---
title: TwirlingOptions (latest version)
description: API reference for qiskit_ibm_runtime.options.TwirlingOptions in the latest version of qiskit-ibm-runtime
source: https://quantum.cloud.ibm.com/docs/en/api/qiskit-ibm-runtime/options-twirling-options
---

# TwirlingOptions

*class* `TwirlingOptions(enable_gates=Unset, enable_measure=Unset, num_randomizations=Unset, shots_per_randomization=Unset, strategy=Unset)`

[GitHub](https://github.com/Qiskit/qiskit-ibm-runtime/tree/stable/0.48/qiskit_ibm_runtime/options/twirling_options.py#L27-L121)

Bases: `object`

Twirling options.

## Attributes

**Parameters**

- **enable\_gates** (*UnsetType | bool*)
- **enable\_measure** (*UnsetType | bool*)
- **num\_randomizations** (*UnsetType | int | Literal\['auto']*)
- **shots\_per\_randomization** (*UnsetType | int | Literal\['auto']*)
- **strategy** (*UnsetType | Literal\['active', 'active-accum', 'active-circuit', 'all']*)

### enable\_gates

Type: `UnsetType | bool`

Default value: `Unset`

Whether to apply 2-qubit Clifford gate twirling.

Default: - For the Sampler: `False`. - For the Estimator: If `enables_gates` is `Unset`, it is determined by the server according to the resilience level: it is `False` for resilience levels 0 and 1, and `True` for resilience level 2.

### enable\_measure

Type: `UnsetType | bool`

Default value: `Unset`

Whether to enable twirling to measurement instructions, as long as the measurement is not involved within a conditional block.

Default: - For the Sampler: `False`. - For the Estimator: If `enable_measure` is `Unset`, it is determined by the server according to the resilience level: it is `False` for resilience level 0, and `True` for resilience levels 1 and 2.

### num\_randomizations

Type: `UnsetType | int | Literal['auto']`

Default value: `Unset`

The number of random samples to use when twirling or peforming sampled mitigation.

If `num_randomizations` is “auto”, for every pub executed `shots` times:

> - If `shots_per_randomization` is also “auto”, `shots_per_randomization` is set first as described below, then `num_randomizations` is set as `ceil(shots/shots_per_randomization)`, where `ceil` is the ceiling function.
> - Otherwise, the value is set to `ceil(shots/shots_per_randomization)`.
>
> Default: `"auto"`.

> **Note**
>
> The `shots` value specified in a PUB or in the `run()` method is considered part of the primitive execution interface and therefore is always obeyed. `default_shots`, on the other hand, is considered a Qiskit Runtime specific option. Therefore, the product of `num_randomizations` and `shots_per_randomization` takes precedence over `default_shots`.

### shots\_per\_randomization

Type: `UnsetType | int | Literal['auto']`

Default value: `Unset`

The number of shots to run for each random sample.

If “auto”, for every pub executed `shots` times:

> - If `num_randomizations` is also “auto”, the value is set to `64` for PEC mitigation or to `max(64, ceil(shots / 32))` in all other cases, where `ceil` is the ceiling function.
> - Otherwise, the value is set to `ceil(shots/num_randomizations)`.
>
> Default: `"auto"`.

> **Note**
>
> The `shots` value specified in a PUB or in the `run()` method is considered part of the primitive execution interface and therefore is always obeyed. `default_shots`, on the other hand, is considered a Qiskit Runtime specific option. Therefore, the product of `num_randomizations` and `shots_per_randomization` takes precedence over `default_shots`.

### strategy

Type: `UnsetType | Literal['active', 'active-accum', 'active-circuit', 'all']`

Default value: `Unset`

Specify the strategy of twirling qubits in identified layers of 2-qubit twirled gates.

Allowed values are:

> - If `"active"` only the instruction qubits in each individual twirled layer will be twirled.
> - If `"active-circuit"` the union of all instruction qubits in the circuit will be twirled in each twirled layer.
> - If `"active-accum"` the union of instructions qubits in the circuit up to the current twirled layer will be twirled in each individual twirled layer.
> - If `"all"` all qubits in the input circuit will be twirled in each twirled layer.
>
> Default: `"active-accum"`.

![Image illustrating the differences among twirling strategies. If "active", only instruction qubits in each layer will be twirled. If "active-circuit", all instruction qubits in the circuit will be twirled. If "active-accum", the union all instruction qubits in the circuit up to the current twirled layer will be twirled. Finally, if "all", all qubits in the input circuit will be twirled in each twirled layer.](https://quantum.cloud.ibm.com/docs/images/api/qiskit-ibm-runtime/twirling_strategy_options.avif)

## Methods