Question about array of activities with Tombstone/Delete

wiktor-k commented

2026-02-02 08:26:46 +00:00

Hi folks,

I've been getting activities from FoundKey and noticed that the Tombstone/Deletes are always packed in an array, like so:

[ // <-- notice the array here
  {
    "@context": [
      "https://www.w3.org/ns/activitystreams",
      "https://w3id.org/security/v1",
      {
        "Emoji": "toot:Emoji",
        "Hashtag": "as:Hashtag",
        "PropertyValue": {
          "@context": {
            "name": "schema:name",
            "value": "schema:value"
          },
          "@id": "schema:PropertyValue"
        },
        "_misskey_quote": {
          "@id": "misskey:_misskey_quote",
          "@type": "@id"
        },
        "_misskey_talk": {
          "@id": "misskey:_misskey_talk",
          "@type": "xsd:boolean"
        },
        "discoverable": {
          "@id": "toot:discoverable",
          "@type": "xsd:boolean"
        },
        "featured": {
          "@id": "toot:featured",
          "@type": "@id"
        },
        "isCat": {
          "@id": "misskey:isCat",
          "@type": "xsd:boolean"
        },
        "manuallyApprovesFollowers": {
          "@id": "as:manuallyApprovesFollowers",
          "@type": "xsd:boolean"
        },
        "misskey": "https://misskey-hub.net/ns#",
        "quoteUri": {
          "@id": "http://fedibird.com/ns#quoteUri",
          "@type": "@id"
        },
        "schema": "http://schema.org/",
        "sensitive": {
          "@id": "as:sensitive",
          "@type": "xsd:boolean"
        },
        "toot": "http://joinmastodon.org/ns#",
        "vcard": "http://www.w3.org/2006/vcard/ns#",
        "xsd": "http://www.w3.org/2001/XMLSchema#"
      }
    ],
    "actor": "https://wake.0am.jp/users/a7gdp23028",
    "id": "https://wake.0am.jp/7de54a42-9695-4d73-9477-84b992be3fb5",
    "object": {
      "id": "https://wake.0am.jp/notes/ai8ghvmj3o",
      "type": "Tombstone"
    },
    "published": "2026-02-02T08:13:03.488Z",
    "type": "Delete"
  }
]

I think this comes from the following line of code:

deliverMultipleToRelays(fetchedUser, content),

I'm trying to understand if this is allowed ActivityPub behavior or a bug somewhere. I've read the relevant specs but can't find anything about sending arrays of activities. Would you be able to help me with clarifying the behavior here?

Thank you for your time and have a nice day! 👋

Hi folks, I've been getting activities from FoundKey and noticed that the Tombstone/Deletes are always packed in an array, like so: ```json [ // <-- notice the array here { "@context": [ "https://www.w3.org/ns/activitystreams", "https://w3id.org/security/v1", { "Emoji": "toot:Emoji", "Hashtag": "as:Hashtag", "PropertyValue": { "@context": { "name": "schema:name", "value": "schema:value" }, "@id": "schema:PropertyValue" }, "_misskey_quote": { "@id": "misskey:_misskey_quote", "@type": "@id" }, "_misskey_talk": { "@id": "misskey:_misskey_talk", "@type": "xsd:boolean" }, "discoverable": { "@id": "toot:discoverable", "@type": "xsd:boolean" }, "featured": { "@id": "toot:featured", "@type": "@id" }, "isCat": { "@id": "misskey:isCat", "@type": "xsd:boolean" }, "manuallyApprovesFollowers": { "@id": "as:manuallyApprovesFollowers", "@type": "xsd:boolean" }, "misskey": "https://misskey-hub.net/ns#", "quoteUri": { "@id": "http://fedibird.com/ns#quoteUri", "@type": "@id" }, "schema": "http://schema.org/", "sensitive": { "@id": "as:sensitive", "@type": "xsd:boolean" }, "toot": "http://joinmastodon.org/ns#", "vcard": "http://www.w3.org/2006/vcard/ns#", "xsd": "http://www.w3.org/2001/XMLSchema#" } ], "actor": "https://wake.0am.jp/users/a7gdp23028", "id": "https://wake.0am.jp/7de54a42-9695-4d73-9477-84b992be3fb5", "object": { "id": "https://wake.0am.jp/notes/ai8ghvmj3o", "type": "Tombstone" }, "published": "2026-02-02T08:13:03.488Z", "type": "Delete" } ] ``` I think this comes from the following line of code: https://akkoma.dev/FoundKeyGang/FoundKey/src/commit/8a4216a37065d41880d253105ec3a7fe0c395b7d/packages/backend/src/services/note/delete.ts#L108 I'm trying to understand if this is allowed ActivityPub behavior or a bug somewhere. I've read the relevant specs but can't find anything about sending arrays of activities. Would you be able to help me with clarifying the behavior here? Thank you for your time and have a nice day! 👋

