Where the data comes from
What you record stays on your server. To value what you hold, that server asks a few public services that answer anyone, and none of them needs an account in your name. A call names one thing: a security, a coin or a public address. Nothing in it identifies you.
| What Badlen shows | Service | What it is sent |
|---|---|---|
| The listing a security trades under, from its ISIN | OpenFIGI, api.openfigi.com |
the ISIN |
| The price of a share, an ETF or a fund, and its past | Yahoo Finance, query1.finance.yahoo.com |
the ticker and exchange of that ISIN |
| A fund’s sectors and largest holdings | Yahoo Finance, query2.finance.yahoo.com, after opening a session on finance.yahoo.com |
that ticker |
| The price of a coin in euros, and its last 365 days | CoinGecko, api.coingecko.com |
the coin’s identifier |
| A coin’s daily closes before those 365 days | Binance, api.binance.com |
the coin’s euro pair, such as BTCEUR |
| What a Bitcoin address holds | mempool.space, or blockstream.info when it does not answer |
the public address |
| The ether an Ethereum address holds | ethereum-rpc.publicnode.com, then eth.llamarpc.com, then cloudflare-eth.com |
the public address |
| The ERC-20 tokens an Ethereum address holds | Moralis, deep-index.moralis.io, and only with a key you supply |
the public address, and your key |
Nothing else is called. The last three rows are only ever reached for a wallet you declared by its public address, so an instance that holds none never contacts them.
Prices come from Yahoo Finance’s free quotes service, which asks for no account and no key. Yahoo publishes no service commitment for it, so a change on its side can pause the price updates until Badlen adapts.
To see where each security stands, the administration’s Prices and sources screen says, line by line, which of these sources gives its price, how old the last one is and what it answered when it gave nothing.
The keys
Section titled “The keys”Three keys are optional, and each one only raises what a service already gives for free.
COINGECKO_DEMO_KEYandOPENFIGI_API_KEYbelong to whoever runs the instance. A free CoinGecko Demo key and an OpenFIGI key raise the rate limits, and Configuration says where they go.- The Moralis key belongs to each user, pasted in Settings → Access under What Badlen reaches. Without it an Ethereum address reports its ether and no tokens; with it, its ERC-20 tokens arrive with their symbol and quantity. A free Moralis account at moralis.com issues one, and Crypto wallets shows what it adds.
Badlen can only quote what these services know, and How it stays current says what that leaves to you.