AccountBalanceQuery returns stale data on testnet after CryptoTransfer

[jmgomezl]

Hey team, first of all thanks for the amazing work on the Agent Kit — it has been a great experience building with it.

We ran into a small issue while building Aivy (aivylabs.xyz) for the APEX Hackathon and wanted to share it in case it helps others or if there is a known workaround we missed.

What happens

After funding an agent account via CryptoTransfer from HashPack, the get_hbar_balance_query_tool returns the old balance for several minutes, while the mirror node API already reflects the correct updated balance.

Steps to reproduce

1. Deploy an agent with a dedicated account (e.g. 0.0.8324060)
2. Fund the account with 10 HBAR via HashPack wallet transfer
3. Immediately ask the agent to check its balance using get_hbar_balance_query_tool
4. The tool returns the pre-funding balance (0.74 HBAR) instead of the actual balance (10.74 HBAR)
5. Meanwhile, the mirror node endpoint /api/v1/balances?account.id=0.0.8324060 already shows 10.74 HBAR

Expected behavior

AccountBalanceQuery should return the current confirmed balance, especially since CryptoTransfer has sub-second finality on Hedera.

Actual behavior

The balance query returns stale data for several minutes. Repeated calls continue to return the old value. It seems like it might be hitting a consensus node that hasn't propagated the latest state yet.

Environment

• Network: testnet
• Hedera SDK: @hashgraph/sdk (latest)
• Agent Kit: hedera-agent-kit (latest)
• The mirror node (testnet.mirrornode.hedera.com) returns the correct balance immediately

Suggestion

Would it make sense to add a mirror node fallback for balance queries, or at least document this behavior? For applications where users fund accounts and immediately interact with agents, the stale reads create a confusing UX — the UI shows one balance (from mirror node) while the agent reports a different one (from SDK).

Happy to provide more details or help test if needed. Thanks again for all the work on this toolkit, it really made our hackathon project possible.