Reference
Chain configuration
Robinhood Chain is an Arbitrum Layer-2 that settles to Ethereum and uses ETH for gas. StockSync supports its mainnet and testnet.
Networks
On mainnet, every onchain value for a request is read at one block through the verified Multicall3
contract. Without a verified Multicall3, StockSync makes parallel calls pinned to the same block
number. Oracle reads on testnet fail with UNSUPPORTED_CHAIN.
Environment variables
Every URL must use https://; plain http:// is accepted only for localhost. An invalid value
fails with CONFIG_INVALID, and the error names the variable without repeating its value.
RPC endpoints
The public endpoints are rate-limited and not intended for production workloads. From shared cloud
egress addresses, such as Cloudflare Workers, most requests are refused with HTTP 429, and StockSync
reports UPSTREAM_RATE_LIMITED. Use a dedicated provider for anything beyond local experiments.
The Robinhood Chain docs recommend Alchemy, which has a free plan: create an app on Robinhood Chain and use its HTTPS endpoint. QuickNode, Blockdaemon, dRPC, and Validation Cloud also support the chain.
On Cloudflare Workers, store the endpoint as a secret with
wrangler secret put STOCKSYNC_RPC_URL_MAINNET rather than in wrangler.jsonc.
StockSync never returns or logs a configured RPC URL. getChainInfo() reports only whether a
configured or public endpoint is in use.
Choosing a chain per request
- CLI:
--chain mainnet,--chain testnet, or a chain ID. - MCP server: tools that read the chain accept
"chain": "mainnet"or"testnet". - SDK: pass
{ chain: 'testnet' }(or a chain ID) in request options, orchainIdwhen verifying.