next/kernel/delivery_worker.erl is the gen_server-per-peer
delivery queue per design §13.4. Step 8a lands the skeleton:
pure-functional state shape + enqueue / drain / deliver_one
helpers + backoff schedule + gen_server wrapper. No retry
timer wiring yet (Step 8b), no persist projection yet (8c),
no outbox dispatch wiring yet (8d), no httpc BIF yet (8e), no
live HTTP yet (8f).
State shape (pure):
[{peer, PeerId},
{pending, [Activity, ...]}, %% FIFO queue
{attempts, [{Cid, AttemptCount}]}, %% per-cid retry count
{dead_letter, [Activity, ...]},
{dispatch_fn, fun/1 | undefined}]
Pure-functional API:
new/1
pending/1, peer/1
enqueue_pure/3 — append to FIFO
drain_pure/1 — attempt every queued; returns
{NewState, DeliveredCids, RetryCids}
deliver_one_pure/2 — single dispatch via :dispatch_fn
Backoff schedule (§13.4): 30s / 5m / 30m / 6h / 24h then dead_letter
backoff_for/1 — attempt -> seconds | dead_letter
schedule_for/1 — attempt -> {retry_in, Sec} | dead_letter
gen_server (registered under peer-id atom):
start_link/1, start_link/2(PeerId, DispatchFn)
stop/1
enqueue/2 — sync call
flush/1 — drain + reply with {ok, Delivered, Retry}
pending_srv/1
set_dispatch_fn/2 — swap dispatch in flight
dispatch_fn is a caller-supplied 1-arity fun so tests can stub the
HTTP POST. Step 8f will plug in a closure over httpc:request/4
without touching the queue logic.
17/17 in next/tests/delivery_worker.sh covering:
- new/peer/pending base cases
- enqueue_pure FIFO append
- drain_pure no-dispatch -> retry, queue intact
- drain_pure ok dispatch -> queue empties + delivered list
- drain_pure failing dispatch -> queue intact + retry list
- deliver_one_pure {ok, Cid} and {error, _, no_dispatch_fn}
- backoff_for slot values match §13.4
- backoff_for >=6 returns dead_letter
- schedule_for wraps the slot or dead_letter
- gen_server start_link + enqueue + pending_srv
- gen_server flush with ok dispatch (delivered)
- gen_server flush with failing dispatch (queue kept)
- gen_server set_dispatch_fn in-flight swap
Conformance 761/761.
next — fed-sx Milestone 1 kernel
Single-instance, single-actor fed-sx server built as Erlang-on-SX modules.
See plans/fed-sx-design.md for the architecture and
plans/fed-sx-milestone-1.md for the build plan + per-step progress log.
Status
Both Step 9 smoke proof points are functional in-process:
- 9a-pure (verb extensibility) —
Create{DefineActivity{Pin}}registers Pin at runtime; subsequentPin{path, cid}activities fold into a pin-state projection. Zero kernel code between definition and use. Seenext/tests/smoke_pin_pure.sh. - 9b-pure (reactive application) — A trigger projection matches Notes
tagged
smoketestand derives aTestEchocarrying the source CID. Seenext/tests/smoke_app_pure.sh.
The remaining 9a-tcp / 9b-tcp deliverables layer TCP transport on top — see
Substrate gaps below.
Layout
next/
├── kernel/ Erlang-on-SX kernel modules (.erl)
├── genesis/ SX source files for the bootstrap bundle
├── tests/ Bash test scripts driving sx_server.exe via the epoch protocol
└── data/ Runtime state — gitignored
Module map
| Module | Role |
|---|---|
nx_cid.erl |
Canonical CID wrapper around the host cid:to_string BIF |
envelope.erl |
Activity envelope shape, canonical bytes, time-aware sig verify |
log.erl |
Per-actor in-memory append log (open / append / tip / replay / entries) |
registry.erl |
Pure-functional + gen_server-wrapped registry keyed by Kind |
pipeline.erl |
Validation driver + stage_envelope/signature/replay/schema |
projection.erl |
Pure projection driver + gen_server-per-projection wrapper |
outbox.erl |
Envelope construct + sign + publish orchestrator + broadcast |
bootstrap.erl |
Genesis read/build/verify/load + one-call start/3 kernel bring-up |
define_registry.erl |
Meta-projection fold for Create{Define*} → registry |
sandbox.erl |
eval_pure/2,3 try/catch envelope for projection folds |
nx_kernel.erl |
Long-lived runtime orchestrator; per-actor bucketed state (m2 Step 1a) |
http_server.erl |
route/1,2 + format-aware GET + POST + Accept header content negotiation |
Genesis bundle
next/genesis/ contains 31 SX files across 7 sections, all consumed as data
(read + serialised by bootstrap:populate_registry, not eval'd):
- 3 activity-types — Create, Update, Delete
- 10 object-types — SXArtifact, Note, Tombstone, 6 Define* meta-types, Snapshot
- 7 projections — activity-log, by-type, by-actor, by-object, actor-state, define-registry, audience-graph
- 3 validators — envelope-shape, signature, type-schema
- 3 codecs — dag-cbor, raw, dag-json
- 2 sig-suites — rsa-sha256-2018, ed25519-2020
- 3 audience predicates — Public, Followers, Direct
manifest.sx is the bundle root, listed in dependency-friendly order.
