Local-first spreadsheet verification for agent workflows

Know whether a recalculated workbook is safe to use.

Recalc Verify opens .xlsx/.xlsm files locally, recalculates without network access, and emits a deterministic, machine-readable report. Unsupported, blocked, and unavailable evidence are refusals—not guessed values.

Get the open-source engine Discuss a production integration

One command, explicit outcome

recalc verify OUTPUT.xlsx \
  --policy recalc-policy.toml --json report.json

Exit 0 is PASS, 1 is a measured FAIL, and 2 is FALLBACK when a safe calculation or requested evidence is unavailable. Reports use recalc.verify.report/v1. Add --baseline BASELINE.xlsx for an explicit local comparison; identified pinned-Excel results remain a separate evidence mode.

Evidence, not adjectives

Computed

Values produced by the engine are reported with workbook and policy hashes.

Compared

Stored values, a supplied baseline, or an explicitly supplied Excel result are labelled separately.

Refused

#UNSUPPORTED!, #BLOCKED!, parse failures, external references, and resource limits remain visible.

A local cached-value match is useful workflow evidence, but it is not an independent pinned-Excel oracle result.

Private by default

The verifier reads and writes only paths you provide. It makes no formula network calls and does not upload workbook content. Diagnostic bundles are explicit and opt-in.

Read the Verify contract Security contact