Enum Destination 

pub enum Destination {
    Local,
    Remote(String),
}

Where a ToolClient sends a call.

Why a transport has to say this

Egress does set membership on a host, and every other outbound path hands it one — a model driver parses its base URL, a peer client its card URL. A tool grant is tool://server/name, which names a catalogue entry and not a destination, so a client cannot be asked to parse a URL it may not have: it declares the answer, and the declaration is what the allowlist judges.

What each answer means, and what it does not claim

Local says this client opens no network connection from this plane: tools compiled into the binary, an MCP server run as a child process over stdio, a test double. It is not a claim that the far side reaches nothing — a child process can open its own socket, and that is the same residual as a compromised allowlisted endpoint. What it claims is that no host of this plane’s choosing is being contacted, which is the question an allowlist can answer.

Remote names the host. Deny-by-default applies to it once an Egress is wired.

Variants

Local

Opens no network connection from this plane.

Remote(String)

Connects to this host.

Implementations

impl Destination

pub fn remote(host: impl Into<String>) -> Self

Name the host this client connects to.

pub fn host(&self) -> Option<&str>

The host an allowlist judges, or None for a local transport.

Trait Implementations

impl Clone for Destination

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 Destination

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

Formats the value using the given formatter.

impl Eq for Destination

impl PartialEq for Destination

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Destination