Traits (L0–L3)

23 traits across 4 levels. What each is, how you get it, what the kernel does with it.

Traits are computed from what a component declares. You don’t label them — the kernel figures out what they are from what they do.

Summary

Trait	Level	Triggered by	Description
identifiable	L0	@component(name)	Has a name, factory, version
lifecycle	L0	@lifecycle.*	Has activate/deactivate callbacks
dependable	L0	@requires	Declares dependencies
registrable	L0	@provides/@requires	Can provide/require services
inspectable	L0	@lifecycle.health	Has a health check
factoryable	L0	@component	Can be instantiated N times
observable	L1	@requires(logger=ILogger)	Has logging/tracing
configurable	L1	@requires(config=IConfig)	Has config
secured	L1	@requires(auth=IAuth)	Has auth/credentials
storable	L1	@requires(storage=IStorage)	Has storage
communicable	L1	has @runnable or @subscribe	Uses the bus
runnable	L2	@runnable	Has callable functions
subscribable	L2	@subscribe	Reacts to events
kinded	L2	@kind	Defines data schemas
skillful	L2	@skill	Provides AI knowledge
routable	L2	@api	Has API surface declarations
reactive	L2	@computed or @effect	Has reactive properties/effects
adaptable	L2	(aspirational)	Wraps external tools
targeted	L3	has @prop declarations	Parameterized with properties
scoped	L3	@requires(creds=ICredentials) or @requires(storage=IStorage)	Uses structurally-scoped services
versioned	L3	version != "0.0.0"	Has a version

How Traits Are Computed

The kernel reads ComponentMeta at discovery time and auto-infers traits:

# This component...
@component("search", version="1.0")
@requires(config=IConfig, logger=ILogger)
@api("rest", prefix="/search")
class SearchApp:
    @computed
    def url(self): return self.rt.config.get("url")

    @runnable("search", params=P, description="Search")
    async def search(self, params): ...

…automatically gets these traits:

• L0: identifiable, lifecycle, dependable, registrable, factoryable
• L1: configurable, observable, communicable
• L2: runnable, routable, reactive
• L3: versioned

Query at runtime:

status = kernel.status()
for comp in status["components"]:
    print(f"{comp['name']}: {comp['traits']}")