input.json creation for antibody design problem (Please help me)

Hello,

Hi RFD3 team,

I'm trying to design nanobody CDRs while keeping the framework regions and target protein fixed. I want to clarify the correct input specification approach.

My goal:

• Keep Framework regions (FR1: F1-26, FR2: F33-52, FR3: F60-101, FR4: F108-116) from input PDB with fixed sequence and coordinates
• Design only CDR1 (length 6-8), CDR2 (length 6-8), and CDR3 (length 9-15) with new sequences and structures
• Keep target protein (chain A, residues 100-550) fixed
• Use hotspot-driven design with specific residues
  here is my current input.json file:

{
"nanobody_cdr_design": {
"input": "nanobody_target.pdb",
"dialect": 2,
"contig": "F1-26,6-8,F33-52,6-8,F60-101,9-15,F108-116,/0,A100-550",
"select_hotspots": "A148,A151,A152,A538,A539",
"infer_ori_strategy": "hotspots",
"plddt_enhanced": true,
"is_non_loopy": true
}
}

Questions:

1. Is this the correct input file for my use case? Does it correctly preserve frameworks and design only CDRs?
2. Should I add any additional parameters (like select_fixed_atoms or select_unfixed_sequence) for this design scenario, or are the defaults sufficient?

Start with the RFD3 input specification and examples, then compare the issue's input.json fields, contig ranges, hotspot selection, and fixed-region requirements against them. Done means providing or recording an authoritative answer about the required parameters for this antibody-design scenario.