Add streaming metrics and attribute

[lmolkova]

Replace #13

• Report time-to-first-chunk and time-between chunks in genai utils for inference
• Onboard anthropic and openai
• Add gen_ai.request.stream attribute

[lmolkova]

todo: let's automate it in post-release workflow

[opentelemetry-pr-dashboard]

Pull request dashboard status

Status: Waiting on reviewers to review the latest changes.

[Copilot]

Pull request overview

This PR extends the shared opentelemetry-util-genai streaming wrappers and invocation lifecycle to emit streaming timing telemetry (TTFC and per-chunk timing) and a gen_ai.request.stream span attribute, then wires those capabilities into the OpenAI and Anthropic instrumentations with added unit/integration/conformance coverage.

Changes:

• Add streaming timing capture plumbing in opentelemetry-util-genai (stream wrappers → invocation → metrics + span attributes).
• Wire invocation=... into OpenAI/Anthropic stream wrappers and add regression tests + conformance scenarios to ensure metrics/attributes are emitted.
• Bump wrapt minimum to 1.14.0 to ensure async ObjectProxy support.

Reviewed changes

Copilot reviewed 33 out of 34 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
uv.lock	Updates resolved wrapt minimum constraint.
tox.ini	Installs util package editable in typecheck env.
util/opentelemetry-util-genai/tests/test_stream.py	Adds seam tests for wrapper → invocation timing callbacks.
util/opentelemetry-util-genai/tests/test_handler_metrics.py	Adds tests for TTFC/per-chunk metrics + new span attributes.
util/opentelemetry-util-genai/src/opentelemetry/util/genai/stream.py	Adds optional invocation to stream wrappers and reports per-chunk timing.
util/opentelemetry-util-genai/src/opentelemetry/util/genai/metrics.py	Adds histograms + recorder APIs for streaming timing metrics.
util/opentelemetry-util-genai/src/opentelemetry/util/genai/instruments.py	Defines streaming timing histograms.
util/opentelemetry-util-genai/src/opentelemetry/util/genai/_invocation.py	Adds streaming state + _on_stream_chunk() timing aggregation/recording.
util/opentelemetry-util-genai/src/opentelemetry/util/genai/_inference_invocation.py	Adds gen_ai.request.stream + gen_ai.response.time_to_first_chunk; caches metric attrs for streaming.
util/opentelemetry-util-genai/README.rst	Documents new streaming timing histograms.
util/opentelemetry-util-genai/pyproject.toml	Raises wrapt minimum to 1.14.0.
util/opentelemetry-util-genai/.changelog/267.fixed	Towncrier fragment for wrapt minimum bump.
util/opentelemetry-util-genai/.changelog/267.added	Towncrier fragment for new streaming metrics/attributes.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/test_responses.py	Adds assertions/tests for streaming timing metrics via Responses API.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/test_response_wrappers.py	Updates wrapper tests to include _on_stream_chunk seam.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/test_conformance.py	Registers new streaming conformance scenarios.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/test_chat_metrics.py	Adds streaming timing metrics tests for chat completions (sync/async).
instrumentation/opentelemetry-instrumentation-genai-openai/tests/test_async_responses.py	Adds async Responses streaming timing metrics test.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/requirements.oldest.txt	Ensures local util is installed for oldest factor until util is released.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/conformance/responses_streaming.py	Adds Responses streaming conformance scenario.
instrumentation/opentelemetry-instrumentation-genai-openai/tests/conformance/inference_streaming.py	Adds chat streaming conformance scenario.
instrumentation/opentelemetry-instrumentation-genai-openai/src/opentelemetry/instrumentation/genai/openai/response_wrappers.py	Passes invocation into util stream wrappers.
instrumentation/opentelemetry-instrumentation-genai-openai/src/opentelemetry/instrumentation/genai/openai/chat_wrappers.py	Passes invocation into util stream wrappers and sets response model eagerly.
instrumentation/opentelemetry-instrumentation-genai-openai/README.rst	Documents new streaming timing metrics behavior.
instrumentation/opentelemetry-instrumentation-genai-openai/pyproject.toml	Bumps util dependency to >=1.1b0.dev.
instrumentation/opentelemetry-instrumentation-genai-openai/.changelog/267.added	Towncrier fragment for OpenAI streaming timing metrics.
instrumentation/opentelemetry-instrumentation-genai-anthropic/tests/test_metrics.py	Adds Anthropic streaming timing metrics tests.
instrumentation/opentelemetry-instrumentation-genai-anthropic/tests/test_conformance.py	Registers new streaming conformance scenario.
instrumentation/opentelemetry-instrumentation-genai-anthropic/tests/test_async_wrappers.py	Updates wrapper tests to include _on_stream_chunk seam.
instrumentation/opentelemetry-instrumentation-genai-anthropic/tests/requirements.oldest.txt	Ensures local util is installed for oldest factor until util is released.
instrumentation/opentelemetry-instrumentation-genai-anthropic/tests/conformance/inference_streaming.py	Adds Anthropic streaming conformance scenario.
instrumentation/opentelemetry-instrumentation-genai-anthropic/src/opentelemetry/instrumentation/genai/anthropic/wrappers.py	Passes invocation into util stream wrappers.
instrumentation/opentelemetry-instrumentation-genai-anthropic/pyproject.toml	Bumps util dependency to >=1.1b0.dev.
instrumentation/opentelemetry-instrumentation-genai-anthropic/.changelog/267.added	Towncrier fragment for Anthropic streaming timing metrics.

[Nik-Reddy]

Thanks for picking this up @lmolkova! I'm glad to see the streaming timing work from my original PR #13 moving forward. Happy to review this since I worked on the initial implementation.

Also happy to co-author this if it helps, since a lot of the design decisions here came out of the iteration on #13. Let me know!