# UDL 1

Read [how Hyperscale fits](https://hyperscale0.ai/docs/runtime.md#how-hyperscale-fits) for provider authority and the shared operation API.

UDL, the Universal Domain Language, describes a company's objects, agreements,
actions and money rules. HSX compiles to this typed contract. An executor reads
UDL and enforces its actors, lifecycle transitions, requirements and effects.
The UDL package validates and serializes contracts; it executes no actions.
This version supports SAR only.

Read the [specification](spec/README.md) for the contract and its runtime obligations.
The [JSON schema](spec/udl.schema.json) defines every field and default.

Install `@hyperscale0/udl` with Node.js 22 or later. `validateUdl` checks a
contract, not an account balance or a deployed executor. `documentDigest`
identifies its stored bytes, and `digest` hashes any plain value through
`canonicalJson`.

From the public source checkout, run `bun install`, then `bun run build`.
`bun run check` checks schema freshness, types and package tests. Edit prose in
`spec/README.md`.