Item Metadata API

Storage · 1 record · JSON

Item Metadata API (MDAPI) as free key-value/JSON store Storage

fails: quotainstitution?card?R

archive.org/developers/metadata.html · academic · storage/item-metadata-api-as-free-key-value-json-store · JSON · compare

Free tier	No per-item metadata size is published; unlimited items x one JSON doc each, transaction-safe, free. unit unlimited; metered on unstated
Price	none stated
Per-object cap	not stated
Retention	not stated
Egress	Free reads (public items), gzip/deflate supported
Identity	institution (placeholder) inferred from the category 'academic'; the source record states no identity cost, so this is a class assumption, not evidence
Binding	none no constraint of a named kind was recorded; the verdict rests on the quota sentence rather than on a named limit
Interface	rest rest
Tooling	ia metadata -m / Python MDAPI; auth via the same IAS3 keys (Authorization: LOW)
Composes with	Side-car index for the 20TiB: one small JSON doc per item holding checksums, shard maps, source URLs — solves IAS3's 'cannot list all my items' problem without running your own database.
Reliability	Safe for bookkeeping, useless for bytes; concurrent writers need the documented concurrency pattern or they clobber metadata.
Notes	No per-item metadata size is published; unlimited items x one JSON doc each, transaction-safe, free.
Evidence rung	reported One page read moves it to documented.
Checked	2026-10-21 (inherited); stale on 2026-11-04

Evidence (2)

date	source	what it proved
2026-10-21	archive.org/developers/metadata.html	(snapshot 2026-02-04) — 'may even store ad hoc JSON data in a transaction-safe manner', 'MDAPI cannot operate on more than one item at a time. There is no wildcarding'
2026-10-21	archive.org/developers/ias3.html	S3 keys sent with 'Authorization: LOW' are accepted by MDAPI write

More fields (1)

{
 "dead_end": {
  "failure_class": "quota",
  "why": "No per-item metadata size is published; unlimited items x one JSON doc each, transaction-safe, free.",
  "retry_when": null,
  "first_recorded": "2026-10-21"
 }
}

Unknown or withheld values (7)

$.extras.dead_end.retry_when process
$.free_tier.notes process
$.identity_cost.kind identity-defaulted
$.per_object_cap.notes not-extracted
$.per_object_cap.stated not-extracted
$.retention.notes not-extracted
$.retention.stated not-extracted