Substack

aid: substack
name: Substack
description: Substack is an independent newsletter and media platform that lets writers, podcasters, video creators, and other
  culture makers publish directly to readers and monetize through paid subscriptions. Founded in 2017 by Chris Best (CEO),
  Jairaj Sethi (CTO), and Hamish McKenzie (CWO) and headquartered in San Francisco with a New York City office, Substack provides
  built-in subscription billing, paid posts, podcasting, chat, video, Notes, and a cross-publication recommendations network.
  Creators keep 90 percent of subscription revenue (less credit card fees) and own their mailing lists and content. The platform
  reports more than five million paid subscriptions and tens of millions of weekly active readers. Substack does not offer
  a general-purpose public REST API for managing publications, posts, or subscribers. It does publish a narrowly scoped official
  Developer API (released April 2026) that allows token-authenticated lookup of public Substack profiles by LinkedIn handle,
  gated by an application and Terms-of-Use process. Substack also runs an official remote MCP server at https://mcp.substack.com/api/v1/mcp,
  documented August 2026, which gives an MCP-capable AI assistant read-only access to publication analytics under OAuth 2.1
  with the mcp:read scope, gated to Admins of Bestseller publications. Read access to public content is otherwise available
  via per-publication RSS feeds, and the broader integration ecosystem relies on reverse-engineered, unofficial JSON endpoints
  used by the Substack web application. Substack publishes no OpenAPI, no AsyncAPI, no webhooks and no first-party SDK in
  any package registry.
type: Index
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source: []
  generated: '2026-07-22'
  method: derived
position: Provider
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/substack.png
tags:
- Newsletters
- Publishing
- Creator Economy
- Subscription
- Email
- Podcasting
- Notes
- Media
- Independent Media
- Paid Content
- MCP
- Agents
- RSS
- Analytics
tags_raw:
- Newsletters
- Publishing
- Creator Economy
- Subscriptions
- Email
- Podcasting
- Notes
- Media
- Independent Media
- Paid Content
- MCP
- Agents
- RSS
- Analytics
url: https://raw.githubusercontent.com/api-evangelist/substack/refs/heads/main/apis.yml
created: '2026-05-08'
modified: '2026-08-13'
specificationVersion: '0.23'
apis:
- name: Substack Developer API
  description: Narrowly scoped official API that returns public Substack profile data for a given LinkedIn handle. Access
    requires accepting the Developer API Terms of Use, applying via form, and generating a token from the Developer API section
    of account settings. Only profiles meeting Substack's authenticity thresholds are returned.
  humanURL: https://support.substack.com/hc/en-us/articles/45099095296916-Substack-Developer-API
  baseURL: https://substack.com
  tags:
  - Profile
  - LinkedIn
  - Read Only
  - Gated
  tags_raw:
  - Profile
  - LinkedIn
  - Read-Only
  - Gated
  properties:
  - type: Documentation
    url: https://support.substack.com/hc/en-us/articles/45099095296916-Substack-Developer-API
  - type: APIReference
    url: https://support.substack.com/hc/en-us/articles/45099095296916-Substack-Developer-API
  - type: TermsOfService
    name: Substack Developer API Terms of Use
    url: https://substack.com/api-tos
  - type: Authentication
    url: authentication/substack-authentication.yml
- name: Substack MCP Server
  description: 'Official remote Model Context Protocol server that connects a Substack publication to an MCP-capable AI assistant
    (Claude, ChatGPT, Cursor). Read-only: it serves publication dashboard metrics, subscriber counts, revenue, post performance,
    traffic sources, retention and publication settings. It cannot publish posts, send Notes or modify the account, and cannot
    read profile or Notes activity. Authorization is OAuth 2.1 authorization-code with PKCE S256 against https://substack.com,
    scope mcp:read, with RFC 9728 protected resource metadata advertised in the endpoint''s own 401 challenge. Connecting
    requires Admin role on a Bestseller publication.'
  humanURL: https://support.substack.com/hc/en-us/articles/50834026608916-How-to-connect-Substack-to-your-AI-Assistant
  baseURL: https://mcp.substack.com/api/v1/mcp
  tags:
  - MCP
  - Agents
  - Analytics
  - Read Only
  - Authentication
  tags_raw:
  - MCP
  - Agents
  - Analytics
  - Read-Only
  - OAuth
  properties:
  - type: MCPServer
    url: mcp/substack-mcp.yml
  - type: Documentation
    url: https://support.substack.com/hc/en-us/articles/50834026608916-How-to-connect-Substack-to-your-AI-Assistant
  - type: GettingStarted
    url: https://support.substack.com/hc/en-us/articles/50834026608916-How-to-connect-Substack-to-your-AI-Assistant
  - type: Authentication
    url: authentication/substack-authentication.yml
  - type: OAuthScopes
    url: scopes/substack-scopes.yml
- name: Substack RSS Feeds
  description: Per-publication public RSS feeds available at https://{publication}.substack.com/feed for syndication and read-only
    access to posts. RSS 2.0 with the content, dc, atom and itunes namespaces; no credential required. Podcast subscribers
    additionally receive a private per-subscriber feed whose contents depend on their subscription tier.
