> For the complete documentation index, see [llms.txt](https://docs.baas.sh/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.baas.sh/baas-sdk/blockchain.md).

# Blockchain interactions

Call smart contracts, send transactions, sign messages, convert amounts, and pick the active network from the BaaS SDK.

Call your registered smart contracts, send transactions, sign messages, convert amounts, and pick the active network, all from the browser.

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>Smart contracts</strong></td><td>Read data, send transactions, simulate, and estimate gas.</td><td><a href="/baas-sdk/blockchain/smart-contracts.md">Smart contracts</a></td></tr><tr><td><strong>Event history</strong></td><td>Read and filter what your contracts emit.</td><td><a href="/baas-sdk/blockchain/events.md">Event history</a></td></tr><tr><td><strong>Wallet operations</strong></td><td>Send transactions, sign messages, and read balances.</td><td><a href="/baas-sdk/blockchain/wallet.md">Wallet operations</a></td></tr><tr><td><strong>Networks</strong></td><td>List your project's supported chains and pick the active one.</td><td><a href="/baas-sdk/blockchain/networks.md">Networks</a></td></tr><tr><td><strong>Smart units</strong></td><td>Pass token amounts like 1.5 and read them back formatted.</td><td><a href="/baas-sdk/blockchain/smart-units.md">Smart units</a></td></tr></tbody></table>