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: European Space Agency (ESA)
providerId: esa
created: '2026-06-13'
modified: '2026-06-13'
reconciled: true
tags:
  - Earth Observation
  - Copernicus
  - Space Weather
  - Rate Limiting
  - Throttling
description: >-
  Rate limits for ESA public APIs are primarily defined by the Copernicus Data Space
  Ecosystem (CDSE) free-tier quotas. Sentinel Hub allows 300 requests/minute and 300
  processing units/minute. openEO is limited to 12 requests/minute (1 per 5 seconds)
  with a maximum of 2 concurrent requests. S3 supports 4 concurrent connections at
  20 MB/s each. Data Workspace allows 2 concurrent processing orders. ESA Gaia TAP,
  ESASky Legacy TAP, and CCI ESGF do not publish explicit numeric rate limits.
  Space Weather HAPI access tokens expire after 300 seconds.
sources:
  - https://documentation.dataspace.copernicus.eu/Quotas.html
  - https://swe.ssa.esa.int/swe-hapi-server
responseCodes:
  throttled: 429
  unauthorized: 401
  forbidden: 403
  serverError: 500
limits:
  - name: Sentinel Hub API Requests per Minute
    scope: user
    api: copernicus-sentinel-hub
    metric: requests
    limit: 300
    timeFrame: minute
    notes: >-
      300 requests/minute and 300 processing units/minute for the Sentinel Hub API.
      Exceeding triggers HTTP 429.

  - name: Sentinel Hub Processing Units per Minute
    scope: user
    api: copernicus-sentinel-hub
    metric: processing_units
    limit: 300
    timeFrame: minute
    notes: >-
      Parallel limit to the request rate; each request may consume multiple
      processing units depending on area and complexity.

  - name: openEO Requests per Minute
    scope: user
    api: copernicus-openeo
    metric: requests
    limit: 12
    timeFrame: minute
    notes: >-
      Approximately 1 request per 5 seconds. Intended to manage cloud
      processing resource fairness across free-tier users.

  - name: openEO Concurrent Requests
    scope: user
    api: copernicus-openeo
    metric: concurrent_requests
    limit: 2
    timeFrame: concurrent
    notes: >-
      Maximum 2 simultaneous openEO batch jobs or processing requests per user.

  - name: S3 Concurrent Connections
    scope: user
    api: copernicus-s3
    metric: concurrent_connections
    limit: 4
    timeFrame: concurrent
    notes: >-
      Up to 4 concurrent S3 connections, each at 20 MB/s bandwidth. Exceeding
      monthly 12 TB transfer quota drops to 1 connection at 1 MB/s.

  - name: S3 Bandwidth per Connection
    scope: connection
    api: copernicus-s3
    metric: bandwidth
    limit: 20
    timeFrame: continuous
    unit: MB/s
    notes: >-
      Each S3 connection is throttled to 20 MB/s under normal quota conditions.

  - name: Active Sessions
    scope: account
    api: copernicus-all
    metric: active_sessions
    limit: 100
    timeFrame: concurrent
    notes: >-
      Maximum 100 active sessions per account across all Copernicus Data Space
      Ecosystem API endpoints.

  - name: Data Workspace Concurrent Processing Orders
    scope: user
    api: copernicus-data-workspace
    metric: concurrent_orders
    limit: 2
    timeFrame: concurrent
    notes: >-
      Maximum 2 simultaneous Data Workspace offline product orders.

  - name: Space Weather HAPI Token Validity
    scope: token
    api: space-weather-hapi
    metric: token_lifetime
    limit: 300
    timeFrame: second
    unit: seconds
    notes: >-
      M2M Bearer tokens expire after 300 seconds. Tokens must be refreshed
      before expiry using the SSO endpoint at
      https://sso.s2p.esa.int/realms/swe/protocol/openid-connect/token.

policies:
  - name: Monthly Quota Reset
    description: >-
      All Copernicus Data Space Ecosystem free-tier quotas (Sentinel Hub requests,
      openEO credits, Data Workspace products, Direct HTTP COG requests) reset on
      the first calendar day of each month.

  - name: Transfer Quota Throttling
    description: >-
      When a user exceeds the 12 TB 30-day rolling S3/OData/STAC transfer limit,
      bandwidth is reduced to 1 MB/s with 1 concurrent connection. Full bandwidth
      is restored when the rolling window drops below the quota.

  - name: Copernicus Authentication Token Lifetime
    description: >-
      Access tokens for authenticated Copernicus APIs are valid for 10 minutes and
      can be refreshed within a 60-minute refresh window using the OpenID Connect
      token endpoint.

  - name: HAPI Token Refresh
    description: >-
      ESA Space Weather HAPI M2M tokens must be refreshed before the 300-second
      expiry. Implement proactive token renewal in programmatic clients to avoid
      failed requests.

  - name: Exponential Backoff on 429
    description: >-
      All ESA/Copernicus APIs return HTTP 429 on rate limit violation. Clients
      should implement exponential backoff with jitter before retrying.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com