WESA is a meta-predictor, based on a Weighted Ensemble of five methods, for Solvent Accessibility of residues.
The input is the protein sequence, in FASTA format. The user can either paste the sequence, or enter the UniProt ID by clicking "Load Sequence From UniProtKB". The server will then retrieve the sequence from the UniProt Knowledgebase (http://www.uniprot.org/help/uniprotkb).
The output is the Solvent Accessibility of each residue. An output example, with explanation, can be seen here