---
title: Qiskit Functions API reference
description: Index of all inputs and outputs of the Qiskit Functions
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/functions
---

# Qiskit Functions API reference

Choose a Qiskit Function from the table of contents to see its API reference documentation. To read more about Qiskit Functions, visit the [Introduction to Qiskit Functions](/docs/guides/functions).


## Contents

- [API index](/docs/api/functions)
- Circuit functions
  - [Algorithmiq Tensor-network error mitigation](/docs/api/functions/algorithmiq-tem)
  - [Q-CTRL Performance Management](/docs/api/functions/q-ctrl-performance-management)
  - [Qedma QESEM](/docs/api/functions/qedma-qesem)
  - [Quantum Elements Orbit](/docs/api/functions/quantum-elements-orbit)
- Application functions
  - [Kipu Quantum Iskay Quantum Optimizer](/docs/api/functions/kipu-optimization)
  - [Multiverse Computing Singularity](/docs/api/functions/multiverse-computing-singularity)
  - [Q-CTRL Optimization Solver](/docs/api/functions/q-ctrl-optimization-solver)
  - [Quantum Portfolio Optimizer by Global Data Quantum](/docs/api/functions/global-data-quantum-optimizer)
  - [QUICK-PDE: A Qiskit Function by ColibriTD](/docs/api/functions/colibritd-pde)
  - [Qunova Computing HI-VQE Chemistry](/docs/api/functions/qunova-chemistry)