[Doc] Reorganize online pooling APIs (#11172)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>
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Cyrus Leung
2024-12-14 00:22:22 +08:00
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parent 238c0d93b4
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@@ -1,13 +1,13 @@
# OpenAI Compatible Server
vLLM provides an HTTP server that implements OpenAI's [Completions](https://platform.openai.com/docs/api-reference/completions) and [Chat](https://platform.openai.com/docs/api-reference/chat) API.
vLLM provides an HTTP server that implements OpenAI's [Completions](https://platform.openai.com/docs/api-reference/completions) and [Chat](https://platform.openai.com/docs/api-reference/chat) API, and more!
You can start the server using Python, or using [Docker](deploying_with_docker.rst):
You can start the server via the [`vllm serve`](#vllm-serve) command, or through [Docker](deploying_with_docker.rst):
```bash
vllm serve NousResearch/Meta-Llama-3-8B-Instruct --dtype auto --api-key token-abc123
```
To call the server, you can use the official OpenAI Python client library, or any other HTTP client.
To call the server, you can use the [official OpenAI Python client](https://github.com/openai/openai-python), or any other HTTP client.
```python
from openai import OpenAI
client = OpenAI(
@@ -25,265 +25,32 @@ completion = client.chat.completions.create(
print(completion.choices[0].message)
```
## API Reference
## Supported APIs
We currently support the following OpenAI APIs:
- [Completions API](https://platform.openai.com/docs/api-reference/completions)
- [Completions API](#completions-api) (`/v1/completions`)
- Only applicable to [text generation models](../models/generative_models.rst) (`--task generate`).
- *Note: `suffix` parameter is not supported.*
- [Chat Completions API](https://platform.openai.com/docs/api-reference/chat)
- [Chat Completions API](#chat-api) (`/v1/chat/completions`)
- Only applicable to [text generation models](../models/generative_models.rst) (`--task generate`) with a [chat template](#chat-template).
- [Vision](https://platform.openai.com/docs/guides/vision)-related parameters are supported; see [Multimodal Inputs](../usage/multimodal_inputs.rst).
- *Note: `image_url.detail` parameter is not supported.*
- We also support `audio_url` content type for audio files.
- Refer to [vllm.entrypoints.chat_utils](https://github.com/vllm-project/vllm/tree/main/vllm/entrypoints/chat_utils.py) for the exact schema.
- *TODO: Support `input_audio` content type as defined [here](https://github.com/openai/openai-python/blob/v1.52.2/src/openai/types/chat/chat_completion_content_part_input_audio_param.py).*
- *Note: `parallel_tool_calls` and `user` parameters are ignored.*
- [Embeddings API](https://platform.openai.com/docs/api-reference/embeddings)
- Instead of `inputs`, you can pass in a list of `messages` (same schema as Chat Completions API),
which will be treated as a single prompt to the model according to its chat template.
- This enables multi-modal inputs to be passed to embedding models, see [this page](../usage/multimodal_inputs.rst) for details.
- *Note: You should run `vllm serve` with `--task embedding` to ensure that the model is being run in embedding mode.*
- [Embeddings API](#embeddings-api) (`/v1/embeddings`)
- Only applicable to [embedding models](../models/pooling_models.rst) (`--task embed`).
## Score API for Cross Encoder Models
In addition, we have the following custom APIs:
vLLM supports *cross encoders models* at the **/v1/score** endpoint, which is not an OpenAI API standard endpoint. You can find the documentation for these kind of models at [sbert.net](https://www.sbert.net/docs/package_reference/cross_encoder/cross_encoder.html).
A ***Cross Encoder*** takes exactly two sentences / texts as input and either predicts a score or label for this sentence pair. It can for example predict the similarity of the sentence pair on a scale of 0 … 1.
### Example of usage for a pair of a string and a list of texts
In this case, the model will compare the first given text to each of the texts containing the list.
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/v1/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"text_1": "What is the capital of France?",
"text_2": [
"The capital of Brazil is Brasilia.",
"The capital of France is Paris."
]
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693570,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": [
0.001094818115234375
]
},
{
"index": 1,
"object": "score",
"score": [
1
]
}
],
"usage": {}
}
```
### Example of usage for a pair of two lists of texts
In this case, the model will compare the one by one, making pairs by same index correspondent in each list.
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/v1/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"encoding_format": "float",
"text_1": [
"What is the capital of Brazil?",
"What is the capital of France?"
],
"text_2": [
"The capital of Brazil is Brasilia.",
"The capital of France is Paris."
