# X402 Checkers Best Move Engine

> X402 Checkers Best Move Engine is a paid API for AI agents from api.x402checkers.com, paid per call via x402, $0.005000/call, status unknown (last checked 2026-09-15).

Returns the best move and evaluation metadata for a given American checkers board position using engine analysis at configurable depth

## Facts

- Endpoint: POST https://api.x402checkers.com/api/bestmove
- Price: $0.005000/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/api-x402checkers-com-c651dc45
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bl0CpIdic-FPFeuw9nuGe

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-x402checkers-com-c651dc45 -d '<json body>'
```

Example prompt: I'm playing American checkers and the current board position in PDN is '[FEN "B:W18,24,27,28,K10,K15:B12,16,20,K9,K11,K19"]' — what's the best move I should play, using depth 10 analysis?

## When to prefer this

Use this endpoint when you need a fast, authoritative engine recommendation for an American checkers (8x8 draughts) position encoded in PDN notation, especially when you need configurable search depth. Ideal for building checkers AI assistants, training tools, or game analysis features.

## Known failure modes

- Invalid PDN format returns error — position string must be valid American checkers PDN
- Depth out of range (below 1 or above 12) may return validation error
- Malformed JSON body causes 400 Bad Request
- Payment failure (insufficient USDC) causes x402 payment required response
- Extremely complex positions at high depth may time out

## How this service works

Request a recommended move for an American checkers position. POST JSON { "pdn": "<PDN position>", "depth": optional integer 1-12 (default 8) }. Response includes the best move in long notation and evaluation metadata.

## Output

A JSON response containing the recommended best move in long notation (e.g. '16-20') along with evaluation metadata such as position score and analysis depth used

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/api-x402checkers-com-c651dc45/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.x402checkers.com](https://www.zero.xyz/host/api.x402checkers.com/llms.txt)