[pull] main from fern-api:main

generators/java/generator-utils/src/main/java/com/fern/java/generators/UndiscriminatedUnionGenerator.java

@@ -601,12 +601,24 @@ private TypeSpec getDeserializer() {
                         .endControlFlow();
             }
         }
-        for (int i = 0; i < membersWithoutLiterals.size(); ++i) {
-            UndiscriminatedUnionMember member = membersWithoutLiterals.get(i);
+        // Sort: members with required key guards first, then unguarded (all-optional) members last.
+        // This prevents all-optional object types from greedily matching payloads intended for
+        // more specific members — e.g. PayMethodCloud (0 required keys) consuming {"achHolder":"x"}
+        // before Check (1 required key) gets a chance.
+        List<UndiscriminatedUnionMember> nonPrimitiveMembers = membersWithoutLiterals.stream()
+                .filter(m -> {
+                    TypeName tn = memberTypeNames.get(m);
+                    return !tn.isPrimitive() && !tn.isBoxedPrimitive();
+                })
+                .collect(Collectors.toList());
+        nonPrimitiveMembers.sort((a, b) -> {
+            boolean aHasGuard = !getRequiredWireKeys(a).isEmpty();
+            boolean bHasGuard = !getRequiredWireKeys(b).isEmpty();
+            if (aHasGuard == bHasGuard) return 0;
+            return aHasGuard ? -1 : 1;
+        });
+        for (UndiscriminatedUnionMember member : nonPrimitiveMembers) {
             TypeName typeName = memberTypeNames.get(member);
-            if (typeName.isPrimitive() || typeName.isBoxedPrimitive()) {
-                continue;
-            }
             List<String> requiredKeys = getRequiredWireKeys(member);
             boolean hasRequiredKeyGuard = !requiredKeys.isEmpty();
             if (hasRequiredKeyGuard) {

generators/java/sdk/changes/4.8.7/fix-undiscriminated-union-all-optional-ordering.yml

@@ -0,0 +1,11 @@
+# yaml-language-server: $schema=../../../../../fern-changes-yml.schema.json
+
+- summary: |
+    Fix undiscriminated union deserialization when one member has all-optional fields.
+    Previously, an all-optional object variant (e.g. `PayMethodCloud`) could greedily
+    consume a payload intended for a more specific variant with required fields (e.g.
+    `Check` requiring `achHolder`), because Jackson's `@JsonIgnoreProperties(ignoreUnknown=true)`
+    silently accepts any JSON object when all fields are optional. The deserializer now
+    emits guarded members (those with at least one required field) before unguarded
+    (all-optional) members, ensuring the more specific match wins.
+  type: fix

generators/java/sdk/versions.yml

@@ -1,4 +1,17 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
+- version: 4.8.7
+  changelogEntry:
+    - summary: |
+        Fix undiscriminated union deserialization when one member has all-optional fields.
+        Previously, an all-optional object variant (e.g. `PayMethodCloud`) could greedily
+        consume a payload intended for a more specific variant with required fields (e.g.
+        `Check` requiring `achHolder`), because Jackson's `@JsonIgnoreProperties(ignoreUnknown=true)`
+        silently accepts any JSON object when all fields are optional. The deserializer now
+        emits guarded members (those with at least one required field) before unguarded
+        (all-optional) members, ensuring the more specific match wins.
+      type: fix
+  createdAt: "2026-05-12"
+  irVersion: 66
 - version: 4.8.6
   changelogEntry:
     - summary: |

generators/ruby-v2/ast/src/ast/Comment.ts

@@ -21,7 +21,7 @@ export class Comment extends AstNode {
     }
 
     public write(writer: Writer): void {
-        if (this.docs != null) {
+        if (this.docs?.trim()) {
             this.docs.split("\n").forEach((line) => {
                 const wrappedLines = this.wrapLine(line, writer);
                 wrappedLines.forEach((wrappedLine) => {

generators/ruby-v2/sdk/changes/1.12.7/fix-empty-comment-rubocop.yml

@@ -0,0 +1,8 @@
+# yaml-language-server: $schema=../../../../../fern-changes-yml.schema.json
+
+- summary: |
+    Fix `Layout/EmptyComment` RuboCop offense emitted for types with no
+    description. The AST `Comment` node now skips writing when `docs` is
+    empty or whitespace-only, so undocumented model classes no longer
+    produce a bare `#` line above their class definition.
+  type: fix