  humanURL: https://support.substack.com/hc/en-us/articles/360038239391-Is-there-an-RSS-feed-for-my-publication
  baseURL: https://{publication}.substack.com
  tags:
  - RSS
  - Read Only
  - Syndication
  tags_raw:
  - RSS
  - Read-Only
  - Syndication
  properties:
  - type: Documentation
    url: https://support.substack.com/hc/en-us/articles/360038239391-Is-there-an-RSS-feed-for-my-publication
  - type: Documentation
    name: Podcast RSS feeds and paid content
    url: https://support.substack.com/hc/en-us/articles/360041722272-Will-my-Podcast-RSS-feed-show-paid-only-content
common:
- type: VulnerabilityDisclosure
  url: security/substack-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/substack-domain-security.yml
- type: Security
  name: Substack Vulnerability Disclosure Policy
  url: https://substack.com/vulnerability-disclosure
- type: MCPServer
  url: mcp/substack-mcp.yml
- type: WellKnown
  url: well-known/substack-well-known.yml
- type: Authentication
  url: authentication/substack-authentication.yml
- type: OAuthScopes
  url: scopes/substack-scopes.yml
- type: Conformance
  url: conformance/substack-conformance.yml
- type: ErrorCatalog
  url: errors/substack-problem-types.yml
- type: Conventions
  url: conventions/substack-conventions.yml
- type: Lifecycle
  url: lifecycle/substack-lifecycle.yml
- type: StatusPage
  url: https://status.substack.com/
- type: ChangeLog
  url: changelog/substack-changelog.yml
- type: RateLimits
  url: rate-limits/substack-rate-limits.yml
- type: Plans
  url: plans/substack-plans-pricing.yml
- type: Packages
  url: packages/substack-packages.yml
- type: Components
  url: components/substack-components.yml
- type: LLMsTxt
  url: llms/substack-llms.txt
- type: Website
  url: https://substack.com/
- type: About
  url: https://substack.com/about
- type: Help
  url: https://support.substack.com/
- type: Documentation
  name: Substack Help Center
  url: https://support.substack.com/hc/en-us
- type: Support
  url: https://support.substack.com/hc/en-us/articles/43904995414164-How-to-contact-Substack-Support
- type: Blog
  url: https://on.substack.com/
- type: BlogRSS
  url: https://on.substack.com/feed
- type: Pricing
  url: https://support.substack.com/hc/en-us/articles/360037607131-How-much-does-Substack-cost
- type: Pricing
  name: Substack revenue calculator
  url: https://substack.com/going-paid
- type: SignUp
  url: https://substack.com/signup
- type: Login
  url: https://substack.com/sign-in
- type: Jobs
  url: https://substack.com/jobs
- type: Contact
  url: https://substack.com/contact
- type: TermsOfService
  url: https://substack.com/tos
- type: PrivacyPolicy
  url: https://substack.com/privacy
- type: ContentGuidelines
  url: https://substack.com/content
- type: Accessibility
  url: https://substack.com/accessibility
- type: Sitemap
  url: https://substack.com/sitemap
- type: BrandAssets
  url: https://substack.com/brand
- type: GitHubOrganization
  url: https://github.com/substackinc
- type: LinkedIn
  url: https://www.linkedin.com/company/substack
- type: Twitter
  url: https://twitter.com/SubstackInc
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-08-13'
  status: enriched
  artifacts_added: 17
  pass: local-v1
x-coverage:
  state: covered
  reason: null
  detail: 'Substack has a real, reachable agent surface — an official remote MCP server at https://mcp.substack.com/api/v1/mcp
    with full RFC 8414 / RFC 9728 OAuth discovery — even though it publishes no OpenAPI. The one wall hit was documentation:
    the Developer API reference article is linked from Substack''s own API Terms of Use but is absent from the public Help
    Center index, its Zendesk API record returns 401, and support.substack.com answers non-browser clients with a Cloudflare
    JavaScript challenge, so the Developer API''s exact auth header and error contract could not be read first-party.'
  evidence:
  - url: https://mcp.substack.com/api/v1/mcp
    status: 401
  - url: https://mcp.substack.com/.well-known/oauth-protected-resource/api/v1/mcp
    status: 200
  - url: https://substack.com/.well-known/oauth-authorization-server
    status: 200
  - url: https://support.substack.com/hc/en-us/articles/45099095296916-Substack-Developer-API
    status: 403
  - url: https://support.substack.com/api/v2/help_center/en-us/articles/45099095296916.json
    status: 401
  - url: https://substack.com/openapi.json
    status: 404
  checked: '2026-08-13'