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: NATS
providerId: nats
created: '2026-05-04'
# Provenance stamped 2026-08-11: this artifact was written by the API Evangelist
# bulk sweep dated 2026-05-04, not harvested from the provider. See roadmap#35.
method: generated
modified: '2026-05-05'
reconciled: true
tags:
  - Rate Limiting
  - Message Broker
  - Pub Sub
  - Streaming
description: NATS open source does not enforce request-per-second rate limits via HTTP — it is a TCP/WebSocket
  messaging server. Operator-enforced limits are configured per Account via JWT claims (max connections,
  max subscriptions, max payload, max data, max leaf nodes). The HTTP monitoring endpoints on port 8222
  are unauthenticated and intended for operations dashboards. Synadia Cloud, the managed offering, enforces
  per-Team quotas defined by subscription tier (connections, subscriptions, network data, storage, message
  size) rather than RPS throttling.
sources:
  - https://docs.nats.io/running-a-nats-service/configuration/securing_nats/jwt
  - https://www.synadia.com/cloud
  - https://docs.synadia.com/cloud/pricing
responseCodes:
  quotaExceeded: -ERR
limits:
  - name: Max connections (per account, OSS)
    scope: account
    metric: concurrent_connections
    limit: see account JWT max_connections claim
    notes: Configured per Account via JWT claims; default unlimited.
  - name: Max subscriptions (per account, OSS)
    scope: account
    metric: concurrent_subscriptions
    limit: see account JWT max_subscriptions claim
    notes: Configured per Account via JWT claims; default unlimited.
  - name: Max payload (per account, OSS)
    scope: account
    metric: bytes_per_message
    limit: see account JWT max_payload claim
    notes: Defaults to server max_payload (1 MB).
  - name: Max data (per account, OSS)
    scope: account
    metric: bytes
    limit: see account JWT max_data claim
    notes: Aggregate JetStream storage cap.
  - name: Synadia Cloud Personal — connections
    scope: team
    metric: concurrent_connections
    limit: 10
    notes: Free tier; 100 subscriptions, 5 GiB storage, 10 GB network data, 1 MiB max message.
  - name: Synadia Cloud Starter — connections
    scope: team
    metric: concurrent_connections
    limit: 100
    notes: $49/mo; 1,000 subscriptions, 10 GiB storage, 100 GB network data.
  - name: Synadia Cloud Pro — connections
    scope: team
    metric: concurrent_connections
    limit: 1000
    notes: $199/mo; 10,000 subscriptions, 50 GiB storage, 1 TiB network data, 2 MiB max message.
  - name: Synadia Cloud Premium — connections
    scope: team
    metric: concurrent_connections
    limit: 10000
    notes: $899/mo; 100,000 subscriptions, 1 TiB storage, 2 TiB network data, 8 MiB max message.
policies:
  - name: Account-scoped quotas (OSS)
    description: NATS enforces resource limits per Account via signed JWT claims rather than per-request
      throttling. Use the operator/account/user hierarchy and `nsc` tool to set max_connections, max_subscriptions,
      max_payload, max_data, and max_leaf_nodes.
  - name: Slow consumer detection
    description: NATS server disconnects subscribers that cannot keep up with publish rate; clients receive
      a slow-consumer error and must reconnect. Publishers receive `-ERR` flow-control messages.
  - name: JetStream backpressure
    description: JetStream applies stream-level limits (max bytes, max messages, max age) and pull/push
      consumer ack windows. Producers are flow-controlled when stream storage thresholds are reached.
  - name: Synadia Cloud quota enforcement
    description: Cloud tier limits are enforced as hard caps on connections, subscriptions, storage, and
      network data. Exceeding network-data or storage caps triggers degraded service until the next billing
      period or until the team upgrades / adds storage packs.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com