diff --git a/examples/function_call_role.rs b/examples/function_call_role.rs
new file mode 100644
index 0000000..94a35c2
--- /dev/null
+++ b/examples/function_call_role.rs
@@ -0,0 +1,126 @@
+use openai_api_rs::v1::api::Client;
+use openai_api_rs::v1::chat_completion::{self, ChatCompletionRequest};
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::{env, vec};
+
+async fn get_coin_price(coin: &str) -> f64 {
+    let coin = coin.to_lowercase();
+    match coin.as_str() {
+        "btc" | "bitcoin" => 10000.0,
+        "eth" | "ethereum" => 1000.0,
+        _ => 0.0,
+    }
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let client = Client::new(env::var("OPENAI_API_KEY").unwrap().to_string());
+
+    let mut properties = HashMap::new();
+    properties.insert(
+        "coin".to_string(),
+        Box::new(chat_completion::JSONSchemaDefine {
+            schema_type: Some(chat_completion::JSONSchemaType::String),
+            description: Some("The cryptocurrency to get the price of".to_string()),
+            enum_values: None,
+            properties: None,
+            required: None,
+            items: None,
+        }),
+    );
+
+    let req = ChatCompletionRequest {
+        model: chat_completion::GPT3_5_TURBO_0613.to_string(),
+        messages: vec![chat_completion::ChatCompletionMessage {
+            role: chat_completion::MessageRole::user,
+            content: Some(String::from("What is the price of Ethereum?")),
+            name: None,
+            function_call: None,
+        }],
+        functions: Some(vec![chat_completion::Function {
+            name: String::from("get_coin_price"),
+            description: Some(String::from("Get the price of a cryptocurrency")),
+            parameters: Some(chat_completion::FunctionParameters {
+                schema_type: chat_completion::JSONSchemaType::Object,
+                properties: Some(properties),
+                required: Some(vec![String::from("coin")]),
+            }),
+        }]),
+        function_call: None,
+        temperature: None,
+        top_p: None,
+        n: None,
+        stream: None,
+        stop: None,
+        max_tokens: None,
+        presence_penalty: None,
+        frequency_penalty: None,
+        logit_bias: None,
+        user: None,
+    };
+
+    let result = client.chat_completion(req).await?;
+
+    match result.choices[0].finish_reason {
+        chat_completion::FinishReason::stop => {
+            println!("Stop");
+            println!("{:?}", result.choices[0].message.content);
+        }
+        chat_completion::FinishReason::length => {
+            println!("Length");
+        }
+        chat_completion::FinishReason::function_call => {
+            println!("FunctionCall");
+            #[derive(Serialize, Deserialize)]
+            struct Currency {
+                coin: String,
+            }
+            let function_call = result.choices[0].message.function_call.as_ref().unwrap();
+            let arguments = function_call.arguments.clone().unwrap();
+            let c: Currency = serde_json::from_str(&arguments)?;
+            let coin = c.coin;
+            
+            let req = ChatCompletionRequest {
+                model: chat_completion::GPT3_5_TURBO_0613.to_string(),
+                messages: vec![chat_completion::ChatCompletionMessage {
+                    role: chat_completion::MessageRole::user,
+                    content: Some(String::from("What is the price of Ethereum?")),
+                    name: None,
+                    function_call: None,
+                }, chat_completion::ChatCompletionMessage {
+                    role: chat_completion::MessageRole::function,
+                    content: Some({
+                        let price = get_coin_price(&coin).await;
+                        format!("{{\"price\": {}}}", price)
+                    }),
+                    name: Some(String::from("get_coin_price")),
+                    function_call: None,
+                }],
+                functions: None,
+                function_call: None,
+                temperature: None,
+                top_p: None,
+                n: None,
+                stream: None,
+                stop: None,
+                max_tokens: None,
+                presence_penalty: None,
+                frequency_penalty: None,
+                logit_bias: None,
+                user: None,
+            };
+            let result = client.chat_completion(req).await?;
+            println!("{:?}", result.choices[0].message.content);
+        }
+        chat_completion::FinishReason::content_filter => {
+            println!("ContentFilter");
+        }
+        chat_completion::FinishReason::null => {
+            println!("Null");
+        }
+    }
+    Ok(())
+}
+
+// OPENAI_API_KEY=xxxx cargo run --package openai-api-rs --example function_call_role
diff --git a/src/v1/chat_completion.rs b/src/v1/chat_completion.rs
index 94ac7a9..7f20a84 100644
--- a/src/v1/chat_completion.rs
+++ b/src/v1/chat_completion.rs
@@ -49,6 +49,7 @@ pub enum MessageRole {
     user,
     system,
     assistant,
+    function,
 }
 
 #[derive(Debug, Serialize, Deserialize)]