Bluesky / AT Protocol PDS

github.com · Storage · 1 record · JSON

Bluesky / AT Protocol PDS — 5 MiB blob default, GC'd unless referenced Storage

fails: quotaemail?card?Rper-object-cap

github.com/bluesky-social/atproto/blob/main/packages/pds/src · atproto-pds · storage/bluesky-at-protocol-pds-5-mib-blob-default-gc-d-unless-r · JSON · compare

Free tier	blobUploadLimit defaults to 5 * 1024 * 1024 = 5 MiB per blob, overridable per-PDS via the BLOB_UPLOAD_LIMIT env var. Per-account: bsky.app's hosted PDS is generous in practice but the protocol layer only guarantees blobs that are REFERENCED by a record. unit mixed; metered on unstated
Price	none stated
Per-object cap	5 MiB per blob (5242880 bytes)
Retention	not stated
Egress	Free on bsky.app's PDS and on any self-hosted PDS (it serves blobs directly from /xrpc/com.atproto.sync.getBlob). No egress meter.
Identity	email (placeholder) not published
Limits	per-object-cap 5 MiB per blob source per-object-cap 5 MiB default (config.ts: `blobUploadLimit: env.blobUploadLimit ?? 5 * 1024 * 1024`); blobs unreferenced within a time window (minutes) are deleted; account-level repo size limits are enforced by the AppView/PDS separately.
Binding	per-object-cap the per-object cap sets the shard size and therefore the object count; it bounds the total more tightly than any headline quota
Interface	cli http-xrpc
Tooling	XRPC: POST /xrpc/com.atproto.repo.uploadBlob (binary body + Content-Type) -> returns a `blob` ref; must then be referenced by a record (e.g. app.bsky.feed.post embed) or it is garbage-collected. Client libs: @atproto/api, atproto Python SDK, `goat` CLI.
Composes with	Self-hosting a PDS removes the 5 MiB default (it is a config value), so a self-hosted PDS is bounded by YOUR disk, not Bluesky's — that makes it a hosting product, not free storage. On bsky.app's PDS the 5 MiB cap plus the reference requirement makes it useless for bulk. The usable margin is only the 'unreferenced blobs are deleted within minutes' semantics working in reverse: referenced blobs are retained indefinitely.
Reliability	Blob GC is literal and fast — an upload without a referencing record vanishes. That is the single most important fact about this candidate.
Notes	blobUploadLimit defaults to 5 * 1024 * 1024 = 5 MiB per blob, overridable per-PDS via the BLOB_UPLOAD_LIMIT env var. Per-account: bsky.app's hosted PDS is generous in practice but the protocol layer only guarantees blobs that are REFERENCED by a record.
Evidence rung	reported One page read moves it to documented.
Checked	2026-10-21 (inherited); stale on 2026-11-04
Parsed numbers	`$.limits[0].value` limit:per-object-cap 5.0 MiB

Evidence (2)

date	source	what it proved
2026-10-21	raw.githubusercontent.com/bluesky-social/atproto/main/packag	`blobUploadLimit: env.blobUploadLimit ?? 5 * 1024 * 1024, // 5mb`
2026-10-21	raw.githubusercontent.com/bluesky-social/atproto/main/lexico	'The blob will be deleted if it is not referenced within a time window (eg, minutes). Blob restrictions (mimetype, size, etc) are enforced when the reference is created. Requires auth, implemented by PDS.'

More fields (3)

{
 "verdict_note": "PLAN.md §3.2 rules fails-quota by default, because no row in this set clears 500 GiB per unit for a user.",
 "unit_note": "free_tier.unit is 'mixed' because the headline is denominated in MiB or KiB, which the schema enum does not carry; the verbatim free_tier.stated keeps the true unit. See the storage-dossier handover.",
 "dead_end": {
  "failure_class": "quota",
  "why": "blobUploadLimit defaults to 5 * 1024 * 1024 = 5 MiB per blob, overridable per-PDS via the BLOB_UPLOAD_LIMIT env var. Per-account: bsky.app's hosted PDS is generous in practice but the protocol layer only guarantees blobs that are REFERENCED by a record.",
  "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.detail defaulted
$.identity_cost.kind identity-defaulted
$.per_object_cap.notes not-extracted
$.retention.notes not-extracted
$.retention.stated not-extracted