Score¶
Source https://github.com/vllm-project/vllm/tree/main/examples/pooling/score.
Cohere Rerank Client¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Example of using the OpenAI entrypoint's rerank API which is compatible with
the Cohere SDK: https://github.com/cohere-ai/cohere-python
Note that `pip install cohere` is needed to run this example.
run: vllm serve BAAI/bge-reranker-base
"""
import cohere
from cohere import Client, ClientV2
model = "BAAI/bge-reranker-base"
query = "What is the capital of France?"
documents = [
"The capital of France is Paris",
"Reranking is fun!",
"vLLM is an open-source framework for fast AI serving",
]
def cohere_rerank(
client: Client | ClientV2, model: str, query: str, documents: list[str]
) -> dict:
return client.rerank(model=model, query=query, documents=documents)
def main():
# cohere v1 client
cohere_v1 = cohere.Client(base_url="http://localhost:8000", api_key="sk-fake-key")
rerank_v1_result = cohere_rerank(cohere_v1, model, query, documents)
print("-" * 50)
print("rerank_v1_result:\n", rerank_v1_result)
print("-" * 50)
# or the v2
cohere_v2 = cohere.ClientV2("sk-fake-key", base_url="http://localhost:8000")
rerank_v2_result = cohere_rerank(cohere_v2, model, query, documents)
print("rerank_v2_result:\n", rerank_v2_result)
print("-" * 50)
if __name__ == "__main__":
main()
Convert Model To Seq Cls¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# ruff: noqa: E501
import argparse
import json
import torch
import transformers
# Usage:
# for BAAI/bge-reranker-v2-gemma
# Caution: "Yes" and "yes" are two different tokens
# python convert_model_to_seq_cls.py --model_name BAAI/bge-reranker-v2-gemma --classifier_from_tokens '["Yes"]' --method no_post_processing --path ./bge-reranker-v2-gemma-seq-cls
# for mxbai-rerank-v2
# python convert_model_to_seq_cls.py --model_name mixedbread-ai/mxbai-rerank-base-v2 --classifier_from_tokens '["0", "1"]' --method from_2_way_softmax --path ./mxbai-rerank-base-v2-seq-cls
# for Qwen3-Reranker
# python convert_model_to_seq_cls.py --model_name Qwen/Qwen3-Reranker-0.6B --classifier_from_tokens '["no", "yes"]' --method from_2_way_softmax --path ./Qwen3-Reranker-0.6B-seq-cls
def from_2_way_softmax(causal_lm, seq_cls_model, tokenizer, tokens, device):
# refer to https://huggingface.co/Qwen/Qwen3-Reranker-0.6B/discussions/3
assert len(tokens) == 2
lm_head_weights = causal_lm.lm_head.weight
false_id = tokenizer.convert_tokens_to_ids(tokens[0])
true_id = tokenizer.convert_tokens_to_ids(tokens[1])
score_weight = lm_head_weights[true_id].to(device).to(
torch.float32
) - lm_head_weights[false_id].to(device).to(torch.float32)
with torch.no_grad():
seq_cls_model.score.weight.copy_(score_weight.unsqueeze(0))
if seq_cls_model.score.bias is not None:
seq_cls_model.score.bias.zero_()
def no_post_processing(causal_lm, seq_cls_model, tokenizer, tokens, device):
lm_head_weights = causal_lm.lm_head.weight
token_ids = [tokenizer.convert_tokens_to_ids(t) for t in tokens]
score_weight = lm_head_weights[token_ids].to(device)
with torch.no_grad():
seq_cls_model.score.weight.copy_(score_weight)
if seq_cls_model.score.bias is not None:
seq_cls_model.score.bias.zero_()
method_map = {
function.__name__: function for function in [from_2_way_softmax, no_post_processing]
}
def converting(
model_name, classifier_from_tokens, path, method, use_pad_token=False, device="cpu"
):
assert method in method_map
if method == "from_2_way_softmax":
assert len(classifier_from_tokens) == 2
num_labels = 1
else:
num_labels = len(classifier_from_tokens)
tokenizer = transformers.AutoTokenizer.from_pretrained(model_name)
causal_lm = transformers.AutoModelForCausalLM.from_pretrained(
model_name, device_map=device
)
seq_cls_model = transformers.AutoModelForSequenceClassification.from_pretrained(
model_name,
num_labels=num_labels,
ignore_mismatched_sizes=True,
device_map=device,
)
method_map[method](
causal_lm, seq_cls_model, tokenizer, classifier_from_tokens, device
)
# `llm as reranker` defaults to not using pad_token
seq_cls_model.config.use_pad_token = use_pad_token
seq_cls_model.config.pad_token_id = tokenizer.pad_token_id
seq_cls_model.save_pretrained(path)
tokenizer.save_pretrained(path)
def parse_args():
parser = argparse.ArgumentParser(
description="Converting *ForCausalLM models to "
"*ForSequenceClassification models."
