Chronicle in your language

Chronicle in your language

One event-sourcing database, idiomatic clients

Chronicle is an event-sourcing database and processing runtime with a language-agnostic gRPC/protobuf boundary. That means the event store is not tied to one runtime: the first-class .NET SDK and the TypeScript, Kotlin/Java, and Elixir clients all work against the same store, the same events, and the same projections — and a Python client is coming soon. Everything is open source and MIT licensed. Client SDK docs →

Event sourcing for .NET

The .NET SDK is the first-class Chronicle client: typed access to event stores, event logs, read models, projections, reducers, reactors, constraints, migrations, namespaces, and hosting integration — including a one-line .NET Aspire resource.

dotnet add package Cratis.Chronicle

• Event sourcing in .NET — the dedicated landing page
• .NET client docs · Get started
• Cratis.Chronicle on NuGet
• Chronicle on GitHub

Event sourcing for TypeScript and Node.js

@cratis/chronicle is the idiomatic TypeScript client for Chronicle, with support for transactions, jobs, webhooks, compliance/PII, and OpenTelemetry. It builds on the @cratis/chronicle.contracts gRPC contracts package.

npm install @cratis/chronicle

• Event sourcing in TypeScript and Node.js — the dedicated landing page
• TypeScript client docs
• @cratis/chronicle on npm
• Chronicle.TypeScript on GitHub

Event sourcing for Kotlin and Java

io.cratis:chronicle is the idiomatic JVM client for Chronicle, usable from Kotlin and Java alike. It ships with a Spring Boot starter and a testing library.

build.gradle.kts

dependencies {
    implementation("io.cratis:chronicle:<version>")
    // Or, in a Spring Boot application:
    implementation("io.cratis:chronicle-spring-boot-starter:<version>")
}

• Event sourcing in Kotlin and Java — the dedicated landing page
• Kotlin/Java client docs
• io.cratis:chronicle on Maven Central
• Chronicle.Kotlin on GitHub

Event sourcing for Elixir

cratis_chronicle is the idiomatic Elixir client for Chronicle, with transactions, optimistic concurrency, webhooks, and resilient reconnection.

mix.exs

defp deps do
  [
    {:cratis_chronicle, "~> 0.0"}
  ]
end

• Event sourcing in Elixir — the dedicated landing page
• Elixir client docs
• cratis_chronicle on Hex
• Chronicle.Elixir on GitHub

Event sourcing for Python — coming soon

A Python client for Chronicle is in development. It is pre-release and not yet published to PyPI, so there is nothing to install yet — follow the repository for progress.

• Event sourcing in Python — the coming-soon landing page
• Chronicle.Python on GitHub

Pre-release

The Python client is pre-alpha. APIs will change, and no package has been published. Watch the repository or ask in the community if it matters to your project.

Any language, one contract

Every client speaks the same gRPC/protobuf contracts, so any language with a gRPC implementation can talk to Chronicle. If your runtime is not listed above, you can implement the contracts directly.

Building a client Implement the Chronicle gRPC contracts for a new language or runtime.

Chronicle architecture How the kernel, the gRPC boundary, and the storage providers fit together.

Chronicle MCP server Connect an AI agent to a running Chronicle — it works regardless of which client language your app uses.

Storage choice Run Chronicle over MongoDB (default), PostgreSQL, Microsoft SQL Server, or SQLite.