Reading Ethereum: Transactions, NFTs, and ERC‑20 Tokens — a Practical Walkthrough

Whoa! I remember the first time I chased a transaction hash across the chain. It felt like tracking a parcel on a bad courier site—confusing, slow, and oddly thrilling. Here’s the thing. If you use the right mental model, reading Ethereum becomes predictable rather than mystical. My instinct said “start with the basics,” and that’s exactly what I did, though I quickly had to revise the plan when I realized the ecosystem throws curveballs—internal txs, token approvals, and metadata that sometimes vanishes into IPFS mist.

Transactions are the atomic events on Ethereum. They have a sender, a recipient (sometimes a contract), a value, and gas details. Short txs are easy. Complex interactions call multiple contracts and emit logs. On one hand, a transfer of 0.1 ETH is straightforward; on the other hand, swapping tokens on a DEX will produce many logs and internal transfers that at first glance look like noise. Initially I thought the log entries were secondary, but then I realized they are often where the truth lives—transfer events reveal token movements that a plain balance check misses.

Transaction status is your first checkpoint. A succeeded tx means the state change stuck. A failed tx ate gas and reverted state. Check the gas used versus gas limit to diagnose failures. For pending txs, look at nonce ordering and replacement transactions—people often send fast-follow replacements with higher gas prices. Pro tip: if somethin’ smells off, inspect the “to” field closely. Contracts are not people, and a harmless-looking address can be a tricky contract, so double-check before approving anything.

ERC‑20 tokens are built on a common rulebook, but the implementations vary. Each token has a decimals field that matters more than most newcomers expect. Without adjusting for decimals, balances look wildly wrong. Seriously? Yes—seeing 1000000000000000000 and not knowing decimals is a rite-of-passage mistake. Look for Transfer events in the logs to verify who actually moved tokens and in what amounts. Also watch for allowances and approvals; those are vectors for rug pulls if you grant unlimited approvals to a malicious contract.

NFTs are different. They’re non-fungible tokens that carry unique IDs and metadata pointers. The tokenURI is the map to art or metadata, and often that URI points to IPFS or an HTTP server. If metadata points to a mutable host, the image could change later—this bugged me when I saw an apparently permanent piece update overnight. NFTs also rely on Transfer events, but you’ll often need to inspect metadata to understand uniqueness and provenance.

Dive deeper with tools like etherscan

When you’re tracking transactions, I recommend using an explorer that exposes transaction details, event logs, and contract source verification—etherscan is the go-to for many people in the US and beyond. It shows internal transactions, decoded logs, and verified contract code when available. That decode is gold—rather than staring at hex data you can read the function calls and arguments in plain text, which saves a lot of guesswork on complex swaps or batched contract calls.

Watch these fields every time. Nonce, gas price (or maxFee/maxPriority in EIP‑1559), gas used, and status. Then scan logs for Transfer, Approval, and custom events defined by the contract. If the contract source is verified, read the constructor and public functions to confirm behavior. If it’s not verified, be more cautious—there’s much more unknown risk. I’ll be honest: verified code doesn’t mean safe, but it does mean you can audit the logic without reverse‑engineering bytecode.

APIs matter too. For automated tooling or dashboards, use an explorer API to fetch tx receipts, token balances, and contract ABIs. Rate limits exist—plan caching and backoff. In production systems, failing to handle rate limits will cause intermittent visibility issues that look like chain problems but are actually your tooling choking on traffic. Oh, and remember: mainnet and testnets can behave differently in performance and available tooling—test with care.

Common pitfalls I see over and over:

• Ignoring decimals and misreporting balances.
• Assuming “to” is an EOA when it’s actually a contract.
• Failing to check approvals before interacting via dapps.
• Not validating tokenURI hosts, which can be mutable.
• Trusting unverified contracts without code review.

For developers tracking transactions programmatically, instrument these steps. First, fetch the receipt and parse logs; second, cross-reference the token’s decimals and symbol; third, reconcile internal transactions if the user-facing balance doesn’t match log-derived transfers. On one side this is straightforward bookkeeping; on the other, real-world UX requires clear explanations for users when fees or failures occur. My team learned that the hard way at a meetup in San Francisco—users hate errors with no context.

Security-minded checks:

• Audit allowances and recommend “use-limited” approvals rather than infinite allowances.
• Warn users when interacting with contracts lacking verified source code.
• Watch for sudden spikes in gas price that suggest frontrunning or sandwich attacks.
• Monitor notorious phishing patterns: token names that differ by one character, or contracts cloned from popular projects but with different withdrawal logic.