generated: '2026-07-24'
method: searched
source: https://developer.paysend.com/authentication-and-idempotency/
docs: https://developer.paysend.com/authentication-and-idempotency/
note: >-
  Derived from the Paysend Enterprise developer portal auth documentation rather
  than an OpenAPI securitySchemes block (no downloadable spec is published). The
  Payout API authenticates every request with an inbound API key plus an HMAC
  digital signature carried in the X-OPP-Signature header. No OAuth2, OpenID
  Connect, or mutual TLS is documented.
summary:
  types: [apiKey, hmac-signature]
  api_key_in: [provisioned]
  oauth2_flows: []
schemes:
  - name: InboundAPIKey
    type: apiKey
    description: >-
      A partner-provisioned inbound API key issued by Paysend during enterprise
      onboarding. Not passed as a bearer token; it is a shared secret used both
      to identify the partner and as an input to the request signature.
    provisioning: enterprise onboarding (partner-provisioned)
    sources: [docs]
  - name: X-OPP-Signature
    type: http
    scheme: hmac-signature
    in: header
    header: X-OPP-Signature
    description: >-
      HMAC-style request signature. For API calls the source string is the
      concatenation {RequestBody}{InboundAPIKey}; for status checks the source
      string is {globalId}{InboundAPIKey}. The agreed hash algorithm is applied
      to the source string and the resulting hash is hex-encoded into the header.
    algorithms: [SHA-256, SHA-512]
    signature_string_api: '{RequestBody}{InboundAPIKey}'
    signature_string_status: '{globalId}{InboundAPIKey}'
    encoding: hexadecimal
    sources: [docs]
idempotency:
  supported: true
  mechanism: >-
    Requests are made idempotent via two required header fields inside the JSON
    request envelope: header.request.id (a unique idempotency key per request)
    and header.request.date (the request timestamp, ISO 8601). The combination
    of the two guarantees an operation is not performed more than once.
  fields:
    - name: header.request.id
      description: Unique idempotency key for each API request.
    - name: header.request.date
      description: Request timestamp (ISO 8601, e.g. 2024-08-15T14:30:00Z).