generators/ruby-v2/sdk/changes/1.12.8/fix-empty-comment-rubocop.yml

@@ -0,0 +1,8 @@
+# yaml-language-server: $schema=../../../../../fern-changes-yml.schema.json
+
+- summary: |
+    Fix `Layout/EmptyComment` RuboCop offense emitted for types with no
+    description. The AST `Comment` node now skips writing when `docs` is
+    empty or whitespace-only, so undocumented model classes no longer
+    produce a bare `#` line above their class definition.
+  type: fix

generators/ruby-v2/sdk/versions.yml

@@ -1,4 +1,24 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
+- version: 1.12.8
+  changelogEntry:
+    - summary: |
+        Fix `Layout/EmptyComment` RuboCop offense emitted for types with no
+        description. The AST `Comment` node now skips writing when `docs` is
+        empty or whitespace-only, so undocumented model classes no longer
+        produce a bare `#` line above their class definition.
+      type: fix
+  createdAt: "2026-05-12"
+  irVersion: 66
+- version: 1.12.7
+  changelogEntry:
+    - summary: |
+        Fix `Layout/EmptyComment` RuboCop offense emitted for types with no
+        description. The AST `Comment` node now skips writing when `docs` is
+        empty or whitespace-only, so undocumented model classes no longer
+        produce a bare `#` line above their class definition.
+      type: fix
+  createdAt: "2026-05-12"
+  irVersion: 66
 - version: 1.12.6
   changelogEntry:
     - summary: |

generators/rust/base/src/asIs/pagination.rs

@@ -526,7 +526,7 @@ mod tests {
     fn test_sync_paginator_error_propagation() {
         let client = make_http_client();
         let mut paginator = SyncPaginator::<String>::new(client, |_client, _cursor| {
-            Err(ApiError::Serialization("test error".to_string()))
+            Err(ApiError::Configuration("test error".to_string()))
         }, None).unwrap();
 
         let result = paginator.next_page();
@@ -537,7 +537,7 @@ mod tests {
     fn test_sync_paginator_iterator_error() {
         let client = make_http_client();
         let mut paginator = SyncPaginator::<String>::new(client, |_client, _cursor| {
-            Err(ApiError::Serialization("test error".to_string()))
+            Err(ApiError::Configuration("test error".to_string()))
         }, None).unwrap();
 
         let item = paginator.next();

generators/rust/sdk/changes/0.36.6/fix-wire-test-environment-and-pagination-error.yml

@@ -0,0 +1,12 @@
+# yaml-language-server: $schema=../../../../../fern-changes-yml.schema.json
+
+- summary: |
+    Fix generated Rust wire tests for single-URL SDKs and pagination error
+    tests. The wire test generator no longer emits `config.environment = None;`
+    when the SDK was generated against a single base URL (since the
+    `environment` field does not exist on `ClientConfig` in that case).
+    The synchronous-paginator error-propagation tests now use
+    `ApiError::Configuration` instead of the non-existent
+    `ApiError::Serialization` variant, so the generated `pagination.rs` test
+    module compiles.
+  type: fix

generators/rust/sdk/src/wire-tests/WireTestGenerator.ts

@@ -251,7 +251,9 @@ export class WireTestGenerator {
                     lines.push(`    };`);
                     // Override base_url and clear environment so requests go to WireMock
                     lines.push(`    config.base_url = wiremock_base_url.to_string();`);
-                    lines.push(`    config.environment = None;`);
+                    if (this.context.hasMultipleBaseUrls()) {
+                        lines.push(`    config.environment = None;`);
+                    }
                     inConfigStruct = false;
                 } else {
                     lines.push(`    ${trimmedLine}`);

generators/rust/sdk/versions.yml

@@ -1,4 +1,18 @@
 # yaml-language-server: $schema=../../../fern-versions-yml.schema.json
+- version: 0.36.6
+  changelogEntry:
+    - summary: |
+        Fix generated Rust wire tests for single-URL SDKs and pagination error
+        tests. The wire test generator no longer emits `config.environment = None;`
+        when the SDK was generated against a single base URL (since the
+        `environment` field does not exist on `ClientConfig` in that case).
+        The synchronous-paginator error-propagation tests now use
+        `ApiError::Configuration` instead of the non-existent
+        `ApiError::Serialization` variant, so the generated `pagination.rs` test
+        module compiles.
+      type: fix
+  createdAt: "2026-05-12"
+  irVersion: 66
 - version: 0.36.5
   changelogEntry:
     - summary: |

