johnnyt · Sep 30, 2026 · Sep 30, 2026 · Sep 30, 2026
diff --git a/README.md b/README.md
@@ -21,8 +21,8 @@ conformance failures. v2 is:
   sessions and timers layered on top
 - **predicator as the datamodel** - safe, non-evaluative expressions; no
   ECMAScript, no eval
-- built **corpus-first** - 275 generated SCION/W3C conformance tests (119
-  SCION + 156 W3C) behind a forward-only regression ratchet inherited from
+- built **corpus-first** - 287 generated SCION/W3C conformance tests (119
+  SCION + 168 W3C) behind a forward-only regression ratchet inherited from
   v1, with the generator committed this time
 
 ## Installation

diff --git a/changelog.d/st-8kn8.md b/changelog.d/st-8kn8.md
@@ -0,0 +1,3 @@
+### Added
+
+- The conformance corpus claims eleven more W3C documents, the Basic HTTP Event I/O Processor's: test509, test510, test518, test519, test520, test522, test531, test532, test534, test567 and test577. test201 is in the corpus and unclaimed. The case schema gains `host.event_io_processors`, the Event I/O Processors a host runs with a location that reaches the session, and the one `host` key a W3C case may carry. A new guide, `docs/basichttp.md`.
diff --git a/conformance/RATCHET.md b/conformance/RATCHET.md
@@ -169,9 +169,30 @@ A case may carry an optional `host` object, reserved by ADR-0070 decision 5
 for what a `statifier` case needs from its host: `send_types`, the send
 types the case registers in
 [ADR-0069](../docs/adr/0069-host-registered-send-types.md)'s sense, and
-`expect_sends`, the sends the case expects handed to the host. Every W3C and
-SCION case omits it, because upstream cases run with no registration, and
-`schema/case.json` refuses a `scion` or `w3c` case that carries it.
+`expect_sends`, the sends the case expects handed to the host. Every SCION
+case omits it, because upstream cases run with no registration, and
+`schema/case.json` refuses a `scion` case that carries it. A W3C case
+carries it only for `event_io_processors`, its one key there, below.
+
+A `host` object may carry `event_io_processors`, the Event I/O Processors
+the host runs, by URI
+([ADR-0075](../docs/adr/0075-basichttp-event-io-processor.md) decision 7).
+It is the one `host` key a W3C case may carry, because the documents that
+need a processor cannot run without one; `schema/case.json` refuses every
+other `host` key on a `w3c` case. The item set is closed, and its one member
+is the Basic HTTP Event I/O Processor's URI,
+`http://www.w3.org/TR/scxml/#BasicHTTPEventProcessor`. A runner honours it
+by registering the processor under that URI and its short form `basichttp`,
+with a location in `_ioprocessors` that reaches the running session, and by
+delivering every send to it, so none is handed to the recording processor
+above. statifier-ex's runner delivers through a loopback HTTP front it
+starts for the case. An implementation that does not run a processor the
+case names leaves the case unclaimed; that is what an optional processor
+means in a registry. A case can be in the corpus and outside every claim:
+`w3c/test201` needs the Basic HTTP processor and is unclaimed, because it
+expects a send delivered from outside the session to arrive ahead of a send
+the same step appends to the session's own external queue, which no
+delivery over HTTP does (ADR-0075 decision 7).
 
 A runner honours the object by registering each of `send_types` with an
 Event I/O Processor of its own, which records every send it is handed and

