Enum Error 

#[non_exhaustive]
pub enum Error {
    Provider(Box<ProviderError>),
    Retry {
        reason: RetryReason,
        attempts: u32,
        errors: Vec<ProviderError>,
    },
    Timeout {
        scope: TimeoutScope,
        elapsed: Duration,
    },
    Cancelled,
    InvalidArgument {
        argument: String,
        message: String,
    },
    InvalidPrompt {
        message: String,
    },
    MessageConversion {
        message: String,
        original_message: Box<Message>,
    },
    Download(Box<DownloadDetails>),
    InvalidDataContent {
        message: String,
        cause: Option<BoxError>,
    },
    NoSuchTool {
        tool_name: ToolName,
        available_tools: Vec<ToolName>,
    },
    InvalidToolInput(Box<InvalidToolInputDetails>),
    ToolCallRepair {
        original: Box<Error>,
        cause: BoxError,
    },
    ToolChoiceViolation {
        expected: ToolName,
        actual: ToolName,
    },
    ToolCallNotFoundForApproval {
        tool_call_id: ToolCallId,
        approval_id: ApprovalId,
    },
    ToolChoiceNotSatisfied {
        expected: Option<ToolName>,
    },
    InvalidToolApproval {
        approval_id: ApprovalId,
        message: String,
    },
    NoObjectGenerated(Box<NoObjectGeneratedDetails>),
    NoOutputGenerated,
    NoImageGenerated {
        responses: Vec<ResponseMetadata>,
    },
    NoSpeechGenerated {
        responses: Vec<ResponseMetadata>,
    },
    NoTranscriptGenerated {
        responses: Vec<ResponseMetadata>,
    },
    NoTranslationGenerated {
        response: Box<ResponseMetadata>,
    },
    NoVideoGenerated {
        responses: Vec<ResponseMetadata>,
    },
    NoSuchProvider(Box<NoSuchProviderDetails>),
    NoDefaultRegistry {
        model_id: String,
    },
    InvalidStreamPart {
        message: String,
    },
    Stream(Box<StreamError>),
    Mcp(BoxError),
    Other(BoxError),
}

Errors returned by the core API.

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.

Provider(Box<ProviderError>)

A provider adapter failed.

Retry

Retries were exhausted or stopped early.

Fields

reason: RetryReason

Why retrying stopped.

attempts: u32

Number of attempts made.

errors: Vec<ProviderError>

Errors of every attempt, oldest first.

Timeout

A configured timeout elapsed.

Fields

scope: TimeoutScope

Which timeout fired.

elapsed: Duration

Time elapsed when it fired.

Cancelled

The caller cancelled the operation.

InvalidArgument

A call setting is invalid.

Fields

argument: String

Name of the offending argument.

message: String

What is wrong with it.

InvalidPrompt

The prompt is invalid (empty, both prompt and messages, …).

Fields

message: String

What is wrong with it.

MessageConversion

A message could not be converted to the specification prompt.

Fields

message: String

What is wrong.

original_message: Box<Message>

The message concerned.

Download(Box<DownloadDetails>)

A URL in the prompt could not be downloaded.

InvalidDataContent

Inline data content (base64, data URL) is invalid.

Fields

message: String

What is wrong.

cause: Option<BoxError>

Underlying cause.

NoSuchTool

The model called a tool that is not in the tool set.

Fields

tool_name: ToolName

The unknown name.

available_tools: Vec<ToolName>

Names the model could have used.

InvalidToolInput(Box<InvalidToolInputDetails>)

The model produced input that does not match the tool schema.

ToolCallRepair

The tool call repair function failed.

Fields

original: Box<Error>

The error the repair function was asked to fix.

cause: BoxError

The repair function’s own error.

ToolChoiceViolation

tool_choice required one tool but the model called another.

Fields

expected: ToolName

The required tool.

actual: ToolName

The tool actually called.

ToolCallNotFoundForApproval

An approval response refers to a tool call missing from the history.

Fields

tool_call_id: ToolCallId

The referenced tool call.

approval_id: ApprovalId

The approval concerned.

ToolChoiceNotSatisfied

The model finished without the tool call that the tool choice required.

Fields

expected: Option<ToolName>

The required tool, when the choice named one.

