Skip to main content
Every row in the Axiom Locus data catalog carries a uniform set of metadata columns called the APRS envelope (AI-Ready Public Record Standard). The envelope makes it possible to deduplicate records, sync incrementally, cite sources, join across datasets, and feed data directly into ML pipelines.

​
Envelope columns

All catalog tables include these columns:
ColumnTypeDescription
record_idtextStable URN for the source document. Format: urn:aprs:record:{namespace}:{source}:{id}
chunk_idtextDeterministic SHA-256 URN for vector indexing. Format: urn:aprs:chunk:{hex}
source_systemtextOriginating system name (e.g. granicus, aisstream, derived).
source_uritextURL or URN pointing to the original upstream record.
schema_versiontextSemver-tagged APRS profile (e.g. aprs.civic/1.0.0).
normalization_versiontextSemver of the normalization pipeline that produced this row.
acl_tiertextAccess tier: research, commercial, or internal.
occurred_attimestamptzWhen the real-world event happened.
ingested_attimestamptzWhen Axiom first ingested the record.
modified_attimestamptzWhen the record was last updated in Axiom.

​
Schema profiles

Each data domain uses a versioned schema profile in schema_version:
ProfileDomain
aprs.civic/1.0.0Civic records (meeting minutes, ordinances, filings)
aprs.permits/1.0.0Building permits
aprs.events/1.0.0Axiom-curated events
aprs.urban/1.0.0Cell-level urban scores
aprs.maritime/1.0.0AIS positions and vessel visits
aprs.complaints/1.0.0311 service requests
aprs.poi/1.0.0Points of interest

​
Record ID format

Every record_id follows a deterministic URN pattern so the same real-world record always maps to the same identifier: 
urn:aprs:record:{namespace}:{source_system}:{local_id}
For example:
  • urn:aprs:record:civic:granicus:12345 — a civic record ingested from Granicus
  • urn:aprs:record:maritime:vessel_visit:9434210:USLAX:7891 — a vessel visit keyed by IMO, port, and visit ID

​
Access tiers

The acl_tier column controls data visibility:
TierDescription
researchPublicly available data suitable for research and analysis.
commercialLicensed data available to commercial-tier subscribers.
internalAxiom-internal data not exposed through APIs.

​
Querying with envelope fields

You can use envelope columns to filter, sort, and join across any Locus table. For example, to find recently ingested records from a specific source: 
select *
from building_permits
where source_system = 'socrata'
  and ingested_at > now() - interval '7 days'
order by ingested_at desc
limit 100;
To join records across tables by time window: 
select bp.record_id, cr.record_id
from building_permits bp
join civic_records cr
  on bp.occurred_at::date = cr.occurred_at::date
  and st_dwithin(bp.geom, cr.geom, 500)
where bp.acl_tier = 'research';

​
Compliance enforcement

Every change to collectors, edge functions, and migrations is validated against the APRS standard before it can be merged. The compliance pipeline runs three checks:
  1. Shape check — verifies that every catalog table with data has envelope coverage tracked. If a table has rows but no record_id population metrics, the change is blocked.
  2. Runtime compliance — samples the last 500 rows per table and validates them against nine APRS rules (valid URN format, non-null source_uri, valid timestamps, correct acl_tier, temporal ordering, and schema version format). Tables below 95% compliance with critical issues block the change.
  3. Static analysis — flags collector files that write to catalog tables without importing the envelope function. This check is advisory and posts a warning rather than blocking.
These checks run automatically — you do not need to trigger them. If you query Locus data through the API, every record you receive has passed these validations.

​
Coverage

The APRS envelope is present on all tables registered in the Locus data catalog. Envelope columns are populated automatically for new records at ingestion time. Historical records are being backfilled progressively — check modified_at to confirm a row has been fully normalized.