Cosmix Self-Aware Layer — The Uniform Property Surface

Split out of SPEC 07 §2 (2026-06-05). This is the property read model — what a property is, the path grammar, props.get, and props.describe. It is the foundational, code-backed read surface (cosmix-lib-props-core) that the SPEC 07 conformance + event-emission contract builds on, and that SPEC 12 (mutation, audit, managed collections) extends. Section numbers are preserved as §2.x so existing "SPEC 07 §2.x" cross-references resolve here.

2. The Uniform Property Surface

Every cosmix daemon (any process registered as a broker service) MUST implement the following commands at conformance level L1 or higher:

2.1 What is a property?

A property is a named, schema-described slot in a daemon's observable state. Properties cover:

• Configuration — values loaded from ~/.config/cosmix/<svc>.toml, command-line flags, environment variables.
• Lifecycle state — uptime, start time, current operating mode, health classification.
• Registered resources — connections, accounts, mailboxes, panels, peers — anything the daemon owns and can enumerate.
• Derived state — counters, queue depths, cache hit rates, only when durable enough to be worth observing (see §7.1 cardinality).

A property is not:

• An ephemeral metric sampled per-request (use a metrics topic instead).
• A high-frequency render value (frame timing, cursor position, GPU framebuffer state).
• A secret in plaintext (use sensitive: true in describe; values are redacted by default — see §7.2).

2.2 Property paths

Property paths use dotted notation: config.bind, lifecycle.uptime_s, mailboxes.inbox.unread. The syntax matches Mix $var.field access (Ch 04) and ABP command naming (Ch 02 §1).

A path identifies either:

• A leaf — a single value (string, number, bool, list, object).
• A subtree — an interior node whose children are themselves paths.

props.get with no path: returns the whole tree. With a path, it returns that subtree (or leaf). props.list returns all leaves; subtree paths are implied by their constituent leaves. props.describe accepts both leaf and subtree paths.

Path segments are case-sensitive, lowercase, alphanumeric + _. The wildcard * is reserved for future use (e.g., subscribe to all children of a subtree) and MUST NOT appear in concrete paths.

2.3 Example: noded.props.get

Request:

---
amp: 1
type: request
to: noded
command: noded.props.get
---

Response:

---
amp: 1
type: response
from: noded
command: noded.props.get
rc: 0
---
{
  "config": {
    "bind": "192.0.2.5:4200",
    "node_name": "alpha",
    "log_level": "info"
  },
  "lifecycle": {
    "started_at": "2026-04-25T08:14:22Z",
    "uptime_s": 38291,
    "health": "ok"
  },
  "services": {
    "registered": ["maild", "indexd", "display", "mix-shell"],
    "count": 4
  },
  "topics": {
    "active": 12,
    "snapshot_bytes": 81920
  }
}

2.4 props.describe

Response shape (JSON body):

{
  "path": "config.bind",
  "type": "string",
  "format": "host:port",
  "mutable": false,
  "sensitive": false,
  "description": "WireGuard interface address and port the broker binds to."
}

Optional fields: format, enum, min, max, default, since, deprecated, transient. Type values: string, number, bool, list, object, null. Subtree descriptions return type: "object" and an additional children: [path] array enumerating direct child paths.

The schema language is defined in §6.4. It is intentionally minimal — a subset of fields agents need, not a full JSON-Schema port.

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