feat(fastapi): Capture request body on segment span under streaming by ericapisani · Pull Request #6136 · getsentry/sentry-python

ericapisani · 2026-04-24T16:48:47Z

Capture the request body as http.request.body.data on the streaming segment span for FastAPI requests, matching the behavior already in place for Starlette.

FastAPI runs its own request-body extraction path, so it was bypassing the data-capture logic that lives in the Starlette integration. This extracts that logic into a shared helper in the Starlette integration and invokes it from FastAPI's request handler once the body has been read.

Stacked on top of #6123.

Refs PY-2322
Fixes #6020

Add span-streaming support to the Starlette integration so middleware spans and active-thread tracking work under the `trace_lifecycle: "stream"` experiment, while preserving the legacy transaction-based behavior. When span streaming is enabled, `_enable_span_for_middleware` starts middleware spans via `sentry_sdk.traces.start_span` with `sentry.op`, `sentry.origin`, and `starlette.middleware_name` attributes instead of the legacy `start_span(op=..., origin=...)` + tag pattern. In `patch_request_response`, when the current scope holds a `StreamedSpan` (and not a `NoOpStreamedSpan`), the profiler hook now calls `_segment._update_active_thread()`; otherwise the legacy `current_scope.transaction.update_active_thread()` path is preserved. Tests are parametrized across streaming and static modes for `test_middleware_spans`, `test_middleware_spans_disabled`, `test_middleware_callback_spans`, and `test_span_origin`. A new `test_active_thread_id_span_streaming` verifies the segment's `thread.id` attribute under streaming. `auto_enabling_integrations` is disabled in tests where auto-instrumented spans would leak into the captured span stream. Refs PY-2362 Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

When span streaming is enabled, attach the request body (serialized via a JSON default that unwraps AnnotatedValue) to the active segment span as `http.request.body.data` inside `patch_request_response`. This mirrors the body capture that the legacy request-event processor does, so streamed spans carry the same payload context without relying on transaction events. PII scrubbing is intentionally not applied here — under span streaming, sanitization is expected to happen in `before_send_span` hooks. Tests cover the unscrubbed passthrough, a top-level AnnotatedValue (raw bytes), and a nested AnnotatedValue inside a multipart form upload. Refs PY-2362 Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

…ontent arg which only happens once httpx is part of starlette

Under span streaming with middleware_spans=True, sentry_sdk.get_current_span() returns the innermost middleware span rather than the segment, so http.request.body.data was being attached to a middleware child span. Route the attribute through current_span._segment so it always lands on the segment, mirroring the _update_active_thread pattern in _sentry_sync_func. Also deduplicate the sentry_sdk.get_client() call in _sentry_async_func, and parametrize the three body-data streaming tests over middleware_spans=[False, True]. Refs PY-2362 Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Rename the `starlette.middleware_name` span attribute to `middleware.name` on middleware spans emitted under span streaming. The non-streaming tag remains unchanged. Update the affected test assertions accordingly. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

FastAPI runs its own request-body extraction and was missing the same logic as that which exists in the Starlette integration. Extract the logic that writes `http.request.body.data` on the streaming segment into a shared helper in the Starlette integration, and call it from FastAPI's request handler once the body has been read.

linear-code · 2026-04-24T16:48:51Z

PY-2322 Migrate fastapi to span first

github-actions · 2026-04-24T16:50:11Z

Codecov Results 📊

✅ 142 passed | Total: 142 | Pass Rate: 100% | Execution Time: 21.48s

All tests are passing successfully.

❌ Patch coverage is 7.69%. Project has 13975 uncovered lines.

Files with missing lines (2)

File	Patch %	Lines
`starlette.py`	5.66%	⚠️ 367 Missing
`fastapi.py`	16.30%	⚠️ 77 Missing

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ericapisani · 2026-04-24T16:50:29Z

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Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 793e2f7. Configure here.}

FastAPI 0.79.1 pulls in Starlette 0.19.1, whose `TestClient` is built on `requests` and does not accept the `content` kwarg. Match the skipif already in place for the analogous Starlette test so CI on older FastAPI versions passes. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

…d do not set the request.body.data attribute in that scenario

…to-span-first-rme79

sentrivana

We should def make sure to call out the change in automatic sanitization and let folks know they'll need to sanitize themselves. Added it to https://linear.app/getsentry/project/span-first-sdk-python-727da28dd037/overview -- we can keep a running list there so that we don't forget about these.

