Assets and chains
USDC
USDC is a US dollar stablecoin issued by Circle. On Base, Polygon, Solana, and the Arc ERC-20 this index scans, the payment token uses 6 decimals. Agent GDP prices those transfers at one dollar per USDC. That is an accounting peg, not a live market-price feed.
Explanation
x402 payment requirements name an asset contract and an amount in that asset's base units. For 6-decimal USDC, 1000000 base units are one dollar. EIP-3009, which USDC implements, lets the holder sign a transfer that a facilitator can submit. Circle publishes the contract address for each chain. The addresses this index follows are Base 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, Polygon 0x3c499c542cEF5E3811e1192ce70d8cc03d5c3359, Solana mint EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v, and Arc 0x3600000000000000000000000000000000000000.
Arc also uses USDC as its documented native gas token, with 18 decimals. Those gas transfers are not the 6-decimal payment token, and this index does not add them to volume. Tempo sessions may settle in USDC.e rather than native USDC. Bridged or wrapped variants are counted only when the methodology names them. Other stablecoins are not given a guessed dollar price.
Current index
| Period | Volume | Payments | Payers | Sellers |
|---|---|---|---|---|
| 24 hours | $9,653 | 110,112 | 23,380 | 7,478 |
| 7 days | $40,132 | 186,961 | 3,727 | 2,456 |
| 30 days | $45,963 | 215,671 | 3,792 | 2,482 |
Backfill in progress on base, solana, tempo. A checkpoint is still open, so recent totals can still move.
Live data
Related terms
Sources
- USDC contract addresses — Circle
- EIP-3009: Transfer With Authorization — Ethereum Improvement Proposals
- Connect to Arc — Arc
- Agent GDP methodology — Agent GDP