glm-5.3-flash
e403b22e26
The backends spec read as if the Backend trait were a general storage abstraction and 'two backends, exactly' banned other storage in a deployment — so a downstream wanting sqlite manifests appeared forced into implementing a third backend, the exact weld ADR-004 forbids. - backends-and-dispatch.md: state plainly that the trait is a CAS-tier contract (immutable digest-keyed entries, GC-shaped list/delete) and never a host for manifest/index storage; consumer storage is beside-the-pool. 'Two, exactly' counts trait impls shipped, not storage per deployment. kv: tier name vs pinned sqlite engine made explicit. - ADR-004: add the explicit corollary under the consumer-seams point.
status, last_updated
| status | last_updated |
|---|---|
| draft | 2026-10-02 |
alkblobs — Architecture
Current State
Phase 1 (Architecture). Phase 0 (Exploration) converged — see
docs/research/phase-0.md for the vision, the evidence trail, and the
POC register (all POCs passed or were absorbed; POC code lives in
standalone crates (/workspace/alkblobs-trait-poc,
/workspace/alkblobs-largeblob-poc); findings live in
docs/research/). No implementation exists yet (src/lib.rs is a
placeholder).
The converged Phase 0 posture has been promoted into the specs and ADRs below. Two framing corrections from the convergence review are captured there — not inherited as hedges:
- ADR-001 makes the substrate posture explicit: the store layer carries no alkcall dependency by design — which is conformance to the family pattern, not deviation from it — and the ops surface rides alkcall, feature-gated.
- ADR-004 fixes the "two backends" framing: the crate ships exactly two backends (kv small / fs large — both required by measured scale economics); the path→hash mapping layer (the alkfs/alknet "vfs" shape) is a consumer-layer concern and must never become a third backend.
Architecture Documents
| Document | Scope | Status |
|---|---|---|
| overview.md | Purpose, consumers, layer map, dependency posture | draft |
| hashing-and-keys.md | Canonical hash, key encoding (the one-way door) | draft |
| store-api.md | Store facade: put/get/stat/range/pin/batch/sweep surface, errors, invariants | draft |
| backends-and-dispatch.md | Backend trait contract, shipped backends, size-threshold dispatch | draft |
| gc-and-namespaces.md | Pooled CAS, liveness seams, mark-and-sweep, delete windows | draft |
| ops-surface.md | alkcall-backed have/need + fetch/put ops, ACL mapping | draft |
| open-questions.md | Centralized OQ tracker (incl. promoted Phase 0 register) | draft |
Decision Records
| ADR | Decision | Status |
|---|---|---|
| 001 | Substrate posture & ops-surface placement (conformance, not deviation) | Accepted |
| 002 | Canonical hash + key encoding (the wire-format ADR; precedes any consumer) | Accepted |
| 003 | Backend contract, shipped backends, dispatch policy | Accepted |
| 004 | Exactly two backends; manifest layers stay above | Accepted |
| 005 | Pooled CAS, liveness seams, mark-and-sweep, delete windows | Accepted |
| 006 | Whole-blob verification; transfer encoding excluded by scoping | Accepted |
Open Questions
Tracked in open-questions.md. The Phase 0 register
(OQ-BL-01..06) is promoted there with its resolutions; two questions
remain parked — OQ-07/OQ-08 externally-owned (alkgit seam mapping,
alkfs intake; carried for visibility, gating nothing here). OQ-09
(namespace-visibility default) resolved closed-by-default. Deferral
policy (the "Schrödinger's code" rule): a decision this crate needs
before shipping may not be deferred on a dependency that is itself
waiting for this crate to exist. Two parking kinds remain legitimate:
deferred(scope) on a deciding fact that exists independently of this
crate, and externally-owned questions (how a consumer maps onto this
crate) that gate no decision here — full definitions in the header of
open-questions.md. A corollary worth restating,
because it recurs: a fact this crate must create (its own first
deployment, its own first consumer) is never a deciding input —
decisions stand on evidence in hand, and future needs reopen via named
requirements, not via waiting.
Lifecycle
Spec docs: draft → reviewed → stable → deprecated. A doc moves
reviewed when every crate-owned open question it references
resolves and an architecture review pass clears it — externally-owned
OQs (OQ-07/OQ-08) gate nothing here by definition and do not block the
lifecycle; their outcomes arrive through their owners' processes.
stable when implementation verifies against it; deprecated when
superseded (kept for reference). ADRs use a separate status set
(Accepted | Proposed | Deprecated | Superseded), defined per ADR file.
This tree is in draft pending the first architecture review cycle.