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: AISHub
providerId: aishub
created: '2026-07-11'
modified: '2026-07-11'
reconciled: false
tags:
- Vessel Tracking
- Maritime
- AIS
- Rate Limiting
- Quotas
description: >-
  AISHub publishes one explicit rate limit for its HTTP web service - do not
  access it more frequently than once per minute. The documentation states the
  web service simply returns nothing (an empty response) when called more
  often, rather than returning an HTTP throttling status. Beyond that
  polling cadence there are no documented per-day quotas or volume caps;
  large result sets are managed through bounding box, MMSI/IMO, and interval
  filters plus optional ZIP/GZIP/BZIP2 compression. Continued API access is
  additionally conditioned on your contributed feed maintaining its quality
  thresholds (10+ vessels coverage, 90%+ uptime over a rolling 7-day period,
  message delay under 10 seconds).
notes: >-
  No 429 or Retry-After behavior is documented - over-polling yields an empty
  body. Clients should schedule requests at 60-second or longer intervals and
  treat empty responses as a signal to back off.
sources:
- https://www.aishub.net/api
- https://www.aishub.net/join-us
responseCodes:
  throttled: none documented (empty response body is returned instead)
limits:
- name: Web Service Polling
  scope: account
  metric: requests
  limit: 1 per minute
  notes: Documented limit for ws.php and stations.php - the service returns nothing if executed more frequently than once per minute.
- name: Result Volume
  scope: request
  metric: records
  limit: not published
  notes: No documented cap; constrain result size via latmin/latmax/lonmin/lonmax bounding box, mmsi/imo filters, and the interval (max position age) parameter, and use compress for large payloads.
- name: Feed Quality Condition
  scope: account
  metric: feed quality
  limit: 10+ vessels, 90%+ uptime (rolling 7 days), <=10s delay
  notes: Not a request limit, but API credentials depend on the contributed AIS feed continuously meeting these thresholds.
policies:
- name: Once-Per-Minute Polling
  description: Poll ws.php and stations.php at 60-second or longer intervals; more frequent calls return an empty response.
- name: Filter Before You Fetch
  description: Use bounding box, MMSI/IMO, and interval parameters to request only the vessels you need instead of pulling the global dataset each minute.
- name: Compression for Bulk Pulls
  description: Use compress=1/2/3 (ZIP/GZIP/BZIP2) when pulling large areas to reduce transfer size.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com