diff --git a/bin/configs/rust-reqwest-object-query-param.yaml b/bin/configs/rust-reqwest-object-query-param.yaml
new file mode 100644
index 00000000000..fb2f687219a
--- /dev/null
+++ b/bin/configs/rust-reqwest-object-query-param.yaml
@@ -0,0 +1,9 @@
+generatorName: rust
+outputDir: samples/client/others/rust/reqwest/object-query-param
+library: reqwest
+inputSpec: modules/openapi-generator/src/test/resources/3_0/objectQueryParam.yaml
+templateDir: modules/openapi-generator/src/main/resources/rust
+validateSpec: "false"
+additionalProperties:
+  supportAsync: "true"
+  packageName: object-query-param-reqwest
diff --git a/modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache b/modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache
index e9cfabc5599..c7133f867b4 100644
--- a/modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache
+++ b/modules/openapi-generator/src/main/resources/rust/reqwest/api.mustache
@@ -155,7 +155,13 @@ pub {{#supportAsync}}async {{/supportAsync}}fn {{{operationId}}}(configuration:
     {{/isArray}}
     {{^isArray}}
     {{^isNullable}}
+    {{#isModel}}
+    let params = crate::apis::parse_flat_object(&serde_json::to_value({{{vendorExtensions.x-rust-param-identifier}}})?);
+    req_builder = req_builder.query(&params);
+    {{/isModel}}
+    {{^isModel}}
     req_builder = req_builder.query(&[("{{{baseName}}}", &{{{vendorExtensions.x-rust-param-identifier}}}.to_string())]);
+    {{/isModel}}
     {{/isNullable}}
     {{#isNullable}}
     {{#isDeepObject}}
@@ -165,9 +171,17 @@ pub {{#supportAsync}}async {{/supportAsync}}fn {{{operationId}}}(configuration:
     };
     {{/isDeepObject}}
     {{^isDeepObject}}
+    {{#isModel}}
+    if let Some(ref param_value) = {{{vendorExtensions.x-rust-param-identifier}}} {
+    let params = crate::apis::parse_flat_object(&serde_json::to_value({{{vendorExtensions.x-rust-param-identifier}}})?);
+    req_builder = req_builder.query(&params);
+    };
+    {{/isModel}}
+    {{^isModel}}
     if let Some(ref param_value) = {{{vendorExtensions.x-rust-param-identifier}}} {
         req_builder = req_builder.query(&[("{{{baseName}}}", &param_value.to_string())]);
     };
+    {{/isModel}}
     {{/isDeepObject}}
     {{/isNullable}}
     {{/isArray}}
@@ -186,7 +200,13 @@ pub {{#supportAsync}}async {{/supportAsync}}fn {{{operationId}}}(configuration:
         req_builder = req_builder.query(&params);
         {{/isDeepObject}}
         {{^isDeepObject}}
+        {{#isModel}}
+        let params = crate::apis::parse_flat_object(&serde_json::to_value(param_value)?);
+        req_builder = req_builder.query(&params);
+        {{/isModel}}
+        {{^isModel}}
         req_builder = req_builder.query(&[("{{{baseName}}}", &param_value.to_string())]);
+        {{/isModel}}
         {{/isDeepObject}}
         {{/isArray}}
     }
diff --git a/modules/openapi-generator/src/main/resources/rust/reqwest/api_mod.mustache b/modules/openapi-generator/src/main/resources/rust/reqwest/api_mod.mustache
index 4d5df28e9bb..dc0797cf3bd 100644
--- a/modules/openapi-generator/src/main/resources/rust/reqwest/api_mod.mustache
+++ b/modules/openapi-generator/src/main/resources/rust/reqwest/api_mod.mustache
@@ -105,6 +105,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/modules/openapi-generator/src/test/resources/3_0/objectQueryParam.yaml b/modules/openapi-generator/src/test/resources/3_0/objectQueryParam.yaml
index c3e7469a199..003c9a49227 100644
--- a/modules/openapi-generator/src/test/resources/3_0/objectQueryParam.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/objectQueryParam.yaml
@@ -14,6 +14,7 @@ paths:
       parameters:
         - in: query
           name: pageQuery
+          required: true
           schema:
             type: object
             properties:
@@ -22,4 +23,13 @@ paths:
                 format: int32
               limit:
                 type: integer
-                format: int32
\ No newline at end of file
+                format: int32
+        - in: query
+          name: notRequired
+          required: false
+          schema:
+            type: object
+            properties:
+              foobar:
+                type: integer
+                format: int32
