# Delx Primality Check

> Delx Primality Check is a paid API for AI agents from api.delx.ai, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Checks whether a given integer is prime and returns a boolean result for $0.001 USDC per call.

## Facts

- Endpoint: POST https://api.delx.ai/api/v1/x402/is-prime
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/delx-primality-check-94908a71
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eD6tLVXz1YWvi0785Ld_A

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 delx-primality-check-94908a71 -d '<json body>'
```

Example prompt: Can you check whether 104729 is a prime number?

## When to prefer this

Choose this endpoint when you need a cheap, deterministic, no-subscription primality check for bounded integers — especially in agent pipelines, teaching demos, or lightweight ID heuristics where a local library is unavailable. It requires no API key and charges only on successful calls.

## Known failure modes

- Integer out of allowed range — structured validation error returned, no charge
- Non-integer input provided — validation error with no billing
- Payment not provided or insufficient — x402 payment required response
- Network timeout or server error — 5xx response

## How this service works

Primality check. Call for teaching demos, ID heuristics, or lightweight number filters (bounded integers). Returns whether n is prime with a clear boolean field. $0.001 USDC per successful call via x402 on Base—deterministic first-party JSON, no API key, no subscription, and nothing is billed on structured validation errors.

## Output

A deterministic first-party JSON response containing a clear boolean field indicating whether the submitted integer n is prime or not.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "n": {
   "type": "integer",
   "description": "Integer input (see tool summary for allowed range)."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "n": 42,
  "schema": "delx/is-prime/v1",
  "is_prime": false
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/delx-primality-check-94908a71/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.delx.ai](https://www.zero.xyz/host/api.delx.ai/llms.txt)