Enum LiterLlmError 

#[non_exhaustive]
pub enum LiterLlmError {
    Authentication {
        message: String,
        status: u16,
    },
    RateLimited {
        message: String,
        retry_after: Option<Duration>,
    },
    BadRequest {
        message: String,
        status: u16,
    },
    ContextWindowExceeded {
        message: String,
    },
    ContentPolicy {
        message: String,
    },
    NotFound {
        message: String,
    },
    ServerError {
        message: String,
        status: u16,
    },
    ServiceUnavailable {
        message: String,
        status: u16,
        retry_after: Option<Duration>,
    },
    Timeout,
    Network {
        message: String,
    },
    Streaming {
        message: String,
    },
    EndpointNotSupported {
        endpoint: String,
        provider: String,
    },
    InvalidHeader {
        name: String,
        reason: String,
    },
    Serialization(Error),
    BudgetExceeded {
        message: String,
        model: Option<String>,
    },
    HookRejected {
        message: String,
    },
    InternalError {
        message: String,
    },
    OutboundForbidden {
        url: String,
        reason: String,
    },
    IdempotencyConflict {
        key: String,
    },
    IdempotencyInFlight {
        key: String,
    },
    ProviderQuotaExceeded {
        message: String,
        status: u16,
    },
}

All errors that can occur when using liter-llm.

Each variant carries a stable numeric error_code (>= 100) that bindings expose across the FFI boundary. Codes are append-only: never renumber or reuse a code.

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.

Authentication

status preserves the exact HTTP status code received (401 or 403).

Fields

message: String

status: u16

RateLimited

Fields

message: String

retry_after: Option<Duration>

BadRequest

status preserves the exact HTTP status code received (400, 405, 413, 422, …).

Fields

message: String

status: u16

ContextWindowExceeded

Fields

message: String

ContentPolicy

Fields

message: String

NotFound

Fields

message: String

ServerError

status preserves the exact HTTP status code received (500, or other 5xx not covered by ServiceUnavailable).

Fields

message: String

status: u16

ServiceUnavailable

status preserves the exact HTTP status code received (502, 503, or 504).

Fields

message: String

status: u16

retry_after: Option<Duration>

Timeout

Network

Fields

message: String

Streaming

A catch-all for errors that occur during streaming response processing.

This variant covers multiple sub-conditions including UTF-8 decoding failures, CRC/checksum mismatches (AWS EventStream), JSON parse errors in individual SSE chunks, and buffer overflow conditions. The message field contains a human-readable description of the specific failure.

Fields

message: String

EndpointNotSupported

Fields

endpoint: String

provider: String

InvalidHeader

Fields

name: String

reason: String

Serialization(Error)

BudgetExceeded

Fields

message: String

model: Option<String>

HookRejected

Fields

message: String

InternalError

An internal logic error (e.g. unexpected Tower response variant).

This should never surface in normal operation — if it does, it indicates a bug in the library.

Fields

message: String

OutboundForbidden

An outbound request was blocked by the active crate::provider::OutboundPolicy.

Returned when register_custom_provider is called with a base_url that violates the policy (e.g. a private-range IP under DenyPrivate), or when the per-connection DNS resolver detects a forbidden address at connect time.

Fields

url: String

reason: String

IdempotencyConflict

A different request body was submitted for an existing Idempotency-Key.

Per the OpenAI Idempotency-Key convention, once a key is used with a particular request body, subsequent requests using the same key must carry an identical body. A body mismatch is a hard error (not retryable).

HTTP equivalent: 409 Conflict.

Fields

key: String

IdempotencyInFlight

The same Idempotency-Key is already in-flight (another request with the same key is currently being processed).

The caller should wait briefly and retry. The response is not yet available, and this request has been short-circuited to avoid running the operation twice.

HTTP equivalent: 409 Conflict (retryable after a brief delay).

Fields

key: String

ProviderQuotaExceeded

The upstream provider rejected the request because the account quota is exhausted.

Fields

message: String

status: u16

Implementations

impl LiterLlmError

pub fn status_code(&self) -> u16

Returns the canonical HTTP status code associated with this error.

Maps error variants to their originating HTTP status code as set by the private from_status constructor. Used by e2e assertions that check error.status_code against the expected HTTP status.

pub fn retry_after(&self) -> Option<Duration>

Returns the server-advertised retry delay, when the error carries one.

Parsed from the upstream Retry-After header on a 429. Exposed as an accessor alongside Self::status_code and Self::error_type so the generated bindings can surface it: the value reached the Rust core but stopped there, leaving every binding consumer to re-derive its own backoff from nothing more than the status code. ~keep

pub fn is_transient(&self) -> bool

Returns true for errors that are worth retrying on a different service or deployment (transient failures).

Used by [crate::tower::fallback::FallbackService] and [crate::tower::router::Router] to decide whether to route to an alternative endpoint.

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

Return the OpenTelemetry error.type string for this error variant.

Used by the tracing middleware to record the error.type span attribute on failed requests per the GenAI semantic conventions.

Trait Implementations

impl Debug for LiterLlmError

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

Formats the value using the given formatter.

impl Display for LiterLlmError

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

Formats the value using the given formatter.

impl Error for LiterLlmError

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 LiterLlmError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for LiterLlmError

Available on crate features native-http or wasm-http only.

fn from(error: Error) -> Self

Converts to this type from the input type.

impl From<LiterLlmError> for BatchWaitError

fn from(err: LiterLlmError) -> Self

Converts to this type from the input type.