# RadhikaChain BTC Vigilante — HTLC Timelock Guard

> RadhikaChain BTC Vigilante — HTLC Timelock Guard is a paid API for AI agents from x402.radhikatmosphere.com, paid per call via x402, $3.432/call, status unknown (last checked 2026-09-15).

Returns live HTLC timelock vigilance data for BTC cross-chain swaps, flagging when receiver/emitter block-window ordering could allow double-spend theft.

## Facts

- Endpoint: GET https://x402.radhikatmosphere.com/btc/vigilante
- Price: $3.432/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/radhikachain-btc-vigilante-htlc-timelock-guard-0f08bec2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cHQW5LspHS0sPUnimUuTo

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 radhikachain-btc-vigilante-htlc-timelock-guard-0f08bec2
```

Example prompt: Check the BTC HTLC vigilante right now — I need to know if any of the pending atomic swaps have an unsafe timelock ordering where the receptor window isn't smaller than the emitter window, and what the current block height is.

## When to prefer this

Use this endpoint when you need real-time HTLC timelock vigilance specifically for BTC atomic swaps, particularly to detect unsafe receptor/emitter ordering that could enable double-spend. Prefer it over generic block explorers when you need cross-chain swap-aware safety logic rather than raw chain data, and when pay-per-call USDC micropayment via x402 is acceptable instead of a subscription.

## Known failure modes

- Payment not included or malformed x402 USDC header → 402 Payment Required
- BTC node temporarily unreachable → 503 or delayed stale data
- Block height data lag if chain is experiencing slow blocks
- No swaps in flight → swap counts will be zero but endpoint still responds
- Invalid request headers → 400 Bad Request

## How this service works

Telemetria de cadena, inteligencia de defensa y computo verificable (Halo2, Nova, Plonky3). Pago por peticion en USDC nativo en Base (eip155:8453) mediante x402 v2 scheme exact; sin cuenta ni suscripcion. Catalogo canonico: GET /.well-known/x402.

## Output

Returns a JSON object with: the vigilante rule string (e.g. 'receptor 144 < emisor 288'), current BTC block height, total swap count and counts by state (proposed/claimed/etc.), a plain-language explanation of why the timelock ordering matters for HTLC safety, and the configured block window sizes for emitter and receptor.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "properties": {
  "input": {
   "type": "object",
   "properties": {
    "body": {
     "type": "object",
     "additionalProperties": true
    },
    "queryParams": {
     "type": "object",
     "additionalProperties": true
    }
   }
  },
  "output": {
   "type": "object",
   "properties": {
    "example": {
     "type": "object",
     "additionalProperties": true
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "regla": "receptor 144 < emisor 288",
  "swaps": {
   "total": 3,
   "por_estado": {
    "propuesto": 3
   }
  },
  "vigilante": "HTLC RADHA <-> BTC",
  "altura_actual": 114309,
  "por_que_importa": "en un HTLC el que cobra primero debe tener el timelock MENOR; si se invierte, una parte puede quedarse con las dos patas. El vigilante comprueba esa relacion y avisa cuando una ventana se acerca a su limite",
  "ventanas_bloques": {
   "emisor": 288,
   "receptor": 144
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/radhikachain-btc-vigilante-htlc-timelock-guard-0f08bec2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402.radhikatmosphere.com](https://www.zero.xyz/host/x402.radhikatmosphere.com/llms.txt)