Module error_code 

V2 标准错误码：定义 13 个规范错误码及其重试/回退语义。

AI-Protocol V2 standard error codes.

This module defines the canonical error code system from the AI-Protocol V2 specification (see ai-protocol/schemas/v2/error-codes.yaml). Each runtime implements these codes for consistent error handling across providers.

Error Code Categories

Prefix	Category	Description
E1xxx	client	Request-side errors
E2xxx	rate	Rate limit and quota errors
E3xxx	server	Provider-side errors
E4xxx	operational	Lifecycle and state conflicts
E9xxx	unknown	Catch-all / unclassified

Example

use ai_lib_rust::error_code::StandardErrorCode;

let code = StandardErrorCode::from_error_class("rate_limited");
assert_eq!(code.code(), "E2001");
assert!(code.retryable());
assert_eq!(code.category(), "rate");

Enums

StandardErrorCode

Standard AI-Protocol V2 error code.