writeonce/docs/plan/00-kanban.md

Plan kanban — backend: runtime, database, API

Status board for every phase doc under docs/plan/. Focus: the backend — the runtime, the database engine, and the REST/.wo-language API. Frontend phases are parked, not deleted. Each phase file carries a matching status banner; this board is the index.

Statuses: ✅ done · 🔄 in progress · ⬜ not started · ⏸ parked (out of backend focus)

Board

Track 1 — Runtime foundations (dependency removal, kernel primitives)

Status	Phase	Doc	Notes
✅	01 crate scaffolding	done/01	15 crates
✅	02 epoll event loop	done/02	runtime/netpoll_epoll.rs
✅	03 hand-rolled HTTP	done/03	+ keep-alive & pipelining (follow-up under plan 09)
✅	04 tokio/axum cutover	done/04	deps now: anyhow, serde, serde_json, libc
⬜	05 hand-rolled JSON	05	removes serde/serde_json — next in this track
⬜	06 bespoke error type	06	removes anyhow
⬜	07 inotify content watcher	07	wo dev hot reload
⬜	08 sendfile static assets	08	needed by parked UI track too

Track 2 — Concurrency & scale-out (plan 09) — 🔄 in progress

Status	Sub-phase	Notes
✅	09a thread-per-core	runtime/scheduler.rs, SO_REUSEPORT, pinned wo-shard-<t> workers
✅	09b sharded engine	shard.rs bus; Arc<Mutex<Engine>> deleted; interleaved ids; fan-out lists
✅	09c per-shard WAL	wal.rs; ack-after-fsync; boot replay; meta shard guard
✅	— keep-alive (follow-up)	reads ×3.4 → 770k/s; C phase-C sequence
✅	— io_uring group commit (follow-up)	netpoll_io_uring.rs raw ring; 4.7× durable writes on real disk
⬜	09d cross-shard subscriptions	LIVE fan-out, one message per shard — pairs with Stage 3
⬜	09e cross-shard transactions (2PC)	needed by fn checkout spanning shards
⬜	09f observability & reshard	per-shard metrics, WO_RESHARD

All numbers + find-and-fix stories: 09-concurrency-scaleout.md shipped notes and the benchmark table.

Track 3 — Storage & durability (plans 10–12)

Status	Phase	Doc	Notes
⬜	10 storage foundations	10	scope reduced: WAL framing/fallocate landed via 09c; @table(name:, index:) surface + RAM secondary indexes landed via 13 follow-up
⬜	11 WAL & recovery	11	remaining: snapshots (.data), compaction, WAL rotation — replay core shipped in 09c
⬜	12 engine disk cutover	12	mmap arena engine (C phase B is the proving ground)

Track 4 — Language & API (.wo on the wire) — 🔄 in progress

Status	Phase	Doc	Notes
✅	13a class surface	13	class parses, CRUD serves, spec amended
✅	13b method execution	13	POST /api/<t>/:id/<method>; row-scoped txn; one WalRec::Txn frame per call; abort → 409 rollback
✅	— @table + indexed DML (follow-up)	13	@table(name:, index:); engine secondary indexes + find_by; select Type{…} in methods; ?field=value REST filters
⬜	13c LIVE pricing push	13	Stage 3 scoped: subscription registry, WS at /api/<t>/live, replaces the 501 stub
⬜	Stage 3 wire layer	../runtime/database/04-client-api.md	full subscription engine + wire protocol; 13c is its beachhead
⬜	13e pricing at scale	13	wires demo to 09; hot-row reads
⬜	15a MCP core + tools	15	JSON-RPC 2.0 on POST /mcp; catalog-generated tools; durable-ack gated; stateless
⬜	15b MCP resources	15	wo:// URIs, templates, cursors
⬜	15c MCP SSE + sessions	15	first streaming response in rt; Mcp-Session-Id; GET stream
⬜	15d service mcp surface	15	ServiceKind::Mcp; 13b methods become tools
⬜	15e MCP live subscriptions	15	resources/subscribe + Last-Event-ID replay — needs 13c + 09d

Ecommerce sample status (verified 2026-06-13, api.rest 17/17 expected statuses pass): route wiring, empty lists, 405 for un-exposed ops, 404 for unregistered routes, 501 Stage-3 stubs — all exactly as documented. fn checkout, on startup seeding, and status-lifecycle triggers await 13b-style execution + 09e.

Track 5 — C proving ground — ✅ done (A–F)

Status	Phase	Doc
✅	A threads · B arena · C io_uring · D WAL · E recovery · F bench+ACID	exploration/c-runtime/00-plan.md

859k reads/s, 618k durable commits/s; found the ack-ordering + fd-ABA bugs the Rust port then avoided. Optional phase G (splice wo-db C++ engine) remains an idea.

Track 6 — Frontend — ⏸ parked (out of backend focus)

Status	Phase	Doc	Notes
⏸	13d pricing UI	13	MVC triplet exists as design artifact
⏸	14 MVC UI implementation (14a–f)	14	htmlx engine, SCSS subset, controllers, SSR, actions, live patching
⏸	UI exploration track	exploration/ui/00-overview.md	00–08 design docs stay current

Suggested order of play (backend)

1. 13b — method execution ✅ shipped — methods run as row-scoped transactions over RPC
2. 13c / Stage 3 LIVE with 09d fan-out (turns every 501 stub real; the ecommerce order-ops board's backend)
3. 09e — 2PC (cross-shard fn checkout — the canonical ACID demo end-to-end; 13b's single-shard txn is its building block)
4. 15a/15b — MCP core, tools, resources (needs nothing unshipped; makes every app agent-callable — 13b methods become MCP tools in 15d; 15e waits on 13c + 09d)
5. 05/06 dependency removal (mechanical, any time)
6. 10–12 storage completion (snapshots/compaction; arena engine)