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Invoke function

This guide explains how developers invoke a deployed function by configuring execution parameters and submitting an execution request. Invocation focuses on providing inputs and selecting execution resources, not on job management or result analysis.

1. Invocation Overview​

Invoking a function means executing a specific function version with a given input on a selected provider and device.

Each invocation:

  • Executes exactly once
  • Uses one function version
  • Creates one execution instance (job) internally

Note: Job lifecycle tracking and result inspection are covered in the Job Management guide.

2. Invocation Preconditions​

A function can be invoked only if:

  • The function status is Ready
  • At least one version has been successfully deployed
  • The selected provider and device are available

3. Selecting a Function to Invoke​

To invoke a function:

  • Choose an existing function from the project
  • Open the function details view
  • Navigate to the Invocation section

The Invocation section is where all execution parameters are defined.

4. Invocation Configuration​

Invocation configuration defines where and how the function is executed, and what input is passed to it.

4.1 Provider​

Select the compute provider that will execute the function.

Available providers depend on the SDK or runtime template used to create the function.

Examples:

  • Qiskit → IBM Quantum, Quapp
  • Braket → Amazon Braket, Quapp

Only compatible providers are shown.

4.2 Device​

After selecting a provider, choose an execution device.

Devices may include:

  • Quantum hardware
  • Simulators

Simulator devices typically include “simulator” in their name.

4.3 Shots​

Shots specify how many times the quantum circuit is executed.

  • Default value: 10
  • Must be an integer

Higher shot counts may improve statistical accuracy but increase execution cost.

4.4 Input Payload​

The input payload is passed directly to the function’s execution entry point:

processing(invocation_input)

Two input modes are supported:

Form Data​

  • Input is provided as key–value pairs
  • Suitable for structured or simple parameters

Raw Input​

  • Input is provided as a raw value

  • Supported formats:

    • JSON
    • String
    • Integer

The input format must match how invocation_input is processed in the function code.

5. Invoking the Function​

After completing the configuration:

  • Submit the invocation request

The system:

  • Validates the configuration
  • Submits the execution request
  • Starts execution using the selected resources

Each invocation request is handled independently.

6. Invocation Notes and Best Practices​

  • Only Ready functions can be invoked
  • Each invocation executes a single function version
  • Always verify provider and device availability
  • Validate input structure against function logic
  • Use minimal shots during development and testing

7. Next Steps​

After invocation, developers typically proceed to:

  • Monitor execution status
  • Inspect execution output
  • Analyze results or retry execution

These topics are covered in:

  • Platform Guide: Job Management
  • Developer Guide: Invoke Function (SDK / API)