MVP Acceptance¶

This document locks the first implementation target for dag-ml-data. It supports the UC6/UC11 target in dag-ml without taking ownership of ML phases or OOF decisions.

Boundary Confirmation¶

Owned by `dag-ml-data`	Owned by `dag-ml`
`DatasetSchema`, source descriptors and semantic axes	`GraphSpec`, nodes, ports and edge contracts
`RepresentationSpec`, `ModelInputSpec` and `AuxInputSpec`	phase flow and executor scheduling
`DataView`, `PresenceMask` and `SampleRelation`	fold construction and fold membership decisions
`DataTypeRegistry`, `AdapterRegistry` and path solving	OOF prediction joins and leakage refusal
`DataPlan` construction and validation	model selection, refit and replay orchestration
alignment, feature fusion and late collation contracts	prediction stores and lineage graph
schema fingerprints and plugin version requirements	bundle-level acceptance/refusal decisions

dag-ml-data may declare fit scopes and sample relations. It must not decide that train predictions are safe for downstream training.

First Acceptance Target¶

The data-side MVP is the minimum needed for dag-ml UC6 and UC11 fixtures:

Capability	Expected result	What it proves
canonical schema parsing	multi-source schema validates and fingerprints deterministically	replay can compare schemas across runs/languages
`ModelInputSpec` contract	a model can declare accepted representations and fusion defaults	planning is model-driven, not hardcoded to NIRS
`AdapterRegistry` path solver	source representation resolves to `tabular_numeric` through declared adapters	custom data types can be added without changing `dag-ml`
`DataPlan` validation	plan contains `materialize -> adapt* -> align -> join -> collate` steps as needed	execution can be audited before runtime
`SampleRelation` exposure	group/origin/sample mappings are available to `dag-ml`	group splits and augmentation checks can be enforced outside the data layer

Required `dag-ml-data` Work Before Full Executor¶

Item	Acceptance check
`ModelInputSpec` and input ports	specs serialize to stable JSON and reject invalid ports
`AdapterSpec` and registry	duplicate adapters are refused and candidates are deterministic
path solver	returns the cheapest non-lossy path unless policy allows lossy adapters
`DataPlan` shape	output representation and every step input/output is explicit
schema fingerprint	source and sample ordering do not change fingerprints
C ABI helper	schema fingerprint plus coordinator identity/target/feature Arrow exports are callable from C ABI

Non-Target For MVP¶

actual file readers;
GPU tensor collation;
full production provider-backed Arrow buffer/view implementation;
nirs4all SpectroDataset connector;
domain-specific adapter defaults.

Green Gate¶

cargo fmt --all --check
cargo clippy --workspace --all-targets -- -D warnings
cargo test --workspace
cargo run -p dag-ml-data-cli -- fingerprint-schema examples/minimal_schema.json
cargo run -p dag-ml-data-cli -- plan-model-input --schema examples/fixtures/oof_campaign/schema_nir_6_samples.json --model-input examples/fixtures/oof_campaign/model_input_tabular_numeric.json --adapters examples/fixtures/oof_campaign/adapter_registry_signal_to_tabular.json --id nir-to-tabular --source nir
cargo run -p dag-ml-data-cli -- fingerprint-plan examples/fixtures/oof_campaign/expected_data_plan_nir_to_tabular.json