DATA CONTRACT AND COVERAGE SANDBOX / V126
Validate structure before analysis.
Exercise nine public synthetic fixtures across schema drift, grain, cardinality, duplicate keys, table hashes, missingness, and explicit coverage denominators.
- Synthetic fixtures
- 9
- Declared schemas
- 9
- Grain contracts
- 4
- Remote writes
- 0
Name schemas, native keys, grains, and expected multiplicity.
Block incompatible structure before any ratio is shown.
Build Common and Union sets from unique declared join keys.
Keep left, right, and union coverage meanings separate.
STRUCTURE-FIRST WORKSPACE
Inspect one contract failure at a time.
Every fixture is synthetic, immutable, and bundled with the public release.
Current-tab only. Bundled synthetic data has not been uploaded, transmitted, or stored.
Choose a bundled structural case.
A declared schema, equal grain, and one-to-one keys permit coverage calculation.
VALID
All declared structural contracts pass.
- Declared
- one-to-one
- Observed
- one-to-one
- Coverage
- Available
- Schema
- Leak
- Hash
- Native keys
- Grain
- Cardinality
Schema, grain, and join contract
clean-site-one-to-onecontext-site-v1
| Field | Type | Required | Key |
|---|---|---|---|
site_alias | string | Yes | Native |
context_class | enum | Yes | - |
metric-site-v1
| Field | Type | Required | Key |
|---|---|---|---|
site_alias | string | Yes | Native |
metric_id | string | Yes | - |
metric_value | number|null | Yes | - |
- Left grain
site.v1site_alias- Right grain
site.v1site_alias- Join keys
site_aliassame-grain- Cardinality
one-to-onedeclared before join
Common Set
Unique declared join keys present on both sides.
Common keys
4 unique keysSYN-S01SYN-S02SYN-S03SYN-S04
Left only
0 unique keysNo unmatched left keys.
Right only
0 unique keysNo unmatched right keys.
Union Set
Unique declared join keys present on either side.
Union keys
4 unique keysSYN-S01SYN-S02SYN-S03SYN-S04
- Left unique
- 4
- Right unique
- 4
- Common
- 4
- Union
- 4
Coverage
The same numerator answers three different denominator questions.
4 common / 4 left unique keys
4 common / 4 right unique keys
4 common / 4 union keys
Missingness is not zero.
Absent or null metric evidence stays missing under every fixture.
- Right records
- 4 synthetic input records
- Missing metrics
- 0 null or absent metric value
- Numeric zeros
- 0 observed literal zero only
- Zero fill
- Forbidden
false in the handoff contractA joined null is retained as missing evidence. No UI view, export, or coverage calculation coerces it to a numeric zero.
Deterministic handoff
Exports preserve the validation state without carrying synthetic records or alias values.
semiagora.data-contract-coverage-handoff.v1Included contract fields
schemareleasefixtureIdschemaspublicAliasRulesmetricContractsgrainContractjoinContracttableHashesvalidationStatecoverageDenominatorsmissingnesssyntheticReproductionStepslimitations
Explicitly excluded
rowsleftRowsrightRowsrawDataaliasValuesproductionIdentifiersprivateSchemainternalAliasMap
Current export state
- Fixture
clean-site-one-to-one- Validation
VALID- Coverage ratios
- Included
- Record payload
- Excluded
SYNTHETIC STRUCTURE BOUNDARY
A valid join is not proof of scientific validity.
Every displayed identifier and value is synthetic. Structural validation does not establish measurement quality, causality, statistical adequacy, model validity, process fitness, or production readiness.