Lifetime Guards

InferDI has three lifetimes:

Kind	Created	Cached on	Disposed by container
singleton	once per owning container	owner container	yes
scoped	once per scope	scope	yes
transient	every resolve	never	no

The Lifetime Rule

A singleton cannot directly depend on a scoped or transient service. A singleton is created once and shared across every request, so if it captures a scoped value — the current request's context, user, or transaction — that one request's state silently bleeds into all the others. InferDI makes that edge unrepresentable in the type system instead of leaving it to code review.

new Container()
  .registerClass('request', RequestContext, [], 'scoped')
  .registerClass('users', UserService, ['request'], 'singleton')

That registration is rejected by TypeScript. In strict mode, the same shape is rejected at runtime if a cast bypasses the type system.

Strict Mode

strict: true is the default. It catches:

• singleton-to-scoped or singleton-to-transient violations introduced by casts
• captured outer-container factory leaks
• synchronous singleton cycles
• synchronous transient cycles
• dynamic-key misuse that bypasses static checking

const root = new Container({ strict: true })

Fast Mode

Use strict: false only after tests prove the graph shape:

const root = new Container({ strict: false })

Fast mode removes runtime cycle and lifetime bookkeeping from the resolve path. It does not change the type-level contract, but it also cannot defend against dishonest casts, captured outer containers, or cycles.

Recommended workflow: develop and test in strict mode, then switch only performance-sensitive production graphs after an audit.