Stream options. (#2533)

* Stream options.

* Fetch stuff from nix integration test for easier testing.

* Adding the assert.

* Only send the usage when asked for.

* Update the docs.

* Impure test because we need network.

* develop.

* Optional usage.

* Fixes.

* Workflow

.github/workflows/nix_tests.yaml

@@ -38,4 +38,4 @@ jobs:
       env:
         HF_TOKEN: ${{ secrets.HF_TOKEN }}
     - name: Rust tests.
-      run: nix build .#checks.$(nix eval --impure --raw --expr 'builtins.currentSystem').rust -L
+      run: nix develop .#test --command cargo test

.github/workflows/tests.yaml

@@ -42,6 +42,7 @@ jobs:
           sudo rm -rf /usr/share/dotnet # will release about 20GB if you don't need .NET
       - name: Install
         run: |
+          sudo apt update
           sudo apt install python3.11-dev -y
           make install-cpu
       - name: Run server tests

.redocly.lint-ignore.yaml

@@ -23,9 +23,11 @@ docs/openapi.json:
     - '#/components/schemas/GenerateResponse/properties/details/nullable'
     - '#/components/schemas/StreamResponse/properties/details/nullable'
     - '#/components/schemas/ChatRequest/properties/response_format/nullable'
+    - '#/components/schemas/ChatRequest/properties/stream_options/nullable'
     - '#/components/schemas/ChatRequest/properties/tool_choice/nullable'
     - '#/components/schemas/ToolChoice/nullable'
     - '#/components/schemas/ChatCompletionComplete/properties/logprobs/nullable'
+    - '#/components/schemas/ChatCompletionChunk/properties/usage/nullable'
     - '#/components/schemas/ChatCompletionChoice/properties/logprobs/nullable'
   no-invalid-media-type-examples:
     - '#/paths/~1/post/responses/422/content/application~1json/example'

Cargo.toml

@@ -5,7 +5,8 @@ members = [
   "backends/grpc-metadata",
   "backends/trtllm",
   "backends/client",
-  "launcher"
+  "launcher",
+  "router"
 ]
 default-members = [
   "benchmark",
@@ -13,7 +14,8 @@ default-members = [
   "backends/grpc-metadata",
   # "backends/trtllm",
   "backends/client",
-  "launcher"
+  "launcher",
+  "router"
 ]
 resolver = "2"
 

clients/python/text_generation/types.py

@@ -168,7 +168,7 @@ class ChatCompletionComplete(BaseModel):
     # Log probabilities for the chat completion
     logprobs: Optional[Any]
     # Reason for completion
-    finish_reason: str
+    finish_reason: Optional[str]
     # Usage details of the chat completion
     usage: Optional[Any] = None
 
@@ -191,6 +191,7 @@ class ChatCompletionChunk(BaseModel):
     model: str
     system_fingerprint: str
     choices: List[Choice]
+    usage: Optional[Any] = None
 
 
 class Parameters(BaseModel):

docs/openapi.json

@@ -742,6 +742,14 @@
           },
           "system_fingerprint": {
             "type": "string"
+          },
+          "usage": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/Usage"
+              }
+            ],
+            "nullable": true
           }
         }
       },
@@ -937,6 +945,14 @@
           "stream": {
             "type": "boolean"
           },
+          "stream_options": {
+            "allOf": [
+              {
+                "$ref": "#/components/schemas/StreamOptions"
+              }
+            ],
+            "nullable": true
+          },
           "temperature": {
             "type": "number",
             "format": "float",
@@ -1912,6 +1928,19 @@
           }
         }
       },
+      "StreamOptions": {
+        "type": "object",
+        "required": [
+          "include_usage"
+        ],
+        "properties": {
+          "include_usage": {
+            "type": "boolean",
+            "description": "If set, an additional chunk will be streamed before the data: [DONE] message. The usage field on this chunk shows the token usage statistics for the entire request, and the choices field will always be an empty array. All other chunks will also include a usage field, but with a null value.",
+            "example": "true"
+          }
+        }
+      },
       "StreamResponse": {
         "type": "object",
         "required": [

