[MCP] Properly handle oneOf and anyOf in generated mcp schema

jbtronics · jbtronics · commit 9ffc5c03e0eb · 2026-05-10T15:28:12.000+02:00
diff --git a/src/Mcp/JsonSchema/SchemaFactory.php b/src/Mcp/JsonSchema/SchemaFactory.php
@@ -109,6 +109,13 @@ public static function resolveNode(array|\ArrayObject $node, array $definitions,
             return self::resolveDeep($merged, $definitions, $resolving);
         }
 
+        // oneOf/anyOf nodes must not receive a type fallback — their type is expressed
+        // through the sub-schemas. Adding 'type: object' here would break schemas like
+        // HydraItemBaseSchema's @context, which is oneOf: [string, object].
+        if (isset($node['oneOf']) || isset($node['anyOf'])) {
+            return self::resolveDeep($node, $definitions, $resolving);
+        }
+
         if (!isset($node['type'])) {
             $node['type'] = 'object';
         }

Original file line number	Diff line number	Diff line change
`@@ -109,6 +109,13 @@ public static function resolveNode(array\|\ArrayObject $node, array $definitions,`
`109`	`109`	`return self::resolveDeep($merged, $definitions, $resolving);`
`110`	`110`	`}`
`111`	`111`
	`112`	`+ // oneOf/anyOf nodes must not receive a type fallback — their type is expressed`
	`113`	`+ // through the sub-schemas. Adding 'type: object' here would break schemas like`
	`114`	`+ // HydraItemBaseSchema's @context, which is oneOf: [string, object].`
	`115`	`+ if (isset($node['oneOf']) \|\| isset($node['anyOf'])) {`
	`116`	`+ return self::resolveDeep($node, $definitions, $resolving);`
	`117`	`+ }`
	`118`	`+`
`112`	`119`	`if (!isset($node['type'])) {`
`113`	`120`	`$node['type'] = 'object';`
`114`	`121`	`}`