# Substack API Reference (Unofficial)

> Substack API Reference documents the web app's undocumented JSON API using curl probes and captured browser requests. It records read and write endpoints, authentication and request bodies, and supplies an OpenAPI 3.1 specification with curl and TypeScript examples. The author reports 129 verified endpoints from 14 capture rounds.

- Type: Documentation
- Targets: Protocol · Website
- Category: Website analysis tools
- Relationship: Learning resource
- Sources reviewed: 2026-11-06
- Added to the catalog: 2026-11-06
- Original resource: <https://github.com/AnthonyDavidAdams/substack-api-reference>
- Primary source: <https://github.com/AnthonyDavidAdams/substack-api-reference/blob/b9ebaf5cd58e527a3dba00689a2933e49a811310/README.md>
- Catalog page: <https://awesomerea.org/resources/substack-api-reference/>
- Record JSON: <https://awesomerea.org/resources/substack-api-reference/record.json>
- Chinese version: [简体中文](https://awesomerea.org/zh/resources/substack-api-reference/index.md)

## Requirements & limits

- **Prerequisites:** A Substack session cookie is needed for authenticated endpoints.
- **Limits:** The internal API can change; entries distinguish author-tested, reported, inferred, dead and gated endpoints.
- **License:** MIT License.

## Primary sources

1. <https://github.com/AnthonyDavidAdams/substack-api-reference/blob/b9ebaf5cd58e527a3dba00689a2933e49a811310/README.md>
2. <https://github.com/AnthonyDavidAdams/substack-api-reference/blob/b9ebaf5cd58e527a3dba00689a2933e49a811310/ENDPOINTS.md>

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## About this entry

The description was reviewed against primary sources.
Original editorial content: MIT. Linked projects, papers and assets retain their own rights and licenses.