fed-prims: Phase J — http-request + 6 tests

NATIVE-ONLY http-request primitive (bin/sx_server.ml). HTTP/1.1 over
Unix sockets + gethostbyname; inline http:// URL parsing (full
url-parse deferred to Phase K); Connection: close + Host +
Content-Length headers auto-supplied; reads response via
Content-Length or read-to-EOF; chunked transfer-encoding rejected.
Test bin/test_http_client.sh spins a Phase-H echo server and drives
a second sx_server: GET+query, POST+body, 404, custom request
header reflected, non-http scheme rejected, integer status — 6/6.
WASM boot green (prim not in lib); Erlang conformance 530/530.

plans/fed-sx-host-primitives.md

@@ -145,6 +145,44 @@ check** → tests → commit → tick box → Progress-log line → push.
 - **Acceptance:** curl test script green; WASM build untouched (prim not in lib).
   Satisfies fed-sx Step 8 transport.
 
+### Phase J — HTTP/1.1 client, **native-only** (`bin/sx_server.ml`) ✅ DONE
+- Mirror of Phase H, inverse direction. TCP connect via `Unix.gethostbyname` +
+  `Unix.socket`/`Unix.connect`. Write request line + headers + body, read
+  response status line + headers + body (Content-Length first; chunked
+  encoding optional v2 — flag as Blockers if a fed-sx need hits it).
+- Primitive `(http-request method url headers body) -> response-dict`
+  registered ONLY in `bin/sx_server.ml`. Response dict shape:
+  `{:status :headers :body}` (mirror of server's request dict). URL must be
+  `http://...` for v1; HTTPS is a separate later phase (needs TLS lib).
+- Tests: `bin/test_http_client.sh` — start a tiny python HTTP server in a
+  subprocess (or reuse Phase H's SX server), drive GET / POST / 404 /
+  custom-header roundtrip via `(http-request ...)` from the epoch protocol,
+  assert response dict shape + body, kill server.
+- **Acceptance:** test script green; WASM build untouched (prim not in lib);
+  Erlang conformance unchanged. Unblocks Erlang Phase 8 `httpc:request/4` BIF
+  wiring and fed-sx Milestone 2 federation `POST /inbox` outbound.
+
+### Phase K — URL parser, pure OCaml, WASM-safe (`lib/sx_url.ml`)
+- `(url-parse "http://host:port/path?q=1") -> {:scheme :host :port :path :query}`
+  — small recursive-descent parser. No external deps. Port is integer when
+  present, absent key otherwise (or default per scheme: 80/443).
+- `(url-encode-component string) -> string` /
+  `(url-decode-component string) -> string` — percent-encoding per RFC 3986
+  (reserved/unreserved sets).
+- Tests: `bin/test_url.ml` — full URL, port-less, path-only, query string with
+  multiple pairs, empty path, percent-encoding round-trips, malformed inputs
+  (return error-shaped result, not exception).
+- **Acceptance:** WASM boot green (pure lib); supports fed-sx kernel actor URL
+  parsing and Phase J HTTP-client url handling.
+
+### Phase L — (open) further client prims as fed-sx kernel needs surface
+- Add new phases here as the kernel loop or design conversations identify
+  needs: chunked HTTP transfer encoding, HTTPS / TLS verify (likely opam-dep
+  Blockers), webfinger HTTP shape, DNS (probably folded into `http-request`).
+- Each new phase: define test vectors / contract → implement → WASM-check
+  (skip for native-only) → commit → Progress log. Same iteration discipline as
+  A–I.
+
 ### Phase I — handoff ✅ DONE
 - Flip the `plans/erlang-on-sx.md` Blockers entry "SX runtime lacks platform
   primitives …" to **RESOLVED**, listing the exact SX primitive names so the
@@ -226,6 +264,20 @@ should leave `httpc`/`sqlite` BIFs blocked with that note.
 
 _Newest first._
 
+- 2026-05-26 — Phase J: `http-request` primitive in `bin/sx_server.ml`
+  (NATIVE ONLY — `Unix.gethostbyname` + `Unix.connect`; HTTP/1.1 with
+  inline `http://` URL parser; sends Connection: close + Host +
+  Content-Length unless caller supplies them; reads status line +
+  headers + body via Content-Length, falling back to read-to-EOF;
+  Transfer-Encoding: chunked rejected with explicit error per plan).
+  Test `bin/test_http_client.sh` spins up a Phase-H echo server in a
+  background sx_server and drives a second sx_server with epoch
+  `(eval …)` calls: GET+query, POST+body, 404, custom request
+  header reflected back, non-http scheme rejected (error path),
+  integer status — 6/6 pass. NOT in lib/ so WASM boot untouched
+  (green); Erlang conformance 530/530 unchanged; run_tests
+  unchanged. Unblocks Erlang Phase 8 `httpc:request/4` BIF wiring
+  and fed-sx Milestone 2 federation `POST /inbox` outbound.
 - 2026-05-18 — Phase I: handoff. `erlang-on-sx.md` Blockers gained one
   RESOLVED entry (no "SX runtime lacks…" entry pre-existed; it read
   "_(none yet)_") mapping every delivered primitive → its Phase 8 BIF,