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: HaneruTo
providerId: hakuto-0209-com
generated: '2026-09-19'
method: searched
created: '2026-09-19'
modified: '2026-09-19'
tags:
- Rate Limiting
- MCP
- A2A
description: >-
  The only numeric limit the provider publishes is on the keyless tier: the agent card states that the
  principles and rules skills "need no key (20 req/min per IP)". The data policy adds that all requests are
  rate limited per IP and that request bodies are capped at 4 MB, without numbers for keyed traffic — the
  paid tier is sold as "a monthly flat fee with a call cap" whose cap "depends on your volume", so the keyed
  limit is contractual, not published. No rate-limit response headers were observed on any probed response
  and the status code on exhaustion is not documented.
sources:
- https://mcp.hakuto-0209.com/.well-known/agent-card.json
- https://mcp.hakuto-0209.com/terms
limit_count: 1
headers:
  rateLimit: null
  rateLimitRemaining: null
  rateLimitReset: null
  retryAfter: null
  requestId: null
responseCodes:
  throttled: null
  payloadTooLarge: null
limits:
- name: Keyless tier (principles, rules)
  scope: ip
  metric: requests_per_minute
  limit: 20
  timeFrame: minute
  applies_to: [b612_principles, b612_rules, A2A skills principles and rules]
  source: https://mcp.hakuto-0209.com/.well-known/agent-card.json
  quote: 'Free to try: principles and rules need no key (20 req/min per IP).'
undocumented:
- name: Keyed tier (all tools/skills with x-b612-key)
  scope: ip and per-licence call cap
  limit: null
  note: '"Requests are rate limited per IP" (terms §5) and "a monthly flat fee with a call cap — the cap depends on your volume" (terms §7); no number published.'
constraints:
- name: Request body size
  limit: 4 MB
  source: https://mcp.hakuto-0209.com/terms
  quote: 'Requests are rate limited per IP. Request bodies are limited to 4 MB.'