JSON-RPC¶

Every STRATO node serves an Ethereum-compatible JSON-RPC API at /rpc. Wallets (MetaMask, the STRATO wallet extension) and EVM libraries (viem, ethers) use it to read chain data and submit signed transactions.

The API is on by default: the ethereum-jsonrpc process listens on port 8545 and nginx proxies /rpc to it. Node operators can turn it off with --jsonrpc=false.

Endpoints¶

Network	URL
Mainnet (upquark), public endpoint	`https://noderpc.strato.nexus/rpc`
Mainnet (upquark), app node	`https://app.strato.nexus/rpc`
Testnet (helium)	`https://app.testnet.strato.nexus/rpc`
Your node	`https://<your-node-host>/rpc`

Send requests as HTTP POST with Content-Type: application/json. Batch requests (a JSON array) are supported. There is no WebSocket endpoint and no subscriptions.

curl -s -X POST https://noderpc.strato.nexus/rpc \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'

Chain IDs¶

Network	`eth_chainId`	Decimal	`net_version` (network ID)
Mainnet (upquark)	`0x7030addddcf2`	`123354377739506`	`33056204878082667`
Testnet (helium)	`0xb165855668ca`	`195049586845898`	`114784819836269`

Use eth_chainId, not net_version

net_version returns STRATO's network ID. That is a different number from the EIP-155 chain ID, and it is larger than JavaScript's Number.MAX_SAFE_INTEGER. Wallets and signing libraries need the chain ID.

Supported Methods¶

Chain and account reads¶

Method	Notes
`eth_chainId`, `net_version`, `web3_clientVersion`, `web3_sha3`
`eth_blockNumber`
`eth_getBlockByNumber`, `eth_getBlockByHash`	Block tags such as `latest` are accepted
`eth_getBlockTransactionCountByNumber`, `eth_getBlockTransactionCountByHash`
`eth_getBalance`	The account's USDST balance (the native token), read through the token contract. The block parameter is ignored.
`eth_getTransactionCount`	The account's current nonce. The block parameter is ignored.
`eth_getCode`	`0x01` if the address is a contract, otherwise `0x`. SolidVM contracts have no EVM bytecode to return.
`eth_call`	Runs a read-only call in the VM. Block tag: `latest`, `pending`, a block number or a block hash. Returns error code `3` if the VM doesn't answer within 30 s.
`eth_getTransactionByHash`, `eth_getTransactionByBlockHashAndIndex`, `eth_getTransactionByBlockNumberAndIndex`
`eth_getTransactionReceipt`, `eth_getBlockReceipts`	Receipts include `status` and `logs`
`eth_getLogs`	Filter by `address`, `topics`, `fromBlock` and `toBlock`. At most 10,000 blocks per query and at most 1,000 matching events. Narrow the range if you hit a limit.
`debug_traceBlockByHash`	Call frames read from stored results (no re-execution)

Writes¶

Method	Notes
`eth_sendRawTransaction`	Accepts a signed legacy Ethereum transaction (EIP-155 or pre-155 `v`) or a signed STRATO transaction, and returns the transaction hash. See Transactions & Fees.

Fixed responses¶

These methods exist for wallet compatibility and always return the same value:

eth_gasPrice returns 0x0.
eth_estimateGas always returns 0x5208.
eth_syncing and eth_mining return "false".
net_listening returns "true".
net_peerCount and eth_hashrate return 0x0.
eth_coinbase returns the zero address.
eth_accounts and eth_getCompilers return "[]".
The uncle methods return 0x0 or null.
eth_protocolVersion returns a constant.
rpc_modules returns a fixed list of module names that doesn't reflect which methods are implemented.

