Fast LiteLLM is a drop-in Rust acceleration layer for LiteLLM — 3.2× faster connection pooling, 1.6× rate limiting, 42× memory savings on high-cardinality workloads. Plus deep technical analysis of LiteLLM internals and consulting from Neul Labs.https://fast-litellm.neullabs.com/en-ushttps://fast-litellm.neullabs.com/knowledge/accelerating-litellm-proxy/https://fast-litellm.neullabs.com/knowledge/accelerating-litellm-proxy/A production-ready guide to running the LiteLLM proxy server with Fast LiteLLM under gunicorn, Docker, and systemd — including the import-order trap that catches most teams.Sun, 12 Apr 2026 00:00:00 GMTguidetutorialproxygunicornuvicorndeploymenthttps://fast-litellm.neullabs.com/knowledge/installing-fast-litellm/https://fast-litellm.neullabs.com/knowledge/installing-fast-litellm/How to install Fast LiteLLM, verify the Rust acceleration is active, and what to do when it isn't.Sun, 12 Apr 2026 00:00:00 GMTguidegetting-startedinstallationgetting-startedpyo3https://fast-litellm.neullabs.com/knowledge/litellm-1-81-perf-regression/https://fast-litellm.neullabs.com/knowledge/litellm-1-81-perf-regression/A walkthrough of how to bisect a performance regression in a release like LiteLLM 1.81.x, the likely culprits in this specific case, and how to verify a fix.Sun, 12 Apr 2026 00:00:00 GMTissueperformanceperformanceregressionbisectpostgreshttps://fast-litellm.neullabs.com/knowledge/litellm-import-speed/https://fast-litellm.neullabs.com/knowledge/litellm-import-speed/A breakdown of LiteLLM's slow import path, the eager-registration anti-pattern that causes it, and the lazy-import refactor that would actually solve it.Sun, 12 Apr 2026 00:00:00 GMTissueperformanceimport-speedperformancelazy-loadinghttps://fast-litellm.neullabs.com/knowledge/litellm-pypi-supply-chain-compromise/https://fast-litellm.neullabs.com/knowledge/litellm-pypi-supply-chain-compromise/A timeline and technical analysis of the March 2026 LiteLLM PyPI compromise, what the malicious payload did, and the defenses every Python team should adopt today.Sun, 12 Apr 2026 00:00:00 GMTissuesecuritysupply-chainsecuritypypisigstorehttps://fast-litellm.neullabs.com/knowledge/rate-limiting-at-scale/https://fast-litellm.neullabs.com/knowledge/rate-limiting-at-scale/Why per-user rate limiting in pure Python eats memory at scale, and how Fast LiteLLM gets to 42× less RSS without changing your config.Sun, 12 Apr 2026 00:00:00 GMTguideperformancerate-limitingmemorydashmapmulti-tenanthttps://fast-litellm.neullabs.com/knowledge/litellm-aiohttp-unclosed-sessions/https://fast-litellm.neullabs.com/knowledge/litellm-aiohttp-unclosed-sessions/Why LiteLLM's concurrent acompletion calls leak aiohttp sessions, what the warning actually means, why some warnings are false alarms, and how to fix the real ones.Sat, 11 Apr 2026 00:00:00 GMTissueconcurrencyaiohttpconcurrencyasynciolifecyclehttps://fast-litellm.neullabs.com/knowledge/litellm-copilot-premium-requests/https://fast-litellm.neullabs.com/knowledge/litellm-copilot-premium-requests/A deep dive into the X-Initiator header semantics, how Copilot's premium request accounting works, and why LiteLLM's transformation layer over-bills compared to Copilot CLI and OpenCode.Sat, 11 Apr 2026 00:00:00 GMTissueprovidergithub-copilotprovidersbillingagentshttps://fast-litellm.neullabs.com/knowledge/litellm-prometheus-multiproc/https://fast-litellm.neullabs.com/knowledge/litellm-prometheus-multiproc/The Prometheus multiprocess problem in a nutshell — what `prometheus_client` actually does across forked workers, why LiteLLM's metrics are unusable with --num_workers, and how to fix it cleanly.Sat, 11 Apr 2026 00:00:00 GMTissueopsprometheusobservabilitygunicornuvicornhttps://fast-litellm.neullabs.com/knowledge/litellm-python-314-uvloop/https://fast-litellm.neullabs.com/knowledge/litellm-python-314-uvloop/Why `litellm[proxy]` crashes on import with Python 3.14, the asyncio API removal that caused it, and what dependency-pinning patterns would have prevented it.Sat, 11 Apr 2026 00:00:00 GMTissuedependenciespython-3-14uvloopdependenciesasynciohttps://fast-litellm.neullabs.com/knowledge/litellm-router-async-callbacks/https://fast-litellm.neullabs.com/knowledge/litellm-router-async-callbacks/A trace through Router.acompletion explaining why CustomLogger async success/failure hooks aren't called, what the right fix looks like, and what to use until then.Sat, 11 Apr 2026 00:00:00 GMTissuecorrectnessroutercallbacksasyncobservabilityhttps://fast-litellm.neullabs.com/knowledge/why-litellm-needs-rust/https://fast-litellm.neullabs.com/knowledge/why-litellm-needs-rust/A measured argument for hybrid Python+Rust in LiteLLM's hot path — and the places where Python is still the right answer.Fri, 10 Apr 2026 00:00:00 GMTarticleopinionrustpythonperformanceffigilhttps://fast-litellm.neullabs.com/knowledge/token-counting-benchmark-deep-dive/https://fast-litellm.neullabs.com/knowledge/token-counting-benchmark-deep-dive/Why tokenization with tiktoken-rs is 1.5–1.7× faster on long inputs and 0.5× as fast on short ones — the FFI overhead curve, fully explained.Thu, 09 Apr 2026 00:00:00 GMTarticlebenchmarktiktokenbenchmarksffitokenization