Struct Capability 

pub struct Capability(/* private fields */);

A capability document: resource pattern → set of allowed operation strings. Operation strings are stored (not the enum) so the BTreeSet sorts lexicographically by wire value, matching Ably’s canonicalization.

Implementations

impl Capability

pub fn new() -> Self

An empty capability document.

pub fn allow( self, resource: impl Into<String>, ops: impl IntoIterator<Item = Operation>, ) -> Self

Grant ops on resource (a channel-name pattern, e.g. "room", "dms:*", "*"). Repeated resources merge.

pub fn to_capability_string(&self) -> String

The canonical capability string for a TokenRequest or an x-ably-capability JWT claim: sorted resource keys, sorted operations, no whitespace.

pub fn for_room( self, room: &str, ops: impl IntoIterator<Item = Operation>, ) -> Self

Grant ops on a chat room, scoped by room name.

Uses the bare room name, which Ably’s product model expands to authorize both the /chat/v4 REST API and the room::$chat channel. Do not pass "{room}::$chat" here — that authorizes only the realtime channel and would 40160 on REST. The explicit product qualifier [chat]{room} is available via Capability::allow.

NOTE (pre-1.0): the exact resource form is confirmed only to moderate-high confidence; verify against a live app before stabilization (see docs/research/2026-07-24-ably-chat-auth-permissions.md §A2.2).

pub fn to_json(&self) -> Value

The capability as a native JSON object (not a stringified value), for the Ably Control API key capability field (ADR-0012 §A2.5).

Trait Implementations

impl Clone for Capability

fn clone(&self) -> Capability

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Capability

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

Formats the value using the given formatter.

impl Default for Capability

fn default() -> Capability

Returns the “default value” for a type.

impl Eq for Capability

impl PartialEq for Capability

fn eq(&self, other: &Capability) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Capability