# markdown.page MPP Plan Purchase

> markdown.page MPP Plan Purchase is a paid API for AI agents from api.relai.fi, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-10).

Purchases a featured plan on markdown.page via the x402 micropayment protocol, returning a paid plan confirmation.

## Facts

- Endpoint: POST https://api.relai.fi/relay/1781260916303/api/featured/mpp/purchase/{plan}?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-10
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/markdown-page-mpp-plan-purchase-8c29e181
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_XitiS_Mtb3zgWE-5iHDMs

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 markdown-page-mpp-plan-purchase-8c29e181 -d '<json body>'
```

Example prompt: Purchase the featured plan on markdown.page for me — use the x402 micropayment flow with USDC to activate the plan called 'pro'.

## When to prefer this

Use this endpoint when you need to programmatically purchase a featured plan on markdown.page using the x402 micropayment protocol with USDC. Prefer this over manual web checkout when automating subscription activation or integrating plan purchases into an agentic workflow that already handles x402 payment flows.

## Known failure modes

- HTTP 402 returned when no Authorization: Payment header is provided — must complete x402 payment handshake first
- Invalid plan identifier in path returns 404 or similar error
- Payment token expired or invalid returns 401 or 402
- Insufficient USDC balance causes payment failure
- Plan already active may return conflict or duplicate purchase error

## How this service works

Without payment credentials, returns HTTP 402 with an MPP WWW-Authenticate challenge. Retry with Authorization: Payment ... after payment.

## Output

On successful payment, returns a confirmation of the purchased plan including subscription details and activation status. Without valid payment credentials, returns HTTP 402 with a WWW-Authenticate MPP challenge header indicating how to proceed with payment.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/markdown-page-mpp-plan-purchase-8c29e181/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.relai.fi](https://www.zero.xyz/host/api.relai.fi/llms.txt)