# API Direct – Substack Post Likes

> API Direct – Substack Post Likes is a paid API for AI agents from x402.apidirect.io, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-30).

Retrieves the list of users who liked a specific Substack post.

## Facts

- Endpoint: GET https://x402.apidirect.io/v1/substack/post/likes?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-direct-substack-post-likes-6c8a3401
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tk3Ut9f22aIvfriiC7R3e

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability api-direct-substack-post-likes-6c8a3401
```

Example prompt: Can you get me the list of people who liked this Substack post: https://www.lennysnewsletter.com/p/all-of-the-lenny-and-friends-summit?

## When to prefer this

Use this endpoint when you need to identify or analyze the specific users who liked a Substack post, for purposes such as audience research, influencer identification, or engagement benchmarking. It supports flexible post identification (URL, post ID, or publication+slug), making it convenient regardless of how you reference the post. Prefer this over scraping Substack directly or using generic web extraction tools when you want structured, ready-to-use liker data without parsing HTML.

## Known failure modes

- Post not found (invalid URL, slug, or post ID returns an error or empty result)
- Publication subdomain provided without slug or vice versa — incomplete identifier
- Post URL exceeds 500 character limit
- Private or paywalled posts may return no likes or an access error
- Rate limiting if too many requests are made in quick succession
- Network timeout if Substack's underlying data is slow to respond

## How this service works

Get the people who liked a Substack post.

## Output

Returns a list of Substack users who liked the specified post, including user profile information (e.g. names, handles, profile URLs) and potentially a total like count. The post can be identified via a full URL, a numeric post ID, or a combination of publication subdomain and slug.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "url": {
       "type": "string",
       "maxLength": 500,
       "description": "Post URL, e.g. https://www.lennysnewsletter.com/p/all-of-the-lenny-and-friends-summit (max 500 characters). Provide url, post_id, or publication and slug."
      },
      "slug": {
       "type": "string",
       "maxLength": 200,
       "description": "Post URL slug, e.g. all-of-the-lenny-and-friends-summit, used together with publication."
      },
      "post_id": {
       "type": "string",
       "description": "Numeric post ID, as returned in post_id. Provide url, post_id, or publication and slug."
      },
      "publication": {
       "type": "string",
       "maxLength": 500,
       "description": "Publication subdomain, host or URL, used together with slug."
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-direct-substack-post-likes-6c8a3401/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.apidirect.io](https://www.zero.xyz/host/x402.apidirect.io/llms.txt)