packages/cli/api-importers/openapi-to-ir/src/3.1/OpenAPIConverter.ts

@@ -262,7 +262,8 @@ export class OpenAPIConverter extends AbstractSpecConverter<OpenAPIConverterCont
                     webhook: convertedWebHook.webhook,
                     operationId,
                     audiences: convertedWebHook.audiences,
-                    group: convertedWebHook.group
+                    group: convertedWebHook.group,
+                    inlinedPayloadPropertiesByAudience: convertedWebHook.inlinedPayloadPropertiesByAudience
                 });
                 this.addTypesToIr(convertedWebHook.inlinedTypes);
             }
@@ -296,15 +297,19 @@ export class OpenAPIConverter extends AbstractSpecConverter<OpenAPIConverterCont
                             endpoint: endpoint.streamEndpoint,
                             audiences: endpoint.audiences,
                             endpointGroup: endpoint.group,
-                            endpointGroupDisplayName: endpoint.groupDisplayName
+                            endpointGroupDisplayName: endpoint.groupDisplayName,
+                            inlinedRequestPropertiesByAudience: endpoint.inlinedRequestPropertiesByAudience,
+                            queryParametersByAudience: endpoint.queryParametersByAudience
                         });
                     }
 
                     this.addEndpointToIr({
                         endpoint: endpoint.endpoint,
                         audiences: endpoint.audiences,
                         endpointGroup: endpoint.group,
-                        endpointGroupDisplayName: endpoint.groupDisplayName
+                        endpointGroupDisplayName: endpoint.groupDisplayName,
+                        inlinedRequestPropertiesByAudience: endpoint.inlinedRequestPropertiesByAudience,
+                        queryParametersByAudience: endpoint.queryParametersByAudience
                     });
 
                     if (endpoint.servers) {
@@ -337,7 +342,8 @@ export class OpenAPIConverter extends AbstractSpecConverter<OpenAPIConverterCont
                         webhook: webhook.webhook,
                         operationId: group.join("."),
                         group,
-                        audiences: webhook.audiences
+                        audiences: webhook.audiences,
+                        inlinedPayloadPropertiesByAudience: webhook.inlinedPayloadPropertiesByAudience
                     });
                 }
                 this.addTypesToIr(convertedPath.inlinedTypes);

packages/cli/api-importers/openapi-to-ir/src/3.1/paths/RequestBodyConverter.ts

@@ -28,6 +28,13 @@ export declare namespace RequestBodyConverter {
     export interface Output extends Converters.AbstractConverters.AbstractMediaTypeObjectConverter.Output {
         requestBody: HttpRequestBody;
         streamRequestBody: HttpRequestBody | undefined;
+        /**
+         * Audience name → wire names of inline request body properties under that
+         * audience. Only populated for `inlinedRequestBody` outputs; `undefined`
+         * (or absent) means no inline property-level audience info to mark on the
+         * IR filter graph.
+         */
+        inlinedPropertiesByAudience?: Record<string, Set<string>>;
     }
 }
 
@@ -180,7 +187,8 @@ export class RequestBodyConverter extends Converters.AbstractConverters.Abstract
                 inlinedTypes: this.context.removeSchemaFromInlinedTypes({
                     id: this.schemaId,
                     inlinedTypes: convertedSchema.inlinedTypes
-                })
+                }),
+                inlinedPropertiesByAudience: convertedSchema.schema?.propertiesByAudience
             };
         } else {
             return {

packages/cli/api-importers/openapi-to-ir/src/3.1/paths/operations/AbstractOperationConverter.ts

@@ -41,6 +41,7 @@ interface ConvertedRequestBody {
     requestBody: HttpRequestBody;
     streamRequestBody: HttpRequestBody | undefined;
     examples?: Record<string, OpenAPIV3_1.ExampleObject>;
+    inlinedPropertiesByAudience?: Record<string, Set<string>>;
 }
 
 export abstract class AbstractOperationConverter extends AbstractConverter<
@@ -238,7 +239,8 @@ export abstract class AbstractOperationConverter extends AbstractConverter<
                 convertedRequestBodies.push({
                     requestBody: convertedRequestBody.requestBody,
                     streamRequestBody: convertedRequestBody.streamRequestBody,
-                    examples: convertedRequestBody.examples
+                    examples: convertedRequestBody.examples,
+                    inlinedPropertiesByAudience: convertedRequestBody.inlinedPropertiesByAudience
                 });
             }
         }