Bump uvicorn from 0.51.0 to 0.52.0

[dependabot]

Bumps uvicorn from 0.51.0 to 0.52.0.

Release notes

Sourced from uvicorn's releases.

Version 0.52.0

This release adds an experimental HTTP/1.1 implementation backed by zttp, a sans-IO HTTP parser I've been developing on the side: a core written in Zig, with bindings to Python. It has been running under a fuzzer for some weeks now, and has been through multiple rounds of security auditing.

It is still experimental, so don't put it in front of production traffic yet. Try it with --http zttp, and please send any feedback to the issue tracker.

Added

• Add an experimental zttp HTTP/1.1 implementation, selectable with --http zttp (#2979)

Fixed

• Keep non-ASCII WebSocket request headers intact with websockets 17.0, which encodes them with ISO-8859-1 (#3036)

Full Changelog: Kludex/uvicorn@0.51.0...0.52.0

Changelog

Sourced from uvicorn's changelog.

0.52.0 (July 29, 2026)

This release adds an experimental HTTP/1.1 implementation backed by zttp, a sans-IO HTTP parser I've been developing on the side: a core written in Zig, with bindings to Python. It has been running under a fuzzer for some weeks now, and has been through multiple rounds of security auditing.

It is still experimental, so don't put it in front of production traffic yet. Try it with --http zttp, and please send any feedback to the issue tracker.

Added

• Add an experimental zttp HTTP/1.1 implementation, selectable with --http zttp (#2979)

Fixed

• Keep non-ASCII WebSocket request headers intact with websockets 17.0, which encodes them with ISO-8859-1 (#3036)

Commits

• 8f1b884 Version 0.52.0 (#3044)
• f6833db Add experimental zttp HTTP/1.1 protocol (#2979)
• d26c85c Prepare compatibility with websockets 17.0. (#3036)
• 7e11cc6 Clarify how limit_concurrency and backlog differ (#3029)
• See full diff in compare view

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[github-actions]

📊 Performance Benchmark Report

Comparing dev (baseline) vs dependabot/uv/dev/uvicorn-0.52.0 (current)

📈 Detailed Results (All Benchmarks)

📋 Complete results for all benchmarks - includes both significant and insignificant changes

🧪 Test Name	📏 Base	📏 Current	📈 Change	🎯 Status
Bloom Filter Dns Mutation Tracking Performance	4.33ms	4.19ms	-3.1% ⚪	✅
Bloom Filter Large Scale Dns Brute Force	18.61ms	18.23ms	-2.0% ⚪	✅
Large Closest Match Lookup	358.87ms	363.57ms	+1.3% ⚪	✅
Realistic Closest Match Workload	196.07ms	195.73ms	-0.2% ⚪	✅
Event Memory Medium Scan	1403 B/event	1402 B/event	-0.1% ⚪	✅
Event Memory Large Scan	1527 B/event	1527 B/event	+0.0% ⚪	✅
Event Validation Full Scan Startup Small Batch	413.18ms	412.38ms	-0.2% ⚪	✅
Event Validation Full Scan Startup Large Batch	553.78ms	548.78ms	-0.9% ⚪	✅
Make Event Autodetection Small	27.05ms	26.08ms	-3.6% ⚪	✅
Make Event Autodetection Large	273.39ms	268.70ms	-1.7% ⚪	✅
Make Event Explicit Types	11.81ms	11.77ms	-0.3% ⚪	✅
Excavate Single Thread Small	4.582s	4.234s	-7.6% ⚪	✅
Excavate Single Thread Large	10.546s	10.023s	-5.0% ⚪	✅
Excavate Parallel Tasks Small	4.756s	4.370s	-8.1% ⚪	✅
Excavate Parallel Tasks Large	6.935s	6.555s	-5.5% ⚪	✅
Intercept Throughput Small	898.08ms	889.94ms	-0.9% ⚪	✅
Intercept Throughput Medium	882.42ms	878.76ms	-0.4% ⚪	✅
Dns Throughput Quiet	2.891s	2.835s	-1.9% ⚪	✅
Dns Throughput Loaded	1.875s	1.881s	+0.4% ⚪	✅
Dns Throughput Inherited	2.570s	2.427s	-5.6% ⚪	✅
Is Ip Performance	2.24ms	2.36ms	+5.3% ⚪	✅
Make Ip Type Performance	228.93µs	239.69µs	+4.7% ⚪	✅
Mixed Ip Operations	2.33ms	2.49ms	+6.6% ⚪	✅
Memory Use Web Crawl	1.0 MB	1.0 MB	-1.0% ⚪	✅
Memory Use Subdomain Enum	28.3 MB	28.3 MB	-0.0% ⚪	✅
Memory Use Deep Chain	5.0 MB	5.0 MB	+0.0% ⚪	✅
Memory Use Parallel Chains	10.7 MB	11.0 MB	+2.5% ⚪	✅
Scan Throughput 100	3.139s	3.053s	-2.7% ⚪	✅
Scan Throughput 1000	22.198s	21.112s	-4.9% ⚪	✅
Typical Queue Shuffle	5.44µs	5.43µs	-0.1% ⚪	✅
Priority Queue Shuffle	26.28µs	26.15µs	-0.5% ⚪	✅

🎯 Performance Summary

✅ No significant performance changes detected (all changes <10%)

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🐍 Python Version 3.11.15