diff --git a/conformance/corpus/w3c.json b/conformance/corpus/w3c.json
diff --git a/conformance/exclusions.json b/conformance/exclusions.json
@@ -39,12 +39,6 @@
       "reason": "duplicates_w3c_corpus",
       "detail": "SCION framework's embedded copy of the W3C IRP suite; duplicates tools/corpus/scxml_w3's output with no predicator transform applied"
     },
-    {
-      "suite": "w3c",
-      "key": "test201",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor as a <send type>: the event is delivered only by a processor that implements HTTP POST"
-    },
     {
       "suite": "w3c",
       "key": "test216",
@@ -79,72 +73,6 @@
       "reason": "needs_invoke_src",
       "detail": "top-level <data> values supplied at instantiation: the child is loaded from src, which is never dereferenced (ADR-0038)",
       "adr": 38
-    },
-    {
-      "suite": "w3c",
-      "key": "test509",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor MUST accept POST requests"
-    },
-    {
-      "suite": "w3c",
-      "key": "test510",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor MUST validate and enqueue the message"
-    },
-    {
-      "suite": "w3c",
-      "key": "test518",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor namelist -> POST parameter mapping"
-    },
-    {
-      "suite": "w3c",
-      "key": "test519",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor param children -> POST parameter mapping"
-    },
-    {
-      "suite": "w3c",
-      "key": "test520",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor content child -> message body"
-    },
-    {
-      "suite": "w3c",
-      "key": "test522",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor _ioprocessors['basichttp'] entry"
-    },
-    {
-      "suite": "w3c",
-      "key": "test531",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor _scxmleventname -> event name"
-    },
-    {
-      "suite": "w3c",
-      "key": "test532",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor HTTP method -> event name fallback"
-    },
-    {
-      "suite": "w3c",
-      "key": "test534",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor send/@event -> _scxmleventname"
-    },
-    {
-      "suite": "w3c",
-      "key": "test567",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor message content -> _event.data"
-    },
-    {
-      "suite": "w3c",
-      "key": "test577",
-      "reason": "needs_basichttp",
-      "detail": "BasicHTTP Event I/O Processor missing target -> error.communication"
     }
   ]
 }
diff --git a/conformance/manifest.json b/conformance/manifest.json
@@ -1,5 +1,5 @@
 {
-  "corpus_hash": "sha256:c15e87820da654e8dde6ae97bed1631051cf6456c461cf67e7b617a36b24b02b",
+  "corpus_hash": "sha256:127a498eb4b44976bf6b1fe8d39d2c7412a4d31b63c991f2d54dd8a525e4eb1c",
   "suites": [
     {
       "suite": "scion",
@@ -9,7 +9,7 @@
     {
       "suite": "w3c",
       "file": "corpus/w3c.json",
-      "case_count": 156
+      "case_count": 168
     },
     {
       "suite": "statifier",

diff --git a/conformance/registry.json b/conformance/registry.json
@@ -1,6 +1,6 @@
 {
   "implementation": "statifier-ex",
-  "corpus_hash": "sha256:c15e87820da654e8dde6ae97bed1631051cf6456c461cf67e7b617a36b24b02b",
+  "corpus_hash": "sha256:127a498eb4b44976bf6b1fe8d39d2c7412a4d31b63c991f2d54dd8a525e4eb1c",
   "claims": ["scion","statifier","w3c-mandatory","w3c-optional"],
   "entries": [
     {"case_id":"scion/actionSend/send1","suite":"scion"},
@@ -292,19 +292,30 @@
     {"case_id":"w3c/test504","suite":"w3c"},
     {"case_id":"w3c/test505","suite":"w3c"},
     {"case_id":"w3c/test506","suite":"w3c"},
+    {"case_id":"w3c/test509","suite":"w3c"},
+    {"case_id":"w3c/test510","suite":"w3c"},
+    {"case_id":"w3c/test518","suite":"w3c"},
+    {"case_id":"w3c/test519","suite":"w3c"},
+    {"case_id":"w3c/test520","suite":"w3c"},
     {"case_id":"w3c/test521","suite":"w3c"},
+    {"case_id":"w3c/test522","suite":"w3c"},
     {"case_id":"w3c/test525","suite":"w3c"},
     {"case_id":"w3c/test527","suite":"w3c"},
     {"case_id":"w3c/test528","suite":"w3c"},
     {"case_id":"w3c/test529","suite":"w3c"},
     {"case_id":"w3c/test530","suite":"w3c"},
+    {"case_id":"w3c/test531","suite":"w3c"},
+    {"case_id":"w3c/test532","suite":"w3c"},
     {"case_id":"w3c/test533","suite":"w3c"},
+    {"case_id":"w3c/test534","suite":"w3c"},
     {"case_id":"w3c/test550","suite":"w3c"},
     {"case_id":"w3c/test551","suite":"w3c"},
     {"case_id":"w3c/test553","suite":"w3c"},
     {"case_id":"w3c/test554","suite":"w3c"},
+    {"case_id":"w3c/test567","suite":"w3c"},
     {"case_id":"w3c/test570","suite":"w3c"},
     {"case_id":"w3c/test576","suite":"w3c"},
+    {"case_id":"w3c/test577","suite":"w3c"},
     {"case_id":"w3c/test579","suite":"w3c"},
     {"case_id":"w3c/test580","suite":"w3c"}
   ]

