Enum ProviderError 

#[non_exhaustive]
pub enum ProviderError {
    Api {
        status: u16,
        code: Option<String>,
        message: String,
    },
    Protocol {
        message: String,
    },
    Decode {
        message: String,
    },
    RateLimited {
        retry_after: Option<Duration>,
    },
    Network(String),
    Timeout(TimeoutStage),
    Cancelled,
    ResponseTooLarge {
        limit_bytes: usize,
    },
    Unsupported {
        capability: &'static str,
    },
}

Why a Provider call failed.

The enum categories cover the cases that need distinguishing, with details carried by fields; vendor-specific errors are mapped into this type at the implementation boundary. #[non_exhaustive] guarantees that adding new categories in the future is not a breaking change.

Error classification is the basis for retry decisions (see the Default judgment of Retryable): Network / Timeout / RateLimited are worth retrying, while Api is judged by status (5xx retried, 4xx not — retrying would not change the outcome). Local decode/protocol errors are distinct from vendor API errors and are not retried by default.

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.

Api

A business/API error returned by the vendor (auth failure / invalid arguments, quota exhaustion, server error), carrying the HTTP status and optional vendor error code.

Fields

status: u16

HTTP status code returned by the vendor.

code: Option<String>

Optional vendor error code.

message: String

Error description text.

Protocol

Provider response was syntactically decoded but violated either the vendor contract or molo’s provider contract.

Fields

message: String

Error description text.

Decode

Provider response body, SSE frame, or encoded payload could not be decoded.

Fields

message: String

Error description text.

RateLimited

Rate limited (HTTP 429): retrying is meaningful, and the default retry policy waits before retrying.

retry_after: the wait duration parsed from the vendor’s Retry-After response header (numeric seconds); None when absent (HTTP date formats are not parsed).

Fields

retry_after: Option<Duration>

The wait duration indicated by the vendor (numeric seconds); None when missing / not numeric.

Network(String)

A network-layer failure (connection failure and other transport errors).

Implementations map concrete transport errors (e.g. reqwest’s) into carried text, so the error type does not depend on a concrete implementation library’s types.

Timeout(TimeoutStage)

Request timeout, carrying the stage at which it occurred (see TimeoutStage): distinguishes “cannot connect”, “total duration elapsed” and “event interval stalled” for easier diagnosis.

Cancelled

Provider request was cancelled through provider context.

ResponseTooLarge

Provider response exceeded a configured local size limit.

Fields

limit_bytes: usize

Configured limit that was exceeded.

Unsupported

Capability was requested from a provider that does not support it.

Fields

capability: &'static str

Unsupported capability name.

Trait Implementations

impl Clone for ProviderError

fn clone(&self) -> ProviderError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ProviderError

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

Formats the value using the given formatter.

impl Display for ProviderError

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

Formats the value using the given formatter.

impl Eq for ProviderError

impl Error for ProviderError

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 PartialEq for ProviderError

fn eq(&self, other: &ProviderError) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ProviderError