specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: Listnr
providerId: listnr
created: '2026-07-11'
modified: '2026-07-11'
reconciled: false
tags:
- AI
- Text to Speech
- TTS
- Voice
- Rate Limiting
- Quotas
description: >-
  Listnr does not publish fixed numeric per-request rate limits for the
  Text-to-Speech API. In practice, usage is bounded by your subscription's
  monthly voice-generation credit allowance (words/characters synthesized)
  rather than by a documented requests-per-second or requests-per-minute cap.
  Long conversions are handled through the asynchronous endpoints
  (convert-text-async / convert-url-async), which return a jobId that clients
  poll via job-status until the job reaches COMPLETED or FAILED, so throughput
  for large jobs is governed by queue processing rather than a synchronous rate
  limit.
notes: >-
  No numeric request-rate limit is documented in Listnr's public API docs as of
  the review date. Values here describe the credit-based quota model, not a
  confirmed per-endpoint throttle; verify against your plan and any headers the
  live API returns.
sources:
- https://github.com/team-listnr/text-to-speech-api
- https://listnr.ai/text-to-speech-api
- https://listnr.ai/pricing
responseCodes:
  throttled: 429
limits:
- name: Text-to-Speech API Requests
  scope: account
  metric: requests
  limit: not published
  notes: No fixed numeric request-rate limit is documented for the TTS API.
- name: Monthly Voice-Generation Credits
  scope: account
  metric: credits
  limit: per plan
  notes: >-
    Usage is capped by the plan's monthly credit allowance (e.g. 1,000 free
    words, 20,000 / 50,000 / 250,000 credits on Individual / Solo / Agency).
- name: Asynchronous Job Processing
  scope: account
  metric: jobs
  limit: queue-bound
  notes: >-
    Large conversions run via the async endpoints and are polled with
    job-status; effective throughput depends on queue processing, not a
    synchronous rate cap.
policies:
- name: Credit-Based Quota
  description: >-
    Requests draw down a monthly credit allowance tied to the subscription
    plan rather than a per-minute request budget.
- name: Async for Large Jobs
  description: >-
    Use convert-text-async / convert-url-async for long inputs and poll
    job-status; sync endpoints are best for short text.
- name: Backoff Strategy
  description: >-
    Clients should implement exponential backoff with jitter and honor
    Retry-After on any 429 response.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com