Wrapped Bitcoin Tracker API
How much Bitcoin lives on Ethereum, and through whose vault, read live and keyless straight from the Ethereum blockchain. Bitcoin itself can't run in DeFi, so it gets "wrapped": a custodian (or a decentralised bridge) locks real BTC and mints a 1:1 ERC-20 that trades on Ethereum. WBTC (BitGo) was the original and long the only one that mattered, but after the 2024 custody controversy a competitive market opened up — Coinbase's cbBTC, the decentralised tBTC (Threshold), Lombard's LBTC, Kraken's kBTC and others now split the pie. The wrappers endpoint lists every tracked wrapped-Bitcoin token ranked by the BTC it holds, each with its issuer/custodian, the BTC backing it, its US-dollar value and its share of all wrapped BTC, plus the totals. The token endpoint returns one wrapper's detail by symbol. The dominance endpoint is the concentration view — WBTC's share, the split between custodial wrappers (a company holds the BTC) and the decentralised one, and how concentrated the market is — the counterparty-risk picture for Bitcoin in DeFi. Each token's BTC backing is read as its on-chain total supply divided by its own decimals (read live from the contract — they are not all 18: WBTC and cbBTC use 8, tBTC uses 18), which equals the BTC held because every wrapper is minted 1:1 against locked Bitcoin. This is the wrapped-BTC / BTC-on-Ethereum cut — distinct from the coin price feeds, the generic ERC-20 token-info feed and the stablecoin feeds. Supplies are in BTC; values in USD (BTC priced from Yahoo Finance). No key, nothing stored beyond a short cache.
api.oanor.com/wrappedbitcoin-api
