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: National Renewable Energy Laboratory
providerId: national-renewable-energy-laboratory
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
  - Government
  - Energy
  - Renewables
description: NREL APIs are fronted by the api.data.gov gateway and apply per-API-key rate limits for
  signed-up keys and per-IP limits for the shared DEMO_KEY. Per-service variation is possible (some APIs
  publish their own quotas), but the platform default is 1,000 requests per hour. Counters reset on a
  rolling hourly basis; 429 is the throttling response.
sources:
  - https://developer.nlr.gov/docs/rate-limits/
  - https://api.data.gov/docs/rate-limits/
headers:
  limit: X-RateLimit-Limit
  remaining: X-RateLimit-Remaining
responseCodes:
  throttled: 429
  quotaExceeded: 429
limits:
  - name: Signed-up API key (default)
    scope: key
    metric: requests_per_hour
    limit: 1000
    timeFrame: hour
    notes: Default for all signed-up keys across every NREL API; some services may publish their own
      caps.
  - name: DEMO_KEY hourly
    scope: IP
    metric: requests_per_hour
    limit: 30
    timeFrame: hour
    notes: Shared demo key — limit is per IP address, not per key.
  - name: DEMO_KEY daily
    scope: IP
    metric: requests_per_day
    limit: 50
    timeFrame: day
    notes: Shared demo key daily ceiling per IP.
policies:
  - name: Rolling window
    description: Hourly limits reset on a rolling basis. After a 429 block, the key automatically resumes
      service within an hour.
  - name: Demo vs signed key
    description: DEMO_KEY is for documentation / tutorial use only; production traffic should use a free
      signed-up API key.
  - name: Service-specific overrides
    description: Some NREL APIs document their own per-service quotas; consult the individual API documentation
      page when those are stricter than the gateway default.
  - name: Domain migration
    description: developer.nrel.gov is being retired in May 2026. Consumers should migrate to developer.nlr.gov
      to avoid disruption.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com