effect-io-ai

Package: effect
Module: References

References.CurrentLogAnnotations

Context reference for managing log annotations that are automatically added to all log entries. These annotations provide contextual metadata that appears in every log message.

When to use

Use to attach shared contextual metadata to every log entry emitted in the current context.

Example (Managing log annotations)

import { Console, Effect, References } from "effect"

const logAnnotationExample = Effect.gen(function*() {
  // Get current annotations (empty by default)
  const current = yield* References.CurrentLogAnnotations
  console.log(current) // {}

  // Run with custom log annotations
  yield* Effect.provideService(
    Effect.gen(function*() {
      const annotations = yield* References.CurrentLogAnnotations
      console.log(annotations) // { requestId: "req-123", userId: "user-456", version: "1.0.0" }

      // All log entries will include these annotations
      yield* Console.log("Starting operation")
      yield* Console.info("Processing data")
    }),
    References.CurrentLogAnnotations,
    {
      requestId: "req-123",
      userId: "user-456",
      version: "1.0.0"
    }
  )

  // Run with extended annotations
  yield* Effect.provideService(
    Effect.gen(function*() {
      const extended = yield* References.CurrentLogAnnotations
      console.log(extended) // { requestId: "req-123", userId: "user-456", version: "1.0.0", operation: "data-sync", timestamp: 1234567890 }

      yield* Console.log("Operation completed with extended context")
    }),
    References.CurrentLogAnnotations,
    {
      requestId: "req-123",
      userId: "user-456",
      version: "1.0.0",
      operation: "data-sync",
      timestamp: 1234567890
    }
  )
})

Signature

declare const CurrentLogAnnotations: Context.Reference<ReadonlyRecord<string, unknown>>

Source

Since v4.0.0