> ## Documentation Index
> Fetch the complete documentation index at: https://developer.ubiquex.io/llms.txt
> Use this file to discover all available pages before exploring further.

# IR

> The typed resource graph schema every medium ultimately compiles down to.

IR (intermediate representation) is the typed resource graph schema
underneath every proposal's `delta`. Whatever authored a change — a
hand-written SDK program, an LLM turning a conversation into intent, a
diagram, a blueprint call — it all compiles down to the same IR before it
can be resolved into a proposal. This is what makes `ubx` a compiler in
the sense the [Overview](/overview) describes: many frontends, one typed,
hashed target.

## Shape

A resource node's real wire shape (from `docs/schema.md`):

```json theme={null}
{
  "kind": "resource",
  "type": "aws_db_instance",
  "name": "payments-db",
  "stack": "payments",
  "provider": { "source": "registry.terraform.io/hashicorp/aws", "version": "6.x" },
  "config": { "...": "typed values" },
  "refs": [
    { "kind": "intra", "to": "aws_vpc.main.id" },
    { "kind": "cross", "to": "@network.vpc_id", "pinned_head": "7fc2..." }
  ],
  "lifecycle": { "status": "pending | in_flight | unknown_post_timeout | applied | failed" }
}
```

## Value encoding carries real distinctions, not just JSON scalars

A config value isn't always a plain concrete value at authoring time, and
the IR's encoding says so explicitly rather than losing the distinction:

* **Concrete** — an ordinary JSON scalar, object, or array.
* **`$computed`** — known only after apply (e.g. a generated ARN). Never
  guessed, never silently treated as if it were already concrete — see
  [Staleness](/concepts/staleness) and [Executor](/concepts/executor) for
  how a `$computed` value gets filled in for real, mid-apply.
* **`$secret`** — a reference to a secret backend and path, never the
  secret's own material. `{"$secret": {"backend": "aws_secrets_manager",
  "path": "db-password"}}` — the envelope shape is what resolve-time
  handling actually checks, not the inner keys.
* **`$ephemeral`** — excluded from persisted state entirely.

## IR came from v1, the syntax didn't

`ubx`'s IR type system — `Computed<T>`, secret refs, ephemeral values,
cross-stack pinned refs — was promoted directly from `ubx` v1 (the XCL
language project). What didn't carry over is XCL's own syntax: XCL as a
language is dead, and where it still appears anywhere in this system it's
at most a debug rendering of the IR, never something a real proposal is
authored in directly.

Full detail, including every amendment to the value-encoding rules since
founding: [`docs/schema.md`](https://github.com/Ubiquex/ubiquex/blob/main/docs/schema.md)
in `ubiquex`.