Johann150 commented

2026-02-28 09:41:38 +00:00

Owner

I've noticed this behaviour from the particular instance you show in your example (wake.0am.jp) too since a while, but I am not sure where it is coming from. I would classify this as a bug and not in line with the ActivityStreams Technical Recommendation.

I'm guessing this might be the case because the particular instance is stuck on some broken older version/commit of Foundkey or perhaps they cherry-picked some commits while leaving out others. In particular, they might be missing commit 1bce487965.

As a more technical explanation: Foundkey in some cases, like deletion of notes, internally groups activities for delivery. This is done by handing an array of activities to the delivery queue. This mechanism is the same for DeliveryManager.execute and deliverMultipleToRelays, since in the end they both insert things into the delivery queue (using the deliver function).

Though the queue worker upon seeing an array should deliver all the activities in separate requests, as implemented in the commit mentioned above. The intended advantage is to use keep-alive HTTP connections more effectively.

I've noticed this behaviour from the particular instance you show in your example (`wake.0am.jp`) too since a while, but I am not sure where it is coming from. I would classify this as a bug and not in line with the ActivityStreams Technical Recommendation. I'm guessing this might be the case because the particular instance is stuck on some broken older version/commit of Foundkey or perhaps they cherry-picked some commits while leaving out others. In particular, they might be missing commit 1bce4879651ee9769db7832c797b7c5338491ff9. As a more technical explanation: Foundkey in some cases, like deletion of notes, internally groups activities for delivery. This is done by handing an array of activities to the delivery queue. This mechanism is the same for `DeliveryManager.execute` and `deliverMultipleToRelays`, since in the end they both insert things into the delivery queue (using the `deliver` function). Though the queue worker upon seeing an array should deliver all the activities in separate requests, as implemented in the commit mentioned above. The intended advantage is to use keep-alive HTTP connections more effectively.

wiktor-k commented

2026-03-05 10:32:09 +00:00

Author

I'm guessing this might be the case because the particular instance is stuck on some broken older version/commit of Foundkey or perhaps they cherry-picked some commits while leaving out others. In particular, they might be missing commit 1bce487965.

Oh, understood! That explains why I couldn't find the exact issue in your recent codebase 😅

So I guess this issue is solved and I'm going to close it.

Much appreciated you taking the time to thoroughly explain it 🙇‍♂️

Have a great day! 👋

> I'm guessing this might be the case because the particular instance is stuck on some broken older version/commit of Foundkey or perhaps they cherry-picked some commits while leaving out others. In particular, they might be missing commit 1bce487965. Oh, understood! That explains why I couldn't find the exact issue in your recent codebase 😅 So I guess this issue is solved and I'm going to close it. Much appreciated you taking the time to thoroughly explain it 🙇‍♂️ Have a great day! 👋

wiktor-k closed this issue

2026-03-05 10:32:09 +00:00

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Question about array of activities with Tombstone/Delete #411