Identifiers truncated in this published copy. The record behind every row is retained in full.
123,751 launches recorded by this archive carried their launch document on one host, metadata.j7tracker.io. On 28 September we asked that host for 400 of those documents, chosen at random. It served 36 and answered 404 for 364. Every request got a definite answer, and the sample puts the share no longer served between roughly 88% and 94%, so on the order of 112,000 documents now exist nowhere but this archive. Stated to the nearest thousand because it is a projection from a 400-document sample; every other figure on this page is a count.
The same host, asked for documents this archive already holds, on four dated occasions. "Served" means the bytes came back; a request that was rate limited or timed out is excluded from the denominator rather than counted as loss. The three smaller samples carry wide margins, and the point survives them.
| Date (2026) | Asked | Served | Share served | Where the sample came from |
|---|---|---|---|---|
| 10 September | 50 | 28 | 56% | first survival probe, random held documents on the host |
| 12 September | 75 | 0 | 0% | the published metadata-retention report, frozen that day |
| 20 September | 30 | 18 | 60% | spot check of held documents older than three days |
| 28 September | 400 | 36 | 9% | this exhibit's probe, random across all 123,751 held |
No retention curve fits those four readings. The share served is not a function of a document's age; it is a property of the host on the day you ask. An inspection on the 20th would say the documents exist. The same inspection on the 12th or the 28th would say they are gone. Both would be describing the weather. The stable fact is the capture: each document was fetched as its launch happened and hashed then, and the archive's copy does not change with the host's serving behavior.
The same day's archive-wide probe, 400 random documents across every host the archive holds.
| Population | Asked and answered | Still served |
|---|---|---|
| Content-addressed (ipfs) | 276 | 276 |
| Every ordinary host except the three that lost | 73 | 73 |
| metadata.j7tracker.io | 49 | 6 |
Content addressing survives because the address is the hash of the content: a pin can lapse, but the host cannot serve different bytes and keep the address. An ordinary host serves at its operator's pleasure. Of the 858,649 documents this archive holds, 577,587 are content-addressed and 123,751 live on the one host in the bottom row.
The collector also keeps its failures: 27,551 launch documents it asked for at launch and never received. Of a random 400 of those re-asked on 28 September, 324 answered 404. Projected over the pool, about 22,300 documents from recorded launches are now gone at any price: no host serves them, no replay of chain history contains them, and this archive never got them. About 2,100 still answer and are being fetched. That number is what capture at the moment of launch is for.
This page states what each request answered on the stated dates and does not call the host's conduct anything. A probe sees answers, not reasons: a retention policy, a storage migration, a lapsed account and a deliberate deletion are indistinguishable from outside, and we do not guess. Nothing here is a statement about any launch whose document the host carried, about the host's operator, or about any token; a document's absence from a host is never evidence about the token it described. We record what was served and when; what it means is the reader's question, taken up with the record in hand.