Enum ProtocolPolicy 

pub enum ProtocolPolicy {
    Auto,
    ModernOnly,
    LegacyOnly,
}

Immutable policy chosen before a client connects or a server binds.

Auto remains the default policy. A policy value does not itself classify a peer or mutate in response to peer bytes, errors, timeouts, or auth events; transport-specific classification belongs to FND-03 integration.

Variants

Auto

Permit both supported eras; transport-specific code classifies once.

ModernOnly

Permit only MCP 2026-07-28.

LegacyOnly

Permit only exact MCP 2024-11-05.

Implementations

impl ProtocolPolicy

pub const fn permits(self, version: ProtocolVersion) -> bool

Returns whether this immutable policy admits a version.

pub const fn supported_versions(self) -> &'static [ProtocolVersion]

Returns the policy-level exact supported-version set.

This answers which eras the selected policy can operate, not which versions a modern Streamable HTTP discovery response advertises. In particular, Auto retains both eras here so its legacy adapter path remains available after isolated transport classification.

pub const fn modern_discovery_versions(self) -> &'static [ProtocolVersion]

Returns the versions advertised by modern Streamable HTTP discovery.

Legacy 2024-11-05 is selected only through the isolated legacy transport path. It is never included inline in a modern discovery response, including when the immutable policy is Auto.

pub const fn preferred_versions(self) -> &'static [ProtocolVersion]

Returns the client preference order for this policy.

Auto prefers the modern revision first; a fallback decision is owned by the isolated client-negotiation layer, never by this value type.

pub const fn requires_legacy_adapter(self) -> bool

Returns whether using this policy requires a legacy adapter receipt.

pub fn validate_for_client( self, legacy_receipt: Option<&LegacyClientAdapterInstalledReceipt>, ) -> Result<ProtocolPolicySelection, ProtocolPolicyError>

Validates a client policy before any connect-side effect.

pub fn validate_for_server( self, legacy_receipt: Option<&LegacyServerAdapterInstalledReceipt>, ) -> Result<ProtocolPolicySelection, ProtocolPolicyError>

Validates a server policy before any bind-side effect.

Trait Implementations

impl Clone for ProtocolPolicy

fn clone(&self) -> ProtocolPolicy

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ProtocolPolicy

impl Debug for ProtocolPolicy

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

Formats the value using the given formatter.

impl Default for ProtocolPolicy

fn default() -> ProtocolPolicy

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ProtocolPolicy

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ProtocolPolicy

impl Hash for ProtocolPolicy

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for ProtocolPolicy

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ProtocolPolicy

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for ProtocolPolicy