Methodology
Version 1 · 22 Oct 2026 · Data until 26 Oct 2026, 09:00 UTC
How Registrai defines and measures the figures on this site. Publishing principles: How we publish. The indices: Indices. API fields: Data API.
Glossary
Parameter values are read from the method parameters the indices publish. Values as of 26 Oct 2026, 09:00 UTC.
- Payment
- A transfer of USDC or another registered stablecoin into one of an app's attributed contracts on Arc mainnet, counted by the index method.
- Paying wallet
- A distinct wallet that made at least one payment to the app within the period.
- New paying wallet
- A wallet paying the app that has not paid the app in the last 30 days, with a payment of at least $10; at most 25 count per app per hour.
- Received (USD)
- The USD value of payments; other stablecoins are converted at the ECB reference rate for their currency. Payments count up to $10,000 per wallet, per app, per hour.
- Attributed contract
- A contract Registrai assigns to an app: its own deployments, pools created by its factories, or a reviewed integration list.
- Index member
- An app included in an index: the Arc Builders Index (apps that started on Arc, plus the Arc base layer), the Arc Integrations Index (products that integrated Arc) or the Arc Ecosystem Index (both, plus the base layer).
- Index points
- Activity points that decay with a half-life of 21 days (about 0.137% an hour). Each payment earns log2(1 + c) + c / $100, where c is the USD it counts for (up to $10,000 per wallet, per app, per hour), plus 1 for a new paying wallet.
- Closed hour, data until
- Figures cover hours that have ended; "data until" is the end of the last closed hour (UTC).
- 7-day window
- The 168 closed hours ending at "data until".
- Directory statuses
- Live: running on Arc mainnet, shown by mainnet evidence (contracts on Arc mainnet, an index id, an explorer link, the project's own mainnet support page, or an official Arc or Circle post saying it is live). Deployed: built on Arc but not yet open for use on mainnet, per its own docs or contracts. Announced: an announcement only, with no deployment we can show.
- The share of USDC moved on Arc that went into index apps: USDC paid into the attributed contracts of Arc Ecosystem Index members (no per-wallet cap) ÷ the estimated USD value of all USDC transfers on Arc (mints and burns excluded), over the same days.
Sources
Where each figure comes from, and how often it is refreshed.
| Source | What we take | How often |
|---|---|---|
| Arc RPC (Blockdaemon, then rpc.mainnet.arc.io) | Blocks, token supplies, transfer logs | Live (Arc in numbers); hourly (indices) |
| Registrai indices (ABI, AII, AEI) | Per-app payments, wallets, USD | Hourly |
| DefiLlama | Arc TVL and stablecoins, always labelled "Source: DefiLlama" | Live, cached 10 min |
| Arc ecosystem directory | Project facts, each with its sources and evidence | Reviewed by hand; the review date is on each page |
The attributed share
The share of USDC moved on Arc that went into index apps: USDC paid into the attributed contracts of Arc Ecosystem Index members (no per-wallet cap) ÷ the estimated USD value of all USDC transfers on Arc (mints and burns excluded), over the same days.
The all-USDC total is estimated from the first 240 blocks of each hour, scaled ×30, so one large transfer moves a one-day figure a lot; over 7 days it is steadier.
Now: 3.43% over 6 of the last 7 days to 26 Oct 2026 (daily 1.04–9.12%).
Known limits
- The all-USDC total is an estimate from sampled blocks.
- Payments to contracts we have not attributed are not counted for any app.
- An hour the keeper misses is filled from the chain at the next close; if it cannot be, totals for that window are lower.
- Directory facts are as current as their review date; corrections are public at /ecosystem/corrections/.
- Other stablecoins are converted to USD, so "Received (USD)" is not USDC only.
Changelog
- v1 (22 Oct 2026): first published version.