> For the complete documentation index, see [llms.txt](https://docs.stacks.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.stacks.co/reference/stacks.js/stacks-bitcoin-staking/fetch/fetchsignercyclemembership.md).

# fetchSignerCycleMembership

Reads which signer-manager a staker stakes to in one reward cycle, and the micro-STX staked to it. Covers STX-only stakers and protocol bond stakers alike. Wraps the pox-5 read-only `get-signer-cycle-membership`, which reads the `staker-signer-cycle-memberships` map.

***

### Usage

```ts
import { fetchPoxInfo, fetchSignerCycleMembership } from '@stacks/bitcoin-staking';

async function signerFor(staker: string) {
  const { rewardCycleId: rewardCycle } = await fetchPoxInfo({ network: 'mainnet' });
  const membership = await fetchSignerCycleMembership({ staker, rewardCycle, network: 'mainnet' });
  return membership?.signer; // signer-manager contract principal, or undefined
}
```

#### Notes

* pox-5 writes an entry for every cycle of a position, for STX-only staking and for protocol bonds: `stake`, `stake-update`, `register-for-bond` and `update-bond-registration` all add it ([add-staker-to-signer-for-cycle](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L1739-L1745), called at [L803](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L803-L805), [L907](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L907), [L1056](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L1056) and [L1146](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L1146)).
* For a protocol bond staker, `amountUstx` is the STX locked with the bond ([register-for-bond](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L751-L755)). For an STX-only staker, it is the STX staked.
* The comment above the map in pox-5.clar ([L228](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L228)) reads "Only used for stx-only staking". The comment is out of date: the map holds protocol bond stakers too, and pox-5 reads it to find a bond staker's signer-manager when it reduces bond shares ([L1364-L1367](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L1364-L1367)).
* Pass `signer` as `signerManager` to the staker reward reads such as [fetchEarnedStakerRewards](/reference/stacks.js/stacks-bitcoin-staking/fetch/fetchearnedstakerrewards.md).
* Resolves to `undefined` when the staker has no entry for the cycle ([get-signer-cycle-membership](https://github.com/stacks-network/stacks-core/blob/10474cdec9f9c0bdf05841b58cffc89cdad87a9b/stackslib/src/chainstate/stacks/boot/pox-5.clar#L3134-L3142)).
* A non-2xx response throws an `Error` whose message starts with `Error calling read-only function.` and includes the status code and URL. If the node reports that the call failed, the `Error` message is the node's `cause`.

[**Reference Link**](https://github.com/stx-labs/stacks.js/blob/6101c99efe5a9616ce7e16cef68e28fd10676e7e/packages/bitcoin-staking/src/fetch.ts#L1353-L1377)

***

### Signature

```ts
function fetchSignerCycleMembership(
  opts: { staker: string; rewardCycle: number } & NetworkClientParam
): Promise<{ amountUstx: bigint; signer: string } | undefined>;
```

`opts` is a [NetworkClientParam](/reference/stacks.js/stacks-network/network/networkclientparam.md) plus `staker` and `rewardCycle`.

***

### Returns

`Promise<{ amountUstx: bigint; signer: string } | undefined>`

Resolves to the membership, or `undefined` when there is none.

| Field        | Type     | Meaning                                                          |
| ------------ | -------- | ---------------------------------------------------------------- |
| `amountUstx` | `bigint` | micro-STX the staker staked to the signer-manager for this cycle |
| `signer`     | `string` | Contract principal of the signer-manager                         |

***

### Parameters

#### opts.staker (required)

* **Type**: `string`

Stacks address of the staker, STX-only or protocol bond.

#### opts.rewardCycle (required)

* **Type**: `number`

Reward cycle to read.

#### opts.network (optional)

* **Type**: `StacksNetworkName | StacksNetwork`

The network to query: a name such as `'mainnet'` or `'testnet'`, or a [StacksNetwork](/reference/stacks.js/stacks-network/network/stacksnetwork.md) object. Defaults to `'mainnet'`.

#### opts.client (optional)

* **Type**: `{ baseUrl?: string; fetch?: FetchFn }`

Overrides the API base URL or the `fetch` function, for example to query your own node. Fields you set replace the network's defaults.


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