> ## Documentation Index
> Fetch the complete documentation index at: https://sure-917046f5-mintlify-docs-update-1787443960777.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# On-chain wallets
> Track self-custody Bitcoin, EVM, and Solana wallets by public address — no keys required.
Sure can track wallets you hold the keys to — Bitcoin, six EVM networks, and Solana — from their **public addresses only**. Nothing is signed, no key or seed phrase is ever entered, and no API key is required for any chain.
## What gets tracked
One Sure account is created per **asset**, per **address**, per **network**. A wallet holding ETH and USDC on Ethereum becomes two accounts, both Crypto accounts with the "wallet" subtype.
For each asset Sure records:
* The **quantity** held, read from the chain
* A **holding** valued at the current price, or at zero when no price is available
* The **transfers** in and out, as investment trades when the price for that day is known, so cost basis and the value chart reconstruct back to acquisition. When that day's price is not known, the transfer still appears as an excluded, zero-amount entry — and it is upgraded to a trade on the first sync after the price becomes available.
Balances are read-only and always derived from the chain. Editing them by hand is pointless: the next sync overwrites them.
## Prices need two settings, not one
On-chain data sources report **quantities, not values**. Prices come from Sure's market data providers, and the only provider that can quote bare crypto symbols is **Binance public** (keyless).
If no crypto-capable market data provider is enabled, every on-chain wallet is tracked by quantity and **valued at zero**. This is by far the most common support report for this feature, and it is a settings issue rather than a sync failure.
The settings panel and the linking modal both warn you before you link anything, and on a self-hosted instance an admin can fix it from the warning itself with **Enable crypto prices** — that adds `binance_public` to the enabled providers and leaves the others alone. Otherwise, enable it under **Settings → Self hosting → Market data providers**, or set `SECURITIES_PROVIDERS` to a comma-separated list including `binance_public`.
### Exchange rates for non-USD families
The crypto provider quotes in USD, so valuing a wallet in any other family currency needs one conversion — and Sure's default exchange rate provider (`twelve_data`) requires an API key. With no key and a non-USD family, there is no FX at all and every on-chain wallet is valued at zero for that second, separate reason.
Set `EXCHANGE_RATE_PROVIDER` (or **Settings → Self hosting**) to a provider you can actually use; `frankfurter` needs no API key. The linking UI warns about this gap specifically, naming your currency, and a USD family never sees the warning because it needs no conversion.
When an asset ends up valued at zero for either reason, it is recorded in **Settings → Debug logs** under the `onchain_wallet` provider, with the reasons listed.
## Data sources
| Network | Source | Key required | Override |
| ------------------ | ----------------------------------------------- | ------------ | ------------------------- |
| Bitcoin | [mempool.space](https://mempool.space) REST API | No | `MEMPOOL_SPACE_URL` |
| Ethereum | Blockscout (`eth.blockscout.com`) | No | `BLOCKSCOUT_ETHEREUM_URL` |
| Base | Blockscout (`base.blockscout.com`) | No | `BLOCKSCOUT_BASE_URL` |
| Arbitrum | Blockscout (`arbitrum.blockscout.com`) | No | `BLOCKSCOUT_ARBITRUM_URL` |
| Optimism | Blockscout (`optimism.blockscout.com`) | No | `BLOCKSCOUT_OPTIMISM_URL` |
| Polygon | Blockscout (`polygon.blockscout.com`) | No | `BLOCKSCOUT_POLYGON_URL` |
| Gnosis | Blockscout (`gnosis.blockscout.com`) | No | `BLOCKSCOUT_GNOSIS_URL` |
| Solana | Public JSON-RPC (`api.mainnet-beta.solana.com`) | No | `SOLANA_RPC_URL` |
| Solana token names | Jupiter token search (`lite-api.jup.ag`) | No | `SOLANA_TOKEN_LIST_URL` |
Every override expects the base URL of a compatible instance, without a trailing slash — useful if you run your own indexer or node, or if a public endpoint rate limits you.
### Optional Etherscan key
Ethereum, and only Ethereum, can be read through Etherscan instead of Blockscout. A key buys nothing except a higher rate limit. Add it under **Settings → Providers → On-chain wallets → Advanced**; it is stored encrypted, per family.
A key only moves **transfer history** onto Etherscan. Balances and network detection always come from the keyless indexer. Leave the field empty unless you are being rate limited.
## Linking a wallet
Go to **Settings → Providers → On-chain wallets → Add wallet**.
Leave the network on "Detect automatically" unless you know which one you want.
If the address format belongs to several networks — every `0x` address is valid on all six EVM networks, and Bitcoin's Base58 shape overlaps Solana's — Sure probes each and asks you to choose, marking the ones where it found activity.
The native coin and assets the data source treats as notable are pre-ticked. "Notable" means a priced holding worth more than a dollar on EVM networks, or a place on Solana's verified token list. You can still track anything listed; unpriceable assets show a quantity and a value of zero.
Nothing is imported that you did not tick.
Never enter a seed phrase or private key. Sure only needs the public wallet address.
## Managing a wallet
Go to **Settings → Providers → On-chain wallets → Manage wallets**.
| Action | Description |
| ----------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Review tokens** | Reopens the asset selection with the address unchanged. Use this to start tracking a token that arrived later, or stop tracking one you no longer want. |
| **Stop tracking** (per asset) | Drops one asset. |
| **Change address** | Corrects the address while keeping the accounts, holdings, and balance history attached to it. |
| **Disconnect wallet** | Drops every asset at one address. |
Disconnecting never deletes an account. The provider link is removed, holdings are detached, and what you can see stays as a manual account that no longer updates. Delete the account itself if you want it gone.
