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HTTP API Auto-Capture

The headline feature of testrelic-pytest is zero-config HTTP API auto-detection. Tests that make httpx, requests, or aiohttp calls are automatically classified as api tests and open the API Session Workspace instead of the Web workspace — no markers, decorators, or configuration required.

How detection works​

During a test, the plugin observes outbound HTTP traffic from httpx, requests, and aiohttp. If a test makes such calls, it is classified as an api test, and its captured HTTP data is surfaced in the Session Workspace.

What is captured​

For each detected request/response, the plugin records:

  • Headers — request and response headers, with sensitive headers masked.
  • Bodies — request and response bodies, truncated at 32 KB by default (configurable redaction). Streamed bodies are never consumed, so capture never disturbs your test.
  • Cookies — structured request and response cookies, with their values masked. They appear in the API workspace Cookies tab.
  • Assertions — real pytest assert statements, recorded with their source expression and evaluated values.

Assertion capture​

Assertions are captured as the source expression plus the evaluated values, so you see exactly what was compared. For example:

tests/test_api.py
assert response.status_code == 201

is recorded as response.status_code == 201 with evaluated values 200 == 201. The failing assertion is captured too, so a red test carries the comparison that broke it.

Redaction and truncation​

Sensitive headers are masked, body redaction is configurable, and bodies (along with captured stdout/stderr/caplog streams) are truncated at a 32 KB default. Adjust the inline threshold with --testrelic-pytest-artifact-threshold-kb N.

Opting out​

To skipUse
HTTP auto-detection--testrelic-pytest-no-autodetect or TESTRELIC_NO_AUTODETECT=1
Request/response bodies--testrelic-pytest-no-capture-bodies or TESTRELIC_NO_CAPTURE_BODIES=1
Request/response headers--testrelic-pytest-no-capture-headers or TESTRELIC_NO_CAPTURE_HEADERS=1
Assertion capture--testrelic-pytest-no-capture-assertions or TESTRELIC_NO_CAPTURE_ASSERTIONS=1
info

With auto-detection enabled, a plain unit test (no HTTP calls) is reported as a normal test, while an API test is upgraded to the api API Session Workspace automatically.