PASQAL Cloud

SDK to be used to access Pasqal Cloud Services.

Installation

To install the latest release of the pasqal-cloud (formerly pasqal-sdk), have Python 3.8.0 or higher installed, then use pip:

pip install pasqal-cloud

If you wish to install the development version of the pasqal-cloud from source instead, do the following from within this repository after cloning it:

git checkout dev
pip install -e .

Bear in mind that this installation will track the contents of your local pasqal-cloud repository folder, so if you check out a different branch (e.g. master), your installation will change accordingly.

Development Requirements (Optional)

To run the tutorials or the test suite locally, run the following to install the development requirements:

pip install -e .[dev]

We use pre-commit hooks to enforce some code linting, you can install pre-commit with Python pip:

python3 -m pip install pre-commit
pre-commit install

Basic usage

Authentication

There are several ways to authenticate using the SDK:

from pasqal_cloud import SDK

project_id = "your_project_id"  # Replace this value with your project_id on the PASQAL platform. It can be found on the user-portal, in the 'project' section.
username = "your_username"  # Replace this value with your username or email on the PASQAL platform.
password = "your_password"  # Replace this value with your password on the PASQAL platform.

Method 1: Username + Password

If you know your credentials, you can pass them to the SDK instance on creation:

sdk = SDK(username=username, password=password, project_id=project_id)

Method 2: Username only

If you only want to insert your username, but want a solution to have your password being secret, you can run the SDK without a password. A prompt will then ask for your password:

sdk = SDK(username=username, project_id=project_id)

Method 3: Use a custom token provider

You can define a custom class to provide the token. For example, if you have a token, you can use it to authenticate with our APIs:

class CustomTokenProvider(TokenProvider):
    def get_token(self):
        return "your-token" # Replace this value with your token


sdk = SDK(token_provider=CustomTokenProvider(), project_id=project_id)

Alternatively, create a custom TokenProvider that inherits from ExpiringTokenProvider. You should define a custom '_query_token' method which fetches your token. See Auth0TokenProvider implementation for an example.

Create a batch of jobs

The package main component is a python object called SDK which can be used to create a Batch.

A Batch is a group of jobs with the same sequence that will run on the same QPU. For each job of a given batch, you must set a value for each variable, if any, defined in your sequence. Once the QPU starts running a batch, only the jobs from that batch will be executed until they all end up in a termination status (DONE, ERROR, CANCELED). The batch sequence can be generated using Pulser. See their documentation, for more information on how to install the library and create your own sequence.

The sequence should be a pulser sequence object. Once it's created, you can serialize like so:

serialized_sequence = sequence.to_abstract_repr()

When creating a job, select a number of runs and set the desired values for the variables defined in the sequence:

job1 = {"runs": 20, "variables": {"omega_max": 6}}
job2 = {"runs": 50, "variables": {"omega_max": 10.5}}

Batches can either be "open" or "closed" (also called "complete"). Open batch may be used to schedule variational algorithm where the next job parameter are derived from the results of the previous jobs, without losing access to the QPU.

You can create a batch of jobs using the create_batch method of the SDK. By default, this will create a closed batch, so all jobs should be passed as arguments right away. You may set the wait argument to True to wait for all the jobs to end up in a termination status before proceeding to the next statement.

# Create a closed batch with 2 jobs and wait for its termination
batch = sdk.create_batch(serialized_sequence, [job1,job2], wait=True)

To create an open batch, set the complete argument to False, you can then add jobs to your batch. Don't forget to mark your batch as closed/complete when you are done adding new jobs to it.

# Create an open batch with 1 job
batch = sdk.create_batch(serialized_sequence, [job1], complete=False)
# Add some jobs to it and wait for the jobs to be terminated
job3 = {"runs": 50, "variables": {"omega_max": 10.5}}
batch.add_jobs([job2, job3], wait=True)
# When you have sent all the jobs to your batch, don't forget to mark it as complete
# Otherwise your batch will be timed out by the scheduler
batch.declare_complete()

You can also choose to run your batch on an emulator using the optional argument emulator. For using a basic single-threaded QPU emulator that can go up to 10 qubits, you can specify the "EMU_FREE" emulator:

from pasqal_cloud.device import EmulatorType
batch = sdk.create_batch(
    serialized_sequence, [job1, job2], emulator=EmulatorType.EMU_FREE
)

Once the API has returned the results, you can access them with the following:

for job in batch.ordered_jobs:
    print(f"job-id: {job.id}, status: {job.status}, result: {job.result}")

Retry a batch of jobs

It is possible to retry a selection of jobs from a CLOSED batch with the rebatch method.

