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v2.0 · maintained with the source

Production inference

driftflow provides the validated sampling runtime and model contract. It does not ship trained GruM or GDSS weights. Production inference therefore requires a separately trained and validated model exported as TorchScript.

Checkpoint contract

The scripted module must accept three inputs:

  1. features: float32 tensor with shape (num_nodes, feature_dim).
  2. adjacency: float32 tensor with shape (num_nodes, num_nodes).
  3. time: scalar float32 diffusion time in [0, 1].

It must return exactly two tensors:

  1. feature drift with shape (num_nodes, feature_dim);
  2. adjacency drift with shape (num_nodes, num_nodes).

The adapter rejects missing checkpoints, digest mismatches, wrong shapes, non-finite outputs, failed inference, and non-production models before the solver can advance a trajectory.

Loading a checkpoint

from driftflow import (
    CommonConfig,
    DvsAdaptiveController,
    DVSSampler,
    GraphState,
    LinearSchedule,
    TorchScriptDriftModel,
    get_dataset_config,
)

model = TorchScriptDriftModel(
    "artifacts/grum-qm9-2.0.0.ts",
    num_nodes=9,
    feature_dim=5,
    device="cpu",
    expected_sha256="<recorded-release-digest>",
)
dataset = get_dataset_config("GruM", "QM9")
sampler = DVSSampler(
    drift_model=model,
    noise_schedule=LinearSchedule(0.01, 0.5),
    controller=DvsAdaptiveController(
        CommonConfig(), dataset, dataset.gamma_euler or 0.0
    ),
    production=True,
)
result = sampler.sample(GraphState.from_lists(features, adjacency), seed=42)

production=True deliberately rejects SimpleGraphDenoiser, GruMApproximation, and GDSSApproximation. Those classes remain available for smoke tests and educational examples only.

Reproducible reference checkpoint

The repository includes a small deployable reference artifact under artifacts/. It is a deterministic synthetic graph-drift model used to prove the production path, not a replacement for the paper's trained GruM/GDSS weights. Rebuild it with:

pip install -e ".[production]"
python scripts/build_reference_model.py --output-dir artifacts
python scripts/validate_reference_model.py --artifact-dir artifacts
python scripts/benchmark_reference_model.py --artifact-dir artifacts --iterations 100

The generated manifest records the checkpoint digest, 4-node/3-feature input contract, canonical feature order, identity preprocessing, training seed, validation loss, parameter count, and eager-versus-TorchScript export error. The checked-in checkpoint is below the 10 MB deployment budget. from_manifest() rejects missing metadata, non-canonical feature order, and unsupported preprocessing before loading the artifact.

The local Apple Silicon baseline is recorded in artifacts/reference-benchmark.json; it is evidence for regression detection, not a production SLO. It includes an independent teacher-quality MSE gate, peak RSS delta, p50/p95/max latency, and concurrent requests per second. Re-run the benchmark on the target host and set service limits from that environment.

The upstream DVS repository is recorded in artifacts/upstream-reference.json. Its published checkpoints are full GruM graph-transformer training artifacts with dataset-specific preprocessing; they are not silently relabeled as this compact reference model. The compact artifact is therefore production-valid for its declared contract, while a GruM/GDSS production claim still requires importing an upstream checkpoint and running the same manifest, quality, and deployment gates against it.

Release gates

Before promoting a checkpoint, record and review:

  • exact model and dataset versions, preprocessing, feature ordering, and graph-size limits;
  • checkpoint SHA-256 and Torch/Python/runtime versions;
  • numerical agreement with the eager reference implementation on a fixed golden corpus;
  • quality metrics on held-out data and adversarial malformed inputs;
  • latency, memory, throughput, and maximum-step behavior under representative load;
  • deterministic replay for a fixed seed and reproducible environment;
  • rollback artifact, monitoring thresholds, and an owner for incidents.

The CI suite verifies package contracts, type checks, coverage, dependency auditing, artifact builds, and the approximation smoke test. It cannot prove model quality or replace checkpoint-specific validation.