Pseudo-parameters

Pseudo-parameters stand in for values that vary by environment. Reference them instead of hard-coding, and the serializer resolves each from an environment variable at build time.

Pseudo-parameter	Environment variable	Fallback
Fly.Region	FLY_REGION	iad
Fly.OrgSlug	FLY_ORG, then FLY_ORG_SLUG	personal
Fly.AppName	FLY_APP_NAME	app

import { App, Machine, MachineConfig, MachineGuest, Fly } from "@intentius/chant-lexicon-fly";

const app = new App({ name: "my-app", org_slug: Fly.OrgSlug });

const web = new Machine({
  region: Fly.Region,
  config: new MachineConfig({
    image: "flyio/hellofly:latest",
    guest: new MachineGuest({ cpu_kind: "shared", cpus: 1, memory_mb: 256 }),
  }),
});

With FLY_REGION=lhr set, region serializes to "lhr"; unset, it falls back to "iad".