@workkit/types

Shared TypeScript types for Cloudflare Workers bindings, handlers, and utilities

Install

bun add @workkit/types

Usage

Before (raw Cloudflare types)

// No type safety on KV values, queue messages, or DO storage
const value = await env.MY_KV.get("key") // string | null — no idea what shape
await env.MY_QUEUE.send({ type: "created" }) // any — no validation

After (workkit types)

import { type TypedKVNamespace, type TypedQueue, Ok, Err, isOk, unwrap } from "@workkit/types"

// Typed bindings — know exactly what's stored
type Env = {
  MY_KV: TypedKVNamespace<User>
  EVENTS: TypedQueue<UserEvent>
}

// Result type for error handling without exceptions
const result: Result<User, Error> = Ok({ name: "Alice" })
if (isOk(result)) {
  const user = unwrap(result) // User
}

// Branded types prevent mixing up string IDs
import { kvKey, d1RowId } from "@workkit/types"
const key = kvKey("user:123") // KVKey (branded string)
const rowId = d1RowId("abc") // D1RowId (branded string)

API

Result Types

• Ok(value) — Wrap a success value
• Err(error) — Wrap an error value
• isOk(result) / isErr(result) — Type guards
• unwrap(result) — Extract value or throw

Branded Types

• kvKey(s), d1RowId(s), r2ObjectKey(s), durableObjectId(s), queueMessageId(s) — Create branded string IDs
• brand<Tag>(s) — Generic branding function

Binding Types

TypedKVNamespace<T>, TypedD1Result<T>, TypedR2Object, TypedQueue<T>, TypedDurableObjectStorage, TypedMessage<T>, TypedMessageBatch<T>

Handler Types

WorkerFetchHandler, WorkerScheduledHandler, WorkerQueueHandler, WorkerEmailHandler, WorkerModule

Utility Types

JsonValue, JsonObject, MaybePromise, Prettify, RequireKeys, DeepPartial, DeepReadonly, NonEmptyArray, Dict

License

MIT