Model reference · open weights
unixcoder is an open-weight embedding model from microsoft. unixcoder-base (BF16) weighs 504 MB; the smallest configuration that runs it is RTX 3060 12 GB.
Summary of the microsoft/unixcoder-base model card, 2026-10-01
What it is
| Released by | microsoft |
|---|---|
| Released | 2022-03-23 |
| VRAM | 504 MB for the weights |
What it runs on
| Card | Runs | Memory |
|---|---|---|
| RTX 3060 12 GB | fits | 11.6 GB |
| RTX 4060 Ti 16 GB | fits | 15.4 GB |
| RTX 3090 24 GB | fits | 23.4 GB |
| RTX 4090 24 GB | fits | 23.4 GB |
| RTX 5090 32 GB | fits | 31.0 GB |
| L40S 48 GB | fits | 44.0 GB |
| A100 80 GB | fits | 78.2 GB |
| H100 80 GB | fits | 78.1 GB |
| RTX PRO 6000 Blackwell 96 GB | fits | 93.8 GB |
| DGX Spark (GB10) 128 GB unified | fits | 107 GB |
| H200 141 GB | fits | 138 GB |
| B200 180 GB | fits | 176 GB |
From the model card
UniXcoder is a unified cross-modal pre-trained model that leverages multimodal data (i.e. code comment and AST) to pretrain code representation.
We implement a class to use UniXcoder and you can follow the code to build UniXcoder. You can download the class by
wget https://raw.githubusercontent.com/microsoft/CodeBERT/master/UniXcoder/unixcoder.py
import torch
from unixcoder import UniXcoder
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
model = UniXcoder("microsoft/unixcoder-base")
model.to(device)
In the following, we will give zero-shot examples for several tasks under different mode, including code search (encoder-only), code completion (decoder-only), function name prediction (encoder-decoder) , API recommendation (encoder-decoder), code summarization (encoder-decoder).
For encoder-only mode, we give an example of code search.
Here, we give an example to obtain code fragment embedding from CodeBERT.
# Encode maximum function
func = "def f(a,b): if a>b: return a else return b"
tokens_ids = model.tokenize([func],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
tokens_embeddings,max_func_embedding = model(source_ids)
# Encode minimum function
func = "def f(a,b): if a<b: return a else return b"
tokens_ids = model.tokenize([func],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
tokens_embeddings,min_func_embedding = model(source_ids)
# Encode NL
nl = "return maximum value"
tokens_ids = model.tokenize([nl],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
tokens_embeddings,nl_embedding = model(source_ids)
print(max_func_embedding.shape)
print(max_func_embedding)
torch.Size([1, 768])
tensor([[ 8.6533e-01, -1.9796e+00, -8.6849e-01, 4.2652e-01, -5.3696e-01,
-1.5521e-01, 5.3770e-01, 3.4199e-01, 3.6305e-01, -3.9391e-01,
-1.1816e+00, 2.6010e+00, -7.7133e-01, 1.8441e+00, 2.3645e+00,
...,
-2.9188e+00, 1.2555e+00, -1.9953e+00, -1.9795e+00, 1.7279e+00,
6.4590e-01, -5.2769e-02, 2.4965e-01, 2.3962e-02, 5.9996e-02,
2.5659e+00, 3.6533e+00, 2.0301e+00]], device='cuda:0',
grad_fn=)
Now, we calculate cosine similarity between NL and two functions. Although the difference of two functions is only a operator (``````), UniXcoder can distinguish them.
# Normalize embedding
norm_max_func_embedding = torch.nn.functional.normalize(max_func_embedding, p=2, dim=1)
norm_min_func_embedding = torch.nn.functional.normalize(min_func_embedding, p=2, dim=1)
norm_nl_embedding = torch.nn.functional.normalize(nl_embedding, p=2, dim=1)
max_func_nl_similarity = torch.einsum("ac,bc->ab",norm_max_func_embedding,norm_nl_embedding)
min_func_nl_similarity = torch.einsum("ac,bc->ab",norm_min_func_embedding,norm_nl_embedding)
print(max_func_nl_similarity)
print(min_func_nl_similarity)
tensor([[0.3002]], device='cuda:0', grad_fn=)
tensor([[0.1881]], device='cuda:0', grad_fn=)
For decoder-only mode, we give an example of code completion.
context = """
def f(data,file_path):
# write json data into file_path in python language
"""
tokens_ids = model.tokenize([context],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
prediction_ids = model.generate(source_ids, decoder_only=True, beam_size=3, max_length=128)
predictions = model.decode(prediction_ids)
print(context+predictions[0][0])
def f(data,file_path):
# write json data into file_path in python language
data = json.dumps(data)
with open(file_path, 'w') as f:
f.write(data)
For encoder-decoder mode, we give two examples including: function name prediction, API recommendation, code summarization.
context = """
def (data,file_path):
data = json.dumps(data)
with open(file_path, 'w') as f:
f.write(data)
"""
tokens_ids = model.tokenize([context],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
prediction_ids = model.generate(source_ids, decoder_only=False, beam_size=3, max_length=128)
predictions = model.decode(prediction_ids)
print([x.replace("","").strip() for x in predictions[0]])
['write_json', 'write_file', 'to_json']
context = """
def write_json(data,file_path):
data = (data)
with open(file_path, 'w') as f:
f.write(data)
"""
tokens_ids = model.tokenize([context],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
prediction_ids = model.generate(source_ids, decoder_only=False, beam_size=3, max_length=128)
predictions = model.decode(prediction_ids)
print([x.replace("","").strip() for x in predictions[0]])
['json.dumps', 'json.loads', 'str']
context = """
#
def write_json(data,file_path):
data = json.dumps(data)
with open(file_path, 'w') as f:
f.write(data)
"""
tokens_ids = model.tokenize([context],max_length=512,mode="")
source_ids = torch.tensor(tokens_ids).to(device)
prediction_ids = model.generate(source_ids, decoder_only=False, beam_size=3, max_length=128)
predictions = model.decode(prediction_ids)
print([x.replace("","").strip() for x in predictions[0]])
['WQuoted from the model card on Hugging Face. The full card is behind the Hugging Face link above.