USL Implementation

USL (Universal Session Log) is the storage-first reference implementation of ASP. ACP handles the live present; USL is the storage engine behind ASP.

Repositories

• usl-core — Rust storage engine: append-only, crash-recoverable, schema-agnostic.
• usl-capture — file-boundary live ingest + framing.
• usl-convert — cross-harness conversion (pi / dimagent / claude / codex).

Quick start

# Rust storage + capture (54 tests)
cargo test --workspace

# TS cross-harness conversion (25 tests)
cd packages/usl-convert && npm install && npm run check

Three core properties

1. Append-log first — every record carries length + CRC; recovery truncates at the first torn frame, byte-deterministically.
2. Opaque payloads — unparseable bytes round-trip via typed unknown blocks.
3. Evidence-layer fidelity — conversion replays importer-native payloads verbatim.

See the repository README for the full story and the architecture wiki.