workkit

Composable utilities for Cloudflare Workers. Think TanStack for Workers.

Every package wraps a Cloudflare binding or API with type safety, better DX, and sensible defaults. Use one package or all of them -- they're independent, tree-shakeable, and designed to compose.

Packages

Package	Description
@workkit/types	Shared TypeScript types for bindings, handlers, and utilities
@workkit/errors	Structured, retryable error classes with HTTP mapping
@workkit/env	Type-safe env validation using Standard Schema (Zod, Valibot, ArkType)
@workkit/kv	Typed KV client with serialization, batching, and key prefixing
@workkit/d1	Typed D1 client with query builder and classified errors
@workkit/r2	Typed R2 client with streaming, multipart uploads, and presigned URLs
@workkit/cache	Cache API wrapper with SWR, cache-aside, and tagged invalidation
@workkit/queue	Typed queue producer/consumer with retry, DLQ, circuit breaker, and workflow primitives
@workkit/do	Typed DO storage, state machines, alarms, event sourcing, and time-series aggregations
@workkit/cron	Declarative cron handler with task routing, dependencies, fluent builder, and jitter
@workkit/ratelimit	KV-backed rate limiting (fixed/sliding/token bucket), tiered limits, and quota tracking
@workkit/crypto	AES-256-GCM encryption, digital signatures, key rotation, AAD, and random utilities
@workkit/ai	Typed Workers AI client with streaming, fallback chains, and retry
@workkit/ai-gateway	Multi-provider AI gateway — Workers AI, OpenAI, Anthropic, custom. Routing, streaming, fallback, retry, prompt caching, Cloudflare AI Gateway routing, cost tracking
@workkit/api	Type-safe API definitions with Standard Schema and OpenAPI generation
@workkit/realtime	SSE-over-Durable-Objects broadcast primitive — per-channel pub/sub with Last-Event-ID replay and a fetch-based client wrapper
@workkit/logger	Structured logging with request context and Hono middleware
@workkit/auth	JWT, session management, and auth middleware
@workkit/testing	In-memory mocks with operation tracking, seed builders, error injection, and snapshots

Integrations

Package	Description
@workkit/hono	Hono middleware for env validation, error handling, rate limiting, tiered limits, quotas, and caching
@workkit/astro	Astro middleware and helpers for Cloudflare bindings
@workkit/remix	Typed Remix loaders and actions with env validation

CLI

Scaffold projects, validate bindings, run migrations, and generate code. The CLI supports interactive mode -- run any command without arguments for guided prompts.

bunx workkit init --template hono --features env,d1

Command	Description
workkit init	Scaffold a new Workers project
workkit add	Add packages to an existing project (interactive multi-select)
workkit check	Validate bindings against env schema
workkit d1 migrate	Run D1 migrations
workkit d1 seed	Seed D1 from fixture files
workkit gen client	Generate typed API client from route definitions
workkit gen docs	Generate OpenAPI docs from route definitions
workkit catalog	Show available packages and their status

Quick Start

1. Install what you need

bun add @workkit/env @workkit/kv @workkit/errors

2. Validate your environment

import { parseEnvSync } from "@workkit/env"
import { z } from "zod"

const env = parseEnvSync(rawEnv, {
  API_KEY: z.string().min(1),
  CACHE: z.any(),
})
// env.API_KEY — string (validated)

3. Use typed bindings

import { kv } from "@workkit/kv"

const cache = kv<User>(env.CACHE, { prefix: "user:", defaultTtl: 3600 })
const user = await cache.get("alice") // User | null

Philosophy

• Composable, not monolithic. Each package solves one thing. Use what you need, ignore the rest.
• Types over docs. APIs are designed so TypeScript tells you what to do. If you need to read docs, the types failed.
• Standard Schema. Validation uses the Standard Schema spec -- bring Zod, Valibot, ArkType, or any compatible library.
• Zero runtime overhead. Thin wrappers that add type safety and DX without performance cost. No ORMs, no heavy abstractions.

License

MIT