---
title: Operator backpropagation (OBP) API documentation (latest version)
description: Index of all the modules in the latest version of qiskit-addon-obp.
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit-addon-obp
---

# `qiskit-addon-obp` API reference

- [Operator backpropagation (`qiskit_addon_obp`)](/docs/api/qiskit-addon-obp/qiskit-addon-obp)
- [Metadata utilities (`qiskit_addon_obp.utils.metadata`)](/docs/api/qiskit-addon-obp/utils-metadata)
- [Noise utilities (`qiskit_addon_obp.utils.noise`)](/docs/api/qiskit-addon-obp/utils-noise)
- [Operator utilities (`qiskit_addon_obp.utils.operations`)](/docs/api/qiskit-addon-obp/utils-operations)
- [Pauli operator simplification (`qiskit_addon_obp.utils.simplify`)](/docs/api/qiskit-addon-obp/utils-simplify)
- [Truncation utilities (`qiskit_addon_obp.utils.truncating`)](/docs/api/qiskit-addon-obp/utils-truncating)
- [Visualization utilities (`qiskit_addon_obp.utils.visualization`)](/docs/api/qiskit-addon-obp/utils-visualization)


## Contents

- [API index](/docs/api/qiskit-addon-obp)
- [Release notes](/docs/api/qiskit-addon-obp/release-notes)
- [qiskit_addon_obp](/docs/api/qiskit-addon-obp/qiskit-addon-obp)
- qiskit_addon_obp.utils.metadata
  - [Module overview](/docs/api/qiskit-addon-obp/utils-metadata)
  - [OBPMetadata](/docs/api/qiskit-addon-obp/utils-metadata-obp-metadata)
  - [SliceMetadata](/docs/api/qiskit-addon-obp/utils-metadata-slice-metadata)
- qiskit_addon_obp.utils.noise
  - [Module overview](/docs/api/qiskit-addon-obp/utils-noise)
  - [PauliLindbladErrorInstruction](/docs/api/qiskit-addon-obp/utils-noise-pauli-lindblad-error-instruction)
- [qiskit_addon_obp.utils.operations](/docs/api/qiskit-addon-obp/utils-operations)
- [qiskit_addon_obp.utils.simplify](/docs/api/qiskit-addon-obp/utils-simplify)
- [qiskit_addon_obp.utils.truncating](/docs/api/qiskit-addon-obp/utils-truncating)
- [qiskit_addon_obp.utils.visualization](/docs/api/qiskit-addon-obp/utils-visualization)