flake.lock

@@ -479,11 +479,11 @@
         "systems": "systems_6"
       },
       "locked": {
-        "lastModified": 1710146030,
-        "narHash": "sha256-SZ5L6eA7HJ/nmkzGG7/ISclqe6oZdOZTNoesiInkXPQ=",
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "b1d9ab70662946ef0850d488da1c9019f3a9752a",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
         "type": "github"
       },
       "original": {
@@ -853,11 +853,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1726280639,
-        "narHash": "sha256-YfLRPlFZWrT2oRLNAoqf7G3+NnUTDdlIJk6tmBU7kXM=",
+        "lastModified": 1726626348,
+        "narHash": "sha256-sYV7e1B1yLcxo8/h+/hTwzZYmaju2oObNiy5iRI0C30=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "e9f8641c92f26fd1e076e705edb12147c384171d",
+        "rev": "6fd52ad8bd88f39efb2c999cc971921c2fb9f3a2",
         "type": "github"
       },
       "original": {

flake.nix

@@ -67,31 +67,38 @@
             '';
           };
         server = pkgs.python3.pkgs.callPackage ./nix/server.nix { inherit nix-filter; };
+        client = pkgs.python3.pkgs.callPackage ./nix/client.nix { };
       in
       {
         checks = {
-          rust = with pkgs; rustPlatform.buildRustPackage {
-            name = "rust-checks";
-            src = ./.;
-            cargoLock = {
-              lockFile = ./Cargo.lock;
+          rust =
+            with pkgs;
+            rustPlatform.buildRustPackage {
+              name = "rust-checks";
+              src = ./.;
+              cargoLock = {
+                lockFile = ./Cargo.lock;
+              };
+              buildInputs = [ openssl.dev ];
+              nativeBuildInputs = [
+                clippy
+                pkg-config
+                protobuf
+                python3
+                rustfmt
+              ];
+              buildPhase = ''
+                cargo check
+              '';
+              checkPhase = ''
+                cargo fmt -- --check
+                cargo test -j $NIX_BUILD_CORES
+                cargo clippy
+              '';
+              installPhase = "touch $out";
             };
-            buildInputs = [ openssl.dev ];
-            nativeBuildInputs = [ clippy pkg-config protobuf python3 rustfmt ];
-            buildPhase = ''
-              cargo check
-            '';
-            checkPhase = ''
-              cargo fmt -- --check
-              cargo test -j $NIX_BUILD_CORES
-              cargo clippy
-            '';
-            installPhase = "touch $out";
-          } ;
         };
-
         formatter = pkgs.nixfmt-rfc-style;
-
         devShells = with pkgs; rec {
           default = pure;
 
@@ -106,10 +113,11 @@
           test = mkShell {
             buildInputs =
               [
-                # benchmark
-                # launcher
-                # router
+                benchmark
+                launcher
+                router
                 server
+                client
                 openssl.dev
                 pkg-config
                 cargo

integration-tests/models/__snapshots__/test_completion_prompts/test_flash_llama_completion_stream_usage.json

+[
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "**",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "Deep",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": " Learning",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": ":",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": " An",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": " Overview",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656043,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "**\n",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656044,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "================================",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656044,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "=====",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": null,
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656044,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": null
+  },
+  {
+    "choices": [
+      {
+        "delta": {
+          "content": "\n\n",
+          "role": "assistant",
+          "tool_calls": null
+        },
+        "finish_reason": "length",
+        "index": 0,
+        "logprobs": null
+      }
+    ],
+    "created": 1726656044,
+    "id": "",
+    "model": "meta-llama/Meta-Llama-3.1-8B-Instruct",
+    "object": "chat.completion.chunk",
+    "system_fingerprint": "2.2.1-dev0-native",
+    "usage": {
+      "completion_tokens": 10,
+      "prompt_tokens": 40,
+      "total_tokens": 50
+    }
+  }
+]

integration-tests/models/test_completion_prompts.py

@@ -3,9 +3,7 @@ import requests
 import json
 from aiohttp import ClientSession
 
-from text_generation.types import (
-    Completion,
-)
+from text_generation.types import Completion, ChatCompletionChunk
 
 
 @pytest.fixture(scope="module")
@@ -50,6 +48,114 @@ def test_flash_llama_completion_single_prompt(
     assert response == response_snapshot
 
