Skip to main content
The SDK ships three built-in environments, all on Arbitrum One. You pick one when constructing Rain:
choose-environment.ts

​
Environment table

The dispute timer (dispute_initial_timer) is the initial oracle resolution duration baked into every market this environment creates — 5 minutes on dev/stage for fast iteration, 2 hours in production. It is not the dispute window, which is a separate on-chain constant per market — read that one with getDisputeWindow().

​
Tokens

Each environment configures two trading tokens. Note that development uses a mock USDT at a different address: The oracle fee actually charged when creating a market is read on-chain from the market factory — on development it currently reads 0n. Each token config also carries an oracle_fixed_fee_per_option constant of 1peroptioninthetoken′sbaseunits(seebelow),butnoSDKcodepathreadsit—itreflectstheprotocol′sintended1 per option in the token's base units (see below), but no SDK code path reads it — it reflects the protocol's intended 1 design, not the number in effect. See Market fees. getTokenPrice only serves whitelisted tokens — for anything else it throws a 404 with {"msg":"Token not found in whitelist"}. The dev mock USDT (USDTm) is not whitelisted.

​
Reading the config at runtime

getEnvironmentConfig() returns the active environment’s full configuration. The config for a development instance:
get-environment-config.ts
getTokenConfig(tokenAddress) looks a single token up by address in the active environment, returning a TokenConfig ({ address, symbol, decimals, oracle_fixed_fee_per_option }) or null if the address isn’t one of the environment’s tokens:
get-token-config.ts

​
RPC selection

If you don’t pass rpcUrl, the constructor picks a random public Arbitrum RPC for that instance. Public RPCs rate-limit and vary in reliability — pass your own endpoint (Alchemy, Infura, a self-hosted node, …) in production.
custom-rpc.ts
The rpcUrl is used by all on-chain reads and by transaction builders that read chain state while building.

​
Overriding the API URL

RainCoreConfig also accepts an apiUrl override, which replaces the environment’s REST base URL (useful for local backends or proxies):
RainCoreConfig (types.d.ts)
The factory address, dispute timer, and token config still come from the selected environment — only the REST base URL changes. Point RainSocket at the same host you use for REST (e.g. new RainSocket('https://dev2-api.rain.one')).