My hypothesis on why Lemmy is rejecting valid activities
General Discussion
10
Posts
4
Posters
47
Views
-
I have not been able to successfully post to a Lemmy instance either as a post or a comment. A cryptic error message is returned where the error is unknown and the message is a generic message:
{"error":"unknown","message":"data did not match any variant of untagged enum AnnouncableActivities"}From my logs, it seems this is happening:
- I make a valid ActivityPub request with the audience of a community (or cc a user).
- Lemmy makes an ActivityPub request back at me at
/. - My web site does not handle ActivityPub at
/, and responds with atext/plainerror message. This is default behavior in Drupal. - Lemmy rejects my request with a 400 response with the error message above.
I tested other instances by making the following get request to the root of each instance (thank you, Daniel Sternberg for maintaining curl):
curl -v -H "Accept: application/activity+json" -H "Content-Type: application/activity+json" <url>- With the following results
- Lemmy returns an Application Actor.
- Misskey returns a 200 response in
text/html. - Mastodon returns a 406 response in
application/json. - NodeBB returns
text/html. - GoToSocial returns a 406 response in
application/json. - Mitra returns a 200 response in
text/html. - Pixelfed returns a 200 response in
text/html. - Peertube returns an empty 406 response.
My hypothesis is that Lemmy is rejecting the request because I return
text/plainand/or it cannot handle a response with that content type.To test that I am working on changing the default behavior. I will need to dynamically add a route based on
system.site.page.frontand return a 406 response in JSON. This is simple enough. If my hypothesis is correct, I can also make a merge request into drupal/activitypub module, which would have the same problem. If not, then I’ll need to go digging further. -
I have not been able to successfully post to a Lemmy instance either as a post or a comment. A cryptic error message is returned where the error is unknown and the message is a generic message:
{"error":"unknown","message":"data did not match any variant of untagged enum AnnouncableActivities"}From my logs, it seems this is happening:
- I make a valid ActivityPub request with the audience of a community (or cc a user).
- Lemmy makes an ActivityPub request back at me at
/. - My web site does not handle ActivityPub at
/, and responds with atext/plainerror message. This is default behavior in Drupal. - Lemmy rejects my request with a 400 response with the error message above.
I tested other instances by making the following get request to the root of each instance (thank you, Daniel Sternberg for maintaining curl):
curl -v -H "Accept: application/activity+json" -H "Content-Type: application/activity+json" <url>- With the following results
- Lemmy returns an Application Actor.
- Misskey returns a 200 response in
text/html. - Mastodon returns a 406 response in
application/json. - NodeBB returns
text/html. - GoToSocial returns a 406 response in
application/json. - Mitra returns a 200 response in
text/html. - Pixelfed returns a 200 response in
text/html. - Peertube returns an empty 406 response.
My hypothesis is that Lemmy is rejecting the request because I return
text/plainand/or it cannot handle a response with that content type.To test that I am working on changing the default behavior. I will need to dynamically add a route based on
system.site.page.frontand return a 406 response in JSON. This is simple enough. If my hypothesis is correct, I can also make a merge request into drupal/activitypub module, which would have the same problem. If not, then I’ll need to go digging further.>Mitra returns a 200 response in text/html.
But it federates with Lemmy
>data did not match any variant of untagged enum AnnouncableActivities
Did you wrap your activity in
Announce? -
>Mitra returns a 200 response in text/html.
But it federates with Lemmy
>data did not match any variant of untagged enum AnnouncableActivities
Did you wrap your activity in
Announce?>Mitra returns a 200 response in text/html.
But it federates with Lemmy
My hypothesis is it's the text/plain is the problem, and that everyone else is doing something acceptable.
Did you wrap your activity in
Announce?Is that necessary? I could not find that in the Federation documentation. I know that Lemmy sends Announces out when it forwards activities, but to me when the documentation states
When a user creates a new post, it is sent to the respective community as
Create/Page. Editing a previously created post sends an almost identical activity, except thetypebeingUpdate.A reply to a post, or to another comment as
Create/Notethat means I should do similarly, right?
-
I have not been able to successfully post to a Lemmy instance either as a post or a comment. A cryptic error message is returned where the error is unknown and the message is a generic message:
{"error":"unknown","message":"data did not match any variant of untagged enum AnnouncableActivities"}From my logs, it seems this is happening:
- I make a valid ActivityPub request with the audience of a community (or cc a user).
