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.

Support Table Preview

inReplyTo	Object	Activity
“http://pasture-one-actor/assets/note1.jsonap”	Object	Activity
“http://invalid.example/”	Object	Activity
[ “http://pasture-one-actor/assets/note1.jsonap” ]	Object 🚨	Activity
{ “type”: “Link”, “href”: “http://pasture-one-actor/assets/note1.jsonap” }	Object 🚨	Activity
[ “http://pasture-one-actor/assets/note1.jsonap”, “http://pasture-one-actor/assets/note2.jsonap” ]	Object 🚨	Activity
{ “type”: “Collection”, “items”: [ “http://pasture-one-actor/actor” ] }	Object 🚨	Activity
{ “@context”: “https://www.w3.org/ns/activitystreams”, “type”: “Note”, “id”: “http://pasture-one-actor/assets/note1.jsonap”, “to”: [ “as:Public” ], “attributedTo”: “http://pasture-one-actor/actor”, “content”: “One”, “published”: “2024-01-06T13:11:45Z” }	Object 🚨	Activity

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/w1MsmTGl5V8",
  "inReplyTo": "http://pasture-one-actor/assets/note1.jsonap",
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#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/ORHBYOzT2E4",
  "inReplyTo": "http://invalid.example/",
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 3

❌❌❌ does not obey schema ❌❌❌

['http://pasture-one-actor/assets/note1.jsonap'] is not of type 'string'

Failed validating 'type' in schema['properties']['inReplyTo']:
    {'description': 'The object being replied to. Currently a string. Not '
                    'sure if this is what I want.',
     'type': 'string'}

On instance['inReplyTo']:
    ['http://pasture-one-actor/assets/note1.jsonap']

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "list",
  "id": "http://actor.example/object/GeSO2V1C1S4",
  "inReplyTo": [
    "http://pasture-one-actor/assets/note1.jsonap"
  ],
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 4

❌❌❌ does not obey schema ❌❌❌

{'type': 'Link', 'href': 'http://pasture-one-actor/assets/note1.jsonap'} is not of type 'string'

Failed validating 'type' in schema['properties']['inReplyTo']:
    {'description': 'The object being replied to. Currently a string. Not '
                    'sure if this is what I want.',
     'type': 'string'}

On instance['inReplyTo']:
    {'type': 'Link', 'href': 'http://pasture-one-actor/assets/note1.jsonap'}

{
  "@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/hEBe7om0e0w",
  "inReplyTo": {
    "href": "http://pasture-one-actor/assets/note1.jsonap",
    "type": "Link"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 5

❌❌❌ does not obey schema ❌❌❌

['http://pasture-one-actor/assets/note1.jsonap', 'http://pasture-one-actor/assets/note2.jsonap'] is not of type 'string'

Failed validating 'type' in schema['properties']['inReplyTo']:
    {'description': 'The object being replied to. Currently a string. Not '
                    'sure if this is what I want.',
     'type': 'string'}

On instance['inReplyTo']:
    ['http://pasture-one-actor/assets/note1.jsonap',
     'http://pasture-one-actor/assets/note2.jsonap']

{
  "@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/_PtOh-sAXUw",
  "inReplyTo": [
    "http://pasture-one-actor/assets/note1.jsonap",
    "http://pasture-one-actor/assets/note2.jsonap"
  ],
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 6

❌❌❌ does not obey schema ❌❌❌

{'type': 'Collection', 'items': ['http://pasture-one-actor/actor']} is not of type 'string'

Failed validating 'type' in schema['properties']['inReplyTo']:
    {'description': 'The object being replied to. Currently a string. Not '
                    'sure if this is what I want.',
     'type': 'string'}

On instance['inReplyTo']:
    {'type': 'Collection', 'items': ['http://pasture-one-actor/actor']}

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "sensitive": "as:sensitive"
    }
  ],
  "attributedTo": "http://actor.example",
  "content": "collection",
  "id": "http://actor.example/object/LEaYkbndb10",
  "inReplyTo": {
    "items": [
      "http://pasture-one-actor/actor"
    ],
    "type": "Collection"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Note"
}

Object 7

❌❌❌ does not obey schema ❌❌❌

{'@context': 'https://www.w3.org/ns/activitystreams', 'type': 'Note', 'id': 'http://pasture-one-actor/assets/note1.jsonap', 'to': ['as:Public'], 'attributedTo': 'http://pasture-one-actor/actor', 'content': 'One', 'published': '2024-01-06T13:11:45Z'} is not of type 'string'

Failed validating 'type' in schema['properties']['inReplyTo']:
    {'description': 'The object being replied to. Currently a string. Not '
                    'sure if this is what I want.',
     'type': 'string'}

On instance['inReplyTo']:
    {'@context': 'https://www.w3.org/ns/activitystreams',
     'type': 'Note',
     'id': 'http://pasture-one-actor/assets/note1.jsonap',
     'to': ['as:Public'],
     'attributedTo': 'http://pasture-one-actor/actor',
     'content': 'One',
     'published': '2024-01-06T13:11:45Z'}

{
  "@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/dDJp1kBU-fw",
  "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": "2025-11-21T12:04:56Z",
  "to": [
    "https://www.w3.org/ns/activitystreams#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/zmuurdyCe-M",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "valid uri",
    "id": "http://actor.example/object/iBWVQNUT2Io",
    "inReplyTo": "http://pasture-one-actor/assets/note1.jsonap",
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/hCQrRKjH2nE",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "invalid uri",
    "id": "http://actor.example/object/IPH4Gf7l200",
    "inReplyTo": "http://invalid.example/",
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/ZGqBO9Qx-Nk",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "list",
    "id": "http://actor.example/object/RkrVAESsrqw",
    "inReplyTo": [
      "http://pasture-one-actor/assets/note1.jsonap"
    ],
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/CH6OJJzYOj0",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "Link in inReplyTo",
    "id": "http://actor.example/object/tRvm8VnmmVc",
    "inReplyTo": {
      "href": "http://pasture-one-actor/assets/note1.jsonap",
      "type": "Link"
    },
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/vihSzjstEvw",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "two elements in inReplyTo",
    "id": "http://actor.example/object/dc1EmkOj0sM",
    "inReplyTo": [
      "http://pasture-one-actor/assets/note1.jsonap",
      "http://pasture-one-actor/assets/note2.jsonap"
    ],
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/MweCxmrvzDg",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "collection",
    "id": "http://actor.example/object/Ih6nIw3j-GE",
    "inReplyTo": {
      "items": [
        "http://pasture-one-actor/actor"
      ],
      "type": "Collection"
    },
    "published": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "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/wmeeuLSp3yY",
  "object": {
    "attributedTo": "http://actor.example",
    "content": "embedded note",
    "id": "http://actor.example/object/fH57aFZj4pI",
    "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": "2025-11-21T12:04:56Z",
    "to": [
      "https://www.w3.org/ns/activitystreams#Public",
      "http://remote.example/"
    ],
    "type": "Note"
  },
  "published": "2025-11-21T12:04:56Z",
  "to": [
    "http://remote.example/",
    "https://www.w3.org/ns/activitystreams#Public"
  ],
  "type": "Create"
}