generated: '2026-09-05'
method: searched
source: https://fourthandheart.com/llms.txt
limit_count: 0
note: >-
  A rate limit is documented in prose but never quantified, and no rate-limit headers were returned on
  observed 200 responses. limit_count is 0 because no numeric limit is published anywhere — an honest
  zero, not an unchecked field. The 429-and-back-off contract below is real and is what an agent
  actually gets.
limits: []
signaling:
  documented: true
  statement: 'The MCP endpoint is rate-limited per IP. Back off on 429 responses.'
  scope: per-ip
  window: unpublished
  limit: unpublished
  burst: unpublished
  status_on_exhaustion: 429
  retry_after_header: unknown
  response_headers_observed: []
  headers_probe:
    url: https://fourthandheart.com/api/ucp/mcp
    method: POST
    http_status: 200
    observed: [content-type, x-request-id]
    note: >-
      No RateLimit-*, X-RateLimit-* or Retry-After header was present on a successful response.
      Whether Retry-After accompanies a 429 was not tested: this pipeline does not generate load to
      force a limit.
  observed: '2026-09-05'