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: Ably
providerId: ably
created: '2026-05-08'
# Provenance stamped 2026-08-11: this artifact was written by the API Evangelist
# bulk sweep dated 2026-05-08, not harvested from the provider. See roadmap#35.
method: generated
modified: '2026-05-08'
reconciled: true
tags:
  - Realtime
  - Rate Limiting
description: >-
  Ably gates per-account concurrent connections, channels, and per-second message rates by plan
  tier. Free is 200 connections / 500 msg/sec; Standard 10K / 2.5K; Pro 50K / 10K; Enterprise
  unlimited. The Control API enforces a separate per-token limit on management calls (typically
  60 rpm). HTTP 429 is returned when caps are exceeded.
sources:
  - https://ably.com/pricing
  - https://ably.com/docs/api/rest-api
responseCodes:
  throttled: 429
limits:
  - name: Free - connections
    scope: account
    metric: concurrent_connections
    limit: 200
  - name: Free - message rate
    scope: account
    metric: messages_per_second
    limit: 500
  - name: Standard - connections
    scope: account
    metric: concurrent_connections
    limit: 10000
  - name: Standard - message rate
    scope: account
    metric: messages_per_second
    limit: 2500
  - name: Pro - connections
    scope: account
    metric: concurrent_connections
    limit: 50000
  - name: Pro - message rate
    scope: account
    metric: messages_per_second
    limit: 10000
  - name: Enterprise
    scope: account
    metric: concurrent_connections
    limit: -1
    notes: Unlimited per contract.
  - name: Control API
    scope: token
    metric: requests_per_minute
    limit: 60
policies:
  - name: Backoff Strategy
    description: Honor 429 Retry-After and apply exponential backoff with jitter.
  - name: Burst Control
    description: Use channel namespacing and shard fan-out across many channels to stay under per-channel caps.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com