)
parser.add_argument(
"--model_name",
type=str,
default="BAAI/bge-reranker-v2-gemma",
help="Model name",
)
parser.add_argument(
"--classifier_from_tokens",
type=str,
default='["Yes"]',
help="classifier from tokens",
)
parser.add_argument(
"--method", type=str, default="no_post_processing", help="Converting converting"
)
parser.add_argument(
"--use-pad-token", action="store_true", help="Whether to use pad_token"
)
parser.add_argument(
"--path",
type=str,
default="./bge-reranker-v2-gemma-seq-cls",
help="Path to save converted model",
)
return parser.parse_args()
if __name__ == "__main__":
args = parse_args()
converting(
model_name=args.model_name,
classifier_from_tokens=json.loads(args.classifier_from_tokens),
method=args.method,
use_pad_token=args.use_pad_token,
path=args.path,
)
Offline Reranker¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# ruff: noqa: E501
from vllm import LLM
model_name = "Qwen/Qwen3-Reranker-0.6B"
# What is the difference between the official original version and one
# that has been converted into a sequence classification model?
# Qwen3-Reranker is a language model that doing reranker by using the
# logits of "no" and "yes" tokens.
# It needs to computing 151669 tokens logits, making this method extremely
# inefficient, not to mention incompatible with the vllm score API.
# A method for converting the original model into a sequence classification
# model was proposed. See:https://huggingface.co/Qwen/Qwen3-Reranker-0.6B/discussions/3
# Models converted offline using this method can not only be more efficient
# and support the vllm score API, but also make the init parameters more
# concise, for example.
# llm = LLM(model="tomaarsen/Qwen3-Reranker-0.6B-seq-cls", runner="pooling")
# If you want to load the official original version, the init parameters are
# as follows.
def get_llm() -> LLM:
"""Initializes and returns the LLM model for Qwen3-Reranker."""
return LLM(
model=model_name,
runner="pooling",
hf_overrides={
"architectures": ["Qwen3ForSequenceClassification"],
"classifier_from_token": ["no", "yes"],
"is_original_qwen3_reranker": True,
},
)