- Lemmy makes an ActivityPub request back at me at
/. - My web site does not handle ActivityPub at
/, and responds with atext/plainerror message. This is default behavior in Drupal. - Lemmy rejects my request with a 400 response with the error message above.
I tested other instances by making the following get request to the root of each instance (thank you, Daniel Sternberg for maintaining curl):
curl -v -H "Accept: application/activity+json" -H "Content-Type: application/activity+json" <url>- With the following results
- Lemmy returns an Application Actor.
- Misskey returns a 200 response in
text/html. - Mastodon returns a 406 response in
application/json. - NodeBB returns
text/html. - GoToSocial returns a 406 response in
application/json. - Mitra returns a 200 response in
text/html. - Pixelfed returns a 200 response in
text/html. - Peertube returns an empty 406 response.
My hypothesis is that Lemmy is rejecting the request because I return
text/plainand/or it cannot handle a response with that content type.To test that I am working on changing the default behavior. I will need to dynamically add a route based on
system.site.page.frontand return a 406 response in JSON. This is simple enough. If my hypothesis is correct, I can also make a merge request into drupal/activitypub module, which would have the same problem. If not, then I’ll need to go digging further.If I do need to wrap it an Announce, then I think I will need to do the following based on how it works on my end.
- Create my post as normal, but don’t address it to the community initially.
- Announce my own post making sure I address it to the community.
I guess that might show up as me boosting my own post on some instances (tooting my own horn? Horning my own toot?), which I would feel ashamed of.
-
If I do need to wrap it an Announce, then I think I will need to do the following based on how it works on my end.
- Create my post as normal, but don’t address it to the community initially.
- Announce my own post making sure I address it to the community.
I guess that might show up as me boosting my own post on some instances (tooting my own horn? Horning my own toot?), which I would feel ashamed of.
mradcliffe@nokoto.org no, Lemmy doesn't check the root for an Application actor (and as you discovered, NodeBB doesn't send one either, and we federate with Lemmy fine.)
Can you share a sample Create you're sending Lemmy? You should only need to have the group actor ID in
toorcc, and probablyas:Publicsomewhere in there too. -
If I do need to wrap it an Announce, then I think I will need to do the following based on how it works on my end.
- Create my post as normal, but don’t address it to the community initially.
- Announce my own post making sure I address it to the community.
I guess that might show up as me boosting my own post on some instances (tooting my own horn? Horning my own toot?), which I would feel ashamed of.
>Is that necessary? I could not find that in the Federation documentation.
The error message says that server expects an
Announceactivity. But yes, group's inbox should also accept replies wrapped inCreate, as well asLikes. -
>Is that necessary? I could not find that in the Federation documentation.
The error message says that server expects an
Announceactivity. But yes, group's inbox should also accept replies wrapped inCreate, as well asLikes.silverpill@mitra.social the group's inbox should, if the post is in local category, but what if it's a post in a remote category? It doesn't ever make it over to the remote server...
-
I have not been able to successfully post to a Lemmy instance either as a post or a comment. A cryptic error message is returned where the error is unknown and the message is a generic message:
{"error":"unknown","message":"data did not match any variant of untagged enum AnnouncableActivities"}From my logs, it seems this is happening:
- I make a valid ActivityPub request with the audience of a community (or cc a user).
- Lemmy makes an ActivityPub request back at me at
/. - My web site does not handle ActivityPub at
/, and responds with atext/plainerror message. This is default behavior in Drupal. - Lemmy rejects my request with a 400 response with the error message above.
I tested other instances by making the following get request to the root of each instance (thank you, Daniel Sternberg for maintaining curl):
curl -v -H "Accept: application/activity+json" -H "Content-Type: application/activity+json" <url>- With the following results
- Lemmy returns an Application Actor.
- Misskey returns a 200 response in
text/html. - Mastodon returns a 406 response in
application/json. - NodeBB returns
text/html. - GoToSocial returns a 406 response in
application/json. - Mitra returns a 200 response in
text/html. - Pixelfed returns a 200 response in
text/html. - Peertube returns an empty 406 response.
