feat(tempo): add native multisig account support

[jxom]

Adds experimental native multisig (TIP-1061) account support to viem/tempo.

Summary

• Account.fromMultisig(config) derives a synthetic local account representing the multisig sender. It is used purely for broadcasting / sender identity — it holds no key and throws on sign/signMessage/signTypedData.
• Re-exports MultisigConfig from ox/tempo so callers pass a config directly (multisig: config); there is no separate Multisig wrapper type.
• Auto-bootstrap: the first transaction from a multisig account registers it on-chain. init is derived from nonce == 0 during serialization — callers never pass init, gas, or type explicitly.
• Broadcasting reuses core sendTransaction/sendTransactionSync with the multisig account + collected owner signatures.

Flow

import { Account, MultisigConfig } from 'viem/tempo'

const config = MultisigConfig.from({
  threshold: 2,
  owners: [
    { owner: owner_1.address, weight: 1 },
    { owner: owner_2.address, weight: 1 },
  ],
})
const account = Account.fromMultisig(config)

const request = await client.prepareTransactionRequest({ /* ... */, multisig: config })

const signature_1 = await client.signTransaction({ ...request, account: owner_1 })
const signature_2 = await client.signTransaction({ ...request, account: owner_2 })

const hash = await client.sendTransaction({
  ...request,
  account,
  signatures: [signature_1, signature_2],
})

Docs

• New Account.fromMultisig API page (Accounts) and a Multisig Transactions guide (Tempo Transactions), both flagged experimental with an EXP sidebar badge.

Testing

• Added multisig e2e tests in src/tempo/Account.test.ts (flat 2-of-2 init + subsequent, 2-of-3 M-of-N, weighted threshold, and hoisted-account send without explicit account).
• Run against a multisig-enabled localnet:

  VITE_TEMPO_TAG=sha-3da8342 VITE_TEMPO_MULTISIG=true pnpm vitest run --config test/vitest.config.ts --project tempo src/tempo/Account.test.ts -t multisig
  

  Passes 4/4. tsc -b clean.

Also bumps ox to 0.14.29.

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Project	Deployment	Actions	Updated (UTC)
viem	Ready	Preview, Comment	Jun 4, 2026 9:50am

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🦋 Changeset detected

Latest commit: 679858a

The changes in this PR will be included in the next version bump.

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Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	ox@​0.14.29

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commit: 0285b67