Version 4.5.0rc0

[T4rk1n]

Release candidate for 4.5.0.

• dash/version.py -> 4.5.0rc0
• npm sub-packages bumped to their release versions (no rc): dash-core-components 4.5.0, dash-html-components 4.5.0, dash-table 7.5.0, dash-renderer 3.5.0 (package.json + _dash_renderer.py __version__/external_url). Lockfiles regenerated with npm i; renderer rebuilt.
• Backfilled the four [Unreleased] CHANGELOG entries that were missing PR references (all Only remount parent-passed components when their identity changed #3881).

Highlights (see CHANGELOG [Unreleased] for the full list)

Added

• Shared storage: backend-agnostic cross-process state manager on every app (Shared storage: backend-agnostic state manager + pub/sub #3930)
• Streaming callbacks via async def generators over a shared SharedWorker connection (Streaming callbacks with multiplexed transport #3931)
• Experimental React 19 support, default stays React 18.3.1 (support react 19 #3646)
• Opt-in partial pattern matching for callback deps via partial_pattern=True (Feature: add partial pattern matching (partial=True) for callbacks #3765)
• Optional callback payload compression (Add options to compress callback request payload #3925)
• plotly-cloud now a default install dependency (Make plotly-cloud a default install dependency #3947)
• dash.remount to force-reset a stateful component from a callback (Only remount parent-passed components when their identity changed #3881)

Removed

• React 16 support (support react 19 #3646)

Plus a batch of renderer reconciliation and pattern-matching fixes and perf improvements.

Before final 4.5.0

• Rename CHANGELOG [Unreleased] -> [4.5.0] - <date>
• Drop the rc0 from dash/version.py

[github-actions]

Dash performance benchmarks

✅ all within thresholds

	scenario	metric	p90 (ms)	median	growth	baseline p90	note
✅	callback_chain	chain_ms	451.3	437.7	0.9x	499.1
✅	callback_chain	graph_ms	2.6	2.6	1.0x	2.4
✅	callback_fanout	fanout_ms	87.5	80.8	0.9x	92.5
✅	deep_nesting	render_ms	52.6	51.4	1.0x	56.8
✅	full_children_replace	replace_ms	5142.7	1975.6	17.38x	4697.1
✅	initial_render_large	render_ms	594.0	571.5	1.0x	694.4
✅	initial_render_small	render_ms	97.8	92.5	0.98x	104.0
✅	patch_append_nested	append_ms	141.5	90.6	2.63x	192.3
✅	patch_append_toplevel	append_ms	122.2	87.3	2.33x	140.2
✅	patch_scalar_update_large	update_ms	155.4	138.6	0.99x	202.9
✅	wildcard_all_resolve	wildcard_ms	317.3	299.9	0.95x	313.6
✅	wildcard_all_resolve	graph_ms	1.2	1.2	1.0x	1.3

growth = late-third / early-third per-op time; ~1 is flat, a large value means the per-op cost scales with accumulated state.

machine scale vs baseline: 0.96x - divided out of the baseline ratios so they compare like for like (the absolute warn/fail ceilings are left un-scaled); calibrated on initial_render_small.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud