hotpath-rs/hotpath

What is it?

Key features

• 01Measures function time, CPU samples and allocations, with per-function reports.
• 02Tracks async futures, channels and streams, including queue depth and latency.
• 03Profiles SQL queries for sqlx and Diesel, and HTTP calls for reqwest and ureq.
• 04Records per-route latency and errors for axum servers.
• 05Exports metrics to Prometheus and Grafana dashboards.
• 06Provides a live TUI dashboard and an MCP server for AI agents.

Use cases

• Finding which functions dominate CPU time or allocate the most memory in a Rust service.
• Telling apart slow code that waits on I/O from code that is CPU-bound.
• Diagnosing lock contention or slow channels in async Tokio applications.
• Monitoring SQL and HTTP latency in production through Prometheus and Grafana.

Quick start

1. 1

   Install the hotpath CLI

   cargo install hotpath --version '^0.28'
2. 2

   Let your AI agent set up profiling in your repo

   hotpath init --agent claude
3. 3

   Or add the hotpath dependency to Cargo.toml manually

   hotpath = "0.28"
4. 4

   Run your program with profiling enabled

   cargo run --features='hotpath,hotpath-alloc'

Things to know

• !Core public APIs are stable, but internal report formats, TUI/MCP internals and advanced config options may change between releases.
• !Full instrumentation requires adding feature-gated macros and dependencies to your own code.

In collections

Topics

FAQ

What is hotpath?

A Rust profiler that measures CPU, memory, async, SQL, HTTP and I/O bottlenecks, with Prometheus and Grafana export. hotpath is a Rust profiling toolkit for finding where code spends time, burns CPU, and allocates memory. It distinguishes functions that are slow because they wait on I/O from those that are CPU-intensive, and it can instrument functions, channels, futures, streams, locks, SQL queries, HTTP calls and byte-level I/O.

Is hotpath free to use? What license does it have?

hotpath is open source under the MIT license. Check the license terms before using it in commercial products.

Is hotpath still maintained?

Actively maintained. The last commit to hotpath was on Oct 21, 2026.

What can I use hotpath for?

Finding which functions dominate CPU time or allocate the most memory in a Rust service. Telling apart slow code that waits on I/O from code that is CPU-bound. Diagnosing lock contention or slow channels in async Tokio applications. Monitoring SQL and HTTP latency in production through Prometheus and Grafana.

How do I install hotpath?

Install the hotpath CLI: cargo install hotpath --version '^0.28' Let your AI agent set up profiling in your repo: hotpath init --agent claude Or add the hotpath dependency to Cargo.toml manually: hotpath = "0.28" Run your program with profiling enabled: cargo run --features='hotpath,hotpath-alloc'

Where can I get hotpath?

The source code and installation instructions are on GitHub: https://github.com/hotpath-rs/hotpath