diff --git a/samples/client/others/rust/reqwest-regression-16119/src/apis/mod.rs b/samples/client/others/rust/reqwest-regression-16119/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest-regression-16119/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest-regression-16119/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/api-with-ref-param/src/apis/mod.rs b/samples/client/others/rust/reqwest/api-with-ref-param/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest/api-with-ref-param/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/api-with-ref-param/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/composed-oneof/src/apis/mod.rs b/samples/client/others/rust/reqwest/composed-oneof/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest/composed-oneof/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/composed-oneof/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/emptyObject/src/apis/mod.rs b/samples/client/others/rust/reqwest/emptyObject/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest/emptyObject/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/emptyObject/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/object-query-param/.gitignore b/samples/client/others/rust/reqwest/object-query-param/.gitignore
new file mode 100644
index 00000000000..6aa106405a4
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/.gitignore
@@ -0,0 +1,3 @@
+/target/
+**/*.rs.bk
+Cargo.lock
diff --git a/samples/client/others/rust/reqwest/object-query-param/.openapi-generator-ignore b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator-ignore
new file mode 100644
index 00000000000..7484ee590a3
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator-ignore
@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md
diff --git a/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/FILES b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/FILES
new file mode 100644
index 00000000000..9ec011cd3ab
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/FILES
@@ -0,0 +1,15 @@
+.gitignore
+.travis.yml
+Cargo.toml
+README.md
+docs/DefaultApi.md
+docs/ListNotRequiredParameter.md
+docs/ListPageQueryParameter.md
+git_push.sh
+src/apis/configuration.rs
+src/apis/default_api.rs
+src/apis/mod.rs
+src/lib.rs
+src/models/list_not_required_parameter.rs
+src/models/list_page_query_parameter.rs
+src/models/mod.rs
diff --git a/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/VERSION b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/VERSION
new file mode 100644
index 00000000000..4c631cf217a
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/.openapi-generator/VERSION
@@ -0,0 +1 @@
+7.14.0-SNAPSHOT
diff --git a/samples/client/others/rust/reqwest/object-query-param/.travis.yml b/samples/client/others/rust/reqwest/object-query-param/.travis.yml
new file mode 100644
index 00000000000..22761ba7ee1
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/.travis.yml
@@ -0,0 +1 @@
+language: rust
diff --git a/samples/client/others/rust/reqwest/object-query-param/Cargo.toml b/samples/client/others/rust/reqwest/object-query-param/Cargo.toml
new file mode 100644
index 00000000000..804300c3832
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "object-query-param-reqwest"
+version = "1.0.0"
+authors = ["OpenAPI Generator team and contributors"]
+description = "No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)"
+license = "Apache-2.0"
+edition = "2021"
+
+[dependencies]
+serde = { version = "^1.0", features = ["derive"] }
+serde_json = "^1.0"
+serde_repr = "^0.1"
+url = "^2.5"
+reqwest = { version = "^0.12", default-features = false, features = ["json", "multipart"] }
diff --git a/samples/client/others/rust/reqwest/object-query-param/README.md b/samples/client/others/rust/reqwest/object-query-param/README.md
new file mode 100644
index 00000000000..b77e5809be9
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/README.md
@@ -0,0 +1,47 @@
+# Rust API client for object-query-param-reqwest
+
+No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+
+
+## Overview
+
+This API client was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.  By using the [openapi-spec](https://openapis.org) from a remote server, you can easily generate an API client.
