DOWNLOAD_DESIGN.md

EmbodiChain report asset download design

Status: design only. The dataset is initialized with documentation and an empty index. The interfaces in this document do not exist yet, and existing benchmark scripts retain their current behavior. The first real asset publication will provide the inputs needed to implement and validate those interfaces.

Goal and ownership

All EmbodiChain benchmark families use one protocol for report-specific input assets from the public dataset DexForceAI/embodichain_reports. Benchmark implementations and suites remain in GitHub; reusable robot/scene assets and model weights retain their existing resolvers and repository ownership.

The common downloader will belong to the benchmark utilities under scripts/benchmark/tech_reports/assets/, with the benchmark command wired through the existing scripts.benchmark.__main__ dispatcher. It will use the project's existing huggingface_hub>=0.35.3,<1.0 dependency. No dependency change, runtime implementation, benchmark adapter, or new benchmark result format is part of this initialization.

Preparation flow

selected benchmark / suite
  -> declared report input bundle IDs (none: no report-repository request)
  -> selected revision resolved once to a full Hugging Face commit SHA
  -> index.json from that exact commit
  -> only the selected bundles' files from that same commit
  -> file-size and SHA-256 verification
  -> local asset paths and provenance
  -> benchmark initialization, warmup, then measured execution

Preparation finishes before simulation/planner initialization and all timed regions. Downloads, index processing, hashing, and repair are excluded from benchmark latency and memory measurements. Existing benchmark timing, quality thresholds, and report/leaderboard contracts remain unchanged.

Only benchmarks or suites explicitly declaring report input bundle IDs use this repository. A benchmark using only existing common assets or generated inputs must not acquire a new report-repository dependency. Report-specific suite declarations will be added with their first real bundles; no speculative declarations are added now. Direct Python entry points and the unified CLI must eventually call the same preparation helper.

Asset index

The root index.json initially contains exactly:

{
  "schema_version": 1,
  "bundles": {}
}

bundles maps stable bundle IDs to input bundle entries. An empty mapping means there are no downloadable bundles; it is a valid initialized repository, not a signal to invent or download a default bundle.

Each future entry has these fields:

Field	Meaning
report_id	Stable report directory ID, for example technical-report-v1.
benchmark_id	Benchmark identity, for example motion-generation.
files	Nonempty list of the exact input files required by this bundle.
files[].path	Repository-relative POSIX file path under reports/<report_id>/inputs/<benchmark_id>/.
files[].size_bytes	Nonnegative integer byte count of the file.
files[].sha256	SHA-256 of the file bytes, as 64 lowercase hexadecimal characters.

For example, a future bundle named technical-report-v1-motion-generation-inputs could contain reports/technical-report-v1/inputs/motion-generation/cases.npz. This is a naming example only; no such bundle or file exists at initialization.

IDs use lowercase letters, digits, hyphens, or underscores and must start with a letter or digit. Paths must be normalized relative file paths without .., empty components, backslashes, or URL schemes. Duplicate file paths within an entry are invalid. Reject unsupported schema versions, malformed entries, unknown bundle IDs, and mismatched report/benchmark path prefixes before downloading bundle files. Results, figures, and videos live outside input bundles and are retrieved separately when requested.

Versions, authentication, and cache

• Dataset requests use repo_type="dataset", the fixed repository ID, and the official endpoint https://huggingface.co. Existing common-asset mirror settings do not select the endpoint for this report repository.
• The future benchmark integration supplies a tested full dataset commit SHA as its default. There is no default asset revision to advertise while the index is empty. The Python helper requires revision explicitly.
• An explicit branch or tag resolves to a full commit once before downloading the index. All file requests use the resolved commit; do not mix a pinned index with files from main. Changes to the code or asset pin receive review together when the first report integration is implemented.
• Public reads must work anonymously; a token is not required. If credentials are used, rely on standard SDK discovery (HF_TOKEN or local login), without custom token storage. Publishing requires write access. Do not send credentials to mirrors or include them in diagnostics/provenance. Offline mode consumes locally cached content and makes no remote permission or metadata request.
• Default cache_dir is ~/.cache/embodichain/report-assets; a caller can override it. Use that root as the Hub cache directory so repository and commit snapshots are isolated by the SDK's normal cache layout. Returned paths are read-only inputs and may use the SDK's normal blob symlinks.
• Offline mode accepts a full commit or a locally cached revision reference. Resolve cached references without a network request. If the reference, index, or any required file is absent, fail with the missing identifier and the corresponding pre-download command. Do not silently select another commit or partially run a benchmark.
• Reuse SDK download locks and interrupted-download handling. Expose bundle paths only after every required file passes byte-size and SHA-256 checks; a partially downloaded bundle is never ready. Concurrent consumers validate their requested bundles before proceeding.
• An online checksum failure triggers one forced re-download of the affected file through the SDK, followed by revalidation. A second failure terminates preparation. Offline corruption terminates immediately. Do not hand-edit Hub cache files or return unverified inputs.