An address can only be tracked once per network. To change which assets are tracked, use **Review tokens** rather than adding the address again.
## Rate limits and request cost
All the default endpoints are free and shared, so they throttle. Per sync, per address, the cost is roughly:
| Network | Requests per sync |
| ------- | --------------------------------------------------------------------------- |
| Bitcoin | 1 + up to 10 history pages |
| EVM | 1 summary + up to 10 pages of transfers + up to 10 pages of token transfers |
| Solana | \~2 + up to 25 transaction reads |
History is capped by default at 10 pages per source and at 25 transactions for Solana. Wallets with more history than that keep their **current balance correct** — balances come from an address summary, never from history — but their oldest transfers are not imported.
Raise both caps with `ONCHAIN_HISTORY_MAX_PAGES` (default 10, maximum 200). The Solana budget scales with it proportionally.
**History is best effort; balances are not.** If a source refuses or times out on the paginated history, the balances are still recorded and the history is marked incomplete. When a cap is hit, the affected address says so in **Manage wallets**, and the event is recorded in **Settings → Debug logs**.
### Token cap per address
Real addresses are airdrop dumping grounds: a well-known Ethereum address holds close to 8,000 ERC-20 tokens. One read surfaces at most **200 tokens** per address, settable with `ONCHAIN_MAX_TOKENS_PER_ADDRESS` (maximum 5,000).
The native coin is never affected, and anything already tracked keeps syncing regardless. On EVM networks the tokens kept are ranked by the market cap the indexer reports, so real assets survive the cap and airdrops fall off the end.
## Limitations
**Only tokens the crypto price provider quotes get a value, and it quotes by symbol.** Valuation goes through a `CRYPTO:` ticker, and a symbol is not a token's identity — its contract is. In practice the provider covers major assets and little else: measured on a real Ethereum address, of its ten largest token positions it quoted two. The other eight — including holdings worth roughly $406,000, $141,000 and \$74,000 — showed a value of zero while their quantities were tracked correctly.
**A zero next to a token you know is worth something almost always means the provider does not list that token, not that the balance is wrong.** Check the quantity, which is read straight from the chain. Native coins (BTC, ETH, SOL, POL, XDAI) and large-cap tokens are the well-covered case.
**DeFi positions are not seen at all.** Staked ETH, liquidity-pool tokens, lending positions, and Solana stake accounts are invisible. A wallet holding most of its value in a staking or lending protocol will report a fraction of it.
**Bitcoin is one address at a time.** Extended keys (`xpub`, `ypub`, `zpub`) are not supported and are rejected as addresses. Most Bitcoin wallets are HD wallets where one extended key derives thousands of addresses — tracking a single address of such a wallet reports only that address's balance.
**Solana token names depend on a token list.** RPC returns mints, not names, so names come from Jupiter's token search — and only for mints it reports as *verified*. Unverified or unknown mints keep a label built from their mint address and are tracked by quantity only. Names are cached for 24 hours per mint.
**Fees are not itemised.** Network fees are included in the net effect of each transfer rather than recorded separately.
**Bridged assets are normalised.** USDC.e, USDbC, USDT0, WETH, and similar 1:1-redeemable forms are tracked as their canonical asset.
**NFTs are not tracked.** They are filtered out by token standard.
## Troubleshooting
**Every wallet shows a value of zero.** Either no crypto-capable market data provider is enabled, or your family currency is not USD and no exchange rate provider is configured. Both are covered above, and the linking UI says which one applies.
**One token shows zero while the others in the same wallet are fine.** The price provider does not quote that token. Pricing is by symbol and covers major assets, so long-tail tokens are tracked by quantity and valued at zero.
**A Bitcoin balance is much lower than my wallet app shows.** You are tracking one address of an HD wallet. See "Limitations" above.
**Sync says the explorer could not be reached.** The public endpoint is down, throttling you, or too slow to answer. Retry later, or point the relevant `*_URL` override at your own instance.
**Solana shows balances but no transfers.** The free endpoint throttles the history methods; balances are kept and the history is marked incomplete. Set `SOLANA_RPC_URL` to your own node or a paid endpoint to get the transfers.
**A token I received is not showing up.** New assets are never imported automatically. Use **Review tokens** and tick it.
**A Solana token shows as `SPL:abcd…wxyz`.** The token list does not vouch for that mint, so Sure will not name or price it. Tick it anyway to track the quantity.
**Transfers appear with a value of 0 and are excluded from totals.** No price was available for that date yet. Once market data covers the range, the next sync upgrades those entries to trades automatically. If they stay at zero, the date is outside what your market data provider can serve.
**Manage wallets says the history is incomplete.** The address has more transfers than one sync reads. Balances are unaffected. Raise `ONCHAIN_HISTORY_MAX_PAGES` if you need the full history and can afford the extra requests.
**Balances are correct but nothing updates.** Syncs only rewrite an account when the chain actually changed — an idle wallet produces no writes at all. Check **Settings → Providers** for the last sync time, and **Settings → Debug logs** filtered to the `onchain_wallet` provider for recorded failures.