ProtocolError

Base branded error class for MCP protocol errors, with code/data fields and factory logic to map error codes to specific error subclasses.

export class ProtocolError extends Error {
    static {
        Object.defineProperty(this, 'mcpBrand', { value: 'mcp.ProtocolError' });
    }

    static override [Symbol.hasInstance](value: unknown): boolean {
        return brandedHasInstance(this, value);
    }

    /**
     * Brand-based type guard: equivalent to `value instanceof this`, as an
     * explicit static predicate (the axios/AWS-SDK `isInstance` style). Reads
     * the caller's own brand via `this`, so every branded subclass gets a
     * correctly-scoped guard by inheritance. Must be invoked on the class —
     * in callback position write `v => SdkError.isInstance(v)`, not
     * `.filter(SdkError.isInstance)` (detached calls throw rather than
     * silently matching nothing).
     */
    static isInstance<T extends ab

... (truncated -- full source via MCP)