# markdown.page API - Purchase Plan

> markdown.page API - Purchase Plan 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 subscription plan on markdown.page via x402 micropayment protocol

## Facts

- Endpoint: POST https://api.relai.fi/relay/1781260916303/api/featured/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-api-purchase-plan-255d8dcd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eAknwKUCkBoB-_SPlRvnR

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-api-purchase-plan-255d8dcd -d '<json body>'
```

Example prompt: Purchase the 'pro' plan on markdown.page for me — go ahead and pay the $0.01 USDC fee using x402.

## When to prefer this

Use this endpoint when you need to programmatically purchase or activate a markdown.page subscription plan using the x402 micropayment protocol with USDC, especially in automated agent workflows that handle crypto-native payments.

## Known failure modes

- HTTP 402 returned if x402 payment credential headers are missing or invalid
- Invalid plan identifier returns 404 or 400
- Insufficient USDC balance causes payment failure
- Network timeout during payment relay
- Plan already active may return conflict error

## How this service works

Without payment credentials, returns HTTP 402 with x402 payment challenge headers. Retry with x402 payment credential headers after payment.

## Output

Returns a confirmation of the plan purchase and activation, including subscription status and plan details after successful x402 micropayment processing.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/markdown-page-api-purchase-plan-255d8dcd/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)