Struct CardClient 

pub struct CardClient { /* private fields */ }

Fetches and checks the cards other agents publish.

Implementations

impl CardClient

pub const DEFAULT_TIMEOUT: Duration

How long a card fetch may take in total.

Ten seconds: a card is a small static document, and a server that cannot produce one in that time is not one worth waiting on. Unbounded is the wrong default anywhere, and here it lets an unknown host hold a task open for as long as it likes.

pub fn new() -> Self

pub const fn allow_loopback(self) -> Self

Permit a card served from this machine.

Behind testkit and therefore absent from a production build, which is the property that matters: an exception that can only be compiled into a test binary cannot be left on by accident in a deployment.

It applies to a host that is a loopback literal or localhost — never to one that merely resolved to one, which is the rebinding attack and stays refused with the flag set. See netguard::is_loopback_name.

pub const fn timeout(self, timeout: Duration) -> Self

Change the whole-request timeout.

Panics

If zero, which would spell never fetch a card as if it were a policy.

pub fn egress(self, egress: Egress) -> Self

Restrict where cards may be fetched from.

pub fn verifying_with(self, verifier: Arc<dyn CardVerifier>) -> Self

Require a signature from a key this verifier trusts.

Off by default, and that is a deliberate choice rather than an oversight: most cards in the wild are unsigned today, and a client that refused them all would simply not be used. Setting this makes verification mandatory — an unsigned card is then refused, because a verifier that accepts an unsigned card whenever one arrives is one an attacker downgrades by stripping the signature.

pub async fn discover(&self, origin: &str) -> Result<AgentCard, DiscoveryError>

Fetch the card an agent publishes at its well-known path.

origin is a scheme and host — the path is the spec’s, not the caller’s, which is the point of a well-known location.

Errors

DiscoveryError::Refused when egress forbids the host, DiscoveryError::Unreachable on a transport failure, DiscoveryError::Malformed when the body is not a card, and DiscoveryError::Signature when verification is required and fails.

pub async fn fetch(&self, url: &str) -> Result<AgentCard, DiscoveryError>

Fetch a card from an exact URL.

Errors

As discover.

Trait Implementations

impl Clone for CardClient

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CardClient

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

Formats the value using the given formatter.

impl Default for CardClient

fn default() -> Self

Returns the “default value” for a type.