fix(spans): Add http.route attribute to HTTP server spans

[mjq]

Description

Currently the HTTP path template is only available in the span name. Make it available as a semantic attribute as well (http.route - definition in conventions).

This will also let us use this in e.g. HTTP server span description generation, which will be necessary to maintain consistent descriptions between transactions and span streaming.

Issues

• resolves: PY-2732
• resolves: http.route missing from HTTP server spans #7182

[linear-code]

PY-2732

[mjq]

@sentry review

[mjq]

@cursor review

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[cursor]

Generic names stored as http.route

Medium Severity

set_transaction_name writes http.route whenever the source is route, including generic fallback names such as generic Starlette request and generic FastAPI request. The ASGI path already skips those defaults, so unmatched or unresolved routes can still get a non-template http.route and skew HTTP server span descriptions.

 

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[github-actions]

Codecov Results 📊

✅ 112468 passed | ⏭️ 6759 skipped | Total: 119227 | Pass Rate: 94.33% | Execution Time: 408m 0s

📊 Comparison with Base Branch

Metric	Change
Total Tests	📈 +5
Passed Tests	📈 +5
Failed Tests	—
Skipped Tests	—

All tests are passing successfully.

✅ Patch coverage is 90.00%. Project has 2486 uncovered lines.
❌ Project coverage is 90.2%. Comparing base (base) to head (head).

Files with missing lines (1)

File	Patch %	Lines
sentry_sdk/integrations/asgi.py	80.00%	⚠️ 1 Missing and 1 partials

Coverage diff

@@            Coverage Diff             @@
##          main       #PR       +/-##
==========================================
- Coverage    90.22%    90.20%    -0.02%
==========================================
  Files          193       193         —
  Lines        25361     25371       +10
  Branches      9302      9308        +6
==========================================
+ Hits         22880     22885        +5
- Misses        2481      2486        +5
- Partials      1436      1433        -3

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[sentry-warden]

scope.py sets http.route on default transaction names without matching guard

The ASGI middleware correctly avoids writing http.route for fallback transaction names, but scope.set_transaction_name() in the same PR lacks the same guard. When FastAPI or Starlette hit a 404 and call scope.set_transaction_name(default, ROUTE), http.route is set to a generic string rather than a route template.

Evidence

• scope.py set_transaction_name unconditionally sets SPANDATA.HTTP_ROUTE whenever source_value == SegmentNameSource.ROUTE.value, without checking name != _DEFAULT_TRANSACTION_NAME.
• Both FastAPI and Starlette call scope.set_transaction_name(_DEFAULT_TRANSACTION_NAME, TransactionSource.ROUTE) when no route matches the request.
• For streaming spans, that causes http.route to be set to values like "generic FastAPI request" in attributes, while this hunk explicitly avoids writing the attribute in the same circumstance.

_{Identified by Warden · code-review · DS5-DYC}