MailOptin · Authentication Profile
Mailoptin Authentication
Authentication
MailOptin declares 3 security scheme(s) across its OpenAPI definitions.
CompanyEmail MarketingMarketing AutomationLead GenerationWordPressNewslettersWebhookMCPPlugins
Methods:
Schemes: 3
OAuth flows:
API key in:
Security Schemes
oauth2
http
scheme: basic
X-WP-Nonce apiKey
· in: header ()
Source
Authentication Profile
generated: '2026-08-12'
method: probed
source: >-
https://mailoptin.io/.well-known/oauth-authorization-server,
https://mailoptin.io/.well-known/oauth-protected-resource,
https://mailoptin.io/wp-json/ (authentication block)
docs: https://mailoptin.io/docs/
note: >-
There is no OpenAPI to derive from — derive-authentication.py found no spec. This
profile is built entirely from documents mailoptin.io actually serves and from live
401 responses observed on 2026-08-12.
schemes:
- id: oauth2_mcp
type: oauth2
applies_to: https://mailoptin.io/wp-json/mcp/mcp-oauth-server
flow: authorization_code
pkce: required
pkce_methods: [S256]
issuer: https://mailoptin.io
authorization_url: https://mailoptin.io/oauth/authorize
token_url: https://mailoptin.io/oauth/token
revocation_url: https://mailoptin.io/oauth/revoke
refresh: true
scopes: [mcp]
token_endpoint_auth_methods: [none]
client_registration: client_id_metadata_document
bearer_methods: [header]
evidence:
url: https://mailoptin.io/.well-known/oauth-authorization-server
http_status: 200
- id: application_passwords
type: http
scheme: basic
applies_to: https://mailoptin.io/wp-json/
description: >-
WordPress Application Passwords. The site's REST API root advertises the
authorization endpoint in its `authentication` block. Per-user credentials issued
from wp-admin; used with HTTP Basic.
authorization_url: https://mailoptin.io/wp-admin/authorize-application.php
evidence:
url: https://mailoptin.io/wp-json/
http_status: 200
- id: cookie_nonce
type: apiKey
in: header
name: X-WP-Nonce
applies_to: https://mailoptin.io/wp-json/
description: >-
WordPress cookie + nonce authentication for same-origin browser requests. Advertised
in the CORS `access-control-allow-headers` response header alongside Authorization.
evidence:
url: https://mailoptin.io/wp-json/wp/v2/posts
http_status: 200
anonymous_access:
available: true
note: >-
Read-only content routes under /wp-json/wp/v2/ answer anonymously (posts returned
x-wp-total 260 on 2026-08-12). Write routes, the Abilities API and both MCP servers
are gated.
observed_denials:
- url: https://mailoptin.io/wp-json/mcp/mcp-oauth-server
http_status: 401
code: mcp_unauthorized
- url: https://mailoptin.io/wp-json/wp-abilities/v1/abilities
http_status: 401
code: rest_forbidden
product_authentication:
note: >-
The MailOptin PRODUCT is a self-hosted WordPress plugin. It authenticates OUTBOUND to
60+ third-party email/CRM providers using each provider's own credentials (API keys,
OAuth). Those are the third parties' schemes, not MailOptin's, and are not recorded
here. MailOptin itself issues a license key, entered in wp-admin, for updates and
premium features.
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