Enum A2AError 

pub enum A2AError {
    JsonRpc {
        code: i32,
        message: String,
        data: Option<Value>,
    },
    JsonParse(Error),
    InvalidRequest(String),
    InvalidParams(String),
    MethodNotFound(String),
    TaskNotFound(String),
    TaskNotCancelable(String),
    PushNotificationNotSupported,
    UnsupportedOperation(String),
    ContentTypeNotSupported(String),
    InvalidAgentResponse(String),
    AuthenticatedExtendedCardNotConfigured,
    Internal(String),
    ValidationError {
        field: String,
        message: String,
    },
    VersionConflict {
        id: String,
        expected: u64,
        actual: u64,
    },
    DatabaseError(String),
    ContextAccessDenied {
        context_id: String,
    },
    Io(Error),
}

Error type for the A2A protocol operations

Variants

JsonRpc

Fields

code: i32

message: String

data: Option<Value>

JsonParse(Error)

InvalidRequest(String)

InvalidParams(String)

MethodNotFound(String)

TaskNotFound(String)

TaskNotCancelable(String)

PushNotificationNotSupported

UnsupportedOperation(String)

ContentTypeNotSupported(String)

InvalidAgentResponse(String)

AuthenticatedExtendedCardNotConfigured

Internal(String)

ValidationError

Fields

field: String

message: String

VersionConflict

Fields

id: String

expected: u64

actual: u64

DatabaseError(String)

ContextAccessDenied

The caller does not own this conversation.

A context_id groups the tasks of one conversation, and reading it back as prompt history means anyone holding the id can read what was said in it. This is the refusal for a principal that is not the one that started the context.

Fields

context_id: String

Io(Error)

Implementations

impl A2AError

pub fn to_jsonrpc_error(&self) -> Value

Convert an A2AError to a JSON-RPC error value

pub fn reason_code(&self) -> &'static str

Stable, machine-readable reason code for this error (SCREAMING_SNAKE_CASE, used as the ErrorInfo.reason on the wire).

pub fn error_details(&self) -> Vec<ErrorDetail>

Typed details for the JSON-RPC error.data array.

Validation failures surface as a Google-RPC BadRequest with field violations; version conflicts attach the expected/actual versions as ErrorInfo metadata; every other variant carries at least its stable reason_code as an ErrorInfo, so a client can branch on a machine code instead of parsing the message string.

Trait Implementations

impl Debug for A2AError

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

Formats the value using the given formatter.

impl Display for A2AError

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

Formats the value using the given formatter.

impl Error for A2AError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for A2AError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for A2AError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<HttpClientError> for A2AError

Available on crate features http-client or jsonrpc-client only.

fn from(error: HttpClientError) -> Self

Converts to this type from the input type.

impl From<HttpServerError> for A2AError

Available on crate feature http-server only.

fn from(error: HttpServerError) -> Self

Converts to this type from the input type.