InvalidToolApproval

An approval response is invalid (unknown request, bad signature).

Fields

approval_id: ApprovalId

The approval concerned.

message: String

What is wrong.

NoObjectGenerated(Box<NoObjectGeneratedDetails>)

Structured output could not be parsed or validated.

NoOutputGenerated

The last step did not qualify for structured output parsing.

NoImageGenerated

Every image call returned no image.

Fields

responses: Vec<ResponseMetadata>

Responses of the attempted calls.

NoSpeechGenerated

The speech model returned no audio.

Fields

responses: Vec<ResponseMetadata>

Responses of the attempted calls.

NoTranscriptGenerated

The transcription model returned no text.

Fields

responses: Vec<ResponseMetadata>

Responses of the attempted calls.

NoTranslationGenerated

The speech translation stream produced no translated text or audio.

Fields

response: Box<ResponseMetadata>

Response metadata accumulated before the stream ended.

NoVideoGenerated

Every video call returned no video.

Fields

responses: Vec<ResponseMetadata>

Responses of the attempted calls.

NoSuchProvider(Box<NoSuchProviderDetails>)

The registry has no provider with the requested id.

NoDefaultRegistry

A provider:model string was used without a default registry.

Fields

model_id: String

The unresolved id.

InvalidStreamPart

The provider stream violated the specification contract.

Fields

message: String

What is wrong.

Stream(Box<StreamError>)

The provider stream reported an error part.

Mcp(BoxError)

An MCP error (type-erased: the core does not depend on the MCP crate).

Other(BoxError)

Any other error.

Implementations

impl Error

pub fn invalid_argument( argument: impl Into<String>, message: impl Into<String>, ) -> Self

Creates an Error::InvalidArgument.

pub fn invalid_prompt(message: impl Into<String>) -> Self

Creates an Error::InvalidPrompt.

pub fn invalid_data_content( message: impl Into<String>, cause: Option<BoxError>, ) -> Self

Creates an Error::InvalidDataContent.

pub fn download( url: Url, status_code: Option<StatusCode>, cause: Option<BoxError>, ) -> Self

Creates an Error::Download.

pub fn no_such_tool( tool_name: impl Into<ToolName>, available_tools: Vec<ToolName>, ) -> Self

Creates an Error::NoSuchTool.

pub fn invalid_tool_input( tool_name: impl Into<ToolName>, tool_input: impl Into<String>, cause: impl Into<BoxError>, ) -> Self

Creates an Error::InvalidToolInput.

pub fn no_object_generated(details: NoObjectGeneratedDetails) -> Self

Creates an Error::NoObjectGenerated.

pub fn no_such_provider(details: NoSuchProviderDetails) -> Self

Creates an Error::NoSuchProvider.

pub fn invalid_stream_part(message: impl Into<String>) -> Self

Creates an Error::InvalidStreamPart.

pub fn stream(error: StreamError) -> Self

Wraps a stream error part as Error::Stream.

pub fn other(error: impl Error + Send + Sync + 'static) -> Self

Wraps any error as Error::Other.

pub fn message(message: impl Into<String>) -> Self

Wraps a message as Error::Other.

pub fn is_retryable(&self) -> bool

Returns true when retrying the operation may succeed.

pub fn is_cancelled(&self) -> bool

Returns true when the error is the result of cancellation.

pub fn status_code(&self) -> Option<StatusCode>

Returns the HTTP status of the underlying provider response, if any.

pub fn as_provider(&self) -> Option<&ProviderError>

Returns the provider error when this error wraps one.

pub fn kind(&self) -> ErrorKind

Returns the coarse category.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

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 StreamErrorInfo

fn from(error: &Error) -> Self

Converts to this type from the input type.

impl From<InvalidArgumentError> for Error

fn from(error: InvalidArgumentError) -> Self

Converts to this type from the input type.

impl From<NoSuchModelError> for Error

fn from(error: NoSuchModelError) -> Self

Converts to this type from the input type.

impl From<ProviderError> for Error

fn from(error: ProviderError) -> Self

Converts to this type from the input type.

impl From<ToolError> for Error

fn from(error: ToolError) -> Self

Converts to this type from the input type.