diff --git a/conformance/schema/case.json b/conformance/schema/case.json
@@ -103,8 +103,15 @@
     },
     "host": {
       "type": "object",
-      "description": "Optional, and carried by no scion or w3c case: what a statifier case needs from the host running it. The host registers each of send_types with an Event I/O Processor of its own, which records every send it is handed and delivers none of them; a delayed send handed to it is its timer, and it never fires one. An expect_sends item's outcome says what more the host does with that send: reports it failed, or is handed a cancel for it. With no host object a case registers nothing. declared_events and expect_accepts are present together or not at all: the host checks the chart's declaration of the event names it accepts before it runs the case. to_source and expect_diff are present together or not at all, and mapping and expect_compatible_at each need them: the host diffs the case's chart to a second chart before it runs the case, and after the last step asks whether the position the steps left is untouched by the edit.",
+      "description": "Optional, carried by no scion case, and carried by a w3c case only with event_io_processors as its one key: what a case needs from the host running it. The host registers each of send_types with an Event I/O Processor of its own, which records every send it is handed and delivers none of them; a delayed send handed to it is its timer, and it never fires one. An expect_sends item's outcome says what more the host does with that send: reports it failed, or is handed a cancel for it. The host registers each of event_io_processors under its URI and its short form, with a location that reaches the running session, and delivers every send to it. With no host object a case registers nothing. declared_events and expect_accepts are present together or not at all: the host checks the chart's declaration of the event names it accepts before it runs the case. to_source and expect_diff are present together or not at all, and mapping and expect_compatible_at each need them: the host diffs the case's chart to a second chart before it runs the case, and after the last step asks whether the position the steps left is untouched by the edit.",
       "properties": {
+        "event_io_processors": {
+          "type": "array",
+          "description": "The Event I/O Processors the host runs, by URI (ADR-0075 decision 7): each is registered under its URI and its short form, with a location in _ioprocessors that reaches the running session through a loopback front, and every send to it is delivered, none recorded. The item set is closed; its one member is the Basic HTTP Event I/O Processor, whose short form is basichttp. A port that does not run a processor named here leaves the case unclaimed.",
+          "items": { "enum": ["http://www.w3.org/TR/scxml/#BasicHTTPEventProcessor"] },
+          "minItems": 1,
+          "uniqueItems": true
+        },
         "send_types": {
           "type": "array",
           "description": "The send type strings the case registers, in ADR-0069's sense: a send whose type is one of them is handed to the host's processor, and its target is that processor's own route string, which the SCXML processor never parses. None is a built-in spelling: not scxml, and not the SCXML Event I/O Processor URI.",
@@ -504,10 +511,14 @@
         "properties": {
           "id": { "pattern": "^w3c/" },
           "conformance": { "enum": ["mandatory", "optional"] },
-          "upstream": { "properties": { "license": { "const": "BSD-3-Clause-W3C" } } }
+          "upstream": { "properties": { "license": { "const": "BSD-3-Clause-W3C" } } },
+          "host": {
+            "properties": { "event_io_processors": true },
+            "required": ["event_io_processors"],
+            "additionalProperties": false
+          }
         },
-        "required": ["upstream"],
-        "not": { "required": ["host"] }
+        "required": ["upstream"]
       }
     },
     {
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		### Added

		- The conformance corpus claims eleven more W3C documents, the Basic HTTP Event I/O Processor's: test509, test510, test518, test519, test520, test522, test531, test532, test534, test567 and test577. test201 is in the corpus and unclaimed. The case schema gains `host.event_io_processors`, the Event I/O Processors a host runs with a location that reaches the session, and the one `host` key a W3C case may carry. A new guide, `docs/basichttp.md`.