generated: '2026-08-13'
method: searched
source: >-
  https://listmonk.app/docs/apis/apis/ (the "Common HTTP error codes" table lists
  429) and https://listmonk.app/docs/maintenance/performance/ , plus a live
  header probe of https://demo.listmonk.app/api/public/lists on 2026-08-13.
limit_count: 4
response_headers: []
response_headers_note: >-
  PROBED, NOT ASSUMED. The live response from
  https://demo.listmonk.app/api/public/lists on 2026-08-13 carried no
  RateLimit-*, X-RateLimit-* or Retry-After header — only date, content-type,
  content-length and Cloudflare edge headers. listmonk documents 429 as a
  possible status but ships no runtime rate-limit signal, so an agent cannot
  learn its remaining budget from a response. This is the single most
  agent-relevant gap in the surface.
status_on_exhaustion: 429
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: listmonk
providerId: listmonk
created: '2026-06-25'
modified: '2026-06-25'
reconciled: false
tags:
- Email
- Newsletter
- Mailing List
- Open Source
- Self-Hosted
- Rate Limiting
- Quotas
- Throttling
description: >-
  As a self-hosted application, listmonk does not impose a vendor-side API
  rate limit; throughput is bounded only by the operator's own server,
  PostgreSQL database, and configuration. The relevant throttles are
  operator-controlled message-sending concurrency and per-messenger sliding
  windows configured in Settings (number of concurrent workers, messages per
  second), plus any rate limits imposed by the downstream SMTP / email
  provider used for outbound delivery. Specific numeric values depend entirely
  on the operator's deployment and are not fixed by the project.
notes: >-
  Outbound email rate limiting is configured under Settings > Performance and
  per-SMTP-server settings (max connections, idle timeout, message rate).
  These are deployment-specific and not reconciled here. The upstream email
  provider (e.g. Amazon SES, SendGrid) enforces its own sending quotas.
sources:
- https://listmonk.app/docs/apis/apis/
- https://listmonk.app/docs/maintenance/performance/
- https://github.com/knadh/listmonk
responseCodes:
  throttled: 429
limits:
- name: API Request Rate
  scope: instance
  metric: requests
  limit: operator-controlled (no vendor limit)
  notes: Bounded only by the self-hosted server and PostgreSQL; not capped by the software.
- name: Message Sending Concurrency
  scope: instance
  metric: workers
  limit: configured in Settings
  notes: Number of concurrent sending workers set by the operator.
- name: Messages Per Second
  scope: messenger
  metric: messages
  limit: configured in Settings
  notes: Per-messenger sliding-window send rate configured by the operator.
- name: SMTP Provider Quota
  scope: external
  metric: messages
  limit: provider-defined
  notes: Enforced by the downstream SMTP / email provider (e.g. SES, SendGrid), not by listmonk.
policies:
- name: Operator-Controlled Throttling
  description: Sending concurrency and per-messenger message rates are tuned by the operator under Settings.
- name: Backoff Strategy
  description: Clients integrating with the API should implement retries with backoff appropriate to their self-hosted instance's capacity.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com