Blockchain Lab Lens

Explain any transaction, address or contract on Etherscan-family block explorers in one click — decoded function call and arguments, decoded event logs, status and fees, EOA vs contract, proxy implementation (EIP-1967 / zeppelinos), EIP-7702 delegation, ENS names and ERC-20 metadata — powered by the free Blockchain Lab Tools.

Built by Blockchain Lab — blockchainlab.com

Install page (bookmarklet drag-link): https://blockchains.github.io/blockchainlab-lens/

Supported explorers: etherscan.io, basescan.org, arbiscan.io, polygonscan.com, optimistic.etherscan.io, bscscan.com, snowtrace.io, and Blockscout for Ethereum / Base / Arbitrum / Polygon / Optimism.

1. Bookmarklet (any browser)

Open the install page and drag 🔍 BL Lens to your bookmarks bar (GitHub strips javascript: links from READMEs, so it lives there). Source: bookmarklet/bookmarklet.src.js; encoded form: bookmarklet/bookmarklet.txt.

2. Chrome / Edge / Brave extension (Manifest V3)

1. Download blockchainlab-lens.zip from Releases and unzip it, or clone this repo.
2. Go to chrome://extensions, turn on Developer mode, click Load unpacked and pick the extension/ folder.
3. On any explorer /tx/0x…, /address/0x… or /token/0x… page, click Explain · Blockchain Lab (bottom right).
4. Or highlight any hash / address / ENS name on any page → right-click → Explain with Blockchain Lab. The toolbar popup takes any hash, address, ENS name or calldata.

Permissions: contextMenus only, plus a content script on the explorer domains. No analytics, no data collection, no backend.

If an explorer page is showing a Cloudflare "verify you are human" screen, its security headers block embedded frames. Finish the check, or use open in tab ↗ in the panel header.

Tests

test_extension.py loads the real unpacked extension in Chromium and checks the button, panel and bookmarklet on Etherscan, Basescan, Arbiscan and Polygonscan URLs. The embedded tools page has to render live on-chain data (USDC contracts, plus a real recent Polygon tx). Explorer HTML is stubbed via request routing because explorers put headless browsers behind a Cloudflare check. The extension only reads the URL, which is the real one. CI runs it on every push (extension-tests).

pip install playwright && python -m playwright install chromium && python test_extension.py

Related

Blockchain Lab Tools · Open Data API · MCP server · Labs

MIT. Not financial advice.

Use as a building block

For AI agents and builders: read AGENTS.md (setup, commands, structure, rules), llms.txt (doc map) and the machine-readable blocks.json (schema). How all Blockchains blocks fit together: Build with Blocks · org catalogue: https://blockchains.github.io/blocks.json.

What it exports

Export	Type	Install / access
BLLens (detect.js)	browser-script	<script src="https://blockchains.github.io/blockchainlab-lens/extension/detect.js"></script>
extension/	file	chrome://extensions → Load unpacked → extension/
bookmarklet	web	https://blockchains.github.io/blockchainlab-lens/

BLLens (detect.js) exports: BLLens.detect(href), BLLens.fromText(text, chain), BLLens.HOSTS, BLLens.TOOLS

Minimal example (detect.js served from GitHub Pages; checked 2026-10-04)

<script src="https://blockchains.github.io/blockchainlab-lens/extension/detect.js"></script>
<script>
  BLLens.fromText("vitalik.eth", "base");
  // → https://blockchains.github.io/blockchainlab-tools/address/?q=vitalik.eth&chain=base&utm_source=blockchainlab-lens
  BLLens.detect("https://basescan.org/tx/0x…");   // { chain: "base", kind: "tx", value, url }
</script>

Inputs → outputs

• In: explorer URL or text (string) tx hash, address, ENS name or calldata; explorer page URLs on the supported Etherscan-family and Blockscout hosts
• Out: tools deep link (URL) blockchainlab-tools tx/address/abi page for the right chain; detection ({chain, kind, value, url})

Composes with

• Blockchains/blockchainlab-tools: every explanation is a tools page
• Blockchains/blockchainlab-api: use with API data in dashboards (Build with Blocks recipe 3)
• Blockchains/blockchainlab-mcp: same deep links in MCP results

Versioning & stability: stable. Extension releases are GitHub Releases (blockchainlab-lens.zip). BLLens.detect/fromText signatures are stable; new explorer hosts may be added to HOSTS.

Configuration

None. The extension and bookmarklet only read the explorer URL and open the matching Blockchain Lab Tools page; no keys, no tracking.

Licence

MIT, see LICENSE.

Contributing

Issues and pull requests are welcome. Please read the contributing guide, code of conduct and security policy first.

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Built by Blockchain Lab — blockchainlab.com