+
+- API version: 1.0.0
+- Package version: 1.0.0
+- Generator version: 7.14.0-SNAPSHOT
+- Build package: `org.openapitools.codegen.languages.RustClientCodegen`
+
+## Installation
+
+Put the package under your project folder in a directory named `object-query-param-reqwest` and add the following to `Cargo.toml` under `[dependencies]`:
+
+```
+object-query-param-reqwest = { path = "./object-query-param-reqwest" }
+```
+
+## Documentation for API Endpoints
+
+All URIs are relative to *http://localhost:8080*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+*DefaultApi* | [**list**](docs/DefaultApi.md#list) | **GET** /pony | 
+
+
+## Documentation For Models
+
+ - [ListNotRequiredParameter](docs/ListNotRequiredParameter.md)
+ - [ListPageQueryParameter](docs/ListPageQueryParameter.md)
+
+
+To get access to the crate's generated documentation, use:
+
+```
+cargo doc --open
+```
+
+## Author
+
+
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/docs/DefaultApi.md b/samples/client/others/rust/reqwest/object-query-param/docs/DefaultApi.md
new file mode 100644
index 00000000000..333be0dc492
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/docs/DefaultApi.md
@@ -0,0 +1,38 @@
+# \DefaultApi
+
+All URIs are relative to *http://localhost:8080*
+
+Method | HTTP request | Description
+------------- | ------------- | -------------
+[**list**](DefaultApi.md#list) | **GET** /pony | 
+
+
+
+## list
+
+> list(page_query, not_required)
+
+
+### Parameters
+
+
+Name | Type | Description  | Required | Notes
+------------- | ------------- | ------------- | ------------- | -------------
+**page_query** | [**ListPageQueryParameter**](.md) |  | [required] |
+**not_required** | Option<[**ListNotRequiredParameter**](.md)> |  |  |
+
+### Return type
+
+ (empty response body)
+
+### Authorization
+
+No authorization required
+
+### HTTP request headers
+
+- **Content-Type**: Not defined
+- **Accept**: Not defined
+
+[[Back to top]](#) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to Model list]](../README.md#documentation-for-models) [[Back to README]](../README.md)
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/docs/ListNotRequiredParameter.md b/samples/client/others/rust/reqwest/object-query-param/docs/ListNotRequiredParameter.md
new file mode 100644
index 00000000000..8386441e98d
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/docs/ListNotRequiredParameter.md
@@ -0,0 +1,11 @@
+# ListNotRequiredParameter
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**foobar** | Option<**i32**> |  | [optional]
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/docs/ListPageQueryParameter.md b/samples/client/others/rust/reqwest/object-query-param/docs/ListPageQueryParameter.md
new file mode 100644
index 00000000000..82f0d548e5f
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/docs/ListPageQueryParameter.md
@@ -0,0 +1,12 @@
+# ListPageQueryParameter
+
+## Properties
+
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**offset** | Option<**i32**> |  | [optional]
+**limit** | Option<**i32**> |  | [optional]
+
+[[Back to Model list]](../README.md#documentation-for-models) [[Back to API list]](../README.md#documentation-for-api-endpoints) [[Back to README]](../README.md)
+
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/git_push.sh b/samples/client/others/rust/reqwest/object-query-param/git_push.sh
new file mode 100644
index 00000000000..f53a75d4fab
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/git_push.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+# ref: https://help.github.com/articles/adding-an-existing-project-to-github-using-the-command-line/
+#
+# Usage example: /bin/sh ./git_push.sh wing328 openapi-petstore-perl "minor update" "gitlab.com"
+
+git_user_id=$1
+git_repo_id=$2
+release_note=$3
+git_host=$4
+
+if [ "$git_host" = "" ]; then
+    git_host="github.com"
+    echo "[INFO] No command line input provided. Set \$git_host to $git_host"
+fi
+
+if [ "$git_user_id" = "" ]; then
+    git_user_id="GIT_USER_ID"
+    echo "[INFO] No command line input provided. Set \$git_user_id to $git_user_id"
+fi
+
+if [ "$git_repo_id" = "" ]; then
+    git_repo_id="GIT_REPO_ID"
+    echo "[INFO] No command line input provided. Set \$git_repo_id to $git_repo_id"
+fi
+
+if [ "$release_note" = "" ]; then
+    release_note="Minor update"
+    echo "[INFO] No command line input provided. Set \$release_note to $release_note"
+fi
+
+# Initialize the local directory as a Git repository
+git init
+
+# Adds the files in the local repository and stages them for commit.