Tests
43 test suites, ~560+ assertions. Each script drives sx_server.exe via the
epoch protocol — loads the Erlang substrate, loads relevant kernel modules
via code:load_binary / erlang-load-module, then exercises behaviour
through erlang-eval-ast.
Conventions:
- Scripts marked
_pure.shexercise pure-functional state. - Scripts marked
_server.sh(or no suffix) exercise gen_server APIs and must inlinestart_linkwith operations — the Erlang-on-SX scheduler doesn't preserve spawned processes across separateerlang-eval-astinvocations. smoke_*_pure.share end-to-end smoke tests demonstrating the §Step 9 proof points without TCP / curl / JSON.
The Erlang-on-SX conformance gate (bash lib/erlang/conformance.sh, 729 /
729) is the no-regression contract — every commit on loops/fed-sx-m1
preserves it.
Substrate
Each .erl source file is hot-loaded at boot via
code:load_binary(Mod, Filename, SourceString) (Phase 7 BIF). Tests drive
the runtime via the epoch protocol:
printf '(epoch 1)\n(load "lib/erlang/runtime.sx")\n(epoch 2)\n<test-expr>\n' \
| hosts/ocaml/_build/default/bin/sx_server.exe
The kernel calls into these host primitives: crypto:hash/2,
cid:from_bytes/1, cid:to_string/1, file:read_file/1, file:write_file/2,
file:delete/1, file:list_dir/1, code:load_binary/3, plus http:listen/2
(the briefing's allowed scope exception, added to lib/erlang/runtime.sx).
Substrate gaps (parked work)
These three gaps block the remaining unchecked deliverables:
-
Term codec (
3b/3c) — all three substrate fixes done 2026-06-05:erlang:binary_to_list/1anderlang:list_to_binary/1registered inlib/erlang/runtime.sx(iolist-aware); the tokenizer's$Xbranch emits the decimal char code;atom_to_list/1andinteger_to_list/1now return Erlang charlists (standard Erlang semantics) withlist_to_atom/list_to_integeraccepting both charlists and SX strings for back-compat. 759/759 conformance. The full term-codec primitive set is in place — Step 3b on-disk segment writer can encode arbitrary Erlang activity terms (atoms, ints, binaries, tuples, lists) into byte sequences using only Erlang-native primitives. -
SX-source eval bridge — There's no BIF that lets Erlang call into the SX evaluator on a parsed source string. Blocks evaluating the
:schema/:fold/:predicate/:verifybodies from the genesis bundle. Erlang-fun stand-ins (pipeline:stage_schema,define_registry:fold, etc.) prove the API shapes; the bridge would let bundle bodies dispatch through them unchanged. -
Dict ↔ proplist marshalling for
http:listen/2— done 2026-06-05.er-bif-http-listenmarshals the native server's request dict ({:method :path :query :headers :body}) into the proplist shape[{method, Bin}, {path, Bin}, {query, Bin}, {headers, [{Name, Value}]}, {body, Bin}]thathttp_server:route/2consumes, and converts the handler's response proplist back to{:status :headers :body}for the native server to serialise. Helpers (er-request-dict-to-proplist,er-proplist-to-dict,er-of-sx-deep,er-to-sx-deep,er-dict-to-header-proplist,er-proplist-fill!) live alongside the BIF wrapper inlib/erlang/runtime.sx. The BIF also spawns the handler into a real Erlang process viaer-spawn-fun+er-sched-run-all!soself()/gen_server:callwork inside route handlers (the kernel and projection gen_servers reach the handler this way). Verified bynext/tests/http_marshal.shand the live TCP smokenext/tests/http_server_tcp.sh/http_server_start.sh. UnblocksStep 8b-start(TCP listener spawn) and the curl-driven 9a-tcp / 9b-tcp smoke tests.
Bringing up the kernel
For tests, bootstrap:start/3(ActorId, KeySpec, ActorState) is the
one-call boot:
KM = <<1,2,3,4>>,
KS = [{key_id, k1}, {algorithm, ed25519}, {value, KM}],
AS = [{public_keys, [[{id, k1}, {created, 0}, {value, KM}]]}],
Pid = bootstrap:start(alice, KS, AS),
%% nx_kernel + registry populated; you now have a kernel.
The HTTP layer (http_server) and nx_kernel:publish/1 flow through the
same in-process gen_servers; http_publish_fold.sh is the end-to-end proof
the chain works.
What's next (when work resumes)
In priority order:
- 8b-start —
http_server:start/1spawns a process hostinghttp:listen/2. (8b-bridge done — see Substrate gap #3.) - 9a-tcp / 9b-tcp — replace the in-process smoke scripts with curl-driven versions hitting the running server.
- Term codec / on-disk log — needs either a new BIF or a temp-file workaround; current in-memory log keeps everything functional otherwise.
- SX-source eval bridge — unlocks real
:schema/:foldbody evaluation from the genesis bundle.