@pumped-fn/lite-extension-observable

Structured lifecycle events for @pumped-fn/lite.

The extension is static composition. Runtime backend choice is a tag. Install observable.extension() once in createScope({ extensions }), then pass sinks and policy with observable.runtime(...) at the scope, request context, or flow execution boundary.

Migration to 1.0.0

Install 1.0 with Lite 6:

npm install @pumped-fn/lite@^6.0.0 @pumped-fn/lite-extension-observable@^1.0.0

import { createScope, flow } from "@pumped-fn/lite"
import { observable } from "@pumped-fn/lite-extension-observable"

const events = observable.memory()
const scope = createScope({
  extensions: [observable.extension()],
  tags: observable.runtime({
    sinks: [events],
    only: ["flow", "resource"],
    input: false,
    output: false,
  }),
})

const run = flow({
  name: "run",
  factory: () => "ok",
})

const ctx = scope.createContext()
await ctx.exec({ flow: run })
await ctx.close()

Runtime

observable.runtime(...) carries backend policy:

| Option | Role | | --- | --- | | sinks | Event destinations. A backend package should adapt to this interface. | | only | Optional target filter: atom, resource, flow, or function. | | input / output | Opt-in payload capture. Defaults stay private. | | redact | Payload mapper used when capture is enabled. | | filter | Final event filter. | | failure | isolate keeps app execution moving; throw makes sink failure fail execution. | | onError | Observes sink failures without hidden swallowed errors. | | now / id | Deterministic clock and id hooks for tests and runtimes. Override id for scoped ids. | | mapError | Error serialization policy. |

The built-in observable.memory() sink is for tests and local inspection; size() returns buffered event count. Production backends stay outside this package and inject their sink through the tag. OpenTelemetry and OTLP collectors are adapter targets for Observable.Sink; this package does not import or ship those backends. Use @pumped-fn/lite-extension-observable-otel when the runtime sink should map events to OpenTelemetry spans. The OTEL adapter stays backend-generic: Grafana, Victoria, and Jaeger compatibility comes from standard OTLP configuration.

Part of pumped-fn — start with the docs or the mental model.