 
+@pytest.mark.release
+async def test_flash_llama_completion_stream_usage(
+    flash_llama_completion, response_snapshot
+):
+    url = f"{flash_llama_completion.base_url}/v1/chat/completions"
+    request = {
+        "model": "tgi",
+        "messages": [
+            {
+                "role": "user",
+                "content": "What is Deep Learning?",
+            }
+        ],
+        "max_tokens": 10,
+        "temperature": 0.0,
+        "stream_options": {"include_usage": True},
+        "stream": True,
+    }
+    string = ""
+    chunks = []
+    had_usage = False
+    async with ClientSession(headers=flash_llama_completion.headers) as session:
+        async with session.post(url, json=request) as response:
+            # iterate over the stream
+            async for chunk in response.content.iter_any():
+                # remove "data:"
+                chunk = chunk.decode().split("\n\n")
+                # remove "data:" if present
+                chunk = [c.replace("data:", "") for c in chunk]
+                # remove empty strings
+                chunk = [c for c in chunk if c]
+                # remove completion marking chunk
+                chunk = [c for c in chunk if c != " [DONE]"]
+                # parse json
+                chunk = [json.loads(c) for c in chunk]
+
+                for c in chunk:
+                    chunks.append(ChatCompletionChunk(**c))
+                    assert "choices" in c
+                    if len(c["choices"]) == 1:
+                        index = c["choices"][0]["index"]
+                        assert index == 0
+                        string += c["choices"][0]["delta"]["content"]
+
+                        has_usage = c["usage"] is not None
+                        assert not had_usage
+                        if has_usage:
+                            had_usage = True
+                    else:
+                        raise RuntimeError("Expected different payload")
+    assert had_usage
+    assert (
+        string
+        == "**Deep Learning: An Overview**\n=====================================\n\n"
+    )
+    assert chunks == response_snapshot
+
+    request = {
+        "model": "tgi",
+        "messages": [
+            {
+                "role": "user",
+                "content": "What is Deep Learning?",
+            }
+        ],
+        "max_tokens": 10,
+        "temperature": 0.0,
+        "stream": True,
+    }
+    string = ""
+    chunks = []
+    had_usage = False
+    async with ClientSession(headers=flash_llama_completion.headers) as session:
+        async with session.post(url, json=request) as response:
+            # iterate over the stream
+            async for chunk in response.content.iter_any():
+                # remove "data:"
+                chunk = chunk.decode().split("\n\n")
+                # remove "data:" if present
+                chunk = [c.replace("data:", "") for c in chunk]
+                # remove empty strings
+                chunk = [c for c in chunk if c]
+                # remove completion marking chunk
+                chunk = [c for c in chunk if c != " [DONE]"]
+                # parse json
+                chunk = [json.loads(c) for c in chunk]
+
+                for c in chunk:
+                    chunks.append(ChatCompletionChunk(**c))
+                    assert "choices" in c
+                    if len(c["choices"]) == 1:
+                        index = c["choices"][0]["index"]
+                        assert index == 0
+                        string += c["choices"][0]["delta"]["content"]
+
+                        has_usage = c["usage"] is not None
+                        assert not had_usage
+                        if has_usage:
+                            had_usage = True
+                    else:
+                        raise RuntimeError("Expected different payload")
+    assert not had_usage
+    assert (
+        string
+        == "**Deep Learning: An Overview**\n=====================================\n\n"
+    )
+
+
 @pytest.mark.release
 def test_flash_llama_completion_many_prompts(flash_llama_completion, response_snapshot):
     response = requests.post(

nix/client.nix

+{
+  buildPythonPackage,
+  poetry-core,
+  huggingface-hub,
+  pydantic,
+}:
+
+buildPythonPackage {
+  name = "text-generation";
+
+  src = ../clients/python;
+
+  pyproject = true;
+
+  build-system = [ poetry-core ];
+
+  dependencies = [
+    huggingface-hub
+    pydantic
+  ];
+}

router/src/lib.rs

@@ -684,6 +684,7 @@ pub(crate) struct ChatCompletionChunk {
     pub model: String,
     pub system_fingerprint: String,
     pub choices: Vec<ChatCompletionChoice>,
+    pub usage: Option<Usage>,
 }
 
