| name | substrate-types |
| description | Use this skill when working with substrate row shape — declaring, serializing, or holding a row without computing on it. Covers Fingerprint256 (the 256-bit four-block container), HLC (hybrid logical clock value), Row / RowLite, LatticeAnchor, AuditEvent (struct shape), MatrixF/C/O/T (storage containers), layout constants (BlockMask, RowBitmaps, BitVector216), TimeRange, and substrate enums (MutationKind, PairingScope, GeneratedByClass, NounType, RowStateValue). Trigger this whenever an agent is about to declare a substrate struct field, define a CloudKit record, write a wire-format encoder, or stub out an audit event. Do NOT trigger for algorithms — those belong to SubstrateKernel or SubstrateML. |
substrate-types — pure shape for the substrate
When this skill applies
An agent is about to:
- Declare a substrate-shaped field on a struct or class
- Serialize a row to or from CloudKit / disk / wire format
- Define a stub
AuditEvent, HLC, or Fingerprint256 for a test
- Add a new enum case to a substrate vocabulary
- Reference a layout constant (block widths, bit positions)
The one rule
If your code computes anything on the data — a Hamming distance, a
fingerprint construction, a decay, a fold, a SHA-256 — you are in
the wrong package. This package holds shape only. The algorithms
live in SubstrateKernel (hot path) or SubstrateML (cold path).
How to use
Swift:
import SubstrateTypes
let fp = Fingerprint256(block0: 0, block1: 0, block2: 0, block3: 0)
let hlc = HLC(physicalTime: now, logicalCount: 0, nodeID: 1)
let row = Row(id: uuid, fingerprint: fp, )
Rust:
use substrate_types::{Fingerprint256, HLC, Row};
let fp = Fingerprint256 { block0: 0, block1: 0, block2: 0, block3: 0 };
let hlc = HLC { physical_time: now, logical_count: 0, node_id: 1 };
Package wiring:
.package(path: "../SubstrateTypes"),
substrate-types = { path = "../../SubstrateTypes/rust" }
What to read
packages/libs/SubstrateTypes/AGENTS.md for the full type-by-type
reference and code examples. docs/engineering/HARNESS_REFERENCE.md
§6.1 for the canonical breakdown of what lives here.
