Fairway

Tiny, independent vertical slices. One shared event log. Zero coupling.

The Problem

Vertical slicing promises independent feature development. Reality usually delivers hidden coupling.

Shared databases — slices touch the same tables. Schema changes require coordination.

Stream-per-aggregate — consistency boundaries are fixed at design time. Commands that cross aggregates need sagas.

The Solution

Events as the only contract. Slices share nothing but the event log. No shared tables, streams, or types.

Dynamic consistency boundaries. Each command's boundary emerges from what it actually reads — not from architectural diagrams.

Read more: Dynamic consistency →

Architecture

┌─────────────────────────────────────────┐
│         Testing Helpers                 │  given / when / then
├─────────────────────────────────────────┤
│         HTTP Layer                      │  HttpChangeRegistry / HttpViewRegistry
├─────────────────────────────────────────┤
│         Framework Layer                 │  Command / View / Automation
├─────────────────────────────────────────┤
│         FoundationDB                    │  events (DCB) / queues / KV read models
└─────────────────────────────────────────┘

One datastore for everything: events, job queues, read model persistence.

Three Patterns

Every module implements one of these:

User action        Event log           Projection
    │                  │                   │
    ▼                  ▼                   ▼
┌──────────┐    ┌───────────────┐    ┌──────────┐
│ Command  │───▶│    Events     │───▶│   View   │
└──────────┘    └───────┬───────┘    └──────────┘
                        │
                ┌───────▼──────┐
                │  Automation  │  (View → Command, no user)
                └──────────────┘

Quick Start

Prerequisites: Go 1.24+, FoundationDB installed.

git clone https://github.com/err0r500/fairway
cd fairway/examples/todolist
go generate ./...
go run .

curl -X POST http://localhost:8080/api/lists/my-list \
     -H "Content-Type: application/json" \
     -d '{"name": "Shopping"}'

curl http://localhost:8080/api/lists/my-list

Package Overview

Package	Description
Framework	Commands, views, automations, queues, KV read models
`dcb/`	DCB-compliant event store on FoundationDB
`utils/`	HTTP helpers, idempotency middleware
`testing/`	`given`, `when`, `then` test helpers

Learn More

The Problem — why vertical slicing fails
The Solution — events as contracts
DCB Store — the foundation
Framework — commands, views, automations

Development

export GOFLAGS="-tags=test"
go test ./...