 #[derive(Clone, Serialize, ToSchema)]
@@ -732,6 +733,7 @@ impl ChatCompletionChunk {
         created: u64,
         logprobs: Option<ChatCompletionLogprobs>,
         finish_reason: Option<String>,
+        usage: Option<Usage>,
     ) -> Self {
         let delta = match (delta, tool_calls) {
             (Some(delta), _) => ChatCompletionDelta::Chat(TextMessage {
@@ -766,6 +768,7 @@ impl ChatCompletionChunk {
                 logprobs,
                 finish_reason,
             }],
+            usage,
         }
     }
 }
@@ -880,6 +883,18 @@ pub(crate) struct ChatRequest {
     #[serde(default)]
     #[schema(nullable = true, default = "null", example = "null")]
     pub guideline: Option<String>,
+
+    /// Options for streaming response. Only set this when you set stream: true.
+    #[serde(default)]
+    #[schema(nullable = true, example = "null")]
+    pub stream_options: Option<StreamOptions>,
+}
+
+#[derive(Clone, Deserialize, ToSchema, Serialize)]
+struct StreamOptions {
+    /// If set, an additional chunk will be streamed before the data: [DONE] message. The usage field on this chunk shows the token usage statistics for the entire request, and the choices field will always be an empty array. All other chunks will also include a usage field, but with a null value.
+    #[schema(example = "true")]
+    include_usage: bool,
 }
 
 pub fn default_tool_prompt() -> String {
@@ -1472,6 +1487,27 @@ mod tests {
         let textmsg: TextMessage = message.into();
         assert_eq!(textmsg.content, "Whats in this image?![](https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/transformers/rabbit.png)");
     }
+
+    #[test]
+    fn test_chat_stream_options() {
+        let json = json!({
+            "model": "",
+            "stream_options": {"include_usage": true},
+            "messages": [{
+                "role": "user",
+                "content": "Hello"
+            }]
+        });
+        let request: ChatRequest = serde_json::from_str(json.to_string().as_str()).unwrap();
+
+        assert!(matches!(
+            request.stream_options,
+            Some(StreamOptions {
+                include_usage: true
+            })
+        ));
+    }
+
     #[test]
     fn openai_output() {
         let message = OutputMessage::ChatMessage(TextMessage {

router/src/server.rs

@@ -13,8 +13,8 @@ use crate::{
     usage_stats, BestOfSequence, Details, ErrorResponse, FinishReason, FunctionName,
     GenerateParameters, GenerateRequest, GenerateResponse, GrammarType, HubModelInfo,
     HubProcessorConfig, HubTokenizerConfig, Info, Message, MessageChunk, MessageContent,
-    OutputMessage, PrefillToken, SimpleToken, StreamDetails, StreamResponse, TextMessage, Token,
-    TokenizeResponse, ToolCallDelta, ToolCallMessage, Url, Usage, Validation,
+    OutputMessage, PrefillToken, SimpleToken, StreamDetails, StreamOptions, StreamResponse,
+    TextMessage, Token, TokenizeResponse, ToolCallDelta, ToolCallMessage, Url, Usage, Validation,
 };
 use crate::{
     ChatCompletion, ChatCompletionChoice, ChatCompletionChunk, ChatCompletionComplete,
@@ -1175,6 +1175,7 @@ async fn chat_completions(
         seed,
         stop,
         stream,
+        stream_options,
         tools,
         tool_choice,
         tool_prompt,
@@ -1265,6 +1266,28 @@ async fn chat_completions(
                 (content, None)
             };
 
+            let (usage, finish_reason) = match stream_token.details {
+                Some(details) => {
+                    let usage = if stream_options
+                        .as_ref()
+                        .map(|s| s.include_usage)
+                        .unwrap_or(false)
+                    {
+                        let completion_tokens = details.generated_tokens;
+                        let prompt_tokens = details.input_length;
+                        let total_tokens = prompt_tokens + completion_tokens;
+                        Some(Usage {
+                            completion_tokens,
+                            prompt_tokens,
+                            total_tokens,
+                        })
+                    } else {
+                        None
+                    };
+                    (usage, Some(details.finish_reason.format(true)))
+                }
+                None => (None, None),
+            };
             event
                 .json_data(CompletionType::ChatCompletionChunk(
                     ChatCompletionChunk::new(
@@ -1274,7 +1297,8 @@ async fn chat_completions(
                         tool_calls,
                         current_time,
                         logprobs,
-                        stream_token.details.map(|d| d.finish_reason.format(true)),
+                        finish_reason,
+                        usage,
                     ),
                 ))
                 .unwrap_or_else(|e| {
@@ -1664,6 +1688,7 @@ StreamDetails,
 ErrorResponse,
 GrammarType,
 Usage,
+StreamOptions,
 DeltaToolCall,
 ToolType,
 Tool,