<!-- SPDX-FileCopyrightText: 2026 CoreWeave, Inc. SPDX-License-Identifier: Apache-2.0 SPDX-PackageName: skills -->

W&B EvalTable previews

Use the bundled helper to preview existing wandb.Table data as wandb.EvalTable data. A preview creates new runs and keys; it never overwrites the source runs or tables.

Read references/EVAL_TABLES.md before converting. It is the canonical source for EvalTable semantics, source selection, limits, column roles, verification, and removal.

Environment

Run the helper from an environment that provides a W&B SDK with wandb.EvalTable and Weave. Use uv to supply missing dependencies:

uv run --with 'wandb[workspaces]>=0.28.1' --with weave \
  python skills/wandb-eval-tables/scripts/table_artifact_to_eval_table.py --help

Credentials and default scope may come from WANDBAPIKEY, WANDBENTITY, and WANDBPROJECT; otherwise pass explicit entity/project arguments. Downloads use the operating system's temporary directory, not a fixed current working directory.

Required workflow

1. Choose the narrowest source that matches the request: exact artifact, one

run, one sweep, or a project/workspace. Do not broaden an explicitly named source.

1. Run scan. This is read-only preflight and is not proof of conversion.
2. Review eligiblesummarybytablekey, table shapes, truncations, warnings,

and existing-preview metadata. Select one table key unless the user asks for a broader batch.

1. Classify columns only when confident. Input tuples must uniquely identify

rows; score columns must be numeric or boolean; free-text labels and rationales are outputs. Leave ambiguous tables untyped.

1. Run preview for exactly one --table-key per invocation. Keep the target

in the source project unless the user requests another writable project.

1. If runs were created, run verify-preview on the final created run and the

exact logged key. Report success only when it returns verified: true.

1. Report created and skipped sources plus every truncation or failed check.

T=skills/wandb-eval-tables/scripts/table_artifact_to_eval_table.py

uv run python "$T" scan \
  --source-workspace ENTITY/PROJECT --max-runs 4

uv run python "$T" preview \
  --source-workspace ENTITY/PROJECT \
  --target-project ENTITY/PROJECT \
  --max-runs 4 \
  --table-key predictions

uv run python "$T" verify-preview \
  --run ENTITY/PROJECT/PREVIEW_RUN_ID \
  --table-key predictions_preview

Safety

• scan and preview --dry-run are read-only. preview creates W&B runs,

EvalTables, and Weave evaluations; run it only when the user requested a conversion.

• The helper caps tables at 10,000 rows and 100 columns, warns above 1,000

rows, and refuses more than 50 eligible table artifacts for one key. Surface every cap; never imply a truncated preview is complete.

• Do not bypass helper failures with ad-hoc logging. Narrow or correct helper

arguments, then retry only when the change is safe.

• Removal deletes both Weave evaluations and preview runs. Run

delete-preview --dry-run first, verify every target is helper-created, and obtain confirmation before the irreversible invocation. Never delete source runs.