My hypothesis is that Lemmy is rejecting the request because I return
text/plainand/or it cannot handle a response with that content type.To test that I am working on changing the default behavior. I will need to dynamically add a route based on
system.site.page.frontand return a 406 response in JSON. This is simple enough. If my hypothesis is correct, I can also make a merge request into drupal/activitypub module, which would have the same problem. If not, then I’ll need to go digging further.Hi, I had a look at the activities sent from your account. Looks like the only problem is that you are missing a
@contextfield. After adding that it parses just fine. What you serve from/is irrelevant, that one is completely optional. -
Hi, I had a look at the activities sent from your account. Looks like the only problem is that you are missing a
@contextfield. After adding that it parses just fine. What you serve from/is irrelevant, that one is completely optional.nutomic oh that's interesting, does Lemmy do JSON-LD validation? I didn't think it would.
-
I have not been able to successfully post to a Lemmy instance either as a post or a comment. A cryptic error message is returned where the error is unknown and the message is a generic message:
{"error":"unknown","message":"data did not match any variant of untagged enum AnnouncableActivities"}From my logs, it seems this is happening:
- I make a valid ActivityPub request with the audience of a community (or cc a user).
- Lemmy makes an ActivityPub request back at me at
/. - My web site does not handle ActivityPub at
/, and responds with atext/plainerror message. This is default behavior in Drupal. - Lemmy rejects my request with a 400 response with the error message above.
I tested other instances by making the following get request to the root of each instance (thank you, Daniel Sternberg for maintaining curl):
curl -v -H "Accept: application/activity+json" -H "Content-Type: application/activity+json" <url>- With the following results
- Lemmy returns an Application Actor.
- Misskey returns a 200 response in
text/html. - Mastodon returns a 406 response in
application/json. - NodeBB returns
text/html. - GoToSocial returns a 406 response in
application/json. - Mitra returns a 200 response in
text/html. - Pixelfed returns a 200 response in
text/html. - Peertube returns an empty 406 response.
My hypothesis is that Lemmy is rejecting the request because I return
text/plainand/or it cannot handle a response with that content type.To test that I am working on changing the default behavior. I will need to dynamically add a route based on
system.site.page.frontand return a 406 response in JSON. This is simple enough. If my hypothesis is correct, I can also make a merge request into drupal/activitypub module, which would have the same problem. If not, then I’ll need to go digging further.Actually I was wrong, there is a context so thats fine. The problem is that
audienceshould be a simple string but you are sending an error, thats why it fails. Anyway that field is optional, so you can leave it out and put the community intoorccinstead.julian No but still the field is mandatory (mainly because that hasnt caused any problems so far).
Gli ultimi otto messaggi ricevuti dalla Federazione
-
@reiver I'd consider interoperating social networks to be "federated", but I know it's not a precise term. There are similar ambiguities with other commonly used terms: decentralization, server, node, instance, and so on. We have our personal definitions but find that others have a different mental model than ours. It might be interesting to have a collaborative social web glossary that captures the variations of how these terms are used.
-
@rimu@mastodon.nzoss.nz Definitely. Offloading the static assets to nginx is a big win. Varnish adds a layer of serving from memory that takes it up a notch. Like having your own Fastly pop.
It does require some configuration nuance to be sure you aren't serving cached assets to the wrong connections (e.g., authenticated GET requests that shouldn't be shared beyond a specific session).
-
-
Is it correct to say the #Fediverse and #BlueSky are "federated" by protocol bridges? I have similar question related to #Nostr and #Threads and other bridged protocols. Given the #Fediverse is #ActivityPub, what this larger federated social web called?
-
@silverpill@mitra.social Thanks - that solves a number of issues I've been encountering. From the outset, I wanted to use the system actor to point at the relevant administrative collections, but couldn't think of a good way to identify the actor to the client (without hard-coding it). That webfinger adjustment solves that.
-
>nodeinfo is a common protocol used for discovering information about ActivityPub-speaking servers
NodeInfo is used primarily by sites like https://fediverse.observer, it is not intended to be used by clients. There is a similar entity in ActivityPub: server actor (instance actor). In your case it seems to be located at https://enigmatick.social/user/system ?
I prefer Webfinger discovery method, as described in this FEP: https://codeberg.org/fediverse/fep/src/branch/main/fep/d556/fep-d556.md.
-
From its conception, #Enigmatick has leaned heavily on the /inbox and /outbox endpoints for client operations. There are some /api endpoints, but I avoid that were I can shoehorn operations into the #ActivityPub specification and #ActivityStreams vocabulary.
While typical operational activities are fairly well accounted for, administration is a weak point. For example: I haven't identified a clear way to use the currently described mechanisms for an administrative user to pull up and manage instances or actors on a server.
