API Documentation

The typed API lives under /v1. It is the surface this site itself renders from, so anything you can see on a page you can also read as JSON, in the same shape.

The compatible API lives at /api?module=…&action=…. It reproduces the de-facto standard explorer REST contract that wallets, indexers, deployment scripts and bots already speak, so existing tooling can be pointed at Arc by changing one base URL. Every scalar in a result is a string, exactly as that contract requires.

GET /v1/blocks/latest
GET /api?module=proxy&action=eth_blockNumber
GET /api?module=account&action=balance&address=0x…

The examples above are a method and a path, with no host in front of them. There is no published API base URL to print yet — see the notice at the top of this page.

Casing:

JSON keys are snake_case. Addresses and hashes on the wire are lowercase; a checksum field carries the display form. Any input case is accepted.

Large integers:

Every value that can exceed 2⁵³ — amounts, gas, supplies — is a decimal string. Block heights are JSON numbers. Parsing an amount as a JavaScript number silently corrupts it.

Amounts:

Amounts cross the wire as a Money object: raw (integer string), decimals, formatted (exact, full precision), usd and symbol. Decimals are always read from the contract; never assume a scale from a symbol.

Time:

Unix seconds, never pre-formatted. Block timestamps have one-second resolution while blocks arrive about twice a second, so timestamps are not a total order — never sort or paginate by them.

Pagination:

Opaque cursors, not page numbers. A cursor stays valid forever because Arc has no reorganisations. Windowed endpoints additionally return the block range that was actually scanned.

/v1/stream/head is a server-sent event stream emitting one head event per committed block. The payload carries server_now so a client can correct for clock skew rather than trusting the browser clock.

event: head
data: {"height":54190133,"hash":"0x…","timestamp":1785345456,"tx_count":11,"server_now":1785345456}

There is no pending-transaction stream. The mempool namespace is disabled on this chain, and with a half-second block time a pending view would show a transaction for less time than it takes to read it.

Gas is paid in dollars:

The gas token is USDC. Fees, balances and transaction values are denominated in dollars, and Arcscan reports an exact dollar figure with no oracle involved.

Values stay 18-decimal in the compatible API:

value, gasPrice, gasUsed and cumulativeGasUsed remain 18-decimal integer strings. Divide by 10¹⁸ and you get the correct dollar figure. We never “helpfully” rescale them — doing so would corrupt every integrating bot by a factor of a trillion.

One dollar, two representations:

The native balance carries 18 decimals; the ERC-20 interface of the same asset carries 6. A precompile keeps them at parity, so erc20 = native / 10^12 exactly. account.balance returns the native figure and account.tokenbalance returns the ERC-20 one. Both are correct. Summing them double-counts the same dollars.

Token decimals are never assumed:

tokenDecimal is always read from the contract. Two contracts on this chain can share a symbol and use different scales, so a symbol-to-decimals table is wrong here by construction.

These return the standard error envelope with HTTP 200 — never a 404, so a client library does not hard-crash. Each carries its own reason rather than one generic sentence: an index we do not build, a structural property of Arc, or a working endpoint under a different name.

• account.getminedblocks
• account.tokennfttx
• account.token1155tx
• account.addresstokennftbalance
• token.tokeninfo
• contract.verifysourcecode

The two NFT history actions are the ones most often reached for, and neither can be answered for an address. The ERC-20 form, account.tokentx, is answered, and requires an explicit startblock and endblock.

Rate limit:

Per-IP token bucket, applied at the edge rather than in the application. The budget that will apply to public callers is not settled, so no figure is printed here; this page will carry it when the API opens.

Log range:

Log queries are clamped to a maximum block span. An over-range request is rejected with the maximum named in the message rather than silently truncated.

Heavy endpoints:

Trace and state-diff endpoints run on a small dedicated pool with a wall-clock budget and a response-size cap, and report truncated: true rather than hanging.