Technical trust
Exabasis binds exact calculations to source facts, dated authority, and historical cutoffs, keeps review attribution attached to the close, and preserves the approved evidence as a versioned release.
Evidence lineage
Each stage fixes the coordinates needed by the next. The result can therefore be reviewed from retained evidence instead of reconstructed from today's mutable state.
01
Sealed rows and durable identities
02
Dated entity and asset evidence
03
Year-pinned authority and tables
04
Exact value with a stable address
05
Approved, hashed evidence package
Published tax evidence
PUBLICATION 946
TABLE A-1
Apply the published five-year, 200% declining-balance, half-year percentages to $100.00 of depreciable basis. The half-year convention produces six recovery rows, and their exact total returns to $100.00.
| Recovery year | Published rate | Deduction | Recovered to date |
|---|---|---|---|
| 1 | 20.00% | $20.00 | $20.00 |
| 2 | 32.00% | $32.00 | $52.00 |
| 3 | 19.20% | $19.20 | $71.20 |
| 4 | 11.52% | $11.52 | $82.72 |
| 5 | 11.52% | $11.52 | $94.24 |
| 6 | 5.76% | $5.76 | $100.00 |
Exact boundary · 40% test
40%
Exactly 40% in the fourth quarter does not trigger mid-quarter.
41%
41% crosses the boundary and triggers mid-quarter.
The candidate basis is measured after section 179 actually elected and after non-business use, with the regulatory exclusions removed from the population.
Published corpus
Tables A-1–A-5, A-6, and A-7a
All 1,152 transcribed IRS percentages are checked. The published cells remain authoritative data, while computed schedules are compared at the publication's precision and must recover the exact basis total.
Primary source: IRS Publication 946, Appendix A
Data integrity
Financial precision, temporal identity, immutable history, and content hashes work together so a reviewed result remains the result that was actually reviewed.
01
Money and rates use decimal values, checked operations, and named rounding. Release documents preserve financial values as strings.
02
Valid dates describe when a fact applies in the world; database-owned recording times describe when the system knew it.
03
A correction adds a new attributed event linked to the event it replaces. Historical projections continue to resolve at their original cutoffs.
04
Canonical documents carry SHA-256 hashes. Projection, workpaper, and approved-release reads verify retained content, while sealed source hashes preserve lineage.
Access and review
Workspace scope, entity visibility, and the required typed permission are resolved inside the same open transaction that reads or changes basis evidence.
Workspace-wide roles use their role scope; entity-scoped roles intersect capability with a live client assignment for each entity-level read and mutation.
Decision reads begin in a transaction, establish workspace scope, and resolve live authorization before evidence is loaded.
Owner, Admin, and Reviewer roles require an enrolled authenticator; time steps are single-use and recovery codes are hash-only.
Browser writes require the exact configured origin and a CSRF value derived from the live session.
Exact release
exabasis.approved_basis_close.v1 fixes the close coordinates, maker-checker approval, evidence hashes, complete projection documents, source workpapers, limitations, and release attribution.
Before sealing, the server rehashes each projection and the workpaper, replays the sealed shareholder and activity decisions, then hashes the complete canonical JSON. It verifies the release hash again when downloaded.
{
"release_kind": "approved_basis_close",
"format_version": "exabasis.approved_basis_close.v1",
"coordinates": {
"entity_name": "Northstar Operating LLC",
"tax_year": 2026,
"year_end": "2026-12-31",
"knowledge_cutoff": "<ISO-8601 timestamp>"
},
"approval": {
"prepared_by": "<user id>",
"approved_by": "<reviewer id>",
"approved_at": "<ISO-8601 timestamp>"
},
"evidence": {
"annual_close_content_hash": "<SHA-256>",
"source_package_content_hash": "<SHA-256>"
},
"asset_projections": [{
"source_asset_id": "NORTHSTAR-FA-001",
"measurement_basis": "federal",
"as_of_date": "2026-12-31",
"balance_hash": "<SHA-256>",
"balances": {
"cost": "75000.00",
"adjusted_basis": "<exact decimal string>"
}
}]
}