Kessoku

Kessoku

[](https://pkg.go.dev/github.com/mazrean/kessoku) [](https://deepwiki.com/mazrean/kessoku) [](https://codecov.io/gh/mazrean/kessoku)

**Kessoku is a compile-time dependency injection library for Go that speeds up application startup through parallel dependency injection.** Unlike traditional DI frameworks that initialize services sequentially, Kessoku automatically executes independent providers in parallel, dramatically reducing startup time for applications with multiple slow services. Built as a powerful alternative to google/wire, it generates optimized code at compile time with zero runtime overhead.

**Sequential:** DB → Cache → Auth = Total waiting time **Parallel:** DB + Cache + Auth = Fastest service wins

// Before: Sequential (google/wire)
wire.Build(NewDB, NewCache, NewAuth, NewApp)     // Each waits for previous

// After: Parallel (Kessoku)  
kessoku.Inject[*App]("InitApp",
    kessoku.Async(kessoku.Provide(NewDB)),      // }
    kessoku.Async(kessoku.Provide(NewCache)),   // } All run together
    kessoku.Async(kessoku.Provide(NewAuth)),    // }
    kessoku.Provide(NewApp),                    // waits for all
)                                               // Fastest possible startup

**Result:** Every restart gets faster. Multiple slow services? Maximum impact.

Why This Matters

**Your typical day:** Restart your app 10 times during development. Each restart wastes time waiting for services to start one by one.

gantt
    title Sequential vs Parallel Startup
    dateFormat X
    axisFormat %L
    
    section Sequential (slow)
    DB Service    :0, 3
    Cache Service :3, 5  
    Auth Service  :5, 6
    
    section Parallel (fast)