generated: '2026-07-22'
method: searched
source: |
  Euronext public client specifications and product pages (fetched 2026-07-22):
  Saturn 2.8.8 spec PDF, EWS Indices v1.3 spec PDF, EWS Historical Data spec
  PDF, Optiq MDG product pages on euronext.com, github.com/euronext.
standards:
- id: mifid-ii-mifir
  conforms: true
  evidence: Saturn is Euronext's purpose-built MiFID II / MiFIR solution -
    RTS22 transaction reporting (ARM), APA pre- and post-trade publication, and
    Off Book On Exchange trade reporting; the check module validates mandatory
    RTS22 fields on submission (Saturn spec 2.8.8, section 1).
- id: iso-6166-isin
  conforms: true
  evidence: Instruments are identified by ISIN throughout the Euronext Web
    Services API (transco.codification "ISIN") and Saturn referential.
- id: iso-10383-mic
  conforms: true
  evidence: Market identification uses ISO 10383 MIC codes (XAMS, XBRU, XLIS,
    XPAR) as the exchCode parameter in EWS and in the Saturn MIC referential.
- id: lei
  conforms: true
  evidence: Saturn carries LEI (Legal Entity Identifier) codes for reporting
    parties and exposes a Retrieve LEI Referential function (spec section 5.2).
- id: fix-sbe
  conforms: true
  evidence: The Optiq Market Data Gateway encodes messages in FIX Simple Binary
    Encoding (SBE); github.com/euronext maintains a fork of
    real-logic/simple-binary-encoding.
- id: mutual-tls
  conforms: true
  evidence: Saturn uses certificate-based mutual authentication with
    DigiCert-issued client certificates (spec section 2.2).
- id: oauth2
  conforms: false
  evidence: No OAuth 2.0 anywhere - EWS uses an authKey query parameter and
    Saturn a proprietary logon-token scheme in the Authorization header.
- id: oidc
  conforms: false
  evidence: No OpenID Connect discovery documents on any Euronext host
    (/.well-known/openid-configuration blocked/absent on all hosts probed).
- id: rfc9457-problem-details
  conforms: false
  evidence: Saturn uses a proprietary StatusCode/Message envelope (200/401/504/600),
    not application/problem+json.
- id: rfc9116-security-txt
  conforms: false
  evidence: /.well-known/security.txt is not served on any Euronext host
    (403/404 on all probes, 2026-07-22).
- id: openapi
  conforms: false
  evidence: No machine-readable API description is published for any Euronext
    API - all client specifications are PDF documents.