spec: API Commons Rate Limits 0.1
provider: LMNT
providerId: lmnt
created: 2026-06-12
modified: 2026-06-12
description: >
  LMNT does not impose concurrency or rate limits on paid plans (Indie, Pro,
  Premium, and Enterprise). The free tier is subject to usage limits enforced
  via monthly character quotas. API version 1.1+ adds a request-id header on
  every response to facilitate debugging and support. Errors use a structured
  error envelope.
rateLimits:
  - name: Free Plan Monthly Character Quota
    scope: account
    type: quota
    limit: 15000
    unit: characters
    period: month
    plans:
      - Free
    enforcement:
      throttled: false
      description: >
        Requests beyond the free monthly quota are blocked until the next billing
        cycle; no overage billing on the free tier.
  - name: Paid Plan Rate Limiting
    scope: account
    type: boolean
    enforced: false
    plans:
      - Indie
      - Pro
      - Premium
      - Enterprise
    description: >
      No concurrency or request rate limits are applied to paid plan accounts.
  - name: Text Input Limit Per Request
    scope: request
    type: quota
    limit: 5000
    unit: characters
    period: request
    description: >
      Each individual speech synthesis request accepts a maximum of 5,000 characters
      of input text.
headers:
  - name: request-id
    description: >
      Unique identifier returned on every API response (API version 1.1+),
      used for support and debugging.
    source: response
  - name: X-API-Key
    description: API key for authentication, passed as a request header.
    source: request
errors:
  - code: 429
    description: >
      Too Many Requests — returned if account-level limits are exceeded. On paid
      plans this should not be encountered under normal operation.
    retryAfter: true
    retryAfterHeader: Retry-After