chore: align ARCP wire protocol version with v1.1

nficano · claude · nficano · commit 60cffe636822 · 2026-05-19T21:42:21.000-04:00
Bumps PROTOCOL_VERSION to "1.1", updates envelope validator tests, and
refreshes wire-format snippets in the v1.1 feature docs.

Co-Authored-By: Claude Opus 4.7 (1M context) &lt;noreply@anthropic.com&gt;
diff --git a/docs/03-features/agent-versions.md b/docs/03-features/agent-versions.md
@@ -22,7 +22,7 @@ default version set via `set_default_agent_version`. Mismatch is a
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ3...",
   "type": "job.submit",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/capability-negotiation.md b/docs/03-features/capability-negotiation.md
@@ -28,7 +28,7 @@ flag vocabulary is the V1.1 set: `heartbeat`, `ack`, `list_jobs`,
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SHY...",
   "type": "session.hello",
   "payload": {
diff --git a/docs/03-features/cost-budget.md b/docs/03-features/cost-budget.md
@@ -23,7 +23,7 @@ subset of the parent's per-currency caps (§9.4 subset rule).
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ5...",
   "type": "job.submit",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/event-ack.md b/docs/03-features/event-ack.md
@@ -23,7 +23,7 @@ the runtime never pauses.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ0...",
   "type": "session.ack",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/heartbeats.md b/docs/03-features/heartbeats.md
@@ -23,7 +23,7 @@ are sent, and idle sessions stay open.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SHZ...",
   "type": "session.ping",
   "session_id": "sess_01J9SHX...",
@@ -33,7 +33,7 @@ are sent, and idle sessions stay open.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SHZ...",
   "type": "session.pong",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/lease-expires-at.md b/docs/03-features/lease-expires-at.md
@@ -23,7 +23,7 @@ with `job.error` carrying the same code.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ4...",
   "type": "job.submit",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/list-jobs.md b/docs/03-features/list-jobs.md
@@ -22,7 +22,7 @@ v1.0 fallback: clients track their own `submit`/event history.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ1...",
   "type": "session.list_jobs",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/progress.md b/docs/03-features/progress.md
@@ -22,7 +22,7 @@ streams).
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ6...",
   "type": "job.event",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/result-chunk.md b/docs/03-features/result-chunk.md
@@ -23,7 +23,7 @@ chunked is `INVALID_REQUEST`. Per-chunk size is capped per spec §14.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ7...",
   "type": "job.event",
   "session_id": "sess_01J9SHX...",
diff --git a/docs/03-features/subscribe.md b/docs/03-features/subscribe.md
@@ -25,7 +25,7 @@ flow.
 
 ```json
 {
-  "arcp": "1",
+  "arcp": "1.1",
   "id": "01J9SJ2...",
   "type": "job.subscribe",
   "session_id": "sess_01J9SHX...",
diff --git a/src/arcp/_version.py b/src/arcp/_version.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-PROTOCOL_VERSION: str = "1"
+PROTOCOL_VERSION: str = "1.1"
 IMPL_VERSION: str = "1.1.0"
 
 V1_1_FEATURES: tuple[str, ...] = (
diff --git a/tests/conformance/test_conformance_harness.py b/tests/conformance/test_conformance_harness.py
@@ -82,10 +82,10 @@ def test_public_symbols_exist(module: str, symbols: list[str]) -> None:
         assert hasattr(mod, sym), f"{module} missing symbol: {sym}"
 
 
-def test_protocol_version_is_1() -> None:
+def test_protocol_version_is_1_1() -> None:
     import arcp
 
-    assert arcp.PROTOCOL_VERSION == "1"
+    assert arcp.PROTOCOL_VERSION == "1.1"
 
 
 def test_v1_1_features_complete() -> None:
diff --git a/tests/unit/envelope/test_envelope_constants.py b/tests/unit/envelope/test_envelope_constants.py
@@ -1,4 +1,4 @@
-"""§5.1 — `arcp` field MUST equal `"1"`."""
+"""§5.1 — `arcp` field MUST equal `"1.1"`."""
