Screen protein and antibody chains for sequence-level developability liabilities before costly downstream work. Each chain gets its isoelectric point, net charge at your pH, molecular mass, GRAVY, instability index, most hydrophobic window, cysteine state and a list of liability motifs — deamidation, isomerization, N-glycosylation, oxidation and fragmentation — and every signal has its own pass flag rather than a single opaque score. The antibody preset numbers each chain and reports liabilities in the CDRs apart from those in the framework. Sequences and the chains of PDB or CIF structures can be screened together.