unionlabs/union · error · Error

Invalid Aptos transport

Error message

Invalid Aptos transport

What it means

getAptosClient with authAccess "key" requires parameters.transport to be a viem-style transport function: it is invoked as transport({}) and the client reads .value?.url for the RPC endpoint. Anything that is not a function — a raw URL string, a plain object, undefined — fails the typeof check and throws 'Invalid Aptos transport'. A parallel check then requires transport({}).value?.url to be non-empty.

Source

Thrown at typescript-sdk/src/aptos/client.ts:56

 * Overloads for retrieving an Aptos client.
 */
async function getAptosClient(
  parameters: AptosClientParameters & { authAccess: "key" },
): Promise<{ authAccess: "key"; aptos: Aptos; signer: AptosAccount }>

// async function getAptosClient(
//   parameters: AptosClientParameters & { authAccess: "wallet" }
// ): Promise<{ authAccess: "wallet"; aptos: Aptos; signer: AptosBrowserWallet }>

async function getAptosClient(
  parameters: AptosClientParameters & { authAccess: AuthAccess },
): Promise<
  | { authAccess: "key"; aptos: Aptos; signer: AptosAccount }
  | { authAccess: "wallet"; aptos: Aptos; signer: AptosBrowserWallet }
> {
  if (parameters.authAccess === "key") {
    if (typeof parameters.transport !== "function") {
      throw new Error("Invalid Aptos transport")
    }
    const rpcUrl = parameters.transport({}).value?.url
    if (!rpcUrl) {
      throw new Error("No Aptos RPC URL found")
    }
    const config = new AptosConfig({
      fullnode: rpcUrl,
      network: Network.CUSTOM,
    })
    return {
      authAccess: "key",
      aptos: new Aptos(config),
      signer: parameters.account as AptosAccount,
    }
  }

  if (parameters.authAccess === "wallet") {
    if (typeof parameters.transport !== "object") {

View on GitHub (pinned to 031785bb6d)

Solutions

1. Wrap the URL in a transport: import { http } from "viem" and pass transport: http("https://fullnode.testnet.aptoslabs.com/v1")
2. For custom transports, make them return { value: { url } } so the client can extract the endpoint
3. Confirm authAccess: "key" is intended — the wallet flow does not hit this check

Example fix

// before
const client = createUnionClient({
  chainId: union.testnet.cosmosChainId,
  transport: "https://fullnode.testnet.aptoslabs.com/v1", // string!
})

// after
import { http } from "viem"

const client = createUnionClient({
  chainId: union.testnet.cosmosChainId,
  transport: http("https://fullnode.testnet.aptoslabs.com/v1"),
})

if (typeof parameters.transport !== "function") {
  throw new Error("transport must be a Transport function, e.g. http(rpcUrl)")
}

import type { Transport } from "viem"

const isTransport = (t: unknown): t is Transport => typeof t === "function"

try {
  const client = await getAptosClient({ authAccess: "key", transport })
} catch (e) {
  if (e instanceof Error && e.message === "Invalid Aptos transport") {
    throw new Error("Pass a viem Transport: http('https://…/v1'), not a URL string")
  }
  throw e
}

When it happens

Trigger: Calling createUnionClient with a string RPC URL instead of http(url); passing a config object as transport; a custom/test-double transport whose return value has no .value.url; omitting transport entirely.

Common situations: Habit of passing URLs directly (common with raw fetch or other SDKs); custom transports built for mocking in tests that don't follow the viem Transport shape.

Related errors

• No Aptos RPC URL found
• no `signer` passed
• Invalid Sui signer: expected Ed25519Keypair
• waiting for transaction failed
• simulation result not found

AI-assisted analysis of unionlabs/union@031785bb6d (2026-08-16). Data as JSON: /api/errors/36d4ee81782b2424. Report an issue: GitHub.