[APIKit] Type mistmatch between txs-service and SDK

[gjeanmart]

Description

There is a mismatch between the APIKit result and the transaction-service response, leading to an undefined value.

The transaction-service returns a masterCopy field as part of the /api/v1/safes/<safe>/ endpoint response:

However, APIKit expects and handles this value under the singleton field:

https://github.com/safe-global/safe-core-sdk/blob/main/packages/api-kit/src/types/safeTransactionServiceTypes.ts#L44-L54

export type SafeInfoResponse = {
  readonly address: string
  readonly nonce: number
  readonly threshold: number
  readonly owners: string[]
  readonly singleton: string // <<<<< HERE
  readonly modules: string[]
  readonly fallbackHandler: string
  readonly guard: string
  readonly version: string
}

This discrepancy results in safe.singleton being undefined when calling:

const safe = await apiKit.getSafeInfo(safe)

Environment

• Safe Core SDK versions:
  • api-kit: 2.5.4
  • protocol-kit:
  • relay-kit:
  • types-kit:
  • sdk-starter-kit:
• Safe contract version:
• Environment:
  • browser
  • non-browser

Steps to reproduce

const safe = '0x...' // some safe on Mainnet
const apiKit = new SafeApiKit({
  chainId: 1
})
const safe = await apiKit.getSafeInfo(safe)
expect(safe.singleton).toBeDefined() // fails

Expected result

The response should consistently return a singleton field, correctly mapping the masterCopy value from the transaction-service response.

Additional context

Workaround:

const safe = '0x...' // some safe on Mainnet
const apiKit = new SafeApiKit({
  chainId: 1
})
const safe = await apiKit.getSafeInfo(safe)
expect(safe['masterCopy']).toBeDefined() // success