# Why do we need hf_overrides for the official original version:
# vllm converts it to Qwen3ForSequenceClassification when loaded for
# better performance.
# - Firstly, we need using `"architectures": ["Qwen3ForSequenceClassification"],`
# to manually route to Qwen3ForSequenceClassification.
# - Then, we will extract the vector corresponding to classifier_from_token
# from lm_head using `"classifier_from_token": ["no", "yes"]`.
# - Third, we will convert these two vectors into one vector. The use of
# conversion logic is controlled by `using "is_original_qwen3_reranker": True`.
# Please use the query_template and document_template to format the query and
# document for better reranker results.
prefix = '<|im_start|>system\nJudge whether the Document meets the requirements based on the Query and the Instruct provided. Note that the answer can only be "yes" or "no".<|im_end|>\n<|im_start|>user\n'
suffix = "<|im_end|>\n<|im_start|>assistant\n<think>\n\n</think>\n\n"
query_template = "{prefix}<Instruct>: {instruction}\n<Query>: {query}\n"
document_template = "<Document>: {doc}{suffix}"
def main() -> None:
instruction = (
"Given a web search query, retrieve relevant passages that answer the query"
)
queries = [
"What is the capital of China?",
"Explain gravity",
]
documents = [
"The capital of China is Beijing.",
"Gravity is a force that attracts two bodies towards each other. It gives weight to physical objects and is responsible for the movement of planets around the sun.",
]
queries = [
query_template.format(prefix=prefix, instruction=instruction, query=query)
for query in queries
]
documents = [document_template.format(doc=doc, suffix=suffix) for doc in documents]
llm = get_llm()
outputs = llm.score(queries, documents)
print("-" * 30)
print([output.outputs.score for output in outputs])
print("-" * 30)
if __name__ == "__main__":
main()
Offline Using Template¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# ruff: noqa: E501
from pathlib import Path
from vllm import LLM
model_name = "nvidia/llama-nemotron-rerank-1b-v2"
# Path to template file
template_path = Path(__file__).parent / "template" / "nemotron-rerank.jinja"
chat_template = template_path.read_text()
llm = LLM(model=model_name, runner="pooling", trust_remote_code=True)
query = "how much protein should a female eat?"
documents = [
"As a general guideline, the CDC's average requirement of protein for women ages 19 to 70 is 46 grams per day. But, as you can see from this chart, you'll need to increase that if you're expecting or training for a marathon. Check out the chart below to see how much protein you should be eating each day.",
"Definition of summit for English Language Learners. : 1 the highest point of a mountain : the top of a mountain. : 2 the highest level. : 3 a meeting or series of meetings between the leaders of two or more governments.",
"Calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional.",
]
outputs = llm.score(query, documents, chat_template=chat_template)
print("-" * 30)
print([output.outputs.score for output in outputs])
print("-" * 30)
Online Using Template¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
# ruff: noqa: E501
"""
Example of using the rerank API with template.
run:
vllm serve nvidia/llama-nemotron-rerank-1b-v2 --runner pooling --trust-remote-code --chat-template examples/pooling/score/template/nemotron-rerank.jinja
"""
import json
import requests
url = "http://127.0.0.1:8000/rerank"
headers = {"accept": "application/json", "Content-Type": "application/json"}
query = "how much protein should a female eat?"
documents = [
"As a general guideline, the CDC's average requirement of protein for women ages 19 to 70 is 46 grams per day. But, as you can see from this chart, you'll need to increase that if you're expecting or training for a marathon. Check out the chart below to see how much protein you should be eating each day.",
"Definition of summit for English Language Learners. : 1 the highest point of a mountain : the top of a mountain. : 2 the highest level. : 3 a meeting or series of meetings between the leaders of two or more governments.",
"Calorie intake should not fall below 1,200 a day in women or 1,500 a day in men, except under the supervision of a health professional.",
]
data = {
"model": "nvidia/llama-nemotron-rerank-1b-v2",
"query": query,
"documents": documents,
}
def main():
response = requests.post(url, headers=headers, json=data)
# Check the response
if response.status_code == 200:
print("Request successful!")
print(json.dumps(response.json(), indent=2))
else:
print(f"Request failed with status code: {response.status_code}")
print(response.text)
if __name__ == "__main__":
main()
OpenAI Cross Encoder Score¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Example online usage of Score API.
Run `vllm serve <model> --runner pooling` to start up the server in vLLM.
