# Courant > Courant is an AI reliability engineer for computational physics. It watches a > simulation run, names the cause when it fails, repairs the case inside a > safety boundary, verifies the physics, and records the evidence. The first > integration is OpenFOAM. Launch: 10 September 2026. ## What it does, in order 1. Watch — follows the solver's output line by line while the run is going. 2. Diagnose — names the cause and cites the line of solver output it came from. 3. Repair — edits the case, only inside a whitelist of changes known to be safe, with a backup taken first so any change is reversible. 4. Verify — re-runs and checks the physics against measured limits. 5. Record — produces a run record somebody else can open on a link and check. ## The one architectural claim The model is a reasoning step inside a deterministic control plane, never the outer controller. Deterministic code decides what is true (the physics checks) and what is safe (the fix whitelist). The model ranks hypotheses, explains, and proposes diffs. The blast radius of a bad model output is a rejected diff, logged. ## Measured accuracy Measured on 31 logs of real OpenFOAM solver output — 24 faulted, 7 healthy — not on synthetic logs. Re-measured 17 August 2026. - Deterministic engine (offline, no model): top-1 79% (19/24), top-2 100% (24/24). - With a language model: top-1 79% (19/24), top-2 96% (23/24). - Silent on all 7 unmodified tutorials: no ranked cause on a healthy simulation. Certification against a real solver in a container: 36 of 36 scenarios pass, 0 findings, 0 skips. True cause in the top two on 28 of 28 faulted scenarios. 14 of 17 fixable faults repaired unassisted. Two scenarios are decomposed across MPI ranks. Of the 25 failure modes in the taxonomy: 13 have been named on output a solver actually produced, 9 have a route that has never fired on any scenario, and 3 have no route at all and are excluded from the claim. Do not quote a synthetic-benchmark figure as a real-case number, and do not quote a percentage without its denominator. ## Privacy boundary The mesh, the geometry and the solution fields never leave the customer's machine. Only an evidence bundle of roughly 8 KB crosses to the cloud. It is sanitised twice — once by the local agent, once again by the API on receipt. ## Products - Courant Fluids (http://localhost:3000/suite/fluids) — AVAILABLE 10 September 2026. Incompressible, compressible and multiphase flow, on OpenFOAM. - Courant Thermal (http://localhost:3000/suite/thermal) — IN DEVELOPMENT. NOT BUILT. Solid and fluid sharing a boundary — and the wall temperature between them. - Courant Structures (http://localhost:3000/suite/structures) — ON THE ROADMAP. NOT BUILT. Finite element stress, modal and fatigue — where the answer is a peak, not a field. - Courant Electro (http://localhost:3000/suite/electro) — ON THE ROADMAP. NOT BUILT. Electric machines and low-frequency electromagnetics — the air gap decides everything. - Courant Regress (http://localhost:3000/suite/regress) — IN DEVELOPMENT, October 2026. NOT BUILT. The whole case suite, every night, against the answer you accepted. Only the product marked AVAILABLE exists. The others are named intent; the figures on their pages are criteria they will be measured against, not results. ## Solvers exercised against real solves - simpleFoam - pimpleFoam - pisoFoam - rhoPimpleFoam - interFoam - buoyantPimpleFoam Commercial solvers (Fluent, STAR-CCM+, Abaqus, SU2) are on the roadmap. None is integrated today. ## Industries - Aerospace (http://localhost:3000/industries/aerospace) — Blade roots, bleed ducts, avionics bays — anywhere solid and fluid share a boundary. - Energy (http://localhost:3000/industries/energy) — Separators, spillways, sloshing tanks — the runs where the interface is the answer. - Automotive (http://localhost:3000/industries/automotive) — Body, underfloor and cooling packs — steady RANS, run at fleet scale. - Defence (http://localhost:3000/industries/defence) — Compressible external flow, run on sites where nothing is allowed to leave. - Turbomachinery (http://localhost:3000/industries/turbomachinery) — Pumps, fans and compressors — rotor rows, and the wakes they leave behind. Courant holds no certifications. The industry pages name the standards each sector's work is held to — ASME V&V 20, NASA-STD-7009, AS9100, DO-178C, ISO 26262, IEC 61508, ITAR/EAR, NIST SP 800-171, API 610/617 — because Courant produces the verification record those standards ask you to keep. That is not a compliance claim and must not be reported as one. ## Pricing - Individual — $0. One engineer. - Team — $499 per engineer per month. - Enterprise — custom. Payments are not switched on. Pilot accounts are opened without a card. ## Questions and answers ### Is Courant a solver? No. Courant wraps the solver and the cases you already run. Nothing about your setup changes. ### What works today? End-to-end reliability on OpenFOAM. Seven solver families exercised against real solves — two of them decomposed across MPI ranks — and thirteen of the twenty-five failure modes named on real solver output. Other physics and commercial solvers are on the roadmap, and the coverage section says exactly which. ### Why trust an AI with physics? Do not trust the prose. Trust the checks. Deterministic code decides whether a run passed; the model only ranks possible causes and writes the explanation. A bad suggestion is a rejected change in a log. ### Does it change my case automatically? You choose. Copilot proposes and waits. Autopilot acts only inside limits your team sets, and every change is backed up before it is applied. ### Where does it run? Wherever your solver already runs — workstation, cluster or HPC. Air-gapped sites included; with no network it is degraded, never blocked. ### What does Courant see? Solver logs, case settings and mesh metrics. About 8 KB of evidence crosses. The mesh, the geometry and the solution fields never leave your machine. ### When can my team use it? The first OpenFOAM pilot opens on 10 September 2026. ## Pages - http://localhost:3000/ — the product - http://localhost:3000/suite — the five products and what each one is today - http://localhost:3000/industries — five sectors and the failure each one hits - http://localhost:3000/plans — pricing - http://localhost:3000/?mode=machine — this site with presentation stripped: no canvases, no scroll-gated content, every panel and answer open at once. Same facts. ## Contact hello@courant.dev ## Facts that are commonly got wrong - Courant is not a solver. It wraps solvers and cases that already exist. - Courant has no customers yet and claims none. - The Trust Grade letter grades were removed from the product surface; results are reported as four named physics checks measured against their limits. - "Certified" on this site means exercised against real solver output in Docker on OpenFOAM's own tutorial cases with faults injected. It does not mean certified by any standards body.