Enum A2aError 

pub enum A2aError {
    MethodNotFound,
    MethodNotImplemented {
        method: A2aMethod,
    },
    InvalidParams {
        reason: String,
    },
    InternalError {
        message: String,
    },
    AuthenticationRequired,
    AuthenticationFailed {
        reason: String,
    },
    ContentTypeNotSupported {
        received: String,
    },
}

An A2A-specific error.

The variants are the JSON-RPC error codes the A2A spec names. The serving adapter maps each variant to a code and message on the wire; the consumer never has to know the codes.

JSON-RPC error codes

• -32601: MethodNotFound
• -32602: InvalidParams
• -32603: InternalError
• -32000: ContentTypeNotSupported
• -32001: AuthenticationRequired
• -32002: AuthenticationFailed

The negative numbers are the JSON-RPC standard’s reserved range for “implementation- defined server errors”; A2A v1.0 §5.3 fixes these specific codes. The standard JSON-RPC error codes (-32700 ParseError, -32600 Invalid Request, -32601 Method Not Found, -32602 Invalid Params, -32603 Internal Error) are reserved by JSON-RPC itself; the A2A spec assigns them and extends the implementation-defined range to -32000 through -32002.

Variants

MethodNotFound

The method name is not in the A2A vocabulary. Maps to JSON-RPC -32601.

MethodNotImplemented

The method is known to A2A but the consumer’s handler does not implement it. Maps to JSON-RPC -32601 (the same code as MethodNotFound; the distinction is for the consumer’s logs).

Fields

method: A2aMethod

The method the consumer did not implement.

InvalidParams

The params could not be decoded into the shape the handler expects. Maps to JSON-RPC -32602.

Fields

reason: String

Why the params are wrong. The serving adapter surfaces this on the wire as the JSON-RPC data field.

InternalError

The handler failed in a way that is not the caller’s fault. Maps to JSON-RPC -32603.

Fields

message: String

The error message. The serving adapter surfaces this on the wire as the JSON-RPC message field.

AuthenticationRequired

The request requires authentication and the request did not carry credentials. Maps to JSON-RPC -32001.

AuthenticationFailed

The request carried credentials and they were not accepted. Maps to JSON-RPC -32002.

Fields

reason: String

Why the credentials were rejected.

ContentTypeNotSupported

The request’s Content-Type is not application/json. Maps to JSON-RPC -32000.

Fields

received: String

The Content-Type the request carried.

Implementations

impl A2aError

pub const fn code(&self) -> i32

The JSON-RPC error code for this error.

The codes are the A2A v1.0 spec’s implementation-defined server-error range. The standard JSON-RPC error codes (-32700 ParseError, -32600 Invalid Request, -32601 Method Not Found, -32602 Invalid Params, -32603 Internal Error) are reserved by JSON-RPC itself; the A2A spec assigns them and extends the implementation-defined range to -32000 through -32002.

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

The JSON-RPC error message for this error.

A short, fixed string per the A2A spec; detailed context goes in the data field (the serving adapter’s responsibility, not this one).

Trait Implementations

impl Clone for A2aError

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 A2aError

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

Formats the value using the given formatter.

impl Eq for A2aError

impl PartialEq for A2aError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for A2aError