Customizing HTTPX User Agents for Effective API Requests

When making requests to web APIs, the User-Agent header allows the API server to identify the application or client making the request. Setting a custom user agent can be beneficial for analytics, compatibility checks, or access control on the server side. The HTTPX Python library makes it easy to configure user agents for your API clients.

Why Customize the User Agent

The default HTTPX user agent looks something like "python-httpx/0.23.0". While this identifies the client as a HTTPX program, it doesn't provide much additional context.

Some reasons you may want to customize the user agent string:

Setting a Custom User Agent with HTTPX

To set a custom user-agent, specify the http2_client parameter when creating the HTTPX client:

import httpx

user_agent = "my_app_name/1.0.0"

client = httpx.Client(http2_client=httpx.Client(headers={"user-agent": user_agent}))

Now any requests made with this client will send the custom user agent string.

Some tips when creating a user agent string:

User Agent Format Standards

There are some common standards and formats used by browsers and crawlers when constructing user agent strings. Using these standards can help ensure compatibility with servers that parse the user agent header.

Some examples:

Setting a thoughtful custom user agent on your HTTPX client can provide more visibility for API analytics and compatibility with certain server use cases. Just be sure not to misrepresent your application!