generated: '2026-07-22'
method: searched
source: |
  Euronext public client-specification PDFs (fetched and read 2026-07-22):
  - https://www.euronext.com/sites/www.euronext.com/files/euronext-saturn-web_services_specifications_2.8.8.pdf
  - https://connect2.euronext.com/sites/default/files/documentation/data/EWS%20API%20-%20Indices%20-%20Client%20Specification_v1.3_27.01.2020.pdf
  - https://connect2.euronext.com/sites/default/files/documentation/data/ews_api_-_historical_data_client_specification.pdf
summary:
  types: [apiKey, token, mutualTLS]
  api_key_in: [query]
  oauth2_flows: []
  note: No OAuth2/OIDC anywhere. All credentials are issued by Euronext at
    onboarding; there is no self-serve signup.
schemes:
- name: EWS authKey
  api: Euronext Web Services (Market Data / Historical / Indices)
  type: apiKey
  in: query
  parameter: authKey
  description: |
    The Euronext Web Services JSON API authenticates with an authentication key
    passed as the authKey query parameter on the gateway.euronext.com/api
    endpoints (e.g. /api/instrumentDetail, /api/intraday). The URL and Key are
    provided by Euronext to the client at integration onboarding; requests use
    the POST HTTP method only (GET is not supported for the EOD Summary service).
    An unauthenticated request to https://gateway.euronext.com/api/instrumentDetail
    returns HTTP 401 (probed 2026-07-22).
  sources:
  - https://connect2.euronext.com/sites/default/files/documentation/data/EWS%20API%20-%20Indices%20-%20Client%20Specification_v1.3_27.01.2020.pdf
  - https://connect2.euronext.com/sites/default/files/documentation/data/ews_api_-_historical_data_client_specification.pdf
- name: Saturn session token
  api: Euronext Saturn Reporting API
  type: token
  in: header
  parameter: Authorization
  description: |
    The client first calls the AuthenticateUser logon function
    (/SaturnWebServices/rest/Authentication/AuthenticateUser) over HTTPS with the
    Saturn username and password - the Username:Password concatenation is MD5
    encrypted then base64 encoded (hexadecimal, lowercase) and carried in the
    Authorization HTTP header. Saturn validates the credentials and returns a
    session token that must be sent in the Authorization header of every
    subsequent request. Tokens expire after a configurable period ("Token
    expired" error); Saturn pins the client IP from the logon request and
    rejects requests from other IPs; only one active session per credential is
    allowed (a new logon invalidates the previous session). Logon status codes:
    200 Success, 401 Access denied, 504 Session expired.
  sources:
  - https://www.euronext.com/sites/www.euronext.com/files/euronext-saturn-web_services_specifications_2.8.8.pdf
- name: Saturn mutual TLS
  api: Euronext Saturn Reporting API
  type: mutualTLS
  description: |
    In addition to token authentication, Saturn uses certificate-based mutual
    authentication - the client presents a client certificate (a DigiCert-issued
    .pfx is distributed by Euronext, with a published DigiCert certificate
    utility for conversion) and both parties verify each other's certificates
    before the encrypted channel is established.
  sources:
  - https://www.euronext.com/sites/www.euronext.com/files/euronext-saturn-web_services_specifications_2.8.8.pdf
- name: Optiq MDG entitlement
  api: Euronext Optiq Market Data Gateway
  type: none
  description: |
    Not an HTTP API - the Optiq Market Data Gateway is a UDP multicast SBE feed.
    Access control is contractual and network-level: a market data agreement,
    entitlement management, and connectivity provisioning (no HTTP
    authentication scheme).
  sources:
  - https://www.euronext.com/en/data/how-access-market-data/euronext-optiq-mdg-cloud