Enum Error 

#[non_exhaustive]
pub enum Error {
    InvalidAgent(String),
    UnknownDriver(String),
    MaxIterations(usize),
    Cancelled,
    Sealed(SealReason),
    HookBlocked {
        reason: String,
        user_message: Option<String>,
    },
    Driver {
        kind: LlmErrorKind,
        message: String,
    },
    Mcp(String),
    EventLog(String),
    EventConflict {
        expected: u64,
        actual: u64,
    },
    Io(Error),
    Json(Error),
    Other(String),
}

Errors surfaced by agentyk.

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.

InvalidAgent(String)

The agent was composed without a model, or is otherwise invalid.

UnknownDriver(String)

No driver registered for the model’s DriverId.

MaxIterations(usize)

A turn hit the iteration ceiling without producing a final response.

Cancelled

The turn was cancelled via a crate::cancellation::CancellationToken.

Sealed(SealReason)

The turn was deliberately sealed — see crate::turn::SealReason.

HookBlocked

A blockable user hook refused the prompt or tool action.

Fields

reason: String

Diagnostic reason supplied by the hook.

user_message: Option<String>

Optional message suitable for a user-facing surface.

Driver

An LLM driver failed. kind classifies whether retrying is worth it — see Error::is_retryable.

Fields

kind: LlmErrorKind

Whether retrying is worth it.

message: String

What the provider or transport reported.

Mcp(String)

An MCP server or transport failed.

EventLog(String)

The event log failed to append or read.

EventConflict

An append expected a different end-of-stream sequence.

Fields

expected: u64

Version supplied by the writer.

actual: u64

Version currently stored.

Io(Error)

Local I/O failed — an event log file, a workspace read.

Json(Error)

Serialization or deserialization failed.

Other(String)

Anything without a more specific variant.

Implementations

impl Error

pub fn driver(kind: LlmErrorKind, message: impl Into<String>) -> Error

Shorthand for Error::Driver { kind, message: message.into() }.

pub fn is_retryable(&self) -> bool

Whether a host should consider retrying the operation that produced this error. Only Error::Driver carries enough information to say yes; every other variant is a local/config problem retrying can’t fix.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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 Error

fn from(source: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(source: Error) -> Error

Converts to this type from the input type.