These policies build on the official download API and cache layout.

Proposed interfaces

Python

Future interface, not available in this change:

from pathlib import Path

def download_report_assets(
    bundle_id: str,
    *,
    revision: str,
    cache_dir: str | Path | None = None,
    local_files_only: bool = False,
) -> tuple[Path, dict[str, object]]:
    ...

The path is the downloaded snapshot's reports/<report_id>/inputs/<benchmark_id>/ directory. Only files explicitly listed in the bundle are guaranteed to be present. The metadata records repo_id, resolved revision, bundle_id, report_id, benchmark_id, the index SHA-256, and each file's path, verified size, and SHA-256. Benchmarks save that provenance with existing run metadata; local paths are not source IDs.

Failures distinguish invalid index/bundle selection, unavailable credentials or repository permission, missing cached files, unavailable remote revision or file, transport errors, and checksum mismatch. Preparation failure exits nonzero before timing; it is not counted as an algorithm success or failure.

CLI

Future commands, not runnable in this initialization:

embodichain benchmark assets list --revision <dataset-commit>
embodichain benchmark assets download <bundle-id> --revision <dataset-commit>
embodichain benchmark assets download <bundle-id> --revision <dataset-commit> --offline

Both subcommands support --revision, --cache-dir, and --offline. The CLI uses a tested pin when a future integration defines one; otherwise require --revision. list reads only the index and displays bundle/report/benchmark IDs and total input bytes. An empty index is a successful empty list. download calls the same helper used by benchmark preparation and prints the local bundle path and resolved commit. Unknown IDs fail nonzero and list available IDs. --offline maps to local_files_only=True for every file request and also disables online revision resolution.

Publication and adoption

Upload real report inputs, the report README, and index entries together, then verify downloads at the resulting dataset commit. Reference that commit from the report release metadata and a future reviewed benchmark integration. Report READMEs record the code commit, exact run commands, benchmark settings, seeds, environment, sources, and per-file licensing. Subsequent dataset commits preserve earlier snapshots for report reproducibility.

Adopt the shared helper only where actual report input dependencies exist. Motion generation/Atomic Skills, kinematic solvers, grasp generation, workspace, RL, rendering, scene, data-pipeline, and other benchmark scripts can use the same protocol without forcing an input bundle onto workloads that do not need one. Model access remains subject to the model repository's existing requirements.

The initialization ships only README.md, DOWNLOAD_DESIGN.md, and the empty index.json. It creates no placeholder report directories, release tag, sample asset, model copy, or automatic publication job. Repository visibility changes and historical asset migration require separate work.

Validation

Initialization acceptance checks:

• Repository owner is DexForceAI, type is dataset, and visibility is public.
• The authorized account can read all three files at the committed SHA and retrieve exactly the uploaded bytes.
• Anonymous metadata and file requests can read the repository contents; publishing still requires write authorization.
• index.json parses to schema version 1 with an empty bundles mapping; Markdown links and layout examples are consistent.

Future implementation tests, with fake Hub clients for protocol failures and a separate real selected-bundle download check:

Scenario	Required outcome
Cold cache	Fetch pinned index and only the selected input files; verify all hashes.
Anonymous access	Public metadata and input files download without a token.
Warm cache	Reuse the same commit snapshot without re-downloading file bodies.
Offline complete cache	Read index and files without any network request.
Offline missing ref/index/file	Fail before benchmark initialization with a pre-download hint.
Version isolation	Two commits cannot mix index or input bytes, including when a tag moves.
Concurrent/interrupted downloads	SDK locking/recovery leaves no partial bundle exposed as ready.
Corrupt input	Detect size/hash mismatch; repair once online or fail immediately offline.
Invalid index	Reject unsupported schema, duplicate/unsafe paths, malformed fields, or unknown IDs.
Permission/revision/network failure	Give a specific actionable diagnostic and exit nonzero before timing.
No declared report dependencies	Make no request to the report repository.
Measurement boundary	Fetching, hashing, and repair never enter latency/memory samples.
Provenance	Save actual resolved dataset commit and verified file identities without credentials.

No runtime tests or performance claims are added by this documentation-only initialization. Existing benchmark output schemas and rankings are preserved.