+git add .
+
+# Commits the tracked changes and prepares them to be pushed to a remote repository.
+git commit -m "$release_note"
+
+# Sets the new remote
+git_remote=$(git remote)
+if [ "$git_remote" = "" ]; then # git remote not defined
+
+    if [ "$GIT_TOKEN" = "" ]; then
+        echo "[INFO] \$GIT_TOKEN (environment variable) is not set. Using the git credential in your environment."
+        git remote add origin https://${git_host}/${git_user_id}/${git_repo_id}.git
+    else
+        git remote add origin https://${git_user_id}:"${GIT_TOKEN}"@${git_host}/${git_user_id}/${git_repo_id}.git
+    fi
+
+fi
+
+git pull origin master
+
+# Pushes (Forces) the changes in the local repository up to the remote repository
+echo "Git pushing to https://${git_host}/${git_user_id}/${git_repo_id}.git"
+git push origin master 2>&1 | grep -v 'To https'
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/apis/configuration.rs b/samples/client/others/rust/reqwest/object-query-param/src/apis/configuration.rs
new file mode 100644
index 00000000000..440e7714254
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/apis/configuration.rs
@@ -0,0 +1,51 @@
+/*
+ * OpenAPI Petstore
+ *
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+
+
+#[derive(Debug, Clone)]
+pub struct Configuration {
+    pub base_path: String,
+    pub user_agent: Option<String>,
+    pub client: reqwest::Client,
+    pub basic_auth: Option<BasicAuth>,
+    pub oauth_access_token: Option<String>,
+    pub bearer_access_token: Option<String>,
+    pub api_key: Option<ApiKey>,
+}
+
+pub type BasicAuth = (String, Option<String>);
+
+#[derive(Debug, Clone)]
+pub struct ApiKey {
+    pub prefix: Option<String>,
+    pub key: String,
+}
+
+
+impl Configuration {
+    pub fn new() -> Configuration {
+        Configuration::default()
+    }
+}
+
+impl Default for Configuration {
+    fn default() -> Self {
+        Configuration {
+            base_path: "http://localhost:8080".to_owned(),
+            user_agent: Some("OpenAPI-Generator/1.0.0/rust".to_owned()),
+            client: reqwest::Client::new(),
+            basic_auth: None,
+            oauth_access_token: None,
+            bearer_access_token: None,
+            api_key: None,
+        }
+    }
+}
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/apis/default_api.rs b/samples/client/others/rust/reqwest/object-query-param/src/apis/default_api.rs
new file mode 100644
index 00000000000..76c54236cd5
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/apis/default_api.rs
@@ -0,0 +1,57 @@
+/*
+ * OpenAPI Petstore
+ *
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+
+use reqwest;
+use serde::{Deserialize, Serialize, de::Error as _};
+use crate::{apis::ResponseContent, models};
+use super::{Error, configuration, ContentType};
+
+
+/// struct for typed errors of method [`list`]
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(untagged)]
+pub enum ListError {
+    UnknownValue(serde_json::Value),
+}
+
+
+pub async fn list(configuration: &configuration::Configuration, page_query: models::ListPageQueryParameter, not_required: Option<models::ListNotRequiredParameter>) -> Result<(), Error<ListError>> {
+    // add a prefix to parameters to efficiently prevent name collisions
+    let p_page_query = page_query;
+    let p_not_required = not_required;
+
+    let uri_str = format!("{}/pony", configuration.base_path);
+    let mut req_builder = configuration.client.request(reqwest::Method::GET, &uri_str);
+
+    let params = crate::apis::parse_flat_object(&serde_json::to_value(p_page_query)?);
