Library Snippets

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What libraries are for

• Reusable helpers (auth, signing, payload builders)
• Constants and configuration values
• Custom loggers and instrumentation
• Domain-specific client wrappers

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Using a library in a test

# In Library: custom_logger.py
def log_ok(client, name):
    client.environment.events.request.fire(
        request_type="CUSTOM",
        name=name,
        response_time=0,
        response_length=0,
        exception=None,
        context={},
    )

# In your locustfile
from locust import HttpUser, task, between
import custom_logger

class User(HttpUser):
    wait_time = between(1, 3)

    @task
    def index(self):
        r = self.client.get("/")
        if r.ok:
            custom_logger.log_ok(self.client, "index")

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Structure and imports

• One module per file, e.g., utils.py → import utils
• Subpackages are not supported; keep modules flat
• Avoid long import times; module code runs on import

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Best practices

• Keep helpers pure and side-effect free when possible
• Version modules via names (e.g., auth_v2.py) if making breaking changes
• Add docstrings and clear function names for readability

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Related

• See API: POST /api/v2/library to create modules programmatically
• See API: GET /api/v2/library to list modules