"""
import argparse
import pprint
import requests
def post_http_request(prompt: dict, api_url: str) -> requests.Response:
headers = {"User-Agent": "Test Client"}
response = requests.post(api_url, headers=headers, json=prompt)
return response
def parse_args():
parser = argparse.ArgumentParser()
parser.add_argument("--host", type=str, default="localhost")
parser.add_argument("--port", type=int, default=8000)
parser.add_argument("--model", type=str, default="BAAI/bge-reranker-v2-m3")
return parser.parse_args()
def main(args):
api_url = f"http://{args.host}:{args.port}/score"
model_name = args.model
text_1 = "What is the capital of Brazil?"
text_2 = "The capital of Brazil is Brasilia."
prompt = {"model": model_name, "text_1": text_1, "text_2": text_2}
score_response = post_http_request(prompt=prompt, api_url=api_url)
print("\nPrompt when text_1 and text_2 are both strings:")
pprint.pprint(prompt)
print("\nScore Response:")
pprint.pprint(score_response.json())
text_1 = "What is the capital of France?"
text_2 = ["The capital of Brazil is Brasilia.", "The capital of France is Paris."]
prompt = {"model": model_name, "text_1": text_1, "text_2": text_2}
score_response = post_http_request(prompt=prompt, api_url=api_url)
print("\nPrompt when text_1 is string and text_2 is a list:")
pprint.pprint(prompt)
print("\nScore Response:")
pprint.pprint(score_response.json())
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."]
prompt = {"model": model_name, "text_1": text_1, "text_2": text_2}
score_response = post_http_request(prompt=prompt, api_url=api_url)
print("\nPrompt when text_1 and text_2 are both lists:")
pprint.pprint(prompt)
print("\nScore Response:")
pprint.pprint(score_response.json())
if __name__ == "__main__":
args = parse_args()
main(args)
OpenAI Cross Encoder Score For Multimodal¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Example online usage of Score API.
Run `vllm serve <model> --runner pooling` to start up the server in vLLM.
"""
import argparse
import pprint
import requests
def post_http_request(prompt: dict, api_url: str) -> requests.Response:
headers = {"User-Agent": "Test Client"}
response = requests.post(api_url, headers=headers, json=prompt)
return response
def parse_args():
parser = argparse.ArgumentParser()
parser.add_argument("--host", type=str, default="localhost")
parser.add_argument("--port", type=int, default=8000)
parser.add_argument("--model", type=str, default="jinaai/jina-reranker-m0")
return parser.parse_args()
def main(args):
api_url = f"http://{args.host}:{args.port}/score"
model_name = args.model
text_1 = "slm markdown"
text_2 = {
"content": [
{
"type": "image_url",
"image_url": {
"url": "https://raw.githubusercontent.com/jina-ai/multimodal-reranker-test/main/handelsblatt-preview.png"
},
},
{
"type": "image_url",
"image_url": {
"url": "https://raw.githubusercontent.com/jina-ai/multimodal-reranker-test/main/paper-11.png"
},
},
]
}
prompt = {"model": model_name, "text_1": text_1, "text_2": text_2}
score_response = post_http_request(prompt=prompt, api_url=api_url)
print("\nPrompt when text_1 is string and text_2 is a image list:")
pprint.pprint(prompt)
print("\nScore Response:")
pprint.pprint(score_response.json())
if __name__ == "__main__":
args = parse_args()
main(args)
OpenAI Reranker¶
# SPDX-License-Identifier: Apache-2.0
# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
"""
Example of using the OpenAI entrypoint's rerank API which is compatible with
Jina and Cohere https://jina.ai/reranker
run: vllm serve BAAI/bge-reranker-base
"""
import json
import requests
url = "http://127.0.0.1:8000/rerank"
headers = {"accept": "application/json", "Content-Type": "application/json"}
data = {
"model": "BAAI/bge-reranker-base",
"query": "What is the capital of France?",
"documents": [
"The capital of Brazil is Brasilia.",
"The capital of France is Paris.",
"Horses and cows are both animals",
],
}
def main():
response = requests.post(url, headers=headers, json=data)
# Check the response
if response.status_code == 200:
print("Request successful!")
print(json.dumps(response.json(), indent=2))
else:
print(f"Request failed with status code: {response.status_code}")
print(response.text)
if __name__ == "__main__":
main()