https://solver.vsnexa.com/ https://solver.vsnexa.com/.well-known/nexa-solver.json https://solver.vsnexa.com/.well-known/nexa-onchain-discovery.json https://solver.vsnexa.com/.well-known/nexa-standards.json https://solver.vsnexa.com/openapi.json https://solver.vsnexa.com/api/v6/solver-discovery