Rate Limit Errors

Errors for rate limiting and quota enforcement.

Overview

Rate limit errors are thrown when a client exceeds request rate limits or usage quotas. Both are public errors that inform the client about the limitation.

Error Reference

RateLimitError

Thrown when a client exceeds the configured request rate limit.

Property	Type	Value
code	string	RATE_LIMIT_EXCEEDED
statusCode	number	429
isPublic	boolean	true

new RateLimitError(retryAfter?: number)

When retryAfter is provided, the message includes the number of seconds the client should wait before retrying.

Example:

import { RateLimitError } from '@frontmcp/sdk';

throw new RateLimitError(60);
// "Rate limit exceeded. Retry after 60 seconds"

throw new RateLimitError();
// "Rate limit exceeded"

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QuotaExceededError

Thrown when a client exceeds a usage quota (e.g., monthly API calls, storage).

Property	Type	Value
code	string	QUOTA_EXCEEDED
statusCode	number	429
isPublic	boolean	true

new QuotaExceededError(quotaType?: string)

Example:

import { QuotaExceededError } from '@frontmcp/sdk';

throw new QuotaExceededError('monthly API calls');
// "monthly API calls quota exceeded"

throw new QuotaExceededError();
// "usage quota exceeded"