+    req_builder = req_builder.query(&params);
+    if let Some(ref param_value) = p_not_required {
+        let params = crate::apis::parse_flat_object(&serde_json::to_value(param_value)?);
+        req_builder = req_builder.query(&params);
+    }
+    if let Some(ref user_agent) = configuration.user_agent {
+        req_builder = req_builder.header(reqwest::header::USER_AGENT, user_agent.clone());
+    }
+
+    let req = req_builder.build()?;
+    let resp = configuration.client.execute(req).await?;
+
+    let status = resp.status();
+
+    if !status.is_client_error() && !status.is_server_error() {
+        Ok(())
+    } else {
+        let content = resp.text().await?;
+        let entity: Option<ListError> = serde_json::from_str(&content).ok();
+        Err(Error::ResponseError(ResponseContent { status, content, entity }))
+    }
+}
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/apis/mod.rs b/samples/client/others/rust/reqwest/object-query-param/src/apis/mod.rs
new file mode 100644
index 00000000000..a046b8e201e
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/apis/mod.rs
@@ -0,0 +1,143 @@
+use std::error;
+use std::fmt;
+
+#[derive(Debug, Clone)]
+pub struct ResponseContent<T> {
+    pub status: reqwest::StatusCode,
+    pub content: String,
+    pub entity: Option<T>,
+}
+
+#[derive(Debug)]
+pub enum Error<T> {
+    Reqwest(reqwest::Error),
+    Serde(serde_json::Error),
+    Io(std::io::Error),
+    ResponseError(ResponseContent<T>),
+}
+
+impl <T> fmt::Display for Error<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let (module, e) = match self {
+            Error::Reqwest(e) => ("reqwest", e.to_string()),
+            Error::Serde(e) => ("serde", e.to_string()),
+            Error::Io(e) => ("IO", e.to_string()),
+            Error::ResponseError(e) => ("response", format!("status code {}", e.status)),
+        };
+        write!(f, "error in {}: {}", module, e)
+    }
+}
+
+impl <T: fmt::Debug> error::Error for Error<T> {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        Some(match self {
+            Error::Reqwest(e) => e,
+            Error::Serde(e) => e,
+            Error::Io(e) => e,
+            Error::ResponseError(_) => return None,
+        })
+    }
+}
+
+impl <T> From<reqwest::Error> for Error<T> {
+    fn from(e: reqwest::Error) -> Self {
+        Error::Reqwest(e)
+    }
+}
+
+impl <T> From<serde_json::Error> for Error<T> {
+    fn from(e: serde_json::Error) -> Self {
+        Error::Serde(e)
+    }
+}
+
+impl <T> From<std::io::Error> for Error<T> {
+    fn from(e: std::io::Error) -> Self {
+        Error::Io(e)
+    }
+}
+
+pub fn urlencode<T: AsRef<str>>(s: T) -> String {
+    ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
+}
+
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
+pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => params.append(&mut parse_deep_object(
+                    &format!("{}[{}]", prefix, key),
+                    value,
+                )),
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.append(&mut parse_deep_object(
+                            &format!("{}[{}][{}]", prefix, key, i),
+                            value,
+                        ));
+                    }
+                },
+                serde_json::Value::String(s) => params.push((format!("{}[{}]", prefix, key), s.clone())),
+                _ => params.push((format!("{}[{}]", prefix, key), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported with style=deepObject")
+}
+
+/// Internal use only
+/// A content type supported by this client.
