Monitor

Subscribe to depeg, utilization, and liquidity alerts over a websocket. Partners connect with headers; anyone else buys a time window with x402 and connects with a session token.

WS wss://si.ampli.net/api/v1/monitor

The monitor checks your subscriptions every 60 seconds and pushes an event the first time a threshold is crossed. An alert is sent once and re-arms after the condition clears.

Event	Fires when
depeg	A stablecoin is more than 3% from its peg
utilization	A market’s utilization is above 95%
liquidity	A market has open borrows and no withdrawable liquidity

Connect

Partner key

Open the socket with the partner headers. There is no time limit.

const socket = new WebSocket("wss://si.ampli.net/api/v1/monitor", {
  headers: { "X-Partner-Name": "your-partner-name", "X-Partner-API-Key": process.env.AMPLI_PARTNER_API_KEY },
});

x402 session

A stream does not fit per-request payment, so you buy a window up front. Call POST /monitor/sessions (MCP tool: create_monitor_session) with the number of hours, from 1 to 24. It is priced per hour and paid with x402 like any other route.

curl -s https://si.ampli.net/api/v1/monitor/sessions \
  -H "Content-Type: application/json" \
  -H "PAYMENT-SIGNATURE: <base64 payment payload>" \
  -d '{"hours": 6}'

{
  "token": "eyJ...",
  "expires_at": "2026-11-12T22:00:00Z",
  "payer": "0xPayerWallet",
  "session_id": "6c1f...",
  "subject": "x402:0xpayerwallet",
  "hours": 6,
  "websocket_url": "wss://si.ampli.net/api/v1/monitor",
  "subscribe_message": {
    "action": "subscribe",
    "events": ["depeg", "utilization", "liquidity"],
    "assets": [{ "chain_id": 8453, "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913" }]
  }
}

Connect to websocket_url with Authorization: Bearer <token>. Clients that cannot set headers can use ?access_token=<token> instead, but the header keeps the token out of URLs and access logs.

const socket = new WebSocket(session.websocket_url, {
  headers: { Authorization: `Bearer ${session.token}` },
});

Subscribe

After the socket opens, send a subscribe message. You can send more later to add assets, or unsubscribe to remove them.

{
  "action": "subscribe",
  "events": ["depeg", "utilization", "liquidity"],
  "assets": [
    { "chain_id": 8453, "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913" },
    { "chain_id": 999, "address": "0xB8CE59FC3717ada4C02eaDF9682A9e934F625ebb" }
  ]
}

• assets takes underlying tokens (every market for that token is watched) or single markets and vaults.
• events is optional. Leave it out to receive all three.
• The server answers {"event": "subscribed", "assets": [...]} and runs a first check straight away.

Events

{
  "event": "utilization",
  "chain_id": 8453,
  "address": "0xedc817a28e8b93b03976fbd4a3ddbc9f7d176c22",
  "protocol": "moonwell",
  "utilization": 0.962,
  "threshold": 0.95
}

Event	Fields besides event and chain_id
depeg	address (the token), price, deviation, threshold
utilization	address (the market), protocol, utilization, threshold
liquidity	address (the market), protocol, total_supply, total_borrows, available_liquidity in base units

Event	Meaning
subscribed, unsubscribed	Your current asset list
depeg, utilization, liquidity	A threshold was crossed
error	Your last message was invalid. The socket stays open
session_expired	The x402 window ended. The server closes with code 1008 right after

A socket with an invalid token or partner key is closed with code 1008 straight away.

Renewing a window

Buy the next session before expires_at, open a second socket, subscribe, then close the old one. Nothing is missed and nothing is paid twice for the same hour.

The MCP tool create_monitor_session only issues the token. It does not hold the socket for you. Your agent or service must open the websocket and keep it open.