effect-io-ai

Package: effect
Module: ConfigProvider

ConfigProvider.layerAdd

Creates a Layer that composes a new ConfigProvider with the currently active one, rather than replacing it.

When to use

Use to add defaults that should only apply when the primary provider has no value for a path, or override specific keys while keeping the rest from the existing provider by setting asPrimary: true.

Details

By default, the new provider acts as a fallback and is consulted only when the current provider returns undefined. Set asPrimary: true to make the new provider the primary source, with the existing one as fallback.

Example (Adding default values)

import { ConfigProvider } from "effect"

const defaults = ConfigProvider.fromUnknown({
  HOST: "localhost",
  PORT: "3000"
})

// The current env provider is tried first; `defaults` is the fallback
const DefaultsLayer = ConfigProvider.layerAdd(defaults)

See

• layer – replace the provider entirely
• orElse – compose providers without layers

Signature

declare const layerAdd: <E = never, R = never>(self: ConfigProvider | Effect.Effect<ConfigProvider, E, R>, options?: { readonly asPrimary?: boolean | undefined; } | undefined) => Layer.Layer<never, E, Exclude<R, Scope>>

Source

Since v4.0.0