eTiKeT Sync Agent - QCoDeS Connector

Connector for synchronizing QCoDeS datasets with the eTiKeT platform. This connector reads measurements from QCoDeS SQLite databases and syncs them to the cloud.

Installation

Install the QCoDeS connector using the eTiKeT Sync SDK:

from etiket_sdk.sync import Connectors

# Install the latest version
Connectors.install_from_pypi("etiket-sync-agent-qcodes")

⚠️ Important: This connector installs a specific version of QCoDeS. If the installed version is newer than what your main environment uses, it may upgrade your database schema, making it unreadable by older QCoDeS versions. See Version Pinning below.

The package is automatically discovered by etiket_sync_agent through the entry-point system. Once installed, you can verify with:

# List installed connectors
print(Connectors.list())

# Get details for the QCoDeS connector
connector = Connectors.get("etiket_sync_agent_qcodes")
print(connector)

Version Pinning

By default, installing the connector also installs the latest version of qcodes. If you need a specific QCoDeS version to match your main working environment, you can install it separately:

Why this matters: Newer QCoDeS versions may upgrade your SQLite database schema. Once upgraded, older QCoDeS versions may not be able to read the database. This is primarily a concern for very old QCoDeS versions.

# Check your current QCoDeS version in your working environment
import qcodes
print(qcodes.__version__)

# Then install a specific QCoDeS version in the sync agent
Connectors.install_from_pypi("qcodes", version="x.x.x")

Updating the Connector

# Update to the latest version
Connectors.update_from_pypi("etiket-sync-agent-qcodes")

What Gets Synchronized

When a QCoDeS measurement is synced, the following data is extracted and uploaded:

QCoDeS Data	eTiKeT Field	Description
guid	alt_uid	Unique identifier for the measurement
Measurement name	name	Name of the dataset
run_timestamp	collected	When the measurement was taken
Parameter labels	tags	Extracted from instrument/parameter metadata
Snapshot instruments	attributes	Instrument settings stored in the snapshot
xarray dataset	HDF5 file	The actual measurement data

Metadata Sources

The connector extracts metadata from multiple sources:

1. QCoDeS Snapshot: Instrument labels and parameter values used in the measurement are added as tags.
2. QHMetaData Instrument: Custom tags and attributes (see below)
3. inspectr_tag metadata: Ranking (star = +1, cross = -1)
4. Config static_attributes: Static attributes defined in the sync source configuration

Configuration

The QCoDeS connector requires a QCoDeSConfigData configuration with the following fields:

Field	Type	Required	Description
database_path	Path or str	Yes	Path to the QCoDeS SQLite database file (.db)
set_up	str	Yes	Name of the experimental setup (added as set-up attribute)
static_attributes	dict[str, str]	No	Optional static key-value pairs added to every dataset

Example Configuration

Example using the etiket-sdk package:

from etiket_sdk.sync import SyncSources

SyncSources.create(
    name="my_qcodes_source",
    connector_identifier="etiket_sync_agent_qcodes",
    config_data={
        "database_path": "/path/to/experiments.db", 
        "set_up": "dilution_fridge_1",
        "static_attributes": { # optional
            "project": "qubit_calibration",
            "lab": "Building A - Room 101"
        }
    },
    default_scope="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
)

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Adding QCoDeS Metadata to a Dataset

You can attach tags and attributes to a dataset by adding the QHMetaData instrument to your QCoDeS Station. Because the instrument is recorded in the QCoDeS snapshot, the sync agent extracts the tags and attributes and adds them to the QHarbor dataset.

You can add both static and dynamic metadata:

• Static metadata: Stays the same for all measurements (e.g., project, lab PC)
• Dynamic metadata: Changes per run (e.g., calibration type, measurement type)

Initializing the Instrument

There are two ways to define the instrument: directly in Python or via a Station YAML file.

Using Python

from etiket_sync_agent_qcodes.qcodes_metadata import QHMetaData
from qcodes import Station

station = Station()

# Create and register the instrument
qh_meta = QHMetaData(
    "qh_meta",
    static_tags=["cool_experiment"],
    static_attributes={"project": "resonator project"},
)
station.add_component(qh_meta)

Note: The instrument name must be qh_meta. Do not change this.

Using a YAML Configuration File

Add the following to your Station YAML config:

instruments:
  qh_meta:
    type: etiket_sync_agent_qcodes.qcodes_metadata.QHMetaData
    init:
      static_tags:
        - "cool_experiment"
      static_attributes:
        project: "resonator project"
        measurement_computer: "LAB-A-PC-5"

Note: The key must be qh_meta. Do not change this.

Load the instrument from the config:

from qcodes import Station

# Replace with your config file name
station = Station(config_file='qc_config.yaml')
station.load_instrument("qh_meta")

For more information, see the QCoDeS docs: Configuring the Station by using a YAML configuration file.

Runtime Usage

Access the instrument and set per-run metadata:

# If defined via Station YAML
qh_meta = station.components["qh_meta"]

# Start of run: clear dynamic values, then set new ones
qh_meta.reset()
qh_meta.add_tags(["testing", "calibration"])
qh_meta.add_attributes({
    "calibration": "ALLXY",
    "qubit": "Q1",
})

# ... measurement happens here ...

Behavior Notes

Aspect	Behavior
Static vs Dynamic	Static tags/attributes are set at construction and persist across reset(). Dynamic ones are cleared by reset().
Attribute Overrides	Dynamic attributes with the same key as a static attribute will override the static value.
Tag Duplicates	Tags are deduplicated using a set().

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Features

• Direct integration with QCoDeS datasets
• Automatic metadata extraction from snapshots
• Live sync support for running measurements
• xarray dataset conversion
• Custom metadata via QHMetaData instrument

Requirements

• Python >= 3.10
• QCoDeS >= 0.52

License

Copyright © 2025 QHarbor. All Rights Reserved. See LICENCE for details.