openreader/docs-site/docs/configure/tts-rate-limiting.md
Richard R 9b9206f50d refactor(audiobooks): migrate audiobook pipeline to object storage
This commit restructures the audiobook generation and serving layer to rely exclusively on S3-compatible blob storage, removing the dependency on local filesystem paths.

- Bundle `ffmpeg` and `ffprobe` binaries via npm to ensure portability across environments.
- Update API routes to stream audio directly from blob storage instead of local disk.
- Remove legacy migration endpoints and filesystem-based indexing logic.
- Add startup scripts to facilitate the transition from local to remote storage.

BREAKING CHANGE: Audiobook functionality is now strictly dependent on S3 configuration. The previous filesystem-based storage method has been removed.
2026-02-11 02:44:34 -07:00

1.5 KiB

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TTS Rate Limiting

This page explains OpenReader's TTS character rate limiting controls.

Overview

  • TTS rate limiting is disabled by default.
  • To enable it, set TTS_ENABLE_RATE_LIMIT=true.
  • Limits are enforced per day in UTC.
  • Enforcement applies only when auth is enabled.

How enforcement works

When enabled, OpenReader enforces:

  • Per-user daily character limits.
  • IP backstop daily character limits.
  • Anonymous device backstop tracking (cookie-based) to reduce limit resets.

If a request exceeds the active limit, the TTS API returns 429 with reset metadata for the next UTC day.

Required auth behavior

  • Auth must be enabled (BASE_URL + AUTH_SECRET) for TTS char limits to apply.
  • If auth is disabled, TTS character limits are effectively unlimited.
  • DISABLE_AUTH_RATE_LIMIT only affects Better Auth's own request throttling.
  • DISABLE_AUTH_RATE_LIMIT does not disable TTS character limits.

Environment variables

Enable/disable:

  • TTS_ENABLE_RATE_LIMIT (default: false)

Per-user daily limits:

  • TTS_DAILY_LIMIT_ANONYMOUS (default: 50000)
  • TTS_DAILY_LIMIT_AUTHENTICATED (default: 500000)

IP backstop daily limits:

  • TTS_IP_DAILY_LIMIT_ANONYMOUS (default: 100000)
  • TTS_IP_DAILY_LIMIT_AUTHENTICATED (default: 1000000)