Lemon Markets Authentication

generated: '2026-07-19'
method: searched
source: openapi/lemon-markets-brokerage-openapi.json
docs:
- https://developer.lemon.markets/docs/getting-started
- https://developer.lemon.markets/docs/webhooks-setup
summary:
  types:
  - http
  api_key_in: []
  oauth2_flows: []
  scopes: none
  model: >-
    A single partner-scoped bearer API key. There is no OAuth, no OpenID Connect, no scope surface and
    no mutual TLS. Authorisation is partner-wide, and the acting principal is carried per request in
    mandatory data-privacy headers rather than in the token.
schemes:
- name: bearerAuth
  type: http
  scheme: bearer
  applied: global (root-level security requirement)
  header: Authorization
  format: Bearer <api-key>
  sources:
  - openapi/lemon-markets-brokerage-openapi.json
required_request_headers:
- name: LMG-Data-Privacy-Access-Principal
  in: header
  required: true
  applies_to: customer-data operations
  description: >-
    Identifies the principal (human or system) on whose behalf the request is made. Declared as a
    required OpenAPI parameter, so requests omitting it fail.
- name: LMG-Data-Privacy-Access-Justification
  in: header
  required: true
  applies_to: customer-data operations
  description: >-
    Free-text justification for accessing customer data in this request, recorded alongside the
    principal for data-protection auditing.
key_management:
  issuance: issued during partner onboarding; the API is invite-only with no self-service signup
  rotation: not documented publicly
  test_vs_live_prefix: not documented; environments are separated by hostname
  scopes_or_permissions: none published
webhook_authentication:
  direction: inbound to the partner
  mechanism: HMAC-SHA256 signature in the LMG-Signature header
  secret: per-webhook signature_secret returned at registration
  detail: asyncapi/lemon-markets-brokerage-webhooks.yml
not_supported:
- oauth2
- openIdConnect
- apiKey query or cookie parameters
- mutualTLS
- sender-constrained / proof-of-possession tokens