I've relied on CLI tools (e.g., ./enigmatick --help) to manage some of that. And in some cases, I know how to manipulate data in my database, so I haven't worried too much about building tooling. But I'd like to ship something that other folks can use to share in my efforts, so I've been thinking about how to model those activities in an ActivityPub-esque way to use in the Svelte UI.
ActivityPub MessagesTo that end, I'm now using Block and Delete activities sent from the client to the server outbox to manage the blocking of instances and purging of data.
{ "@context": [ "https://www.w3.org/ns/activitystreams", { "ek": "https://enigmatick.social/ns#", "Instance": "ek:Instance" } ], "id": "https://enigmatick.social/activities/550e8400-e29b-41d4-a716-446655440000", "type": "Block", "actor": "https://enigmatick.social/user/system", "object": { "type": "Instance", "id": "https://spammy-instance.example" } }In practice, my client does not generate the id, but that attribute is generated by the server and the Activity is stored alongside other typically federated activities. These local Block activities are not federated out to other servers; they are intended solely for local server management.
The Block activity is sent as a message signed at the client by a user with administrative privileges on the server. Enigmatick's user authentication is unique (i.e., I use a separate set of encryption keys for client-signing executed by a wasm module in the browser). That can be a topic for a future article.
That the actor as the system Application user is important. That is used by the server to establish the scope of this action as system-wide, not just for a single user. The system actor is discoverable in the nodeinfo metadata.
I'm using a typed object rather than just an id reference. This is so that I can use this same flow for blocking and purging Actor objects (i.e., the type would be Person, Service, or Application).
The purge action is similar, using the Delete activity.
{ "@context": [ "https://www.w3.org/ns/activitystreams", { "ek": "https://enigmatick.social/ns#", "Instance": "ek:Instance" } ], "id": "https://enigmatick.social/activities/550e8400-e29b-41d4-a716-446655440000", "type": "Delete", "actor": "https://enigmatick.social/user/system", "object": { "type": "Instance", "id": "https://spammy-instance.example" } }The term, "delete" is a bit of a misnomer in this case as it applies to the instance specifically. The instance will remain, but the objects, activities, and actors associated with that instance will be fully deleted (i.e., not set to Tombstone).
Collection EndpointsTo facilitate the UI operations, I've created two new collection endpoints on my server: /instances and /actors. These endpoints provide typical ActivityPub Collection objects.
{ "@context": [ "https://www.w3.org/ns/activitystreams", { "Instance": "ek:Instance", "activitiesCount": "ek:activitiesCount", "actorsCount": "ek:actorsCount", "blocked": "ek:blocked", "ek": "https://enigmatick.social/ns#", "lastMessageAt": "ek:lastMessageAt", "objectsCount": "ek:objectsCount" } ], "type": "OrderedCollection", "id": "https://enigmatick.social/instances", "totalItems": 7702, "orderedItems": [ { "type": "Instance", "id": "https://example-instance.name", "blocked": false, "created": "2025-12-16T16:56:33Z", "lastMessageAt": "2025-12-16T16:56:33Z", "actorsCount": 0, "objectsCount": 1, "activitiesCount": 0 } ], "first": "https://enigmatick.social/instances?max=9223372036854775807", "last": "https://enigmatick.social/instances?min=0", "next": "https://enigmatick.social/instances?max=1765657395402834" }I've added some extensions in the @context to account for a few non-standard attributes.
That collection is used by the UI.
Collection Discovery
nodeinfo is a common protocol used for discovering information about ActivityPub-speaking servers. I've extended my use of that to facilitate client-discovery of these new endpoints using the metadata object contained in the nodeinfo JSON.
"metadata": { "actor": "https://enigmatick.social/user/system", "adminActors": "https://enigmatick.social/actors", "adminInstances": "https://enigmatick.social/instances", "domain": "enigmatick.social", "url": "https://enigmatick.social" } Final ThoughtsAs I'm reading through this, I see some opportunities for refinement. I should probably be using OrderedCollectionPage instead of OrderedCollection for my collection endpoints. I'm sure there are other tweaks to be made.
-
Agreed that forums are definitely needed, and the energy NodeBB has brought to the Fediverse has been very welcome indeed! The coexistence is often smooth but sometimes quite clunky (although of course that's true for ActivityPub platforms in general).
Specifically for the deletes, I had also run into problems where they weren't getting propagated everywhere. Not sure if there's a similar thing happening here; If I recall correctly, the issue I was experiencing related to unsigned fetches.
