Glossary

Coverage certificate

A coverage certificate records coverage for one source on one day. It contains a source_id, a partition_date, and a status of complete, partial, or missing. It also includes a row_count, which is JSON null when the status is missing.

Updated 2026-08-26. Corpus figures come from a running server.

The object

{
  "source_id": "sec.edgar",
  "partition_date": "2023-03-10",
  "status": "complete",
  "row_count": 3124,
  "scope": {
    "scope_id": "sec.edgar.forms.v1",
    "selection": "form_allowlist",
    "forms": [
      "10-K", "10-K/A", "10-Q", "10-Q/A", "13D", "13D/A", "13G", "13G/A",
      "4", "4/A", "6-K", "6-K/A", "8-K", "8-K/A",
      "SC 13D", "SC 13D/A", "SC 13G", "SC 13G/A"
    ],
    "scope_sha256": "d17340d6247e3e26ea015c6bcbf5ad5a6f5fa8881f689508455e0b9985e5e2af"
  }
}

A row_count of null means the day was never ingested. A row_count of zero means the day was fetched, but the publisher issued no matching records. For example, EDGAR publishes no daily index on 2023-03-11 or 2023-03-12. Both days have a missing certificate with a null count.

Complete is scoped

A complete status is scoped. It certifies only the form set named in the certificate, not every item issued by the publisher that day. For example, sec.edgar tracks 18 form types from the EDGAR daily index. On 2023-03-10, it certifies 3,124 rows out of 5,461 in the index. Every sec.edgar certificate includes that form set and its scope_sha256 for complete, partial, and missing statuses. A certificate with no scope makes no claim about the publisher’s full row set.

Coverage keys in the envelope

Every API response includes an envelope wrapper. Inside the envelope, coverage.touched and coverage.missing contain coverage keys instead of full certificates. A key uses one of two formats.

Shape	Example	What it identifies
Partition	`sec.edgar/2023-03-10`	One source, one UTC day.
Identity	`identity.ticker/FB@2023-03-10`	One ticker’s identity, one UTC day.

Tickers contain no /, so partition keys and identity keys do not collide. Both use daily granularity. If a key appears in missing, its count is JSON null.

An identity key in missing means no interval matches that ticker at the requested as_of timestamp. This occurs if the ticker was never curated, the interval lapsed, or the symbol was renamed. For example, querying ticker=FB at as_of=2023-03-10 returns a missing key because CIK 1326801 became META on 2022-06-09, even though the SEC partition for that day is complete.

Zero rows and no coverage

	Certified day, nothing matched	Day not ingested
HTTP	200	409
`status`	`ok`	`coverage_missing`
`count`	`0`	JSON `null`
`results`	`[]`	`[]`
What it records	The coverage is held and nothing matched the cut.	The coverage is not held, so the number of matching rows is unknown.

Fetch certificates using GET /v1/coverage, or GET /v1/sample/coverage?example=svb without an API key. Requesting a source and date that were never ingested returns a missing certificate instead of a 404.

Coverage in this corpus

The sec.edgar source contains 303 daily partitions: 204 certified complete and 99 missing (88 of which are weekends). Federal Register public inspection contains 182 complete and 91 missing. In the contiguous window from 2022-11-01 to 2023-03-31, 151 SEC days carry a certificate: 103 complete and 48 missing (42 weekend days and six federal holidays).