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<BodyType>,
    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

Strictness

The struct-level #[serde(default)] is deliberately NOT present: max_body_bytes, max_attachment_bytes, max_attachments_per_message, and supports_threads are spec-required fields (draft-atwood-jmap-chat-00 §3 lines 171-184). A server returning {} for this capability is non-compliant, and consumers surface that via a deserialize error rather than silently defaulting every field to 0 / false (which would cause callers to refuse to send any message because max_body_bytes == 0).

supported_body_types carries field-level #[serde(default)] only — see its rustdoc for the forward-compat tolerance rationale.

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<BodyType>

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

Spec requirements for compliant servers:

• MUST include BodyType::Plain ("text/plain").
• SHOULD include BodyType::Markdown ("text/markdown", RFC 7763 CommonMark).
• SHOULD include BodyType::Rich ("application/jmap-chat-rich").
• SHOULD include BodyType::Other("application/mls-ciphertext".into()) for E2EE deployments.
• MAY include BodyType::Other("application/mimi-content".into()).

An empty Vec is non-compliant per spec (BodyType::Plain is mandatory) but consumers tolerate 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 variant).

Element type is BodyType rather than String so callers can match on the typed variants directly; canonical MIME-type wire strings deserialize to their typed variant and any unknown wire string lands in BodyType::Other per the impl_string_enum! round-trip contract.

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).

The five aggregate-count caps maxGroupMembers, maxSpaceMembers, maxRolesPerSpace, maxChannelsPerSpace, and maxCategoriesPerSpace are not advertised on this capability in the current draft-atwood-jmap-chat-00 §3 — 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<(), Error>

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

fn deserialize<__D>( __deserializer: __D, ) -> Result<ChatCapability, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for ChatCapability

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.