[ephraimduncan]

Each contract in the TypeScript packages and the Python SDKs now has one owner test, usually through the real provider client with a fake network. Tests that did the same check again with hand-built events, private helpers, or transport retry replays are removed. The tests have 1,814 fewer lines, and the production code has 62 fewer lines.

Some kept assertions could not fail, and the audit repaired them. For example, the ai@7 step-end test called onStepEnd by hand, so it could not see a second step-end hook. It now runs through the real generateText dispatcher, and a second hook makes a second span. For each assertion that the audit added or repaired, a deliberate error in the owner code made the test fail.

Reviewers who did not write the changes compared the deleted coverage with the owner tests. They found contracts with no remaining proof. One example is the restore of a send method that another wrapper installed before instrumentBedrock(). Each contract is back in its owner test.

The audit found one product defect. The Python Anthropic integration recorded a fallback content block with the wire key from and also with the Python field name from_. The SDK model keeps the field under from_ and the wire key as an extra field. The unary path now dumps the model by alias, and the stream path changes field names to their aliases. The OpenRouter, LiteLLM, and Google GenAI integrations do not have this defect.

# Before: the captured output of a beta message with a fallback block
{"type": "fallback", "from_": {"model": "claude-opus-5"}, "from": {"model": "claude-opus-5"}, "to": {"model": "claude-opus-4-8"}}
# After
{"type": "fallback", "from": {"model": "claude-opus-5"}, "to": {"model": "claude-opus-4-8"}}

The fix is the fix(sdk-anthropic) commit. Merge this PR with a merge commit, so that release-please sees that commit and proposes a telemetry-dev-anthropic release.

The production changes remove only private code that tests alone used, such as the max_attribute_sets parameter of OutputChunkAggregation and the expect_message_stop flag of the Anthropic stream state. The public package entries do not change. postOtlp and maybeGzip stay public exports of @telemetry-dev/otel, although only the package uses them.

Related: #83

Telemetry.dev PR: telemetry-dev/telemetry.dev#447