Feat/sse

[NEFORCEO]

🚀 Description

Add @app.sse() decorator for Server-Sent Events (SSE) — real-time event streaming over plain HTTP, alongside the existing HTTP and WebSocket routes.

Includes:

• fasthttp/sse.py — SSEEvent dataclass with event, data, id, retry fields
• @app.sse() decorator on FastHTTP — supports headers, reconnect, max_retries, tags
• _run_sse() — async SSE parser using httpx.AsyncClient streaming, parses the standard text/event-stream format (data:/event:/id:/: lines)
• SSE streams run in parallel with HTTP requests and WebSocket connections in app.run()
• Auto-reconnect with exponential backoff and Last-Event-ID resumption

Documentation and examples:

• docs/en/tutorial/sse/index.md — English tutorial (quick start, API reference, SSE vs WebSocket comparison)
• docs/ru/tutorial/sse/index.md — Russian tutorial
• examples/sse/basic.py — Wikimedia EventStreams real-world example
• examples/sse/reconnect.py — reconnection example with auth headers

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🧩 Type of Change

• feat: New feature
• docs: Documentation update

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✅ Checklist

• Tests added or updated
• Documentation updated
• No breaking changes
• Code follows project style

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🔗 Related Issues

N/A

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📸 Additional Context

SSE streams complete alongside HTTP requests — if the server closes the stream, the app exits normally. For infinite streams (e.g. Wikimedia), the app stays alive until Ctrl+C.

[github-actions]

👋 Thanks for your contribution, @NEFORCEO!

Please make sure:

• Code is clean and formatted
• Tests are passing
• PR description is clear

Maintainers will review it soon.

[codspeed-hq]

Merging this PR will improve performance by 42.09%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 6 improved benchmarks
✅ 6 untouched benchmarks

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
⚡	test_response_req_text_from_json	213.2 µs	134.4 µs	+58.66%
⚡	test_response_repr	196.4 µs	131.9 µs	+48.91%
⚡	test_response_property_access	194.5 µs	131.6 µs	+47.8%
⚡	test_response_json_parsing	205.6 µs	141.9 µs	+44.83%
⚡	test_response_creation	201.3 µs	140.1 µs	+43.64%
⚡	test_middleware_after_response	403.1 µs	355.9 µs	+13.28%

Tip

Curious why this is faster? Comment @codspeedbot explain why this is faster on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing feat/sse (53ec719) with master (6f3d441)¹}

Footnotes

1. No successful run was found on master (936008b) during the generation of this report, so 6f3d441 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