# Retry all jobs from a given batch
sdk.rebatch(batch.id)

# Retry the first job of a batch
sdk.rebatch(batch.id, job_ids=[batch.ordered_jobs[0].id])

# Retry all jobs in error
sdk.rebatch(batch.id, status="ERROR")

# Retry canceled jobs created in a given period
sdk.rebatch(batch.id, status="CANCELED", start_date=datetime(...), end_date=datetime(...))

# Retry jobs that have a run number between 5 and 10
sdk.rebatch(batch.id, min_runs=5, max_runs=10)

Retry a job in an open batch

It is possible to rety a single job in a same open batch as an original job using batch.retry. The batch must be open in order for this method to work.

batch = sdk.create_batch(..., complete=False)

batch.retry(batch.ordered_jobs[0])

# Like for adding a job you can choose to wait for results.
batch.retry(batch.ordered_jobs[0], wait=True)

Create a workload

A workload is a unit of work to be executed on Pasqal Cloud Services infrastructure.

To submit a new workload, select a type, target one of the available backends and provide a configuration object to execute it.

You can create a workload through the SDK with the following command:

workload=sdk.create_workload(workload_type="<WORKLOAD_TYPE>",backend="<BACKEND>",config={"config_param_1":"value"})

You can cancel the workload by doing:

sdk.cancel_workload(workload.id)

Or refresh the workload status/results by with the following:

workload=sdk.get_workload(workload.id)

Once the workload has been processed, you can fetch the result like this:

print(f"workload-id: {workload.id}, status: {workload.status}, result: {workload.result}")

Advanced usage

Extra emulator configuration

Some emulators, such as EMU_TN and EMU_FREE, accept further configuration to control the emulation. This is because these emulators are more advanced numerical simulation of the quantum system.

By default, validation rules are more permissive for jobs targeting an emulator than on the Fresnel QPU when submitting jobs to the cloud platform.

You may however wish to validate that your job running on an emulator is compatible with Fresnel. To that extent, set the strict_validation key in the configuration to True. Defaults to False.

from pasqal_cloud.device import EmulatorType, EmuFreeConfig, EmuTNConfig

configuration = EmuTNConfig(strict_validation=True)
batch = sdk.create_batch(serialized_sequence, [job1,job2], emulator=EmulatorType.EMU_TN, configuration=configuration)

# or

configuration = EmuFreeConfig(strict_validation=True)
batch = sdk.create_batch(serialized_sequence, [job1,job2], emulator=EmulatorType.EMU_FREE, configuration=configuration)

For EMU_TN you may add the integrator timestep in nanoseconds, the numerical accuracy desired in the tensor network compression, and the maximal bond dimension of tensor network state.

from pasqal_cloud.device import EmulatorType, EmuTNConfig

configuration = EmuTNConfig(dt = 10.0, precision = "normal", max_bond_dim = 100)
batch = sdk.create_batch(serialized_sequence, [job1,job2], emulator=EmulatorType.EMU_TN, configuration=configuration)

For EMU_FREE, you may add some default SPAM noise. Beware this makes your job take much longer.

from pasqal_cloud.device import EmulatorType, EmuFreeConfig

configuration = EmuFreeConfig(with_noise=True)
batch = sdk.create_batch(serialized_sequence, [job1,job2], emulator=EmulatorType.EMU_FREE, configuration=configuration)

Replace the corresponding section in the code examples above with this to add further configuration.

List of supported device specifications

The SDK provides a method to retrieve the device specs currently defined on PASQAL's cloud platform. They define the physical constraints of our QPUs, and these constraints enforce some rules on the pulser sequence that can be run on QPUs (e.g., max number of atoms, available pulse channels, ...)

sdk.get_device_specs_dict()

The method returns a dict object mapping a device type to a serialized device specs. These specs can be used to instantiate a Device instance in the Pulser library.

Target different API endpoints

This is intended for the package developers or users which were given access to non-prod environments of the PASQAL cloud platform.

To target a specific environment (prod, preprod or dev), instantiate the SDK class using PASQAL_ENDPOINTS['env'] for the parameter endpoints and AUTH0_CONFIG['env'] for auth0 with env being the environment you want to target.

Example:

from pasqal_cloud import AUTH0_CONFIG, SDK, PASQAL_ENDPOINTS

sdk = SDK(..., endpoints=PASQAL_ENDPOINTS['preprod'], auth0=AUTH0_CONFIG['preprod'])

By default, the targeted environment for endpoints and auth0 is prod.