One sealed solution. Same bytes as POST /solve. Send parameters, or example in their place: the name of a worked example describe_solver lists (example_solve, or a key beginning example_solve_), so a long worked input need not be typed again; the request is filled with that example's parameters, and the filled request is the one solved, sealed and returned as inputs. The receipt covers the request as it was written, number spellings included, while a seal covers its values: a request sent with 310 and the same request sent with 310.0 give different receipts and the same seal, so a receipt that differs between two such answers is not a sign of tampering. To check a solution later, send this request, or its inputs, and its solution_seal to verify_solution. On this open connection one address holds at most 1 physics permit at a time, and a solve, a dataset job and a run of more than 10000 steps are long work, of which 1 runs at a time: a call that finds no permit or no place is answered "Too many concurrent physics tasks." and is sent again; nothing waits. An answer is waited for 60 seconds.