Artifacts

An artifact combines a payload with metadata describing its identity, type, integrity, and lineage. Provium supplies JsonArtifact; applications can define their own formats with a reader, writer, and artifact class.

Define a custom type

import struct

from provium import Artifact, ArtifactReader, ArtifactWriter

INTEGER = struct.Struct(">q")


class IntegerReader(ArtifactReader):
    def read(self) -> int:
        return INTEGER.unpack(self.body.read(INTEGER.size))[0]

    def inspect(self) -> object:
        return {"value": self.read()}


class IntegerWriter(ArtifactWriter):
    def write(self, value: int) -> None:
        self.body.write(INTEGER.pack(value))


class IntegerArtifact(Artifact[IntegerReader, IntegerWriter]):
    reader = IntegerReader
    writer = IntegerWriter

Typed calls such as IntegerArtifact.open() can read these artifacts directly. The optional inspect() method supplies body details for provium inspect --body. Its return value is rendered as JSON when possible, with unsupported objects represented using repr().

Register a stable identifier

Registration is optional. Register a type when you want a stable identifier, aliases, or dynamic loading through provium.open_artifact():

from provium import ArtifactCatalog

from .artifacts import IntegerArtifact

catalog = ArtifactCatalog()
catalog.register("example.IntegerV1", IntegerArtifact)

Expose the catalog through a package entry point:

[project.entry-points."provium.catalogs"]
example = "your_package.catalog:catalog"

Without registration, Provium stores the artifact class's full import path as its identifier.