Struct ChatCapability 

#[non_exhaustive]
pub struct ChatCapability {
    pub max_body_bytes: u64,
    pub max_attachment_bytes: u64,
    pub max_attachments_per_message: u64,
    pub supports_threads: bool,
    pub supported_body_types: Vec<String>,
    pub extra: Map<String, Value>,
}

Account-level capability object for "urn:ietf:params:jmap:chat".

Found at accounts[id].accountCapabilities["urn:ietf:params:jmap:chat"].

Spec: draft-atwood-jmap-chat-00 §3

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

max_body_bytes: u64

Maximum UTF-8 byte length of a Message body.

max_attachment_bytes: u64

Maximum single attachment blob size in bytes.

max_attachments_per_message: u64

Maximum number of attachments per message.

supports_threads: bool

Whether the server supports the optional thread model.

supported_body_types: Vec<String>

The set of Message bodyType values this server understands (draft-atwood-jmap-chat-00 §3).

Spec requirements for compliant servers:

• MUST include "text/plain".
• SHOULD include "text/markdown" (RFC 7763 CommonMark).
• SHOULD include "application/jmap-chat-rich".
• SHOULD include "application/mls-ciphertext" for E2EE deployments.
• MAY include "application/mimi-content".

An empty Vec is non-compliant per spec ("text/plain" is mandatory) but the client tolerates it via Default — the consumer is responsible for enforcing the MUST and acting accordingly (e.g. refusing to send rich messages to a server that does not advertise the matching bodyType).

extra: Map<String, Value>

Catch-all for vendor / site / private extension fields not covered by the typed fields above. Preserves unknown fields across deserialize/serialize round-trip per workspace extras-preservation policy (see workspace AGENTS.md).

Per draft-atwood-jmap-chat-00 §3 (revised 2026-05-11, spec commit 80d5e11), the five aggregate-count caps maxGroupMembers, maxSpaceMembers, maxRolesPerSpace, maxChannelsPerSpace, and maxCategoriesPerSpace are no longer advertised on this capability — they are implementation-defined and enforced via standard overQuota SetError (RFC 8620 §5.3) at Chat/set and Space/set time. Servers that still emit them will round-trip the values harmlessly through extra.

Trait Implementations

impl Clone for ChatCapability

fn clone(&self) -> ChatCapability

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ChatCapability

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ChatCapability

fn default() -> ChatCapability

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ChatCapability

where ChatCapability: Default,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.