Enum AppErrorKind 

pub enum AppErrorKind {
    NotFound,
    Validation,
    Conflict,
    Unauthorized,
    Forbidden,
    NotImplemented,
    Internal,
    BadRequest,
    TelegramAuth,
    InvalidJwt,
    Database,
    Service,
    Config,
    Turnkey,
    Timeout,
    Network,
    RateLimited,
    DependencyUnavailable,
    Serialization,
    Deserialization,
    ExternalApi,
    Queue,
    Cache,
}

Canonical application error taxonomy.

Keep it small, stable, and framework-agnostic. Each variant has a clear, documented meaning and a predictable mapping to an HTTP status code.

Variants

NotFound

Resource does not exist or is not visible to the caller.

Maps to 404 Not Found.

Validation

Input failed validation (shape, constraints, business rules).

Prefer this over BadRequest when you validate structured input. Maps to 422 Unprocessable Entity.

Conflict

State conflict with an existing resource or concurrent update.

Typical cases: unique key violation, version mismatch (ETag). Maps to 409 Conflict.

Unauthorized

Authentication required or failed (missing/invalid credentials).

Maps to 401 Unauthorized.

Forbidden

Authenticated but not allowed to perform the operation.

Maps to 403 Forbidden.

NotImplemented

Operation is not implemented or not supported by this deployment.

Maps to 501 Not Implemented.

Internal

Unexpected server-side failure not captured by more specific kinds.

Use sparingly; prefer a more precise category when possible. Maps to 500 Internal Server Error.

BadRequest

Malformed request or missing required parameters.

Prefer Validation for structured input with field-level issues. Maps to 400 Bad Request.

TelegramAuth

Telegram authentication flow failed (signature, timestamp, or payload).

Treated as an authentication failure. Maps to 401 Unauthorized.

InvalidJwt

Provided JWT is invalid (expired, malformed, wrong signature/claims).

Treated as an authentication failure. Maps to 401 Unauthorized.

Database

Database-related failure (query, connection, migration, etc.).

Keep driver-specific details out of the public contract. Maps to 500 Internal Server Error.

Service

Generic service-layer failure (business logic or internal orchestration).

Use when no more specific category applies. Maps to 500 Internal Server Error.

Config

Configuration error (missing/invalid environment or runtime config).

Maps to 500 Internal Server Error.

Turnkey

Failure in the Turnkey subsystem/integration.

Maps to 500 Internal Server Error.

Timeout

Operation did not complete within the allotted time.

Typically returned by timeouts around I/O or remote calls. Maps to 504 Gateway Timeout.

Network

Network-level error (DNS, connect, TLS, request build).

For upstream HTTP status failures use ExternalApi instead. Maps to 503 Service Unavailable.

RateLimited

Client exceeded rate limits or quota.

Maps to 429 Too Many Requests.

DependencyUnavailable

External dependency is unavailable or degraded.

Examples: cache down, message broker unreachable, third-party outage. Maps to 503 Service Unavailable.

Serialization

Failed to serialize data (encode).

Maps to 500 Internal Server Error.

Deserialization

Failed to deserialize data (decode).

Maps to 500 Internal Server Error.

ExternalApi

Upstream API returned an error or the call failed at protocol level.

Use Network for connect/build failures; use this for HTTP status errors. Maps to 500 Internal Server Error by default.

Queue

Queue processing failure (publish/consume/ack).

Maps to 500 Internal Server Error.

Cache

Cache subsystem failure (read/write/encoding).

Maps to 500 Internal Server Error.

Implementations

impl AppErrorKind

pub const fn label(&self) -> &'static str

Human-readable label exposed in HTTP and telemetry payloads.

pub fn http_status(&self) -> u16

Framework-agnostic mapping to an HTTP status code (u16).

This mapping is intentionally conservative and stable. It should not leak environment-specific details (e.g. DB driver error codes or HTTP library errors).

Trait Implementations

impl Clone for AppErrorKind

fn clone(&self) -> AppErrorKind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for AppErrorKind

impl Debug for AppErrorKind

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

Formats the value using the given formatter.

impl Display for AppErrorKind

Available on non-crate feature colored only.

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

Formats the value using the given formatter.

impl Eq for AppErrorKind

impl Error for AppErrorKind

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<AppErrorKind> for AppCode

fn from(kind: AppErrorKind) -> Self

Map internal taxonomy (AppErrorKind) to public machine code (AppCode).

The mapping is 1:1 today and intentionally conservative.

impl PartialEq for AppErrorKind

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for AppErrorKind