generated: '2026-07-24'
method: searched
source: https://developer.myzeller.com/.well-known/oauth-authorization-server
docs: https://developer.myzeller.com/
summary:
  types: [oauth2, openIdConnect]
  oauth2_flows: [authorizationCode, clientCredentials, refreshToken]
  api_key_in: []
  gated: true
schemes:
- name: PortalOAuth2
  type: oauth2
  description: >-
    OAuth2 / OpenID Connect protecting the Zeller developer portal (Redocly Realm
    "Reunite") and its hosted MCP server. Issuer auth.cloud.redocly.com; PKCE S256;
    dynamic client registration supported.
  issuer: https://auth.cloud.redocly.com
  authorization_endpoint: https://developer.myzeller.com/_mcp/oauth2/auth
  token_endpoint: https://developer.myzeller.com/_mcp/oauth2/token-portal
  registration_endpoint: https://developer.myzeller.com/_mcp/register
  flows: [authorizationCode, clientCredentials, refreshToken]
  scopes: [openid, profile, email, offline_access]
  pkce: S256
  sources: [well-known/zeller-oauth-authorization-server.json]
notes: >-
  Only the developer-portal / MCP OAuth surface is publicly discoverable. The
  Zeller payments API (Terminal, Online, Tap to Pay) authenticates via credentials
  issued after creating a free Zeller Developer account; its authentication model is
  documented only behind that login and no anonymous OpenAPI securitySchemes are
  published. apis.yml notes the portal historically fronted an Auth0 (OIDC) tenant;
  the live well-known now resolves to Redocly's hosted auth.