…first-rme79

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…etsentry#6136) Refs PY-2322 Fixes getsentry#6020

) Removes `_serialize_request_body_data` from `sentry_sdk/integrations/starlette.py`. Nothing calls it. It was added in #6136 to serialize the request body for the segment span under span streaming. #6286 changed the FastAPI path to serialize the cached `request._json` / `request._form` directly and removed the only call site (`_serialize_request_body_data(info["data"])`). The definition stayed behind. Why it's safe: - The underscore-prefixed name doesn't appear anywhere else in the repo: no references in `sentry_sdk/`, `tests/`, `scripts/`, or docs. - None of the open PRs use it. - The module still uses the `json` and `AnnotatedValue` imports elsewhere, so this change doesn't remove any imports. - Users see no change in behavior or public API.  via [automation `sched_65eed06cc199036c2b13411096f412d4`](https://junior-prod.sentry.dev/automations/sched_65eed06cc199036c2b13411096f412d4) · Run ID `sched_65eed06cc199036c2b13411096f412d4:1793267486380`.    -- [View Junior Session](https://junior-prod.sentry.dev/conversations/agent-dispatch%3Adispatch_d52fabcfb189e56dc472324ad6411165) [[Sentry]](https://sentry.sentry.io/explore/conversations/agent-dispatch%3Adispatch_d52fabcfb189e56dc472324ad6411165/?project=4510944073809921)  Co-authored-by: sentry-junior[bot] <264270552+sentry-junior[bot]@users.noreply.github.com>

ericapisani and others added 8 commits April 21, 2026 13:15

skip test in earlier version of starlette since it does not support c…

50352ea

…ontent arg which only happens once httpx is part of starlette

Merge branch 'master' into ep/py-2362-2mw

943c3d4

Rename test because it's not accurate

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ericapisani marked this pull request as ready for review April 24, 2026 17:09

ericapisani requested a review from a team as a code owner April 24, 2026 17:09

Renames

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Comment thread sentry_sdk/integrations/starlette.py Resolved

sentrivana added the skip-changelog label Apr 27, 2026

ericapisani and others added 4 commits April 27, 2026 13:52

Address code review comments regarding the middleware tests

29de949

Catch any raised exceptions from the serialization json.dumps call an…

48415ad

…d do not set the request.body.data attribute in that scenario

Merge branch 'ep/py-2362-2mw' into py-2322-port-event-processor-data-…

4505486

…to-span-first-rme79

Merge branch 'ep/py-2362-2mw' into py-2322-port-event-processor-data-…

5fafecf

…to-span-first-rme79

sentrivana approved these changes Apr 28, 2026

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Base automatically changed from ep/py-2362-2mw to master April 28, 2026 12:46

Merge branch 'master' into py-2322-port-event-processor-data-to-span-…

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…first-rme79

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Comment thread tests/integrations/fastapi/test_fastapi.py Resolved

update tests

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ericapisani merged commit bd50a8e into master Apr 28, 2026
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ericapisani deleted the py-2322-port-event-processor-data-to-span-first-rme79 branch April 28, 2026 14:41

mgaligniana pushed a commit to mgaligniana/sentry-python that referenced this pull request Aug 9, 2026

feat(fastapi): Capture request body on segment span under streaming (g…

3b2f209

…etsentry#6136) Refs PY-2322 Fixes getsentry#6020

sentry-junior Bot mentioned this pull request Oct 29, 2026

ref(starlette): Remove unused _serialize_request_body_data helper #8146

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feat(fastapi): Capture request body on segment span under streaming - #6136

feat(fastapi): Capture request body on segment span under streaming#6136
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