]
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693447,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": [
1
]
},
{
"index": 1,
"object": "score",
"score": [
1
]
}
],
"usage": {}
}
```
### Example of usage for a pair of two strings
In this case, the model will compare the strings of texts.
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/v1/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"encoding_format": "float",
"text_1": "What is the capital of France?",
"text_2": "The capital of France is Paris."
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693447,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": [
1
]
}
],
"usage": {}
}
```
## Extra Parameters
vLLM supports a set of parameters that are not part of the OpenAI API.
In order to use them, you can pass them as extra parameters in the OpenAI client.
Or directly merge them into the JSON payload if you are using HTTP call directly.
```python
completion = client.chat.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
messages=[
{"role": "user", "content": "Classify this sentiment: vLLM is wonderful!"}
],
extra_body={
"guided_choice": ["positive", "negative"]
}
)
```
### Extra HTTP Headers
Only `X-Request-Id` HTTP request header is supported for now.
```python
completion = client.chat.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
messages=[
{"role": "user", "content": "Classify this sentiment: vLLM is wonderful!"}
],
extra_headers={
"x-request-id": "sentiment-classification-00001",
}
)
print(completion._request_id)
completion = client.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
prompt="A robot may not injure a human being",
extra_headers={
"x-request-id": "completion-test",
}
)
print(completion._request_id)
```
### Extra Parameters for Completions API
The following [sampling parameters (click through to see documentation)](../dev/sampling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-completion-sampling-params
:end-before: end-completion-sampling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-completion-extra-params
:end-before: end-completion-extra-params
```
### Extra Parameters for Chat Completions API
The following [sampling parameters (click through to see documentation)](../dev/sampling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-chat-completion-sampling-params
:end-before: end-chat-completion-sampling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-chat-completion-extra-params
:end-before: end-chat-completion-extra-params
```
### Extra Parameters for Embeddings API
The following [pooling parameters (click through to see documentation)](../dev/pooling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-embedding-pooling-params
:end-before: end-embedding-pooling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-embedding-extra-params
:end-before: end-embedding-extra-params
```
- [Tokenizer API](#tokenizer-api) (`/tokenize`, `/detokenize`)
- Applicable to any model with a tokenizer.
- [Score API](#score-api) (`/score`)
- Only applicable to [cross-encoder models](../models/pooling_models.rst) (`--task score`).
(chat-template)=
## Chat Template
In order for the language model to support chat protocol, vLLM requires the model to include
@@ -329,7 +96,56 @@ the detected format, which can be one of:
If the result is not what you expect, you can set the `--chat-template-content-format` CLI argument
to override which format to use.
## Command line arguments for the server
## Extra Parameters
vLLM supports a set of parameters that are not part of the OpenAI API.
In order to use them, you can pass them as extra parameters in the OpenAI client.
Or directly merge them into the JSON payload if you are using HTTP call directly.
```python
completion = client.chat.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
messages=[
{"role": "user", "content": "Classify this sentiment: vLLM is wonderful!"}
],
extra_body={
"guided_choice": ["positive", "negative"]
}
)
```
## Extra HTTP Headers
Only `X-Request-Id` HTTP request header is supported for now.
```python
completion = client.chat.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
messages=[
{"role": "user", "content": "Classify this sentiment: vLLM is wonderful!"}
],
extra_headers={
"x-request-id": "sentiment-classification-00001",
}
)
print(completion._request_id)
completion = client.completions.create(
model="NousResearch/Meta-Llama-3-8B-Instruct",
prompt="A robot may not injure a human being",
extra_headers={
"x-request-id": "completion-test",
}
)
print(completion._request_id)
```
## CLI Reference
(vllm-serve)=
### `vllm serve`
The `vllm serve` command is used to launch the OpenAI-compatible server.
```{argparse}
:module: vllm.entrypoints.openai.cli_args
@@ -337,12 +153,10 @@ to override which format to use.
:prog: vllm serve
```
#### Configuration file
### Config file
The `serve` module can also accept arguments from a config file in
`yaml` format. The arguments in the yaml must be specified using the
long form of the argument outlined [here](https://docs.vllm.ai/en/latest/serving/openai_compatible_server.html#command-line-arguments-for-the-server):
You can load CLI arguments via a [YAML](https://yaml.org/) config file.
The argument names must be the long form of those outlined [above](#vllm-serve).
For example:
@@ -354,10 +168,268 @@ port: 6379
uvicorn-log-level: "info"
```
To use the above config file:
```bash
$ vllm serve SOME_MODEL --config config.yaml
```
---
**NOTE**
In case an argument is supplied simultaneously using command line and the config file, the value from the commandline will take precedence.
