Enum LlmError 

#[non_exhaustive]
pub enum LlmError {
    Http {
        status: Option<StatusCode>,
        message: String,
        retryable: bool,
    },
    Auth(String),
    InvalidRequest(String),
    Provider {
        code: String,
        message: String,
        retryable: bool,
    },
    ResponseFormat {
        message: String,
        raw: String,
    },
    SchemaValidation {
        message: String,
        schema: Value,
        actual: Value,
    },
    ToolExecution {
        tool_name: String,
        source: Box<dyn Error + Send + Sync>,
    },
    RetryExhausted {
        attempts: u32,
        last_error: Box<LlmError>,
    },
    Timeout {
        elapsed_ms: u64,
    },
    MaxDepthExceeded {
        current: u32,
        limit: u32,
    },
}

The unified error type returned by all provider operations.

Variants are #[non_exhaustive] — new error kinds may be added in minor releases without breaking downstream matches (always include a wildcard arm).

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.

Http

An HTTP-level failure (transport error, unexpected status code).

status is None when the request never received a response (e.g. DNS failure, connection reset).

Fields

status: Option<StatusCode>

The HTTP status code, if one was received.

message: String

A human-readable description of the failure.

retryable: bool

Whether the caller should retry this request.

Auth(String)

The API key or token was rejected.

InvalidRequest(String)

The request was malformed (missing fields, invalid parameters).

Provider

A provider-specific error that doesn’t map to another variant.

Fields

code: String

Provider-defined error code (e.g. "overloaded").

message: String

Human-readable error description.

retryable: bool

Whether the caller should retry this request.

ResponseFormat

The response body could not be parsed.

Fields

message: String

What went wrong during parsing.

raw: String

The raw response body, for diagnostics.

SchemaValidation

A structured-output response failed JSON Schema validation.

Fields

message: String

Concatenated validation error messages.

schema: Value

The schema the value was validated against.

actual: Value

The value that failed validation.

ToolExecution

A tool invocation raised an error.

Fields

tool_name: String

The name of the tool that failed.

source: Box<dyn Error + Send + Sync>

The underlying error.

RetryExhausted

A retry policy exhausted its budget without a successful response.

Fields

attempts: u32

How many attempts were made.

last_error: Box<LlmError>

The error from the final attempt.

Timeout

The operation exceeded its deadline.

Fields

elapsed_ms: u64

Milliseconds elapsed before the timeout fired.

MaxDepthExceeded

A nested tool loop exceeded the maximum allowed depth.

This occurs when tool_loop is called recursively (e.g., a tool spawning a sub-agent) and the nesting depth exceeds max_depth in ToolLoopConfig.

Fields

current: u32

The depth at which the error was raised.

limit: u32

The configured maximum depth.

Implementations

impl LlmError

pub fn is_retryable(&self) -> bool

Returns true if the error is transient and the request may succeed on retry.

Useful for retry interceptors. This checks the retryable flag on applicable variants and treats timeouts as always retryable.

Example

use llm_stack::LlmError;

let err = LlmError::Timeout { elapsed_ms: 5000 };
assert!(err.is_retryable());

let err = LlmError::Auth("bad key".into());
assert!(!err.is_retryable());

Trait Implementations

impl Debug for LlmError

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

Formats the value using the given formatter.

impl Display for LlmError

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

Formats the value using the given formatter.

impl Error for LlmError

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 LlmError

fn from(err: Error) -> Self

Converts to this type from the input type.