https://nalar.dev/tags/contextvars/ Recent content in Contextvars on Nalar Hugo en-us Wed, 02 Sep 2026 00:00:00 +0700 https://nalar.dev/request-scoped-state-in-python-with-contextvars/ Wed, 02 Sep 2026 00:00:00 +0700 https://nalar.dev/request-scoped-state-in-python-with-contextvars/ <p>Applications often need small pieces of context to follow a request through several layers: a request ID, tenant identifier, locale, or tracing field. Passing every value through every function is explicit, but can become noisy when the value is cross-cutting rather than part of the function&rsquo;s business input.</p> <p>Python&rsquo;s <code>contextvars</code> module provides context-local state designed to work with asynchronous code.</p> <h2 id="why-a-normal-global-is-unsafe">Why a normal global is unsafe</h2> <p>A module-level variable is shared by all concurrent requests:</p>