Altar Cherimoya binding

altar-cherimoya is the lightweight control-plane binding between Altar and the Cherimoya variant-effect runtime. Installing it registers CHERIMOYA in the canonical altar.model_plugins discovery group.

The binding owns Cherimoya's artifact schema, score schema, prioritization predicate, resource requests, and backend-neutral container plan. It does not import PyTorch, Cherimoya, a model registry, object-storage SDK, or compute-provider SDK. The heavyweight cherimoya-score CLI and independently locked image live under runtimes/cherimoya in this repository.

pip install altar-cherimoya

from altar.models import get_model_plugin

plugin = get_model_plugin("CHERIMOYA")

CherimoyaConfiguration.image defaults to the immutable runtime digest tested with the installed binding. Callers may override it with another name@sha256:<digest> image reference; mutable tags remain invalid. Its weights tuple contains one generic ResourceReference per fold, each with a required SHA-256 digest. The URI may be local, HTTPS, GCS, S3, Hugging Face, or any other location understood by the selected storage adapter. The digest, not the location, defines scientific identity. Mutable images and unidentified weight bytes fail validation before a plan can be built.

The binding emits one GPU scoring task per weight resource followed by one CPU summarize task. Every weight is staged to a stable logical path, and the runtime receives only that mounted path and expected digest. It does not download weights or know which provider stored them.

The runtime streams large variant files in fixed outer batches and validates CATv1's single-track output contract. profile_l1 is defined over softmax-normalized profile distributions.

The tests compose altar.testing.ModelResultContract and ContainerScorerContract and fake only the outer Modal and Kubernetes clients, so they verify both result semantics and the plan/fan-in contract without an ML framework, cloud account, cluster, GPU, or image pull.