Mesh a design with GD Structured or GD Unstructured. Standard CGNS export by default; explicit GD CGNS, .msh or OpenFOAM exports. Memory-limited compute: usually a few minutes and under 2 credits; estimate_cost gives the figure. Not needed when an owned mesh for the same geometry and settings already exists and the user accepts reuse. Create a new mesh job per request with a fresh idempotency key. Reuse old compute only when the user requests or accepts reuse. Re-meshing a surface within 24 hours is a retry; on retry_not_allowed ask the user. Same-job transport recovery keeps its key; a reviewed new attempt uses reviewed_job_id and a fresh key. Default retry_policy=review stops after one full attempt; do not silently retry a completed or failed mesh. A verified count miss returns awaiting_decision; report evidence and use review_job to accept/discard, or obtain explicit authority before new compute. Use this job's mesh_cgns for views. For a generic view use view_mesh or the default interactive 3D browser viewer (cell surfaces, quality metrics, true slices); PNGs or 2D sections alone are insufficient. Mesh an owned ready geometry artifact. Structured requests select engine=structured; generic unstructured requests prefer engine=octree_prism when configured; export_formats selects files independently of the engine. Default [cgns] delivers Standard CGNS NGON/NFACE. Preserve an explicit format choice. get_job.mesh_exports identifies the primary downloadable artifact; retain mesh_cgns for views and Fluxcore simulation. All engines default to ±30% cell-count tolerance; omit cell_count_tolerance unless the user asks for another. get_request_schema(mesh) has the full schema; inspect_mesh_geometry gives bounds and assessed component IDs when available. Before an octree mesh, check_geometry finds holes and other surface problems, and plan_mesh shows the sizes, predicted cells and any refusal, without compute. Solid-only uses structured.workflow=solid and flow_region={kind: solid, component_id: inspected ID}; no fluid box is required. Never switch solid/internal/external/CHT intent to bypass a failure. Ask about consequential preferences such as stair_step/cut_cell and boundary layers; otherwise use disclosed best judgment. For an external octree mesh, state intent in octree_prism.controls (flow, wake, layers) and leave sizes out unless the user gives them: the mesher resolves the rest from the geometry, and other octree fields override what it resolves. get_mesh_controls lists surface, volume/wake, layer, topology and boundary settings. Structured has no prism layers; octree controls.boundary_layer.layers=0 and openfoam.n_prism_layers=0 disable layers. For an already-enclosed fluid STL or STEP surface, use octree_prism.workflow=internal with explicit geometry bounds, minimum/maximum spacing and at least one prism layer; cht_ports are points near flat inlet/outlet faces. It meshes only the enclosed fluid and keeps its boundary; MRF zones are not supported. Optional internal_small_feature_size is an explicit meter-valued cutoff for removing tiny disconnected boundary shells, including solid islands; disclose this geometry simplification and keep it omitted unless requested or accepted. A disconnected fluid source is refused by default; internal_component_policy=largest_connected explicitly keeps its largest fluid volume and reports excluded pockets, while refusing nested cavity shells or ambiguous equal volumes. Octree CHT needs the STEP's actual material names and an explicit n_prism_layers: 0 for the octree CHT route, more for prism layers on the coolant walls (a fluid region named with fluid or coolant, and cht_ports near the inlet and outlet; sizes are absolute). Meshing admission is memory limited. Record assumptions in decision_context. At most 50 million cells. Use artifact summaries to inspect patches/zones before simulation. Each person runs one meshing job at a time; a further one waits, and its queue.message says why: tell the user rather than resubmitting. Returns a job ID; may incur compute charges.