Struct OAuthAuthenticator 

pub struct OAuthAuthenticator<A> { /* private fields */ }

Authenticates bearer tokens against a TokenSource.

Generic over the source rather than holding a dyn, following TokenSource’s own rule: the call site takes impl TokenSource, so this monomorphises and the per-request cost is a direct call rather than a boxed future behind a vtable. The scopes and the clock are dyn because a deployment supplies them by value at construction and they are one call each.

Implementations

impl<A> OAuthAuthenticator<A>

pub fn new( source: A, metadata: ResourceMetadata, version: ProtocolVersion, scopes: impl ScopePolicy + 'static, clock: impl WallClock + 'static, ) -> Self

An authenticator for source, protecting metadata’s resource under the model version selects.

Examples

use protocol_droid::adapters::primary::transport::http::{
    OAuthAuthenticator, SystemClock,
};
use protocol_droid::application::oauth::NoScopes;
use protocol_droid::domain::{ProtocolVersion, mcp::{ResourceMetadata, ResourceUri}};

let metadata = ResourceMetadata::new(ResourceUri::new("https://example.com/mcp")?);
let authenticator = OAuthAuthenticator::new(
    (),                 // a real deployment passes a `TokenSource`
    metadata,
    ProtocolVersion::V2025_06_18,
    NoScopes,
    SystemClock,
);

pub fn with_expected_issuer(self, issuer: impl Into<Arc<str>>) -> Self

Requires tokens to name issuer, rather than accepting any.

Off by default because RFC 9728 publishes a list of authorization servers this resource trusts, so a deployment fronted by more than one legitimately accepts more than one issuer. Turning it on is how a single-issuer deployment says so.

pub fn metadata(&self) -> &ResourceMetadata

The resource this authenticator protects.

Trait Implementations

impl<A> Authenticator for OAuthAuthenticator<A>

where A: TokenSource,

fn authenticate<'a>( &'a self, presented: &'a Credentials<'_>, ) -> Pin<Box<dyn Future<Output = AuthContext> + Send + 'a>>

The context presented is allowed to act under.

impl<A> Debug for OAuthAuthenticator<A>

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

Prints the configuration only.

Written by hand rather than derived, and not for the usual reason of a field that is awkward to format: the derive would demand A: Debug on the source — which for a JWT source would mean formatting its key set — and dyn Debug on two fields that are behaviour, not state. What is left is what an operator actually needs when a 401 shows up: which resource is protected, under which revision’s model, and whether an issuer was pinned. The expected issuer is printed; nothing else on this type is secret, and no token ever reaches it.