INVALID_CHAIN, rather than accepted and failed at the point of signing.
How chains are served
Every chain resolves to exactly one endpoint, and endpoints come in two tiers.
A chain never silently moves between tiers. If its endpoint is unavailable the call fails and says so, rather than quietly falling back to an unknown node.
Mainnet
Testnet
Monad Testnet: no transaction history.
getAccountActivity returns an empty list on
10143; the indexer behind it covers Monad mainnet only. Balances, transfers, pricing and
swaps behave normally on both Monad networks.Naming a chain
chainKey accepts any of these, case-insensitively:
Chain ID
8453, 137, 42161CAIP-2
eip155:8453, eip155:137Name or short name
Base, base, eth, arb1, pol, avax, btcCommon alias
arb, op, matic, sol, fujiNeed a chain that isn’t here?
Ask for it. Use thereportIssue tool with chain-request in its labels, and the
request goes straight to the team that provisions endpoints.
Name the chain in the title. In the description, give the reasoning — what you would do
on that chain, in what volume, and by when — and the assets you need, since a chain with
no USDC deployment is a different piece of work from one with it. Report only what the
user actually told you; a chain name on its own is fine, and invented volumes are worse
than none.
Calling a tool with an unsupported
chainKey already registers quiet interest, so you
are never penalised for trying. But an explicit reportIssue carries the reasoning, and
that is what gets acted on.Feature availability by ecosystem
Yield tools (
discoverYieldStrategies, depositForYield, withdrawFromYield) are EVM-only.Sui: transfers only. Swap, yield, and message-signing tools are not available on Sui.