Foundry376/Mailspring · error · UsageExceededError

UsageExceededError

UsageExceededError

Error message

UsageExceededError

What it means

Raised by GrammarCheckService.check when the identity backend answers HTTP 400 ('Quota Reached') for POST /api/grammar/check, meaning the account has exhausted its grammar-check quota. It is a sentinel error type the package uses to distinguish quota exhaustion from other failures.

Source

Thrown at app/internal_packages/composer-grammar-check/lib/grammar-check-service.ts:135

    this._readConfig();

    let data: LanguageToolResponse;
    try {
      data = await MailspringAPIRequest.makeRequest({
        server: 'identity',
        method: 'POST',
        path: '/api/grammar/check',
        json: true,
        body: {
          messageId,
          text,
          language: language || this.language,
        },
      });
    } catch (err) {
      // 400 = quota reached ("Quota Reached")
      if (err.statusCode === 400) {
        throw new UsageExceededError();
      }
      // 429 = rate limited — surface as a transient error, caller will retry on next dirty check
      if (err.statusCode === 429) {
        throw new Error('Grammar check rate limit reached, please try again shortly.');
      }
      // 502 = LanguageTool backend unavailable
      if (err.statusCode === 502) {
        throw new Error('Grammar check service is temporarily unavailable.');
      }
      throw err;
    }

    const filtered = data.matches.filter((match) => match.rule.issueType !== 'misspelling');

    return filtered.map((match) => ({
      offset: match.offset,
      length: match.length,
      message: match.message,

View on GitHub (pinned to 648c685d60)

Solutions

1. Surface an inline notice in the composer that the free grammar-check quota is used up and offer a link to upgrade or wait for the quota window to reset
2. Cache the UsageExceededError state so subsequent dirty checks skip the API call until the window resets

When it happens

Trigger: Thrown at app/internal_packages/composer-grammar-check/lib/grammar-check-service.ts:135 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of Foundry376/Mailspring@648c685d60 (2026-09-03). Data as JSON: /api/errors/caf67939c75358b3. Report an issue: GitHub.