diff --git a/core/pom.xml b/core/pom.xml
index ad284b22..e5af61a6 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -117,11 +117,9 @@
**/tests/draft2019-09/additionalItems.json
-->
**/tests/draft2020-12/additionalProperties.json
-
**/tests/draft2020-12/anyOf.json
+ **/tests/draft2020-12/oneOf.json
**/tests/draft2020-12/boolean_schema.json
**/tests/draft2020-12/const.json
**/tests/draft2020-12/contains.json
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java
index 58848975..1dc844f2 100644
--- a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java
+++ b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/ApplicatorVocabulary.java
@@ -50,6 +50,7 @@ public ApplicatorVocabulary() {
URI.create("https://json-schema.org/draft/2020-12/vocab/applicator"),
new SchemaArrayKeywordType(AllOfKeyword.NAME, AllOfKeyword::new),
new SchemaArrayKeywordType(AnyOfKeyword.NAME, AnyOfKeyword::new),
+ new SchemaArrayKeywordType(OneOfKeyword.NAME, OneOfKeyword::new),
new NamedJsonSchemaKeywordType(PropertiesKeyword.NAME, PropertiesKeyword::new),
new SubSchemaKeywordType(AdditionalPropertiesKeyword.NAME, AdditionalPropertiesKeyword::new),
new NamedJsonSchemaKeywordType(PatternPropertiesKeyword.NAME, PatternPropertiesKeyword::new),
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeyword.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeyword.java
new file mode 100644
index 00000000..a3054172
--- /dev/null
+++ b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeyword.java
@@ -0,0 +1,70 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2024 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.applicator;
+
+import io.github.sebastiantoepfer.ddd.common.Media;
+import io.github.sebastiantoepfer.jsonschema.JsonSchema;
+import io.github.sebastiantoepfer.jsonschema.keyword.Applicator;
+import jakarta.json.JsonValue;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * oneOf : Array
+ * An instance validates successfully against this keyword if it validates successfully against exactly one schema
+ * defined by this keyword’s value.
+ *
+ * kind
+ *
+ *
+ * source: https://www.learnjsonschema.com/2020-12/applicator/oneof/
+ * spec: https://json-schema.org/draft/2020-12/json-schema-core.html#section-10.2.1.3
+ */
+final class OneOfKeyword implements Applicator {
+
+ static final String NAME = "oneOf";
+ private final Collection schemas;
+
+ public OneOfKeyword(final Collection schemas) {
+ this.schemas = List.copyOf(schemas);
+ }
+
+ @Override
+ public boolean applyTo(final JsonValue instance) {
+ return schemas.stream().map(JsonSchema::validator).filter(v -> v.isValid(instance)).limit(2).count() == 1;
+ }
+
+ @Override
+ public boolean hasName(final String name) {
+ return Objects.equals(NAME, name);
+ }
+
+ @Override
+ public > T printOn(final T media) {
+ return media.withValue(NAME, schemas);
+ }
+}
diff --git a/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeywordTest.java b/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeywordTest.java
new file mode 100644
index 00000000..94315583
--- /dev/null
+++ b/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/applicator/OneOfKeywordTest.java
@@ -0,0 +1,197 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2024 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.applicator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasEntry;
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.hasKey;
+import static org.hamcrest.Matchers.is;
+
+import io.github.sebastiantoepfer.ddd.media.core.HashMapMedia;
+import io.github.sebastiantoepfer.jsonschema.core.DefaultJsonSchemaFactory;
+import io.github.sebastiantoepfer.jsonschema.core.keyword.type.SchemaArrayKeywordType;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import jakarta.json.Json;
+import jakarta.json.JsonObject;
+import jakarta.json.JsonValue;
+import org.hamcrest.Matcher;
+import org.junit.jupiter.api.Test;
+
+class OneOfKeywordTest {
+
+ @Test
+ void should_know_his_name() {
+ final Keyword items = createKeywordFrom(
+ Json.createObjectBuilder().add("oneOf", Json.createArrayBuilder().add(JsonValue.TRUE)).build()
+ );
+
+ assertThat(items.hasName("oneOf"), is(true));
+ assertThat(items.hasName("test"), is(false));
+ }
+
+ @Test
+ void should_be_printable() {
+ assertThat(
+ createKeywordFrom(
+ Json.createObjectBuilder()
+ .add(
+ "oneOf",
+ Json.createArrayBuilder()
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("foo", Json.createObjectBuilder().add("type", "string"))
+ )
+ .add("required", Json.createArrayBuilder().add("foo"))
+ )
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("bar", Json.createObjectBuilder().add("type", "number"))
+ )
+ .add("required", Json.createArrayBuilder().add("bar"))
+ )
+ )
+ .build()
+ ).printOn(new HashMapMedia()),
+ (Matcher) hasEntry(is("oneOf"), hasItem((hasKey("properties"))))
+ );
+ }
+
+ @Test
+ void should_be_valid_if_exactly_one_schema_applies() {
+ assertThat(
+ createKeywordFrom(
+ Json.createObjectBuilder()
+ .add(
+ "oneOf",
+ Json.createArrayBuilder()
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("foo", Json.createObjectBuilder().add("type", "string"))
+ )
+ .add("required", Json.createArrayBuilder().add("foo"))
+ )
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("bar", Json.createObjectBuilder().add("type", "number"))
+ )
+ .add("required", Json.createArrayBuilder().add("bar"))
+ )
+ )
+ .build()
+ )
+ .asApplicator()
+ .applyTo(Json.createObjectBuilder().add("foo", "foo").build()),
+ is(true)
+ );
+ }
+
+ @Test
+ void should_be_invalid_if_none_schema_not_apply() {
+ assertThat(
+ createKeywordFrom(
+ Json.createObjectBuilder()
+ .add(
+ "oneOf",
+ Json.createArrayBuilder()
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("foo", Json.createObjectBuilder().add("type", "string"))
+ )
+ .add("required", Json.createArrayBuilder().add("foo"))
+ )
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("bar", Json.createObjectBuilder().add("type", "number"))
+ )
+ .add("required", Json.createArrayBuilder().add("bar"))
+ )
+ )
+ .build()
+ )
+ .asApplicator()
+ .applyTo(Json.createObjectBuilder().add("foo", 3).add("bar", "bar").build()),
+ is(false)
+ );
+ }
+
+ @Test
+ void should_be_invalid_if_more_than_one_schema_apply() {
+ assertThat(
+ createKeywordFrom(
+ Json.createObjectBuilder()
+ .add(
+ "oneOf",
+ Json.createArrayBuilder()
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("foo", Json.createObjectBuilder().add("type", "string"))
+ )
+ .add("required", Json.createArrayBuilder().add("foo"))
+ )
+ .add(
+ Json.createObjectBuilder()
+ .add(
+ "properties",
+ Json.createObjectBuilder()
+ .add("bar", Json.createObjectBuilder().add("type", "number"))
+ )
+ .add("required", Json.createArrayBuilder().add("bar"))
+ )
+ )
+ .build()
+ )
+ .asApplicator()
+ .applyTo(Json.createObjectBuilder().add("foo", "foo").add("bar", 33).build()),
+ is(false)
+ );
+ }
+
+ private static Keyword createKeywordFrom(final JsonObject json) {
+ return new SchemaArrayKeywordType("oneOf", OneOfKeyword::new).createKeyword(
+ new DefaultJsonSchemaFactory().create(json)
+ );
+ }
+}