Architect drift review (f68258b..HEAD) found no code drift — the firewall is
real at the dependency-graph level (aura-core/std/engine/cli carry no external
dep; the chrono/regex/zip tree is confined to aura-ingest), and C3/C7/C1 are
faithfully realized. Four ledger-level items, all resolved here:
- [ledger-drift] The zero-external-dependency commitment — the load-bearing
rationale for making aura-ingest a crate rather than a feature-gate — lived
only in spec 0011. Recorded in the ledger: C16 now states the engine workspace
is zero-external-dependency by commitment, names aura-ingest as the ingestion
edge / external-dependency firewall, and forbids an external dep in any engine
crate other than aura-ingest.
- [ledger-drift] C16's reuse taxonomy did not place aura-ingest. C16 now lists
the non-node engine crates (aura-engine, aura-cli, aura-ingest).
- [ledger-debt] C12's eager-materialization-now / Arc<[T]>-sharing-later choice
was only in the spec. C12 now carries a "Status (cycle 0011)" note recording
the deliberate gap.
- [debt] aura-engine/Cargo.toml carried a stale comment ("data-server enters
when the ingestion task starts") that contradicted the firewall it should
protect. Replaced with the dependency-pure / firewall-in-aura-ingest note.
The External components data-server bullet is updated to reality (pulled in by
aura-ingest; workspace now resolves from a populated cargo cache, not fully
offline).
Regression gate: no-op (commands.regression empty); architect is the sole gate.
Cycle 0011 is drift-clean. (Drift-clean, not a milestone close — the
Walking-skeleton milestone close additionally needs its end-to-end milestone
fieldtest, a separate deliberate act.)
Cycle 0003: aura-engine's first real content — a Sim that runs a wired DAG of
nodes deterministically, cycle by cycle. First point in the project where
authored nodes execute against data, not just under a hand-fed Ctx.
- `Sim` (aura-engine) — a bootstrapped, frozen root graph: a flat Vec<NodeBox>
(each node owns its input columns, the cycle-0002 shape) + an index edge
table, topologically ordered (Kahn). `bootstrap` sizes every input column from
its node's schema, kind-checks each edge and source target, and rejects
directed cycles — C7's "type check paid once at wiring" generalized to the
whole topology (`BootstrapError::{KindMismatch, BadIndex, Cycle}`).
- `run` — the deterministic loop: per record, forward the source value into its
target slots, evaluate nodes in topo order, capture the observed node's output
at eval time, and forward each `Some` output into its consumers' input columns
(a `None` forwards nothing — the structural seed of sample-and-hold). The loop
destructures `&mut self` into disjoint field borrows and allocates nothing on
the per-cycle path. This is the flat, monomorphized sharpening of RustAst's
reference-counted, interior-mutable observer push graph (C1/C7).
- `Edge` / `Target` (aura-engine) — producer->consumer and source->consumer wiring.
- `Sub` (aura-std) — a 2-input f64-difference node, so the loop is proven on a
real fan-out + join DAG (source -> {SMA(2), SMA(4)} -> Sub), with a determinism
assertion (C1: a second identical run is bit-identical).
Engine library depends only on aura-core; a test-only dev-dependency on aura-std
lets the integration test wire real Sma/Sub nodes. Sim carries a hand-written,
node-opaque `Debug` impl (Box<dyn Node> is not Debug; the impl prints
nodes.len() + the index/topology fields, needed by the bootstrap-rejection tests'
`unwrap_err`).
Deliberately deferred (recorded as decisions): freshness-gated recompute /
sample-and-hold (C5 -> cycle 0004, with the second source that makes it testable);
the explicit monotonic cycle_id counter (its first reader is freshness, 0004);
the Source trait + data-server ingestion + k-way merge (C3/C11); the builder API
(C19); the real sink + run registry (C18/C22).
Gates green: cargo build/test (26: 18 aura-core + 3 aura-std + 5 aura-engine)/
clippy -D warnings clean; surface-purity grep (no dyn-Any / Rc / RefCell) clean.
refs walking-skeleton
Cargo workspace aura-core -> aura-engine -> aura-cli (bin `aura`) plus nodes/ for hot-reloadable cdylib node crates. Crate bodies are intentionally API-free; types arrive from the first spec. Adds the skills profile (.claude/dev-cycle-profile.yml), the project CLAUDE.md with the eight domain invariants, and the design-ledger skeleton.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Brummel