# Random Fact by Topic

> Random Fact by Topic is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.0025/call, status unknown (last checked 2026-09-15).

Returns one curious, true fact in English or Spanish, optionally filtered by topic (science, computing, history, or nature), with a unique ID for session deduplication and seed support for reproducibility.

## Facts

- Endpoint: POST https://flat-rate-llm.kikoribera03.workers.dev/v1/content/fact
- Price: $0.0025/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/random-fact-by-topic-50a82659
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NAdS3LoqwkOp8jCER8E5p

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 random-fact-by-topic-50a82659 -d '<json body>'
```

Example prompt: Give me a curious true fact about computing in English, and skip IDs 4 and 9 that I've already seen this session.

## When to prefer this

Choose this endpoint when you need a single, categorized, deduplicated curiosity fact with reproducibility support — especially in sessions where repeat-avoidance matters (e.g., daily trivia bots, quiz flows). Prefer it over generic LLM prompting when you need consistent IDs to track seen facts, topic filtering across science/computing/history/nature, or bilingual (en/es) delivery at a flat per-call rate.

## Known failure modes

- Invalid topic value returns an error or falls back to any topic
- Invalid language code may default to English or return an error
- All facts excluded via the exclude list may return an empty result or an error
- Invalid or missing seed format may be silently ignored
- Network or worker-side errors return a non-200 HTTP status with no fact body

## How this service works

60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.

## Output

A JSON object containing a unique fact ID (for deduplication across a session), the fact text, the topic category, the language, and the total number of available facts in the dataset.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "seed": {
   "type": "string",
   "description": "Same seed always returns the same fact."
  },
  "topic": {
   "type": "string",
   "description": "science | computing | history | nature. Omit for any."
  },
  "exclude": {
   "type": "array",
   "description": "Ids already seen, comma-separated in a GET."
  },
  "language": {
   "type": "string",
   "description": "en | es. Defaults to en."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "id": {
   "type": "string"
  },
  "fact": {
   "type": "string"
  },
  "topic": {
   "type": "string"
  },
  "total": {
   "type": "number"
  },
  "language": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/random-fact-by-topic-50a82659/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from flat-rate-llm.kikoribera03.workers.dev](https://www.zero.xyz/host/flat-rate-llm.kikoribera03.workers.dev/llms.txt)