test(conformance): drive json-schema-2020-12-preservation and pin the alpha.11 referee

Register the client-side json-schema-2020-12-preservation scenario in the
everything client (tools/list, then echo the observed inputSchema through
json_schema_echo; modern lifecycle under a 2026-07-28 run), bump
@modelcontextprotocol/conformance 0.2.0-alpha.10 -> 0.2.0-alpha.11 and
record the reconciliation in both expected-failures baselines. All four
legs pass with no new entries.

Author: felixweinberger

pnpm-lock.yaml

@@ -12,8 +12,16 @@
 # 2025 legs.
 #
 # Baseline established against the published @modelcontextprotocol/conformance
-# release pinned in package.json. Newer conformance releases are adopted by
-# deliberately bumping the pin and reconciling this file in the same change.
+# release pinned in package.json (0.2.0-alpha.11). Newer conformance releases
+# are adopted by deliberately bumping the pin and reconciling this file in the
+# same change.
+#
+# alpha.10 -> alpha.11 reconciliation: `json-schema-2020-12-preservation`
+# (client leg; everythingClient negotiates via server/discover like tools_call)
+# passes at 2026-07-28 — the referee reports it as added-after-release, unscored
+# on the frozen 2026-07-28 set — and `server-session-lifecycle` is not
+# applicable at 2026-07-28 (removed in that revision, skipped by
+# --spec-version), so both sections stay empty.
 #
 # NOTE: the SDK's modern-path rejection codes are aligned with what this
 # referee asserts — both sides have adopted the spec#2907 / conformance#353

test/conformance/expected-failures.2026-07-28.yaml

@@ -2,10 +2,17 @@
 # CI exits 0 if only these fail, exits 1 on unexpected failures or stale entries.
 #
 # Baseline established against the published @modelcontextprotocol/conformance
-# release pinned in package.json (0.2.0-alpha.10). Newer conformance releases
+# release pinned in package.json (0.2.0-alpha.11). Newer conformance releases
 # are adopted by deliberately bumping the package.json pin and reconciling
 # this file in the same change.
 #
+# alpha.10 -> alpha.11 reconciliation: the referee added two scenarios, both
+# passing, so neither is baselined — `json-schema-2020-12-preservation`
+# (client; SEP-1613/SEP-2106 keyword round-trip, driven by everythingClient.ts)
+# and `server-session-lifecycle` (server; Streamable HTTP session teardown).
+# The referee now also sends HTTP DELETE after every session-bound scenario
+# (conformance#316); the everything server already answers it.
+#
 # NOTE: the SDK's modern-path rejection codes are aligned with what this
 # referee asserts — both sides have adopted the spec#2907 / conformance#353
 # renumber (-32020 HeaderMismatch / -32021 MissingRequiredClientCapability /

test/conformance/expected-failures.yaml

@@ -38,7 +38,7 @@
         "test:conformance:all": "pnpm run test:conformance:client:all && pnpm run test:conformance:server:all"
     },
     "devDependencies": {
-        "@modelcontextprotocol/conformance": "0.2.0-alpha.10",
+        "@modelcontextprotocol/conformance": "0.2.0-alpha.11",
         "@modelcontextprotocol/client": "workspace:^",
         "@modelcontextprotocol/server": "workspace:^",
         "@modelcontextprotocol/core-internal": "workspace:^",

test/conformance/package.json

@@ -802,6 +802,62 @@ async function runJsonSchemaRefNoDerefClient(serverUrl: string): Promise<void> {
 
 registerScenario('json-schema-ref-no-deref', runJsonSchemaRefNoDerefClient);
 
+// ============================================================================
+// JSON Schema 2020-12 keyword preservation scenario (SEP-1613, SEP-2106)
+// ============================================================================
+
+/** The tool whose `inputSchema` carries the full JSON Schema 2020-12 fixture. */
+const JSON_SCHEMA_2020_12_TOOL = 'json_schema_2020_12_tool';
+/** The permissive echo tool that hands the observed schema back to the referee. */
+const JSON_SCHEMA_ECHO_TOOL = 'json_schema_echo';
+
+/**
+ * The scenario advertises a focal tool whose inputSchema uses `$schema`,
+ * `$defs` (with `$anchor`), `additionalProperties`, composition
+ * (`allOf`/`anyOf`) and conditional (`if`/`then`/`else`) keywords. The client
+ * lists tools and passes that inputSchema back verbatim — exactly as
+ * `listTools()` exposes it — through `tools/call json_schema_echo`, so the
+ * referee can diff what survived the SDK's parsing against its fixture.
+ *
+ * The scenario spans both eras: under a 2026-07-28 run the client negotiates
+ * the modern lifecycle via server/discover (as tools_call does) and drives the
+ * same list → echo flow.
+ */
+async function runJsonSchema2020_12PreservationClient(serverUrl: string): Promise<void> {
+    const client = new Client(
+        { name: 'json-schema-2020-12-preservation-client', version: '1.0.0' },
+        isModernConformanceRun() ? { capabilities: {}, versionNegotiation: { mode: 'auto' } } : { capabilities: {} }
+    );
+
+    const transport = new StreamableHTTPClientTransport(new URL(serverUrl));
+
+    await client.connect(transport);
+    logger.debug('Successfully connected to MCP server');
+
+    const tools = await client.listTools();
+    logger.debug(
+        'Available tools:',
+        tools.tools.map(t => t.name)
+    );
+
+    const focal = tools.tools.find(t => t.name === JSON_SCHEMA_2020_12_TOOL);
+    if (!focal) {
+        throw new Error(`Tool '${JSON_SCHEMA_2020_12_TOOL}' not advertised by the server`);
+    }
+    logger.debug('Observed inputSchema:', JSON.stringify(focal.inputSchema, null, 2));
+
+    const result = await client.callTool({
+        name: JSON_SCHEMA_ECHO_TOOL,
+        arguments: { schema: focal.inputSchema }
+    });
+    logger.debug('Echo result:', JSON.stringify(result, null, 2));
+
+    await client.close();
+    logger.debug('Connection closed successfully');
+}
+
+registerScenario('json-schema-2020-12-preservation', runJsonSchema2020_12PreservationClient);
+
 // ============================================================================
 // Main entry point
 // ============================================================================