# ENC-ASL-HOST/1 - On-Disk Layout for ASL/HOST

Status: Draft
Owner: Architecture
Version: 0.1.0
SoT: No
Last Updated: 2026-01-17
Tags: [ops, host, layout]

**Document ID:** `ENC-ASL-HOST/1`
**Layer:** O1E - Host layout profile (storage-agnostic)

**Depends on (normative):**

* `ASL/HOST/1`
* `ASL/1-STORE`
* `ASL/LOG/1`

**Informative references:**

* `ASL/DAM/1`
* `ASL/DAP/1`
* `ENC-ASL-LOG`
* `ENC-ASL-CORE-INDEX`

---

## 0. Conventions

The key words **MUST**, **MUST NOT**, **REQUIRED**, **SHOULD**, and **MAY** are to be
interpreted as in RFC 2119.

This document defines directory and file placement only. It does not define
byte-level encodings or storage engine internals.

---

## 1. Purpose and Scope

ENC-ASL-HOST/1 specifies a minimal, storage-agnostic on-disk layout for
ASL/HOST implementations. It standardizes where host metadata, domain data,
logs, and snapshots live.

---

## 2. Root Layout

```
/asl-host/
├── host/
├── domains/
├── federation/
└── quarantine/
```

All host-managed state MUST live under `/asl-host`.

---

## 3. Host-Level Metadata

```
/asl-host/host/
├── host-id
├── host-policy
└── trusted-roots/
```

* `host-id` is a stable identifier for the host.
* `host-policy` contains local policy constraints.
* `trusted-roots/` contains offline trust anchors.

---

## 4. Domain Root

Each domain has a single root directory:

```
/asl-host/domains/<domain-id>/
```

Nothing outside this directory MAY be interpreted as part of the domain state.

---

## 5. Domain Descriptor

```
/asl-host/domains/<domain-id>/domain.json
```

The descriptor contains host-derived metadata (not signed):

```
{
  "domain_id": "...",
  "state": "COURTESY|FULL|SUSPENDED|REVOKED",
  "created_at": "...",
  "admitted_at": "...",
  "root_key_fingerprint": "...",
  "policy_hash": "...",
  "current_snapshot": "...",
  "current_logseq": 0
}
```

---

## 6. Admission Records

```
/asl-host/domains/<domain-id>/admission/
├── dam.cbor
├── dam.sig
├── admission-request.cbor
├── admission-decision.cbor
└── admission-decision.sig
```

Admission records are immutable and MUST be retained.

---

## 7. Authority Material

```
/asl-host/domains/<domain-id>/auth/
├── root.pub
├── operators/
├── device.pub
└── revocations/
```

Private keys MAY exist only temporarily and SHOULD NOT be required for
steady-state operation.

---

## 8. Store Area

```
/asl-host/domains/<domain-id>/store/
├── blocks/
│   ├── open/
│   ├── sealed/
│   └── gc/
├── objects/
└── encryption/
```

* `open/` blocks are writable and may be lost on crash.
* `sealed/` blocks are immutable.
* `gc/` is host-managed reclaim staging.

---

## 9. Index Area

```
/asl-host/domains/<domain-id>/index/
├── segments/
├── bloom/
└── tmp/
```

Segment encodings are defined by `ENC-ASL-CORE-INDEX`.

---

## 10. Log Area

```
/asl-host/domains/<domain-id>/log/
```

Log records and envelopes are defined by `ENC-ASL-LOG`.

---

## 11. Snapshot Area

```
/asl-host/domains/<domain-id>/snapshots/
```

Snapshot metadata MUST include the log sequence boundary and segment set used
for deterministic replay.

---

## 12. Leases

```
/asl-host/domains/<domain-id>/leases/
```

Courtesy lease metadata is stored here and MUST NOT be interpreted by
ASL/1-STORE.

---

## 13. Temporary Workspace

```
/asl-host/domains/<domain-id>/tmp/
```

The host MAY use this directory for temporary, non-authoritative files.
It MUST NOT be required for deterministic replay.

---

## 14. Federation (Optional)

```
/asl-host/federation/
├── peers/
├── exports/
└── imports/
```

Federation caches are optional and MUST NOT change local domain state.

---

## 15. Quarantine

```
/asl-host/quarantine/
```

Untrusted or failed admissions MAY be staged here for inspection.

---

## 16. Versioning

Backward-incompatible layout changes MUST bump the major version.