Add messages api compatibility docs (#1478)

This PR adds a new page to the docs that describes the Messages API and
how to use it.

Additionally this page will contain cloud provider specific information
for enabling and using this feature. This PR includes a SageMaker
example/information.

docs/source/_toctree.yml

@@ -7,6 +7,8 @@
     title: Installation
   - local: supported_models
     title: Supported Models and Hardware
+  - local: messages_api
+    title: Messages API
   title: Getting started
 - sections:
   - local: basic_tutorials/consuming_tgi

docs/source/messages_api.md

+# Messages API
+
+_Messages API is compatible to OpenAI Chat Completion API_
+
+Text Generation Inference (TGI) now supports the Message API which is fully compatible with the OpenAI Chat Completion API. This means you can use OpenAI's client libraries to interact with TGI's Messages API. Below are some examples of how to utilize this compatibility.
+
+## Making a Request
+
+You can make a request to TGI's Messages API using `curl`. Here's an example:
+
+```bash
+curl localhost:3000/v1/chat/completions \
+    -X POST \
+    -d '{
+  "model": "tgi",
+  "messages": [
+    {
+      "role": "system",
+      "content": "You are a helpful assistant."
+    },
+    {
+      "role": "user",
+      "content": "What is deep learning?"
+    }
+  ],
+  "stream": true,
+  "max_tokens": 20
+}' \
+    -H 'Content-Type: application/json'
+```
+
+## Streaming
+
+You can also use OpenAI's Python client library to make a streaming request. Here's how:
+
+```python
+from openai import OpenAI
+
+# init the client but point it to TGI
+client = OpenAI(
+    base_url="http://localhost:3000/v1",
+    api_key="-"
+)
+
+chat_completion = client.chat.completions.create(
+    model="tgi",
+    messages=[
+        {"role": "system", "content": "You are a helpful assistant." },
+        {"role": "user", "content": "What is deep learning?"}
+    ],
+    stream=True
+)
+
+# iterate and print stream
+for message in chat_completion:
+    print(message)
+```
+
+## Synchronous
+
+If you prefer to make a synchronous request, you can do so like this:
+
+```python
+from openai import OpenAI
+
+# init the client but point it to TGI
+client = OpenAI(
+    base_url="http://localhost:3000/v1",
+    api_key="-"
+)
+
+chat_completion = client.chat.completions.create(
+    model="tgi",
+    messages=[
+        {"role": "system", "content": "You are a helpful assistant." },
+        {"role": "user", "content": "What is deep learning?"}
+    ],
+    stream=False
+)
+
+print(chat_completion)
+```
+
+## Cloud Providers
+
+TGI can be deployed on various cloud providers for scalable and robust text generation. One such provider is Amazon SageMaker, which has recently added support for TGI. Here's how you can deploy TGI on Amazon SageMaker:
+
+## Amazon SageMaker
+
+To enable the Messages API in Amazon SageMaker you need to set the environment variable `MESSAGES_API_ENABLED=true`. 
+
+This will modify the `/invocations` route to accept Messages dictonaries consisting out of role and content. See the example below on how to deploy Llama with the new Messages API.
+
+```python
+import json
+import sagemaker
+import boto3
+from sagemaker.huggingface import HuggingFaceModel, get_huggingface_llm_image_uri
+
+try:
+	role = sagemaker.get_execution_role()
+except ValueError:
+	iam = boto3.client('iam')
+	role = iam.get_role(RoleName='sagemaker_execution_role')['Role']['Arn']
+
+# Hub Model configuration. https://huggingface.co/models
+hub = {
+	'HF_MODEL_ID':'HuggingFaceH4/zephyr-7b-beta',
+	'SM_NUM_GPUS': json.dumps(1),
+    'MESSAGES_API_ENABLED': True
+}
+
+# create Hugging Face Model Class
+huggingface_model = HuggingFaceModel(
+	image_uri=get_huggingface_llm_image_uri("huggingface",version="1.4.0"),
+	env=hub,
+	role=role, 
+)
+
+# deploy model to SageMaker Inference
+predictor = huggingface_model.deploy(
+	initial_instance_count=1,
+	instance_type="ml.g5.2xlarge",
+	container_startup_health_check_timeout=300,
+  )
+  
+# send request
+predictor.predict({
+"messages": [
+        {"role": "system", "content": "You are a helpful assistant." },
+        {"role": "user", "content": "What is deep learning?"}
+    ]
+})
+```
\ No newline at end of file

router/src/main.rs

@@ -72,7 +72,7 @@ struct Args {
     #[clap(long, env)]
     ngrok_edge: Option<String>,
     #[clap(long, env, default_value_t = false)]
-    chat_enabled_api: bool,
+    messages_api_enabled: bool,
 }
 
 #[tokio::main]
@@ -104,7 +104,7 @@ async fn main() -> Result<(), RouterError> {
         ngrok,
         ngrok_authtoken,
         ngrok_edge,
-        chat_enabled_api,
+        messages_api_enabled,
     } = args;
 
     // Launch Tokio runtime
@@ -348,7 +348,7 @@ async fn main() -> Result<(), RouterError> {
         ngrok_authtoken,
         ngrok_edge,
         tokenizer_config,
-        chat_enabled_api,
+        messages_api_enabled,
     )
     .await?;
     Ok(())

router/src/server.rs

@@ -708,7 +708,7 @@ pub async fn run(
     ngrok_authtoken: Option<String>,
     ngrok_edge: Option<String>,
     tokenizer_config: HubTokenizerConfig,
-    chat_enabled_api: bool,
+    messages_api_enabled: bool,
 ) -> Result<(), axum::BoxError> {
     // OpenAPI documentation
     #[derive(OpenApi)]
@@ -872,7 +872,7 @@ pub async fn run(
         .route("/metrics", get(metrics));
 
     // Conditional AWS Sagemaker route
-    let aws_sagemaker_route = if chat_enabled_api {
+    let aws_sagemaker_route = if messages_api_enabled {
         Router::new().route("/invocations", post(chat_completions)) // Use 'chat_completions' for OAI_ENABLED
     } else {
         Router::new().route("/invocations", post(compat_generate)) // Use 'compat_generate' otherwise