Not supported¶

These return error -32601:

eth_sendTransaction and eth_sign. The node holds no keys; sign in the client and use eth_sendRawTransaction.
eth_getStorageAt
Filters: eth_newFilter, eth_newBlockFilter, eth_newPendingTransactionFilter, eth_getFilterChanges, eth_getFilterLogs, eth_uninstallFilter. Use eth_getLogs instead.
eth_compileSolidity, eth_compileLLL, eth_compileSerpent
eth_getWork, eth_submitWork, eth_submitHashrate

Any method not listed here returns Method not found. That includes eth_subscribe, EIP-1559 fee methods and txpool_*.

STRATO Extensions (`strato_*`)¶

Method	Parameters	Purpose
`strato_simulateV1`	`payload`, `blockTag`	Runs calls in sequence in one sandbox (shaped like `eth_simulateV1`; `stateOverrides` and `blockOverrides` are not supported)
`strato_traceCall`	`txObject`, `blockTag`, `traceConfig`	Traces a call without committing it
`strato_traceTransaction`	`txHash`, `traceConfig`	Re-executes and traces a mined transaction
`strato_traceBlockByHash`, `strato_traceBlockByNumber`	block, `traceConfig`	Traces every transaction in a block
`strato_traceBlock`	`rlpBlock`, `traceConfig`	Traces an RLP-encoded block
`strato_getFinalizedHeader`	`blockNumber`	Signed block header for light-client verification
`strato_getReceiptProof`	`blockNumber`, `txIndex`	Receipt inclusion proof

Blocked on public /rpc

strato_* methods re-execute transactions in the VM, so nginx blocks the whole namespace on /rpc by default. They return HTTP 403 with JSON-RPC error -32601 ("method not available on the public RPC endpoint"). A batch that includes any strato_* call is rejected as a whole.

To simulate on public nodes, use the Bloc /transaction/simulate endpoint instead. An operator can expose strato_* on their own node with --publicStratoRpc.

Wallet Setup¶

To add STRATO to MetaMask or another EIP-1193 wallet, open Add network → Add a network manually and enter:

Field	Mainnet	Testnet
Network name	STRATO	STRATO Helium
RPC URL	`https://noderpc.strato.nexus/rpc`	`https://app.testnet.strato.nexus/rpc`
Chain ID	`123354377739506`	`195049586845898`
Currency symbol	`USDST`	`USDST`
Block explorer	`https://stratoscan.strato.nexus`	`https://stratoscan.testnet.strato.nexus`

What to expect:

Balance: the wallet's native balance is your USDST balance.
Gas: the wallet shows a gas price of 0. The real fee is 0.01 USDST or one voucher per transaction, charged on-chain by the Decider contract, not through gas. See Transactions & Fees.
Transactions: the STRATO app has MetaMask sign transactions with EIP-712 through your on-chain User wallet. You don't have to send Ethereum-format transactions yourself.

Library Examples¶

Both examples were checked against testnet.

viemethers v6

import { createPublicClient, defineChain, http, parseAbi } from "viem";

const stratoHelium = defineChain({
  id: 195049586845898,
  name: "STRATO Helium",
  nativeCurrency: { name: "USDST", symbol: "USDST", decimals: 18 },
  rpcUrls: { default: { http: ["https://app.testnet.strato.nexus/rpc"] } },
});

const client = createPublicClient({ chain: stratoHelium, transport: http() });

const blockNumber = await client.getBlockNumber();
const symbol = await client.readContract({
  address: "0x937efa7e3a77e20bbdbd7c0d32b6514f368c1010", // USDST
  abi: parseAbi(["function symbol() view returns (string)"]),
  functionName: "symbol",
});
console.log(blockNumber, symbol); // ... "USDST"

import { Contract, JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider(
  "https://app.testnet.strato.nexus/rpc",
  195049586845898,
  { staticNetwork: true },
);

const usdst = new Contract(
  "0x937efa7e3a77e20bbdbd7c0d32b6514f368c1010",
  ["function decimals() view returns (uint8)"],
  provider,
);
console.log(await provider.getBlockNumber(), await usdst.decimals()); // ... 18n

Core Platform API: REST access to blocks, transactions and contract state
Cirrus: indexed contract data
Transactions & Fees