+#[allow(dead_code)]
+enum ContentType {
+    Json,
+    Text,
+    Unsupported(String)
+}
+
+impl From<&str> for ContentType {
+    fn from(content_type: &str) -> Self {
+        if content_type.starts_with("application") && content_type.contains("json") {
+            return Self::Json;
+        } else if content_type.starts_with("text/plain") {
+            return Self::Text;
+        } else {
+            return Self::Unsupported(content_type.to_string());
+        }
+    }
+}
+
+pub mod default_api;
+
+pub mod configuration;
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/lib.rs b/samples/client/others/rust/reqwest/object-query-param/src/lib.rs
new file mode 100644
index 00000000000..e1520628d76
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/lib.rs
@@ -0,0 +1,11 @@
+#![allow(unused_imports)]
+#![allow(clippy::too_many_arguments)]
+
+extern crate serde_repr;
+extern crate serde;
+extern crate serde_json;
+extern crate url;
+extern crate reqwest;
+
+pub mod apis;
+pub mod models;
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/models/list_not_required_parameter.rs b/samples/client/others/rust/reqwest/object-query-param/src/models/list_not_required_parameter.rs
new file mode 100644
index 00000000000..ccaf52a1b6b
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/models/list_not_required_parameter.rs
@@ -0,0 +1,27 @@
+/*
+ * OpenAPI Petstore
+ *
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+use crate::models;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
+pub struct ListNotRequiredParameter {
+    #[serde(rename = "foobar", skip_serializing_if = "Option::is_none")]
+    pub foobar: Option<i32>,
+}
+
+impl ListNotRequiredParameter {
+    pub fn new() -> ListNotRequiredParameter {
+        ListNotRequiredParameter {
+            foobar: None,
+        }
+    }
+}
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/models/list_page_query_parameter.rs b/samples/client/others/rust/reqwest/object-query-param/src/models/list_page_query_parameter.rs
new file mode 100644
index 00000000000..808b1b56a90
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/models/list_page_query_parameter.rs
@@ -0,0 +1,30 @@
+/*
+ * OpenAPI Petstore
+ *
+ * No description provided (generated by Openapi Generator https://github.com/openapitools/openapi-generator)
+ *
+ * The version of the OpenAPI document: 1.0.0
+ * 
+ * Generated by: https://openapi-generator.tech
+ */
+
+use crate::models;
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
+pub struct ListPageQueryParameter {
+    #[serde(rename = "offset", skip_serializing_if = "Option::is_none")]
+    pub offset: Option<i32>,
+    #[serde(rename = "limit", skip_serializing_if = "Option::is_none")]
+    pub limit: Option<i32>,
+}
+
+impl ListPageQueryParameter {
+    pub fn new() -> ListPageQueryParameter {
+        ListPageQueryParameter {
+            offset: None,
+            limit: None,
+        }
+    }
+}
+
diff --git a/samples/client/others/rust/reqwest/object-query-param/src/models/mod.rs b/samples/client/others/rust/reqwest/object-query-param/src/models/mod.rs
new file mode 100644
index 00000000000..b50743f7435
--- /dev/null
+++ b/samples/client/others/rust/reqwest/object-query-param/src/models/mod.rs
@@ -0,0 +1,4 @@
+pub mod list_not_required_parameter;
+pub use self::list_not_required_parameter::ListNotRequiredParameter;
+pub mod list_page_query_parameter;
+pub use self::list_page_query_parameter::ListPageQueryParameter;
diff --git a/samples/client/others/rust/reqwest/oneOf-array-map/src/apis/mod.rs b/samples/client/others/rust/reqwest/oneOf-array-map/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest/oneOf-array-map/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/oneOf-array-map/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/oneOf-reuseRef/src/apis/mod.rs b/samples/client/others/rust/reqwest/oneOf-reuseRef/src/apis/mod.rs
index fdcc89b3606..a046b8e201e 100644
--- a/samples/client/others/rust/reqwest/oneOf-reuseRef/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/oneOf-reuseRef/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/others/rust/reqwest/oneOf/src/apis/mod.rs b/samples/client/others/rust/reqwest/oneOf/src/apis/mod.rs
