aid: mailoptin
name: MailOptin
description: 'MailOptin is a WordPress lead-generation and email-automation plugin that
  converts website visitors into subscribers with popups, slide-ins, notification bars and
  inline optin forms, then sends one-off newsletters and event-triggered automated emails.
  It connects WordPress to more than sixty email marketing platforms, CRMs, form plugins,
  e-commerce and membership systems — Mailchimp, ActiveCampaign, HubSpot, AWeber, Klaviyo,
  Brevo, Salesforce, WooCommerce and others — and can post optin submissions to an
  arbitrary endpoint through a generic webhook connection. MailOptin is self-hosted
  software rather than a hosted service: it publishes no product API, no OpenAPI and no
  client SDK, and all functionality runs inside the customer''s own WordPress
  installation. Its own website, mailoptin.io, runs WordPress and does serve a public
  self-describing REST API together with an OAuth-protected Model Context Protocol server.'
image: https://mailoptin.io/wp-content/uploads/2014/05/mailoptin-plugin-banner.png
url: https://raw.githubusercontent.com/api-evangelist/mailoptin/refs/heads/main/apis.yml
x-type: company
x-source: harvest:marketing-integration-graph
specificationVersion: '0.23'
created: '2026-08-12'
modified: '2026-08-12'
tags:
- Company
- Email Marketing
- Marketing Automation
- Lead Generation
- WordPress
- Newsletters
- Webhooks
- Model Context Protocol
- Plugins
apis:
- aid: mailoptin-site
  name: MailOptin Site REST API and MCP Server
  description: 'The WordPress REST API served by mailoptin.io, plus the Model Context
    Protocol server exposed through the WordPress MCP Adapter at the mcp namespace. The
    REST root is a public, self-describing route index — 35 namespaces and 771 routes,
    each with its argument schema — and content routes under wp/v2 answer anonymously. The
    MCP endpoint is live but auth-gated, returning 401 mcp_unauthorized with a
    WWW-Authenticate Bearer challenge that links to RFC 9728 protected-resource metadata.
    This is the company website''s own surface, not a product API for the MailOptin
    lead-generation service, which ships as a self-hosted WordPress plugin.'
  humanURL: https://mailoptin.io/
  baseURL: https://mailoptin.io/wp-json
  tags:
  - WordPress
  - Model Context Protocol
  - OAuth
  properties:
  - type: MCPServer
    url: mcp/mailoptin-mcp.yml
  - type: Authentication
    url: authentication/mailoptin-authentication.yml
  - type: OAuthScopes
    url: scopes/mailoptin-scopes.yml
  - type: ErrorCatalog
    url: errors/mailoptin-problem-types.yml
  - type: Conventions
    url: conventions/mailoptin-conventions.yml
  - type: RateLimits
    url: rate-limits/mailoptin-rate-limits.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Website
  url: https://mailoptin.io/
- type: Documentation
  url: https://mailoptin.io/docs/
- type: GettingStarted
  url: https://mailoptin.io/section/getting-started/
- type: Support
  url: https://mailoptin.io/support/
- type: Blog
  url: https://mailoptin.io/blog/
- type: BlogRSS
  url: https://mailoptin.io/blog/feed/
- type: GitHubOrganization
  url: https://github.com/mailoptin
- type: Pricing
  url: https://mailoptin.io/pricing/
- type: SignUp
  url: https://my.mailoptin.io/login/
- type: TermsOfService
  url: https://mailoptin.io/terms-conditions/
- type: PrivacyPolicy
  url: https://mailoptin.io/privacy-policy/
- type: ChangeLog
  url: changelog/mailoptin-changelog.yml
- type: Lifecycle
  url: lifecycle/mailoptin-lifecycle.yml
- type: Plans
  url: plans/mailoptin-plans-pricing.yml
- type: RateLimits
  url: rate-limits/mailoptin-rate-limits.yml
- type: Packages
  url: packages/mailoptin-packages.yml
- type: Webhooks
  url: asyncapi/mailoptin-webhooks.yml
- type: Conformance
  url: conformance/mailoptin-conformance.yml
- type: Conventions
  url: conventions/mailoptin-conventions.yml
- type: ErrorCatalog
  url: errors/mailoptin-problem-types.yml
- type: Authentication
  url: authentication/mailoptin-authentication.yml
- type: OAuthScopes
  url: scopes/mailoptin-scopes.yml
- type: MCPServer
  url: mcp/mailoptin-mcp.yml
- type: WellKnown
  url: well-known/mailoptin-well-known.yml
- type: LLMsTxt
  url: llms/mailoptin-llms.txt
- type: DomainSecurity
  url: security/mailoptin-domain-security.yml
x-enrichment:
  date: '2026-08-12'
  status: enriched
  artifacts_added: 17
  pass: local-v1
x-coverage:
  state: covered
  reason: covered
  detail: >-
    MailOptin ships no product API, but mailoptin.io serves real machine-readable
    documents — RFC 8414 authorization-server metadata, RFC 9728 protected-resource
    metadata, a live OAuth-gated MCP server and a public 771-route WordPress REST index —
    all of which were fetched and recorded.
  evidence:
  - url: https://mailoptin.io/.well-known/oauth-protected-resource
    status: 200
  - url: https://mailoptin.io/wp-json/mcp/mcp-oauth-server
    status: 401
  checked: '2026-08-12'
x-vouched-by:
- Drip
- MailerLite
- SendPulse
x-vouch-count: 3