/test/multi.js
index f34d6cb..9a4f0af 100644
--- a/test/multi.js
+++ b/test/multi.js
@@ -1,7 +1,7 @@
 const test = require('tape')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 const total = 250
 
diff --git a/test/ping.js b/test/ping.js
index 84cb5f4..7451a37 100644
--- a/test/ping.js
+++ b/test/ping.js
@@ -2,7 +2,7 @@ const test = require('tape')
 const {timeout} = require('./_timeout')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/stats.js b/test/stats.js
index 6679321..424984f 100644
--- a/test/stats.js
+++ b/test/stats.js
@@ -2,7 +2,7 @@ const test = require('tape')
 const {timeout} = require('./_timeout')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/test/visibility.js b/test/visibility.js
index 5fa6153..2596dac 100644
--- a/test/visibility.js
+++ b/test/visibility.js
@@ -2,7 +2,7 @@ const test = require('tape')
 const {timeout} = require('./_timeout')
 
 const setup = require('./setup.js')
-const MongoDbQueue = require('../')
+const MongoDbQueue = require('../').default
 
 setup().then(({client, db}) => {
 
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..77858df
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "es6",
+    "noImplicitAny": true,
+    "noUnusedLocals": true,
+    "moduleResolution": "node",
+    "sourceMap": true,
+    "declaration": true,
+  },
+  "exclude": [
+    "test/"
+  ],
+}