attachment_size_limit is MAX(default_limit, user_limit, guild_limit)

Author: colinloretz

docs/change-log/2025-04-03-per-attachment-file-upload-limit.md

@@ -1,18 +1,18 @@
 ---
-title: "Per-Attachment File Upload Limit for Apps"
+title: "Per-Attachment File Upload Behavior for Apps"
 date: "2025-04-03"
 breaking: false
 topics:
 - "HTTP API"
 - "Interactions"
 ---
 
-Starting today, file upload limits for apps are checked per-attachment rather than per-message. This change makes the attachment behavior for apps the same as when a user uploads multiple attachments on a single message.
+Starting today, file upload limits for apps are checked per-attachment rather than per-message. This change makes the app attachment behavior the same as when a user uploads multiple attachments on a single message.
 
 - File size limits now apply to each individual attachment
 - Previously, limits were applied to the combined size of all attachments in a message
 - This aligns app attachment handling with user attachment behavior
 
-Additionally, the interaction payload will include a new `attachment_size_limit` key that specifies the maximum allowed attachment size, which may exceed the default attachment size limit in boosted guilds.
+The interaction payload will also include a new `attachment_size_limit` key that specifies the maximum allowed attachment size. This limit may be higher than the default attachment size limit, depending on the guild's boost status or the invoking user's Nitro status.
 
 For more information, check out [our documentation on file uploads](#DOCS_REFERENCE/uploading-files).

docs/reference.mdx

@@ -397,7 +397,7 @@ https://cdn.discordapp.com/attachments/1012345678900020080/1234567891233211234/m
 ## Uploading Files
 
 > info
-> The file upload size limit applies to each file in a request. While the limit depends on the [**Boost Tier**](https://support.discord.com/hc/en-us/articles/360028038352-Server-Boosting-FAQ-#h_419c3bd5-addd-4989-b7cf-c7957ef92583) of a guild, it is `10 MiB` by default. The `attachment_size_limit` value is provided to your app [when working with interactions](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/interaction-object-interaction-structure). 
+> The file upload size limit applies to each file in a request. The default limit is `10 MiB` for all users, but may be higher for users depending on their [Nitro](https://support.discord.com/hc/en-us/articles/115000435108-What-are-Nitro-Nitro-Basic) status or by the server's [Boost Tier](https://support.discord.com/hc/en-us/articles/360028038352-Server-Boosting-FAQ-#h_419c3bd5-addd-4989-b7cf-c7957ef92583). The `attachment_size_limit` value provided [when working with interactions](#DOCS_INTERACTIONS_RECEIVING_AND_RESPONDING/interaction-object-interaction-structure) is calculated as the maximum of these values.
 
 Some endpoints support file attachments, indicated by the `files[n]` parameter. To add file(s), the standard `application/json` body must be replaced by a `multipart/form-data` body. The JSON message body can optionally be provided using the `payload_json` parameter.