Variations of inReplyTo

The property is defined here. The goal of this support table is to show how applications react to inReplyTo containing a wide variation of allowed objects. As Fediverse applications generally only give one the option to reply to a single element, the lacking support should not be surprising.

Objects

Object 1

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "valid uri",
  "id": "http://actor.example/object/mX8qOSD1hTs",
  "inReplyTo": "http://pasture-one-actor/assets/note1.jsonap",
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 2

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "invalid uri",
  "id": "http://actor.example/object/7sK-hsJB0JE",
  "inReplyTo": "http://invalid.example/",
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 3

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "list",
  "id": "http://actor.example/object/B_ahtZmgVGE",
  "inReplyTo": [
    "http://pasture-one-actor/assets/note1.jsonap"
  ],
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 4

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "Link in inReplyTo",
  "id": "http://actor.example/object/jpsio7lrZUg",
  "inReplyTo": {
    "href": "http://pasture-one-actor/assets/note1.jsonap",
    "type": "Link"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 5

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "two elements in inReplyTo",
  "id": "http://actor.example/object/Nqe3aUYa5TY",
  "inReplyTo": [
    "http://pasture-one-actor/assets/note1.jsonap",
    "http://pasture-one-actor/assets/note2.jsonap"
  ],
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 6

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "collection",
  "id": "http://actor.example/object/QLOzh64ukHA",
  "inReplyTo": {
    "items": [
      "http://pasture-one-actor/actor"
    ],
    "type": "Collection"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Object 7

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "embedded note",
  "id": "http://actor.example/object/dlkfqZZGeyw",
  "inReplyTo": {
    "@context": "https://www.w3.org/ns/activitystreams",
    "attributedTo": "http://pasture-one-actor/actor",
    "content": "One",
    "id": "http://pasture-one-actor/assets/note1.jsonap",
    "published": "2024-01-06T13:11:45Z",
    "to": [
      "as:Public"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public"
  ],
  "type": "Note"
}

Activities

Activity 1

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/_Jz6pyYKXww",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "valid uri",
    "id": "http://actor.example/object/XBpnLKQ0jtw",
    "inReplyTo": "http://pasture-one-actor/assets/note1.jsonap",
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 2

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/Y9peYitZ2ls",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "invalid uri",
    "id": "http://actor.example/object/3cuLqad81u8",
    "inReplyTo": "http://invalid.example/",
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 3

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/T4aUOKh2Y6k",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "list",
    "id": "http://actor.example/object/Vcc7P-ixtX0",
    "inReplyTo": [
      "http://pasture-one-actor/assets/note1.jsonap"
    ],
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 4

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/8d6mEmTDyc4",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "Link in inReplyTo",
    "id": "http://actor.example/object/GwvbQHWqKbI",
    "inReplyTo": {
      "href": "http://pasture-one-actor/assets/note1.jsonap",
      "type": "Link"
    },
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 5

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/TsKYH3t_F_Y",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "two elements in inReplyTo",
    "id": "http://actor.example/object/vFaPPT5hN8k",
    "inReplyTo": [
      "http://pasture-one-actor/assets/note1.jsonap",
      "http://pasture-one-actor/assets/note2.jsonap"
    ],
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 6

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/xIXjZxl41Sg",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "collection",
    "id": "http://actor.example/object/Lx8c27BnNF4",
    "inReplyTo": {
      "items": [
        "http://pasture-one-actor/actor"
      ],
      "type": "Collection"
    },
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}

Activity 7

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "actor": "http://actor.example",
  "id": "http://actor.example/activity/G4x2Zahui3A",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "embedded note",
    "id": "http://actor.example/object/1QKoVSCD96w",
    "inReplyTo": {
      "@context": "https://www.w3.org/ns/activitystreams",
      "attributedTo": "http://pasture-one-actor/actor",
      "content": "One",
      "id": "http://pasture-one-actor/assets/note1.jsonap",
      "published": "2024-01-06T13:11:45Z",
      "to": [
        "as:Public"
      ],
      "type": "Note"
    },
    "published": "2025-08-15T08:43:29Z",
    "to": [
      "as:Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-08-15T08:43:29Z",
  "to": [
    "as:Public",
    "http://remote.example/"
  ],
  "type": "Create"
}