specification: API Commons Rate Limits
specificationVersion: '0.1'
provider: Delx
providerId: delx-ai
generated: '2026-09-19'
method: probed
created: '2026-09-19'
modified: '2026-09-19'
sources:
- Response headers observed on POST https://api.delx.ai/mcp, /v1/mcp and /v1/mcp/protocol (tools/list) 2026-09-19
- https://ontology.delx.ai/legal/terms (section 5, Rate Limits and Fair Use)
description: 'Delx does not publish a numeric limit in its docs (the Terms say "Current limits are documented in the discovery
  documentation", and ontology.delx.ai/docs/rate-limits 404s). The runtime signal is complete, though: every api.delx.ai response
  carries x-ratelimit-limit, x-ratelimit-remaining and x-ratelimit-reset, and the Terms commit to 429 on exhaustion with mandatory
  exponential backoff and possible IP-level blocking for persistent abuse.'
limit_count: 1
headers:
  limit: x-ratelimit-limit
  remaining: x-ratelimit-remaining
  reset: x-ratelimit-reset (seconds until reset)
  retryAfter: retry-after (exposed via Access-Control-Expose-Headers; not observed on a 2xx)
  requestId: x-delx-request-id
responseCodes:
  throttled: 429
limits:
- name: Anonymous requests to api.delx.ai (observed)
  scope: unknown (per-IP or per-key not documented; observed on anonymous requests)
  metric: requests_per_window
  limit: 60
  window: reset counter observed at 21-23 s after four requests in one minute; window length not documented
  timeFrame: window
  observed:
    x-ratelimit-limit: '60'
    x-ratelimit-remaining: 45 -> 44 -> 43 across three consecutive tools/list calls
    x-ratelimit-reset: 23 -> 22 -> 21
    fetched: '2026-09-19'
    endpoint: https://api.delx.ai/mcp
policy:
  docs: https://ontology.delx.ai/legal/terms
  quote: The Service enforces rate limits to ensure fair access. Current limits are communicated via standard HTTP headers
    ( X-RateLimit-Limit , X-RateLimit-Remaining , X-RateLimit-Reset ). Agents that exceed rate limits will receive HTTP 429
    responses. Agents must implement exponential backoff when receiving 429s. Persistent abuse of rate limits may result in
    temporary or permanent IP-level blocking.