 
 from __future__ import annotations
 
@@ -9,16 +9,16 @@
 from arcp._ulid import new_ulid
 
 
-def test_arcp_constant_is_one() -> None:
-    assert PROTOCOL_VERSION == "1"
+def test_arcp_constant_is_one_one() -> None:
+    assert PROTOCOL_VERSION == "1.1"
 
 
-def test_envelope_default_arcp_is_one() -> None:
+def test_envelope_default_arcp_is_one_one() -> None:
     env = Envelope(id=new_ulid(), type="session.ping", payload={})
-    assert env.arcp == "1"
+    assert env.arcp == "1.1"
 
 
-@pytest.mark.parametrize("bad", ["1.0", "2", "", "01"])
+@pytest.mark.parametrize("bad", ["1", "1.0", "2", "", "01"])
 def test_envelope_rejects_wrong_arcp(bad: str) -> None:
     with pytest.raises(ValidationError):
         Envelope(arcp=bad, id=new_ulid(), type="session.ping", payload={})
diff --git a/tests/unit/envelope/test_envelope_unknown_fields.py b/tests/unit/envelope/test_envelope_unknown_fields.py
@@ -8,7 +8,7 @@
 
 def test_unknown_field_passes_through() -> None:
     raw = {
-        "arcp": "1",
+        "arcp": "1.1",
         "id": new_ulid(),
         "type": "session.ping",
         "payload": {"nonce": "abc", "sent_at": "2026-05-14T12:00:00Z"},
@@ -23,7 +23,7 @@ def test_unknown_field_passes_through() -> None:
 
 def test_roundtrip_preserves_unknown_field() -> None:
     raw = {
-        "arcp": "1",
+        "arcp": "1.1",
         "id": new_ulid(),
         "type": "session.ping",
         "payload": {},

Original file line number	Diff line number	Diff line change
@@ -22,7 +22,7 @@ default version set via `set_default_agent_version`. Mismatch is a
`22`	`22`
`23`	`23`	```json
`24`	`24`	`{`
`25`		`- "arcp": "1",`
	`25`	`+ "arcp": "1.1",`
`26`	`26`	`"id": "01J9SJ3...",`
`27`	`27`	`"type": "job.submit",`
`28`	`28`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
@@ -28,7 +28,7 @@ flag vocabulary is the V1.1 set: `heartbeat`, `ack`, `list_jobs`,
`28`	`28`
`29`	`29`	```json
`30`	`30`	`{`
`31`		`- "arcp": "1",`
	`31`	`+ "arcp": "1.1",`
`32`	`32`	`"id": "01J9SHY...",`
`33`	`33`	`"type": "session.hello",`
`34`	`34`	`"payload": {`
Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,7 @@ subset of the parent's per-currency caps (§9.4 subset rule).`
`23`	`23`
`24`	`24`	```json
`25`	`25`	`{`
`26`		`- "arcp": "1",`
	`26`	`+ "arcp": "1.1",`
`27`	`27`	`"id": "01J9SJ5...",`
`28`	`28`	`"type": "job.submit",`
`29`	`29`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,7 @@ the runtime never pauses.`
`23`	`23`
`24`	`24`	```json
`25`	`25`	`{`
`26`		`- "arcp": "1",`
	`26`	`+ "arcp": "1.1",`
`27`	`27`	`"id": "01J9SJ0...",`
`28`	`28`	`"type": "session.ack",`
`29`	`29`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
@@ -23,7 +23,7 @@ with `job.error` carrying the same code.
`23`	`23`
`24`	`24`	```json
`25`	`25`	`{`
`26`		`- "arcp": "1",`
	`26`	`+ "arcp": "1.1",`
`27`	`27`	`"id": "01J9SJ4...",`
`28`	`28`	`"type": "job.submit",`
`29`	`29`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
@@ -22,7 +22,7 @@ v1.0 fallback: clients track their own `submit`/event history.
`22`	`22`
`23`	`23`	```json
`24`	`24`	`{`
`25`		`- "arcp": "1",`
	`25`	`+ "arcp": "1.1",`
`26`	`26`	`"id": "01J9SJ1...",`
`27`	`27`	`"type": "session.list_jobs",`
`28`	`28`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
`@@ -22,7 +22,7 @@ streams).`
`22`	`22`
`23`	`23`	```json
`24`	`24`	`{`
`25`		`- "arcp": "1",`
	`25`	`+ "arcp": "1.1",`
`26`	`26`	`"id": "01J9SJ6...",`
`27`	`27`	`"type": "job.event",`
`28`	`28`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
@@ -23,7 +23,7 @@ chunked is `INVALID_REQUEST`. Per-chunk size is capped per spec §14.
`23`	`23`
`24`	`24`	```json
`25`	`25`	`{`
`26`		`- "arcp": "1",`
	`26`	`+ "arcp": "1.1",`
`27`	`27`	`"id": "01J9SJ7...",`
`28`	`28`	`"type": "job.event",`
`29`	`29`	`"session_id": "sess_01J9SHX...",`
Original file line number	Diff line number	Diff line change
`@@ -25,7 +25,7 @@ flow.`
`25`	`25`
`26`	`26`	```json
`27`	`27`	`{`
`28`		`- "arcp": "1",`
	`28`	`+ "arcp": "1.1",`
`29`	`29`	`"id": "01J9SJ2...",`
`30`	`30`	`"type": "job.subscribe",`
`31`	`31`	`"session_id": "sess_01J9SHX...",`