Document Python stream_abstraction config option

[devin-ai-integration]

Summary

stream_abstraction is a new Python SDK generator option that gives streaming endpoints a real stream object instead of a bare generator. With it enabled, SSE consumers can read event metadata (the event id, event type, and retry interval) through with_metadata() — a supported public API — rather than reaching into SDK internals to re-parse the raw response. The stream also owns the HTTP response and releases it for them (on exhaustion, on error, via close(), or as a context manager), and stays lazy so errors still surface on first iteration. It's off by default because turning it on changes the return type of streaming methods.

Implements docs for: feat(python): add stream_abstraction for SSE event metadata (fern-api/fern#17482)

Pages changed:

• fern/products/sdks/generators/python/configuration.mdx — new stream_abstraction <ParamField> (alphabetical position, matching neighbors), with a with_metadata() snippet, the laziness/response-lifecycle behavior, AsyncStream awaitability, and the breaking-change reason for the false default.
• fern/products/sdks/deep-dives/sse-metadata.mdx — Python added to the metadata-aware iteration section (this is where a customer looks for SSE metadata; TypeScript and Go were already there), plus the version note now covers Python 5.29.0+ and links to the config option that gates it.

No SDK changelog entry, per the generator changelog being handled separately.

Link to Devin session: https://app.devin.ai/sessions/49f2b332dc3147dd971e9b371031f8b8

[devin-ai-integration]

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[github-actions]

🌿 Preview your docs: https://fern-preview-devin-1787418465-python-stream-abstraction.docs.buildwithfern.com/learn

Here are the markdown pages you've updated:

• learn/sdks/deep-dives/sse-metadata
• learn/sdks/generators/python/configuration