index 36835a5e8fa..9596ea3c671 100644
--- a/samples/client/others/rust/reqwest/oneOf/src/apis/mod.rs
+++ b/samples/client/others/rust/reqwest/oneOf/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/name-mapping/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/name-mapping/src/apis/mod.rs
index df474de3782..c66c58a48e6 100644
--- a/samples/client/petstore/rust/reqwest/name-mapping/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/name-mapping/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-async-middleware/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-async-middleware/src/apis/mod.rs
index b27445925dc..2c38595d5bb 100644
--- a/samples/client/petstore/rust/reqwest/petstore-async-middleware/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-async-middleware/src/apis/mod.rs
@@ -70,6 +70,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-async-tokensource/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-async-tokensource/src/apis/mod.rs
index c55f52db30b..2adec55a9f6 100644
--- a/samples/client/petstore/rust/reqwest/petstore-async-tokensource/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-async-tokensource/src/apis/mod.rs
@@ -64,6 +64,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-async/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-async/src/apis/mod.rs
index a075c841443..37a5419c07b 100644
--- a/samples/client/petstore/rust/reqwest/petstore-async/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-async/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-avoid-box/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-avoid-box/src/apis/mod.rs
index a075c841443..37a5419c07b 100644
--- a/samples/client/petstore/rust/reqwest/petstore-avoid-box/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-avoid-box/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-awsv4signature/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-awsv4signature/src/apis/mod.rs
index c03ebdf001f..ad6845bce02 100644
--- a/samples/client/petstore/rust/reqwest/petstore-awsv4signature/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-awsv4signature/src/apis/mod.rs
@@ -65,6 +65,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore-model-name-prefix/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore-model-name-prefix/src/apis/mod.rs
index a075c841443..37a5419c07b 100644
--- a/samples/client/petstore/rust/reqwest/petstore-model-name-prefix/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore-model-name-prefix/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];
diff --git a/samples/client/petstore/rust/reqwest/petstore/src/apis/mod.rs b/samples/client/petstore/rust/reqwest/petstore/src/apis/mod.rs
index a075c841443..37a5419c07b 100644
--- a/samples/client/petstore/rust/reqwest/petstore/src/apis/mod.rs
+++ b/samples/client/petstore/rust/reqwest/petstore/src/apis/mod.rs
@@ -61,6 +61,33 @@ pub fn urlencode<T: AsRef<str>>(s: T) -> String {
     ::url::form_urlencoded::byte_serialize(s.as_ref().as_bytes()).collect()
 }
 
+pub fn parse_flat_object(value: &serde_json::Value) -> Vec<(String, String)> {
+    if let serde_json::Value::Object(object) = value {
+        let mut params = vec![];
+
+        for (key, value) in object {
+            match value {
+                serde_json::Value::Object(_) => {
+                    unimplemented!(
+                        "Only flat objects are supported, use parse_deep_object() instead"
+                    )
+                }
+                serde_json::Value::Array(array) => {
+                    for (i, value) in array.iter().enumerate() {
+                        params.push((format!("{key}[{i}]"), value.to_string()));
+                    }
+                }
+                serde_json::Value::String(s) => params.push((key.to_string(), s.clone())),
+                _ => params.push((key.to_string(), value.to_string())),
+            }
+        }
+
+        return params;
+    }
+
+    unimplemented!("Only objects are supported")
+}
+
 pub fn parse_deep_object(prefix: &str, value: &serde_json::Value) -> Vec<(String, String)> {
     if let serde_json::Value::Object(object) = value {
         let mut params = vec![];