# send(_:path:) Sends a JSON-RPC request directly to the in-process `bitcoin_rpc()` C bridge. ``` func send(_ request: JSONRPCRequest, path: String?) async throws -> Data ``` ## Discussion `bitcoin_rpc()` is synchronous and may block indefinitely waiting for internal locks (e.g. `cs_main` during initial block download). To honor Swift concurrency’s forward-progress contract, the blocking call is dispatched to a GCD thread and bridged back via a checked continuation. If the call does not complete within [`timeout`](/documentation/Bitcoin/DirectTransport/timeout) seconds, the continuation resumes with a timeout error. The underlying C call continues on its GCD thread — its memory is freed when it returns. Wallet-scoped calls (non-nil `path`) are not supported over the direct transport and throw [`RPCClientError.walletPathNotSupported`](/documentation/Bitcoin/RPCClientError/walletPathNotSupported).