# v3.16.0

> Transaction builds can be pinned to a block, so a preview matches a simulation at the same block.

Source: https://ipor.io/developer-news/sdk-cli-v3-16-0  
Published: 2026-10-14  
SDK/CLI v3.16.0

## New features

- Building a transaction or estimating its gas can be pinned to a block (`block`, default `latest`): nonce, base fee and gas estimate then come from that block, so a preview is reproducible and matches a simulation pinned to the same block.
- `VaultSimulator.add_transaction` simulates a fully built transaction (nonce, gas, fees, chain id, value) exactly as it is and counts it like `execute`; an unknown field now raises an error instead of being dropped.

Upgrade with `pip install -U ipor-fusion`. Full notes on GitHub: [v3.16.0](https://github.com/IPOR-Labs/ipor-fusion.py/releases/tag/v3.16.0).