@rail402.dev/errors

The shared, machine-readable error registry used across the Rail402 facilitator, Bazaar, and MCP server. Every rejection carries a stable code, a non-null human-legible reason, and a retryable flag, so an agent can reason about a failure instead of parsing prose.

Install

npm install @rail402.dev/errors

Usage

import { X402Error, isErrorCode, ERROR_REGISTRY } from "@rail402.dev/errors";

try {
  // ... a facilitator, Bazaar, or agent call ...
} catch (err) {
  if (err instanceof X402Error) {
    console.error(err.code, err.reason, err.retryable);
  }
}

// Validate a code coming off the wire, or look one up:
isErrorCode("invalid_exact_stellar_payload_authorization_replayed"); // => true
ERROR_REGISTRY["invalid_exact_stellar_payload_authorization_replayed"].reason;

Adding an error means adding it to the registry (never an inline string), so the set stays enumerable and documented.

Exports: X402Error, createError, isErrorCode, enrichUpstreamCode, ERROR_REGISTRY, ALL_ERROR_CODES, and the ErrorCode type.

Part of Rail402. Apache-2.0.