Suggestions:
It usually takes several hours for a single library design. For saving your time, you are strongly suggested to use UniProt number as the input, which allows immediate extraction of the previously designed libraries.

Restrictions: 
Only single sequence per submission and each sequence not more than 8,000 amino acids. The library design is only for proteins whose variants can be screened using high-throughput methods such as yeast-two-hybrid method. Now, the parameters were optimized with GPCRs as the target protein and the library capacity is set as 2 million.

Confidentiality: 
The sequence is kept confidential and will be deleted after processing. However, if you use Uniprot number as input and use the default parameters, the design will be deposited for retrieval. This is for saving the computing power and serving more users.