Enum SecurityScheme 

#[non_exhaustive]
pub enum SecurityScheme {
    ApiKey(ApiKeySecurityScheme),
    Http(HttpAuthSecurityScheme),
    OAuth2(Box<OAuth2SecurityScheme>),
    OpenIdConnect(OpenIdConnectSecurityScheme),
    MutualTls(MutualTlsSecurityScheme),
}

A security scheme supported by an agent.

Wire format

In A2A v1.0 this is the SecurityScheme oneof from a2a.proto, so its ProtoJSON encoding is a single-key object naming the arm:

{"apiKeySecurityScheme": {"location": "header", "name": "X-Api-Key"}}
{"httpAuthSecurityScheme": {"scheme": "bearer", "bearerFormat": "JWT"}}

v0.3 used the OpenAPI-style internally tagged form instead ({"type": "apiKey", "in": "header", …}). Both are accepted; only the v1.0 form is emitted, because §5.5 governs emission and the schema is the normative definition of the JSON shape.

This changed in 0.8: earlier releases emitted the v0.3 form. A reference a2a-sdk client parsed that via its own legacy-compatibility shim, but a peer feeding the card straight to ParseDict(…, ignore_unknown_fields=True) silently got schemes with empty contents — it saw the agent declare authentication it could not use. See docs/official-tck-findings.md §7.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

ApiKey(ApiKeySecurityScheme)

API key authentication (apiKeySecurityScheme).

Http(HttpAuthSecurityScheme)

HTTP authentication, e.g. Bearer or Basic (httpAuthSecurityScheme).

OAuth2(Box<OAuth2SecurityScheme>)

OAuth 2.0 (oauth2SecurityScheme).

Boxed to reduce the enum’s stack size.

OpenIdConnect(OpenIdConnectSecurityScheme)

OpenID Connect (openIdConnectSecurityScheme).

MutualTls(MutualTlsSecurityScheme)

Mutual TLS (mtlsSecurityScheme).

Implementations

impl SecurityScheme

pub const fn arm_name(&self) -> &'static str

The ProtoJSON oneof arm name this variant serializes under.

Trait Implementations

impl Clone for SecurityScheme

fn clone(&self) -> SecurityScheme

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for SecurityScheme

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SecurityScheme

fn deserialize<D>( deserializer: D, ) -> Result<SecurityScheme, <D as Deserializer<'de>>::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<LegacySecurityScheme> for SecurityScheme

fn from(v: LegacySecurityScheme) -> SecurityScheme

Converts to this type from the input type.

impl Serialize for SecurityScheme

fn serialize<S>( &self, serializer: S, ) -> Result<<S as Serializer>::Ok, <S as Serializer>::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<SecurityScheme> for SecurityScheme

type Error = ConvertError

The type returned in the event of a conversion error.

fn try_from( value: SecurityScheme, ) -> Result<SecurityScheme, <SecurityScheme as TryFrom<SecurityScheme>>::Error>

Performs the conversion.

impl TryFrom<SecurityScheme> for SecurityScheme

type Error = ConvertError

The type returned in the event of a conversion error.

fn try_from( value: SecurityScheme, ) -> Result<SecurityScheme, <SecurityScheme as TryFrom<SecurityScheme>>::Error>

Performs the conversion.