```{note}
In case an argument is supplied simultaneously using command line and the config file, the value from the command line will take precedence.
The order of priorities is `command line > config file values > defaults`.
```
## API Reference
(completions-api)=
### Completions API
Refer to [OpenAI's API reference](https://platform.openai.com/docs/api-reference/completions) for more details.
#### Extra parameters
The following [sampling parameters (click through to see documentation)](../dev/sampling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-completion-sampling-params
:end-before: end-completion-sampling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-completion-extra-params
:end-before: end-completion-extra-params
```
(chat-api)=
### Chat Completions API
Refer to [OpenAI's API reference](https://platform.openai.com/docs/api-reference/chat) for more details.
#### Extra parameters
The following [sampling parameters (click through to see documentation)](../dev/sampling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-chat-completion-sampling-params
:end-before: end-chat-completion-sampling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-chat-completion-extra-params
:end-before: end-chat-completion-extra-params
```
(embeddings-api)=
### Embeddings API
Refer to [OpenAI's API reference](https://platform.openai.com/docs/api-reference/embeddings) for more details.
If the model has a [chat template](#chat-template), you can replace `inputs` with a list of `messages` (same schema as [Chat Completions API](#chat-api))
which will be treated as a single prompt to the model.
```{tip}
This enables multi-modal inputs to be passed to embedding models, see [this page](../usage/multimodal_inputs.rst) for details.
```
#### Extra parameters
The following [pooling parameters (click through to see documentation)](../dev/pooling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-embedding-pooling-params
:end-before: end-embedding-pooling-params
```
The following extra parameters are supported by default:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-embedding-extra-params
:end-before: end-embedding-extra-params
```
For chat-like input (i.e. if `messages` is passed), these extra parameters are supported instead:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-chat-embedding-extra-params
:end-before: end-chat-embedding-extra-params
```
(tokenizer-api)=
### Tokenizer API
The Tokenizer API is a simple wrapper over [HuggingFace-style tokenizers](https://huggingface.co/docs/transformers/en/main_classes/tokenizer).
It consists of two endpoints:
- `/tokenize` corresponds to calling `tokenizer.encode()`.
- `/detokenize` corresponds to calling `tokenizer.decode()`.
(score-api)=
### Score API
The Score API applies a cross-encoder model to predict scores for sentence pairs.
Usually, the score for a sentence pair refers to the similarity between two sentences, on a scale of 0 to 1.
You can find the documentation for these kind of models at [sbert.net](https://www.sbert.net/docs/package_reference/cross_encoder/cross_encoder.html).
#### Single inference
You can pass a string to both `text_1` and `text_2`, forming a single sentence pair.
Request:
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"encoding_format": "float",
"text_1": "What is the capital of France?",
"text_2": "The capital of France is Paris."
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693447,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": 1
}
],
"usage": {}
}
```
#### Batch inference
You can pass a string to `text_1` and a list to `text_2`, forming multiple sentence pairs
where each pair is built from `text_1` and a string in `text_2`.
The total number of pairs is `len(text_2)`.
Request:
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"text_1": "What is the capital of France?",
"text_2": [
"The capital of Brazil is Brasilia.",
"The capital of France is Paris."
]
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693570,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": 0.001094818115234375
},
{
"index": 1,
"object": "score",
"score": 1
}
],
"usage": {}
}
```
You can pass a list to both `text_1` and `text_2`, forming multiple sentence pairs
where each pair is built from a string in `text_1` and the corresponding string in `text_2` (similar to `zip()`).
The total number of pairs is `len(text_2)`.
Request:
```bash
curl -X 'POST' \
'http://127.0.0.1:8000/score' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"model": "BAAI/bge-reranker-v2-m3",
"encoding_format": "float",
"text_1": [
"What is the capital of Brazil?",
"What is the capital of France?"
],
"text_2": [
"The capital of Brazil is Brasilia.",
"The capital of France is Paris."
]
}'
```
Response:
```bash
{
"id": "score-request-id",
"object": "list",
"created": 693447,
"model": "BAAI/bge-reranker-v2-m3",
"data": [
{
"index": 0,
"object": "score",
"score": 1
},
{
"index": 1,
"object": "score",
"score": 1
}
],
"usage": {}
}
```
#### Extra parameters
The following [pooling parameters (click through to see documentation)](../dev/pooling_params.rst) are supported.
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-score-pooling-params
:end-before: end-score-pooling-params
```
The following extra parameters are supported:
```{literalinclude} ../../../vllm/entrypoints/openai/protocol.py
:language: python
:start-after: begin-score-extra-params
:end-before: end-score-extra-params
```