Modular building blocks for modern Scala applications—no effect system required.
What Is ZIO Blocks?
ZIO Blocks is a family of type-safe, modular building blocks for Scala applications. Each block is a standalone library with zero or minimal dependencies, designed to work with any Scala stack—ZIO, Cats Effect, Kyo, Ox, Akka, or plain Scala.
The philosophy is simple: use what you need, nothing more. Each block is independently useful and designed to compose with other blocks or your existing code.
Core Principles
- Zero Lock-In: No dependency on ZIO, Cats Effect, or any other effect system. Use a block with whatever stack you already have.
- Modular: Each block is a separate artifact. Depend on exactly what you need.
- Cross-Platform: Most blocks cross-build for JVM and Scala.js, and for Scala 2.13 and 3.x with source compatibility—adopt Scala 3 on your timeline, not ours. The catalog below records the exceptions per block.
- High Performance: Implementations that avoid boxing, minimize allocations, and use platform-specific features where they pay off.
- Type Safety: Scala's type system carries the correctness guarantees, without runtime overhead.
To call ZIO Blocks from a ZIO or cats-effect application, see How to Use ZIO Blocks in a ZIO or cats-effect Application.
Getting Started
Add a block and use it. Nothing else to wire up—no runtime to install, no effect
type to adopt:
libraryDependencies += "dev.zio" %% "zio-blocks-schema" % "0.0.56"
That line is for Scala 2.13 and Scala 3.3 to 3.8. On Scala 3.9 and newer, use zio-blocks-next-schema and add scalacOptions += "-experimental". See How to Add ZIO Blocks to Your Build for Scala.js, scala-cli, and cross-building.
import zio.blocks.schema._
case class Person(name: String, age: Int)
object Person {
implicit val schema: Schema[Person] = Schema.derived
}
val alice = Person("Alice", 30)
// One schema, every format
val jsonStr = alice.toJsonString // {"name":"Alice","age":30}
val parsed = """{"name":"Bob","age":25}""".fromJson[Person]
New to ZIO Blocks? Getting Started is a short tour of the core ideas, and the Your First Schema tutorial is the first hands-on lesson.
The four blocks below get a full walkthrough because they have no close
equivalent elsewhere in Scala. Every other block is one row away in the catalog,
and each row links to its own reference page.
All Blocks
Every block is published under the dev.zio organization. Most cross-build for
Scala 2.13 and 3.x on both JVM and Scala.js with full source compatibility —
adopt Scala 3 on your timeline, not ours. The handful of modules that are narrower
say so in their own row.
Meta Programming
JSON support is built into zio-blocks-schema; the modules below add further formats.
| Block | Artifact | Platform | Scala | Description |
|---|
| Schema | zio-blocks-schema | JVM · JS | 2.13 · 3.x | Type-safe schemas with automatic codec, optic, and validator derivation |
| Avro Codec | zio-blocks-schema-avro | JVM | 2.13 · 3.x | Apache Avro binary serialization with automatic schema generation |
| BSON Codec | zio-blocks-schema-bson | JVM | 2.13 · 3.x | MongoDB-compatible BSON serialization with native type support |
| CSV Codec | zio-blocks-schema-csv | JVM · JS | 2.13 · 3.x | RFC 4180-compliant CSV serialization |
| MessagePack Codec | zio-blocks-schema-messagepack | JVM · JS | 2.13 · 3.x | Compact binary serialization with optimized streaming |
| Thrift Codec | zio-blocks-schema-thrift | JVM | 2.13 · 3.x | Apache Thrift binary serialization with TBinaryProtocol |
| TOON Codec | zio-blocks-schema-toon | JVM · JS | 2.13 · 3.x | Token-oriented notation 30–60% smaller than JSON, tuned for LLM prompts |
| XML Codec | zio-blocks-schema-xml | JVM · JS |
This is the beginning of the README. Read the rest at the original. Read the full README ↗
