Base Builder Code data goes public with new tracker — Champz reports 40,000 transactions

In Brief:

• BaseBuilderCodes.com, a free tool from Matt Wong, plots the on-chain activity tied to any app’s Base Builder Code and is built on top of Coinbase Developer Platform’s SQL API.
• Champz fed both of its Base apps into the tracker and shared the results: roughly 40,000 transactions across six months, of which 21,900 came from Legends of Champz and 17,900 from its miniapp.
• The codes supply Base’s ERC-8021 attribution layer, which Base has described as an input for future rewards programs and leaderboard placement.

A new site from Matt Wong, BaseBuilderCodes.com, converts an app’s Base Builder Code into a publicly viewable activity readout.

“Visualize your @Base Builder Code activity,” Wong wrote in the post announcing it, adding that the tool is “Powered by the @CoinbaseDev SQL API!”

On GitHub, Wong is listed as an engineering student at the University of Waterloo and an incoming Coinbase employee.

Underneath the tool sits Coinbase Developer Platform’s indexing endpoint for Base. Per CDP documentation, the SQL API answers custom queries against blocks, transactions, token transfers and decoded events, with query latency under 500ms and freshness of less than 250ms from the tip of chain. Queries can also be run without API keys through a playground in the CDP portal.

Champz publishes its numbers

Champz was among the first to post results. The studio said its two Base apps had recorded roughly 40,000 on-chain transactions over the past six months.

Of that total, Legends of Champz contributed 21,900 across 154 active days and carries a current streak of 142 days. The Champz miniapp registered 17,900 transactions over 185 active days on a 185-day streak — meaning it hasn’t missed a day in the window measured.

“Builder Codes don’t lie,” the studio said.

What a Builder Code counts

Under ERC-8021, a byte suffix is added to a transaction’s calldata to identify the app that facilitated it. Indexers read it in reverse: a 16-byte marker first, then the schema ID, then schema-specific data. Because contracts disregard bytes appended past the arguments they expect, the suffix passes through execution without touching contract behavior. The overhead is 16 gas per non-zero byte.

The codes themselves are issued as an ERC-721 collection. Their on-chain metadata carries a payout address declaring where any rewards should be sent, while off-chain metadata holds the app name and site. Developers register on base.dev, where the code appears under Settings, then Builder Code.

A single suffix can also hold multiple codes separated by commas, which covers transactions facilitated by both a frontend app and a backend relay.

Why Base wants the data

Attribution is the gap the codes address. Linking a transaction to a protocol is trivial, since the contract is on-chain. Linking it to the app that produced it isn’t, because apps are off-chain interfaces, bots and backend jobs with no native tie to the transactions they generate.

Builder Codes went live for all apps on Base in early March 2026. Antonio García Martínez, Head of Growth at Base, said the codes provide chain-level attribution for all activity on Base.

“Builder Codes help apps and protocols get recognized for value created,” Base’s builder account said.

Base’s pitch to developers who adopt them has three parts: an analytics suite, placement on leaderboards and in the Base App, and eligibility for potential rewards as the data is measured.

The system was extended to x402 in June 2026, with schema 2 codes appended to settlement transaction calldata so that x402 payments can be attributed to the apps that drive or serve them.

Hyperliquid coined the term, letting apps annotate transactions to claim a cut of swap fees, and Polymarket shipped a version of its own. Both were scoped to their own venues. ERC-8021, by contrast, works on any EVM chain and is supported on Ethereum L1, Optimism and Arbitrum alongside Base.

Background

Champz bills itself as an indie gaming studio on Base L2, building skill-based strategy games in which players collect NFTs and compete for rewards. Legends of $CHAMPZ opened to all users through base.app, with free packs, ranked battles, a Guardian throne mechanic and USDC and $CHAMPZ payouts.

The economics come with gates. Per the project’s documentation, players must hold at least 25,000 $CHAMPZ to withdraw truffles as USDC. Free-to-play players can earn truffles in-game but have no way to exchange them. Holding more than 50,000 $CHAMPZ removes the character cap on a wallet.

The Base CHAMPZ contract sits at 0xd4f00B4972eF5e88D667e1f9CB593fB6DbDdd180. As of Aug. 15, an older Ethereum deployment traded near $0.0002 with about 588 holders.

In a separate post, the studio said it had “officially hit the 100 ETH mark distributed to our players.”