New federation inbound pipeline that runs envelope-shape -> peer
signature -> replay against the receiving actor's inbox log.
pipeline.erl additions:
validate_inbound/3(Activity, PeerActorState, InboxLog)
runs inbound_stages(PeerAS, InboxLog) and halts on first
failure (existing run_stages/2 driver). Returns ok |
{error, Reason}.
inbound_stages/2(PeerAS, InboxLog)
[stage_envelope, stage_signature(PeerAS), stage_replay(InboxLog)]
M1's validate_inbound/1 and the static inbound_stages/0 (envelope-
only) are preserved — outbox-side callers don't have to re-key on
a peer-AS they don't have.
Signature verification routes through the peer's actor-state
:public_keys (NOT the local kernel's actor-state). Peer-AS
resolution is the caller's responsibility for 5b; Step 5c wires
the peer-actors cache lookup.
14 cases in next/tests/inbox_pipeline.sh:
- happy path: valid signed activity + correct peer AS + empty
inbox -> ok
- bad envelope shape -> {error, _} (stage_envelope rejects)
- unsigned activity -> stage_envelope rejects on
{missing_field, signature} before sig runs
- wrong peer AS (peer's claimed key bytes differ from real) ->
{error, bad_signature}
- replay: inbox already contains the same activity -> {error, replay}
- inbox with a different activity doesn't trigger replay
- inbound_stages/2 returns exactly 3 stages
- inbound_stages/0 still returns 1 stage
- validate_inbound/1 still works
- shape failure short-circuits before sig
- sig failure short-circuits before replay
- two distinct activities both verify against empty inbox
- inbox-of-one doesn't replay the other
Conformance 761/761. 130/130 across 10 Step-5-adjacent suites
(pipeline_envelope, pipeline_signature, pipeline_replay,
pipeline_driver, inbox_pipeline, inbox_bucket, nx_kernel_multi,
bootstrap_start, http_publish, outbox_publish, smoke_app_pure).
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.