Read Ethereum payloads without sending them anywhere.

Why a workbench and not an API

The name suggests a data service, but a website that runs only in your browser cannot be a blockchain data provider, and pretending otherwise would mean showing stale numbers as current. CryptoAPIs does the parts of API work that need no network: building correct requests, reading the responses you already have, decoding contract data, and testing your code against realistic fixtures.

What it gets right that ad-hoc scripts often miss

• Integers stay exact. JSON numbers and uint256 values beyond 2^53 never pass through floating point.
• "0x0" (the number zero) and "0x" (empty bytes) are kept apart, as are missing fields, null and zero.
• Batch replies are matched by id, not position, and a string id "2" is not the number 2.
• Hostile calldata with impossible lengths produces a diagnostic, not a frozen tab.
• Saved responses are always labelled as snapshots, including one called "latest balance".
• Token decimals are never assumed to be 18.

Privacy by construction

Every tool runs in your browser. The content-security policy blocks network requests to anywhere except this site's own files, and no tool tries to make one. Drafts are saved in your browser only; the redaction workspace is not saved at all. Hashing uses the audited @noble/hashes library.