# Substack Category Leaderboard

> Substack Category Leaderboard 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).

Returns the ranked list of top Substack publications in a given category, with full details including subscriber badge, pricing, paid tier, and author info.

## Facts

- Endpoint: GET https://x402.apidirect.io/v1/substack/category/publications?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/substack-category-leaderboard-048b3568
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1bTZwFGBhhjAqov1NoQ7y

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 substack-category-leaderboard-048b3568
```

Example prompt: Can you pull up the Substack leaderboard for the technology category — show me the top paid publications on page 1?

## When to prefer this

Use this endpoint when you need ranked leaderboard data for Substack publications within a specific category, including tier filtering (all, paid, rising) and pagination. Prefer this over the Substack search endpoint when you want Substack's own ranking signal rather than keyword-based search results.

## Known failure modes

- Invalid or unrecognized category ID/slug returns an error or empty results
- Page number out of range (above 21 for standard, above 4 for rising/bestsellers/podcasts) returns an error
- Invalid tier enum value returns a validation error
- Payment not processed results in 402 response
- Rate limits exceeded return a 429 error

## How this service works

Get a Substack category's leaderboard: the top publications ranked by Substack, each with its full details (subscriber badge, paid band, prices, author) and rank.

## Output

A paginated ranked list of Substack publications for the specified category, each entry including rank position, publication name, subdomain, subscriber badge level, paid subscription band, pricing tiers, and author details. Up to 25 publications per page.

## 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": [
      "category"
     ],
     "properties": {
      "page": {
       "type": "integer",
       "default": 1,
       "maximum": 21,
       "minimum": 1,
       "description": "Page number (default: 1), 25 publications per page. Up to 21 pages; rising 10; bestsellers and podcasts 4"
      },
      "tier": {
       "enum": [
        "all",
        "paid",
        "rising"
       ],
       "type": "string",
       "description": "all, paid or rising (bestsellers: rising; podcasts: all or paid)"
      },
      "category": {
       "type": "string",
       "description": "Category ID or slug, e.g. 4 or technology (bestsellers and podcasts for the site-wide boards). See Category IDs (https://apidirect.io/docs/substack-category-ids)"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/substack-category-leaderboard-048b3568/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)