Phase 1 — Monitor a Pool

A read-only agent that watches a Cetus trading pool. No funds at risk — it just observes price movement and simulates what a position would do.

Time: ~10 minutes | Risk: None (read-only)

What you’ll build

An agent that runs in a loop and:

Connects to a Cetus pool on Sui
Reads the current market price every 5 minutes
Simulates a position and checks if it would need repositioning
Logs everything to a JSON file

The code

Create agent.js:


import { initCetusSDK } from '@cetusprotocol/cetus-sui-clmm-sdk';
import { getFullnodeUrl, SuiClient } from '@mysten/sui/client';
import fs from 'fs';
import dotenv from 'dotenv';
 
dotenv.config();
 
const AGENT_ID = 'sui-cetus-yield';
const LOG_FILE = process.env.LOG_FILE || `${AGENT_ID}.log`;
const CHECK_INTERVAL = parseInt(process.env.CHECK_INTERVAL_MS || '300000');
const POOL_ID = process.env.CETUS_POOL_ID;
const THRESHOLD = parseInt(process.env.REBALANCE_THRESHOLD_TICKS || '100');
const RANGE = parseInt(process.env.POSITION_RANGE_TICKS || '200');
 
// --- Logging ---
 
function log(level, message, data = {}) {
  const entry = { ts: new Date().toISOString(), agent: AGENT_ID, level, message, ...data };
  const line = JSON.stringify(entry);
  console.log(line);
  try { fs.appendFileSync(LOG_FILE, line + '\n'); } catch {}
}
 
// --- Cetus SDK ---
 
const client = new SuiClient({ url: process.env.SUI_RPC || getFullnodeUrl('mainnet') });
const sdk = initCetusSDK({ network: process.env.NETWORK || 'mainnet' });
 
async function getPoolState() {
  return await sdk.Pool.getPool(POOL_ID);
}
 
// --- Simulated Position ---
 
let simPosition = null; // { tickLower, tickUpper, center, openedAt }
 
function simulatePositionCheck(currentTick) {
  if (!simPosition) {
    // Open a simulated position centered on current price
    const tickLower = currentTick - RANGE;
    const tickUpper = currentTick + RANGE;
    simPosition = { tickLower, tickUpper, center: currentTick, openedAt: new Date().toISOString() };
    log('event', 'sim_position_opened', { tickLower, tickUpper, center: currentTick });
    return;
  }
 
  const drift = Math.abs(currentTick - simPosition.center);
  const outOfRange = currentTick < simPosition.tickLower || currentTick > simPosition.tickUpper;
 
  if (outOfRange || drift > THRESHOLD) {
    log('event', 'sim_drift_detected', { drift, threshold: THRESHOLD, currentTick });
    // Simulate rebalance: close old, open new
    simPosition = {
      tickLower: currentTick - RANGE,
      tickUpper: currentTick + RANGE,
      center: currentTick,
      openedAt: new Date().toISOString(),
    };
    log('event', 'sim_rebalance', { newTickLower: simPosition.tickLower, newTickUpper: simPosition.tickUpper });
  } else {
    log('info', 'Simulated position in range', { currentTick, drift, threshold: THRESHOLD });
  }
}
 
// --- Main Loop ---
 
async function runAgent() {
  log('info', 'Agent starting', { mode: 'monitor', pool: POOL_ID, checkInterval: CHECK_INTERVAL });
 
  while (true) {
    try {
      const pool = await getPoolState();
      const currentTick = pool.current_tick_index;
 
      log('info', 'Cycle', {
        mode: 'monitor',
        tick: currentTick,
        sqrtPrice: pool.current_sqrt_price,
      });
 
      simulatePositionCheck(currentTick);
    } catch (error) {
      log('error', 'Cycle failed', { error: error.message });
    }
 
    log('info', `Next check in ${CHECK_INTERVAL / 1000}s`);
    await new Promise(r => setTimeout(r, CHECK_INTERVAL));
  }
}
 
runAgent().catch(err => {
  log('error', 'Fatal', { error: err.message });
  process.exit(1);
});

Run it


node agent.js

You should see output like:


{"ts":"...","agent":"sui-cetus-yield","level":"info","message":"Agent starting","mode":"monitor","pool":"0xb8d7..."}
{"ts":"...","agent":"sui-cetus-yield","level":"info","message":"Cycle","mode":"monitor","tick":69758}
{"ts":"...","agent":"sui-cetus-yield","level":"event","message":"sim_position_opened","tickLower":69558,"tickUpper":69958}

The agent logs every check to sui-cetus-yield.log. Let it run for a few cycles to see how the price moves.

What just happened

The agent is watching the SUI/USDC pool on Cetus. Every 5 minutes it reads the current price (represented as a “tick” — an index into a price grid). It simulates holding a position and checks whether the price has drifted far enough to require a reposition.

No transactions are sent. No funds are needed. This is purely observational.

Next step

Ready to earn real fees? Phase 2 — Earn Fees adds transaction signing via WaaP CLI and opens a real position.