Substrate fix: two-line change to lib/erlang/runtime.sx that lets
http-listen handler routes call gen_server:call without deadlocking.
1. er-sched-step-alive!: pass :pending-args (when set) to the
initial-fun call instead of always passing an empty list.
Default behavior (no field) stays (list) — drop-in safe.
2. er-bif-http-listen sx-handler: instead of er-apply-fun handler
inline (which blows up on receive's er-suspend-marker because
the connection thread has no scheduler step on its stack),
create a real er-process with :initial-fun = handler and
:pending-args = (list req-pl), then er-sched-run-all! to drain.
Any receive (e.g. gen_server:call) suspends + resumes inside
the SX scheduler frame the process owns. Read :exit-result
for the response proplist; marshal back to SX dict.
Investigation arc (see plans/fed-sx-milestone-2.md Blockers #4 +
Progress log):
- loops/fed-prims bf8d0bf2 diagnosed it as Erlang-substrate, not
OCaml mutex (Pattern A wrong, Pattern B right but sketchy).
- First Pattern B attempt failed: tried er-spawn-fun on a raw SX
lambda, hit (er-fun? fv) gate. Connection-thread bisect
pinpointed the exact line.
- Real fix: use the existing er-fun (user's handler) directly,
but feed it via :pending-args so step-alive's hardcoded
(list) doesn't drop the request arg.
Acceptance:
- new next/tests/smoke_kernel_route.sh: 6/6 over real HTTP
(welcome /, /actors/alice, /actors/alice/outbox with
gen_server-backed tip, /actors/alice/inbox, unknown-actor,
via http_server:start(P, [{kernel, nx_kernel}])).
- next/tests/http_server_tcp.sh: 5/5 (bumped wait_bound from
30s to 180s — cold boot is slow under sibling-loop CPU load
and the per-handler scheduler ramp adds a small margin).
- Erlang conformance: 761/761.
Step 12's two-instance smoke test is now unblocked — its full
Follow / Accept / Note flow can layer on top of this kernel-route
surface. m2 plan updated.
Pre-existing httpc_request.sh flakiness ("Undefined symbol:
http-request" on the live-call epochs) reproduces WITHOUT this
change — see git stash A/B in the investigation. Unrelated.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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.