Courant
Physics acceptance testing for machine-produced simulation. Courant is a read-only, deterministic gate between a simulation (an AI agent's or an engineer's) and the person who signs it. Without a task specification it decides whether an OpenFOAM run is valid; with the task the run was asked to solve, it decides whether the run is the problem that was asked.
Every verdict is accept, reject or insufficient, and every reason cites the file it read,
the method, the threshold and the value. Deterministic code decides every verdict; no language
model is in the verdict's path. Courant never edits a case, never runs a solver, and its checks
never use the network.
Licensed under the Apache License 2.0.
Install
pip install 'courant-dev[mcp]' # Python 3.11 or later; the command is `courant`
The distribution is named courant-dev (PyPI's courant is an unrelated project); the import
package and the commands are courant and courant-mcp.
A single-file binary for Linux and macOS, which needs no Python, is attached to every
release, with SHA256SUMS and its Ed25519
signature:
curl -fsSL https://github.com/courantdev/courant/releases/latest/download/install.sh | sh
The installer checks the binary's SHA-256 against the release's SHA256SUMS, and the signature
of SHA256SUMS against the release key it carries when python3 with the cryptography package
or OpenSSL 3 is on the machine. With neither, it says that only the checksum was checked and how
to check the signature by hand; COURANT_REQUIRE_SIGNATURE=1 makes it refuse instead.
courant update installs nothing unless the signature verifies against the key built into the
binary.
Try it offline
These run on the real OpenFOAM runs that ship inside the package, with no network:
courant demo # four real runs and an HTML report
courant verify --about # the error rates published for this version
What it does
| Command | What it does |
|---|---|
courant verify <case or log> |
accept, reject or insufficient (exit 0, 2 or 3; courant.verdict/2), with the basis it was judged on and what was not checked. --spec with --spec-sha256 checks every value a task specification names against the case. --html, --report md, --json, --pack and --check-pack (an evidence pack anyone can re-derive), --batch with --junit, --record, --about |
courant spec init / hash / check / lock / confirm / extract |
Draft a task specification from a reference case, lock it by hash, and check a case against it before or after its run |
courant gate |
The CI check, and the GitHub Action: verify the runs a repository names, one summary row per run, one evidence pack per run |
courant preflight <case> |
A broken setup, caught before the solver spends anything |
courant convergence <case> |
Where the monitored answer stopped changing, and the iterations, wall clock and core-hours after it |
courant watch <case> |
A read-only live advisory while the solver runs, with --exit-on-fail for job scripts |
courant audit <dir> |
What a folder of runs cost, and how much of it bought nothing |
courant test run --judge … |
The Courant Test: score any judge, including an AI model, on real OpenFOAM runs |
courant mcp |
The same tools for any AI agent over MCP, read-only and confined to the directories named; score_agent_output tells an agent, before it reports, whether its run is a silent error |
courant doctor, courant update, courant version |
Diagnostics and a support bundle you send yourself; a signed update of the binary |
The checks never use the network. A command contacts something only when that is its purpose
and you ran it, and it names the host first: courant update (github.com), courant doctor --models, and a language model you name
(NETWORK.md). Start with
GETTING-STARTED.md.
What is measured
On OpenFOAM v2406, with every figure carrying its denominator (courant verify --about prints
the rates that ship with each version):
- Detection: 31 of 31 real runs judged correctly. 0 of 23 wrong results accepted and 0 of 8 good results rejected.
- The wrong problem: on 20 real runs with the right physics and a wrong input (inlet doubled, viscosity tripled, gravity rotated, geometry scaled, end time cut), the verdict without a specification rejected 8 of 20; against the task specification, 20 of 20.
- Before the run: preflight caught 8 of 23 broken setups, and flagged 0 of 8 good ones.
- Fixed budgets: where the answer settled, 1,023 of 1,999 iterations (51.2%, pitzDaily) and 547 of 999 (54.8%, T3A) came after it.
- Reproducible: evidence packs re-derive byte for byte, 31 of 31.
"Certified" here means measured against a real solver, with the error rate published. It is not a regulator's approval. Courant has no account, no telemetry and no service of its own.
Contributing and security
See CONTRIBUTING.md and SECURITY.md.
Copyright 2026 Shivanshu Dwivedi (Courant, https://courant.dev)
1 maintainer
Metadata
1 maintainer
Release files for courant-dev 0.5.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| courant_dev-0.5.0.tar.gz | 2.3 MB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| courant_dev-0.5.0-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 4.7 MB
Release files / courant_dev-0.5.0.tar.gz
| Download URL | courant_dev-0.5.0.tar.gz |
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| Size | 2.3 MB |
| Tags | Source |
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