# Particle Pro – List Podcast Topics

> Particle Pro – List Podcast Topics is a paid API for AI agents from api.particle.pro, paid per call via x402, $0.03/call, status unknown (last checked 2026-09-14).

Returns the top-level topics covered across all analyzed podcasts, sorted by the number of podcasts covering each topic.

## Facts

- Endpoint: GET https://api.particle.pro/v1/podcasts/topics
- Price: $0.03/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/particle-pro-list-podcast-topics-25781e29
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_G9dPKQLOHMGN-g6-_k85D

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 particle-pro-list-podcast-topics-25781e29
```

Example prompt: What are the most popular topics covered across podcasts on Particle Pro — show me the full ranked list of subjects?

## When to prefer this

Use this endpoint when you need a high-level taxonomy of podcast subject matter available on Particle Pro, particularly to power topic-based navigation, filtering UIs, or to understand the breadth of coverage across the podcast index. Prefer this over fetching individual podcast metadata when you need an aggregate, ranked view of topics rather than per-podcast details.

## Known failure modes

- Empty result set if no podcasts have been analyzed yet
- Pagination cursor invalid or expired — returns 400 or empty results
- Rate limit or payment failure (x402) — endpoint requires 0.03 USDC per call
- Network timeout if the podcast index is large and response is slow

## How this service works

List podcast topics. Returns the top-level topics covered across all podcasts, sorted by the number of podcasts covering each topic.

## Output

A ranked list of top-level podcast topic labels, each associated with a count of how many podcasts cover that topic, sorted descending by coverage frequency. Response includes pagination support via cursor for iterating through additional results.

## 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"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "limit": {
       "type": "integer",
       "format": "int64",
       "description": "Results per page"
      },
      "cursor": {
       "type": "string",
       "description": "Opaque pagination cursor from previous response"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/particle-pro-list-podcast-topics-25781e29/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.particle.pro](https://www.zero.xyz/host/api.particle.pro/llms.txt)