Add OpenTelemetry instrumentation for the Anthropic Claude Python SDK

[vasantteja]

What problem do you want to solve?

Add OpenTelemetry instrumentation for the Anthropic Claude Python SDK (anthropic package) to support tracing of Messages API calls, following the same pattern as the existing OpenAI instrumentation.

Describe the solution you'd like

Create a new instrumentation package opentelemetry-instrumentation-anthropic (or similar naming) that:

1. Instruments the Anthropic Messages API (anthropic.messages.create())
2. Captures request/response attributes following GenAI semantic conventions
3. Emits log events for messages (with opt-in content capture)
4. Records metrics for operation duration and token usage
5. Supports both sync and async operations
6. Handles streaming responses

Describe alternatives you've considered

No response

Additional Context

1. Follow the same structure as opentelemetry-instrumentation-openai-v2
2. Use gen_ai.system = "anthropic"
3. Map Anthropic's stop_reason (single value) to gen_ai.response.finish_reasons (array format)
4. Handle Anthropic's content block structure (array of content blocks vs OpenAI's string/array)
5. Support opt-in content capture via OTEL_INSTRUMENTATION_GENAI_CAPTURE_MESSAGE_CONTENT

Would you like to implement a fix?

Yes

Tip

References

1. https://docs.claude.com/en/api/messages

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[lmolkova]

Discussed at the GenAI semconv and instr call:

• let's do it in small pieces
• let's opt into typing right away
• please add yourself to the component owners and it'd be good to have one or more component owner

[aabmass]

Re typing, the opt in is this list in pyproject.toml

opentelemetry-python-contrib/pyproject.toml

Lines 192 to 230 in 5279805

	# https://github.com/microsoft/pyright/blob/main/docs/configuration.md#type-check-rule-overrides
	[tool.pyright]
	typeCheckingMode = "strict"
	reportUnnecessaryTypeIgnoreComment = true
	reportMissingTypeStubs = false
	pythonVersion = "3.9"
	reportPrivateUsage = false # Ignore private attributes added by instrumentation packages.
	# Add progressively instrumentation packages here.
	include = [
	"instrumentation/opentelemetry-instrumentation-aiokafka",
	"instrumentation/opentelemetry-instrumentation-asyncclick",
	"instrumentation/opentelemetry-instrumentation-threading",
	"instrumentation-genai/opentelemetry-instrumentation-vertexai",
	"instrumentation-genai/opentelemetry-instrumentation-langchain",
	"instrumentation-genai/opentelemetry-instrumentation-weaviate",
	"util/opentelemetry-util-genai",
	"exporter/opentelemetry-exporter-credential-provider-gcp",
	]
	# We should also add type hints to the test suite - It helps on finding bugs.
	# We are excluding for now because it's easier, and more important to add to the instrumentation packages.
	exclude = [
	"instrumentation/opentelemetry-instrumentation-aiokafka/tests/**/*.py",
	"instrumentation/opentelemetry-instrumentation-asyncclick/tests/**/*.py",
	"instrumentation/opentelemetry-instrumentation-threading/tests/**",
	"instrumentation-genai/opentelemetry-instrumentation-vertexai/tests/**/*.py",
	"instrumentation-genai/opentelemetry-instrumentation-vertexai/examples/**/*.py",
	"instrumentation-genai/opentelemetry-instrumentation-langchain/tests/**/*.py",
	"instrumentation-genai/opentelemetry-instrumentation-langchain/examples/**/*.py",
	"instrumentation-genai/opentelemetry-instrumentation-weaviate/tests/**/*.py",
	"instrumentation-genai/opentelemetry-instrumentation-weaviate/examples/**/*.py",
	"util/opentelemetry-util-genai/tests/**/*.py",
	]
	[dependency-groups]
	dev = [
	"tox",
	"tox-uv>=1",
	"pre-commit",
	]

Running the typechecking is integrated with tox,

tox -e typecheck