Introduction

go-sequent documentation

Documentation for go-sequent, a Go library for CQRS and event sourcing built for ledgers and payments. Start here to find guides, API reference, operations runbooks and security notes.

go-sequent documentation

go-sequent is a Go library for CQRS and event sourcing, aimed at financial ledgers and payment systems. You write commands, aggregates, events and projections. The library runs them inside one database transaction, with optimistic concurrency, unique keys, tenant-scoped idempotency and hash-chain integrity already wired in.

It is a pure library. There is no HTTP or gRPC server in the repository; you embed it in your own service. The Go module is github.com/go-sequent/go-sequent, released under the MIT license.

The design follows the concepts of Sequent for Ruby (command, aggregate root, event store, projector, workflow). The Go APIs and the PostgreSQL schema are written from scratch. go-sequent never reads or imports a Ruby Sequent database.

Where to start

If you want to…	Read
Run the bank example in five minutes	Getting started
Decide whether the library fits your system	What is go-sequent
See how one command travels through the code	Core loop
Build an aggregate step by step	Modelling the domain
Understand how OCC, idempotency and the UnitOfWork fit together	Write-path consistency
Look up a specific API	The Reference section below
Run it in production	Operations overview

Introduction

Getting started: install, run the bank example, first commands.
What is go-sequent: scope, fit, and what it deliberately does not do.
Core loop: CommandService.Execute from entry to commit.

Guides

Modelling the domain: a tutorial built around the bank Account aggregate.
Write-path consistency: UnitOfWork, OCC and idempotency, and what each one covers.
Bank example: a tour of examples/bank and examples/bankpg.