hotpath Cloud - Performance regression feedback for developers and AI agents
hotpath Cloud turns hotpath-rs profiling data into automated PR performance checks. It analyzes performance signals and helps developers and coding agents detect meaningful regressions before they are merged.
Open beta: free to use. Public repositories will remain free after beta. See Pricing.
To get started, log in at hotpath.rs/app. The hotpath-rs GitHub App asks for minimal permissions: no access to your code, only pull request write access to post comments, and checks to optionally report the status of each benchmark. The only data it gets from your CI is the benchmark reports your workflow uploads.
The GitHub Actions integration compares benchmark results against a baseline and posts a PR comment whenever a significant regression or improvement is detected:
You can define acceptable regression thresholds using a customizable regression policy and set fine-tuned performance budgets. This helps eliminate noisy alerts and ensures that warnings are emitted only when performance changes in a meaningful way.
For CPU work, benchmarks run in merged mode: the same build runs natively and under Callgrind, and one report carries the native timings next to instruction counts, a reproducible measure of computational work for deterministic workloads, unaffected by the noise of shared CI runners. The counts are judged; the timings are shown.
# hotpath/policy.toml (excerpt)
# Flag a function whose allocations grow by 20% or more
[functions.alloc]
judged = true
min_percent_change = 20
metrics = ["avg", "total"]
# The hot path must never allocate, regardless of the baseline
[[functions.budgets]]
match = "my_crate::router::route"
alloc = { total = "0 B" }
message = "route() is on the hot path and must not allocate"
# Prevent N+1 calls: at most 5 SQL queries per request, on every route
[[server.budgets]]
match = "*"
timing = { sql_per_request = 5 }
message = "too many SQL queries per request, check for N+1 calls"
The hotpath cloud CLI and the hotpath-rs agent skill bring the same feedback loop to coding agents. Agents can analyze benchmark results, identify regressions, and use the profiling data to guide performance optimization:
Benchmark reports are persisted in hotpath Cloud, making it easy to share results with your team and compare each report against its baseline:
Getting Started
hotpath Cloud supports hotpath version 0.28 or newer.
AI Setup (Recommended)
The quickest way to set up hotpath Cloud is to let your own AI coding agent do it. Paste this prompt into your coding agent, inside your project repo:
Set up hotpath Cloud CI in this Rust project using the instructions at https://hotpath.rs/agent/init_cloud
If the project does not use hotpath yet, the agent sets up profiling first. It then picks a benchmark with a fixed workload (asking you when the choice is not obvious), adds the hotpath-cloud feature (and, for a CPU-bound benchmark on hotpath 0.29.2 or newer, sets up merged mode: native timing + Callgrind instruction counts in one report), a regression policy file (an existing one is kept), a GitHub Actions benchmark workflow and the README badge, and runs the benchmark locally to verify the report. For public repositories, it asks whether pull requests from forks should be benchmarked too: they need a separate setup with a relay workflow for security reasons.
The agent does not commit, install the GitHub App or upload anything for you. Install the hotpath GitHub App from hotpath.rs/app and merge the workflow: the first push to the default branch uploads the baseline, and from then on every pull request gets a performance comment.
Your agent remains in control: you review and approve edits through its regular permission prompts.
Manual setup
Follow the CI integration guide to add the benchmark workflow by hand.
README badge
Link your repository’s hotpath Cloud page from its README:
[](https://hotpath.rs/app/repos/OWNER/NAME)
Replace OWNER/NAME with your GitHub repository. The page opens once the hotpath GitHub App is installed on the repository. Reports of a public repository are public by default; for a private repository the page opens only for users with access to it.
Pricing
hotpath Cloud is free during the open beta. Public repositories will remain free. Paid plans for private repositories and optional features will be introduced later.