Dojo.js Events & Token Tracking

When to Use

Use this skill when:

• Subscribing to game events
• Tracking token balances
• Monitoring token transfers
• Tracking achievements and activities

Event Subscriptions

Subscribe to Event Messages

import { ToriiQueryBuilder } from "@dojoengine/sdk";
import { useDojoSDK } from "@dojoengine/sdk/react";

const { sdk } = useDojoSDK();

const [initialEvents, subscription] = await sdk.subscribeEventQuery({
    query: new ToriiQueryBuilder<typeof schema>()
        .addEntityModel("game-GameEvent")
        .withLimit(100),
    callback: ({ data, error }) => {
        if (error) {
            console.error("Event error:", error);
            return;
        }
        console.log("New event:", data);
    }
});

// Process initial events
initialEvents.items.forEach(event => {
    console.log(event.models.game.GameEvent);
});

// Cleanup
subscription.cancel();

Get Event Messages (One-time)

const events = await sdk.getEventMessages({
    query: new ToriiQueryBuilder<typeof schema>()
        .addEntityModel("game-PlayerAction")
        .addOrderBy("game-PlayerAction.timestamp", "Desc")
        .withLimit(50)
});

Token Balance Tracking

Subscribe to Token Balances

const [balances, subscription] = await sdk.subscribeTokenBalance({
    // Contract addresses must be full hex strings with 0x prefix
    contractAddresses: ["0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7"],
    accountAddresses: [playerAddress],
    callback: (balance) => {
        console.log("Balance updated:", balance.balance);
    }
});

// Initial balances
balances.items.forEach(b => {
    console.log(`Token: ${b.token_id}, Balance: ${b.balance}`);
});

Get Token Balances

const balances = await sdk.getTokenBalances({
    contractAddresses: ["0x..."],
    accountAddresses: [playerAddress],
    pagination: { limit: 100 }
});

Track Balance Updates Only

const subscription = await sdk.onTokenBalanceUpdated({
    contractAddresses: ["0x049d36570d4e46f48e99674bd3fcc84644ddd6b96f7c741b1562b82f9e004dc7"],
    accountAddresses: [playerAddress],
    // Empty array for all tokens (ERC20); for ERC721 use specific IDs: ["0x1", "0x2"]
    tokenIds: [],
    callback: (balance) => {
        updateUI(balance);
    }
});

Token Transfer Tracking

const [transfers, subscription] = await sdk.subscribeTokenTransfer({
    contractAddresses: ["0x..."],
    accountAddresses: [playerAddress],
    callback: (transfer) => {
        console.log(`Transfer: ${transfer.from} -> ${transfer.to}`);
    }
});

Token Queries

// Get tokens
const tokens = await sdk.getTokens({
    contractAddresses: ["0x..."],
    pagination: { limit: 100 }
});

// Get token contracts
const contracts = await sdk.getTokenContracts({
    contractTypes: ["ERC20", "ERC721"]
});

Achievement Tracking

// Get achievements
const achievements = await sdk.getAchievements({
    worldAddresses: [worldAddress],
    namespaces: ["game"]
});

// Get player achievements
const playerAchievements = await sdk.getPlayerAchievements({
    playerAddresses: [playerAddress]
});

// Subscribe to achievement progress
const subscription = await sdk.onAchievementProgressionUpdated({
    worldAddresses: [worldAddress],
    playerAddresses: [playerAddress],
    callback: (progression) => {
        console.log("Achievement progress:", progression);
    }
});

Activity Tracking

// Get activities
const activities = await sdk.getActivities({
    world_addresses: [worldAddress],
    namespaces: ["game"],
    caller_addresses: [playerAddress]
});

// Subscribe to activities
const subscription = await sdk.onActivityUpdated(
    [worldAddress],
    ["game"],
    [playerAddress],
    (activity) => {
        console.log("New activity:", activity);
    }
);

Aggregations

// Get aggregated data
const aggregations = await sdk.getAggregations({
    aggregator_ids: ["total_players", "total_games"],
    pagination: { limit: 10 }
});

// Subscribe to aggregation updates
const subscription = await sdk.onAggregationUpdated(
    ["total_players"],
    null,
    (aggregation) => {
        console.log("Aggregation updated:", aggregation);
    }
);

Update Subscriptions

// Update token balance subscription
await sdk.updateTokenBalanceSubscription({
    subscription,
    contractAddresses: newContracts,
    accountAddresses: newAccounts,
    tokenIds: []
});

// Update entity subscription
await sdk.updateEntitySubscription(
    subscription,
    newClause
);

React Effect Atoms

For complex async state:

import { createEventQueryAtom, createEventUpdatesAtom } from "@dojoengine/react/effect";

// One-time event query
const eventsAtom = createEventQueryAtom(runtime, query);

// Live event updates
const updatesAtom = createEventUpdatesAtom(runtime, clauses);

// Combined query + updates
const liveEventsAtom = createEventQueryWithUpdatesAtom(runtime, query, clauses);

Common Pitfalls

1. Subscription cleanup: Always cancel subscriptions when component unmounts
2. Contract addresses: Must be padded hex strings with 0x prefix
3. Token IDs: Format depends on token type (ERC20 vs ERC721)
4. Rate limiting: Avoid creating too many subscriptions
5. Callback errors: Wrap callbacks in try-catch to prevent unhandled errors