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: Kno2
providerId: kno2
created: '2026-07-12'
modified: '2026-08-14'
method: derived
limit_count: 0
reconciled: false
tags:
- Healthcare Interoperability
- Direct Secure Messaging
- FHIR
- Rate Limiting
- Quotas
description: >-
  Kno2 does not publish fixed numeric rate limits for the Communication API. As a
  partner/enterprise, per-subscription API, throughput and any throttling are
  governed by the subscription agreement rather than a public per-minute cap.
  Kno2's own reference client consumes inbound messages by polling GET
  /api/messages on a loop with a 10-second wait between empty polls, which
  implies clients are expected to poll on a modest cadence rather than hammer the
  endpoint. All values here are modeled - confirm concrete limits with Kno2
  during onboarding.
notes: >-
  Kno2 requires TLS 1.2+ and an IP allowlist per subscription. Implement
  exponential backoff with jitter and honor Retry-After on any 429 responses.
  Poll intake queues on a reasonable interval (the reference client uses ~10s).
  limit_count is set to 0 because no fixed numeric rate limit is documented
  anywhere publicly - throughput is governed per subscription agreement, an
  honest zero rather than an unset field.
sources:
- https://kno2.com/api/
- https://developer.kno2.com
- https://github.com/Kno2/Kno2.ApiTestClient
responseCodes:
  throttled: 429
limits:
- name: Communication API Requests
  scope: subscription
  metric: requests
  limit: not published
  notes: No fixed numeric request-rate limit is documented; governed per subscription agreement.
- name: Intake Polling
  scope: subscription
  metric: requests
  limit: client-paced (~10s interval in reference client)
  notes: The reference client polls GET /api/messages and waits 10 seconds between empty polls.
- name: IP Allowlist
  scope: subscription
  metric: source-ip
  limit: allowlisted only
  notes: Calls are rejected unless the caller's public IP is allowlisted by a Kno2 admin.
policies:
- name: Backoff Strategy
  description: Clients should implement exponential backoff with jitter and honor Retry-After on 429 responses.
- name: Polling Cadence
  description: Intake/receive is client-initiated polling; poll on a modest interval rather than continuously.
- name: Transport Security
  description: TLS 1.2 or higher is required for all integrations.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com