Middleware

Middleware runs before or around endpoint execution. It operates on the raw HTTP context and controls whether the next delegate should continue.

middleware.go

type Middleware interface {
	// Invoke handles the current request and calls next to continue the pipeline.
	Invoke(ctx *Context, next RequestDelegate) error
}

Use middleware for cross-cutting HTTP behavior such as logging, correlation IDs, authentication, metrics, or request/response decoration.

logging.go

type LoggingMiddleware struct {
	logger *slog.Logger
}

func NewLoggingMiddleware(logger *slog.Logger) *LoggingMiddleware {
	return &LoggingMiddleware{logger: logger}
}

func (m *LoggingMiddleware) Invoke(
	ctx *http.Context,
	next http.RequestDelegate,
) error {
	start := time.Now()
	err := next(ctx)

	m.logger.Info("request completed",
		"method", ctx.Request().Method(),
		"path", ctx.Request().Path(),
		"status", ctx.Response().Status(),
		"duration", time.Since(start),
	)

	return err
}

Call next(ctx) when the request should continue to the next middleware or matched endpoint. Return early when the middleware should stop the pipeline.