hotpath-rs is a Rust profiler that measures where programs spend time, use CPU and memory, wait on I/O, and perform database, HTTP, or asynchronous operations. Rust developers use it to locate performance bottlenecks and inspect timing, allocation, and async-flow data.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add pawurb/hotpath-rs --skill hotpath_initgit clone --depth 1 https://github.com/pawurb/hotpath-rsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/pawurb/hotpath-rs/hotpath_init)<a href="https://agentmods.dev/skills/pawurb/hotpath-rs/hotpath_init"><img src="https://agentmods.dev/badge/skills/pawurb/hotpath-rs/hotpath_init/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/pawurb/hotpath-rs/hotpath_init"><img src="https://agentmods.dev/badge/skills/pawurb/hotpath-rs/hotpath_init.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00088 | $0.02372 |
| Opus 5.5 | $0.00035 | $0.00949 |
| Sonnet 5.5 | $0.00018 | $0.00474 |
| Haiku 4.5 | $0.00009 | $0.00237 |
Grade A, and why
hotpath_init scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
curl -sL -H 'Accept: text/markdown' https://hotpath.rs/functions How it starts
The opening of the file, as written. The whole thing — 132 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Initialize hotpath Profiling
Set up hotpath profiling in the current Rust project. The setup is fully feature-gated: zero compile-time and runtime overhead unless the hotpath feature is explicitly enabled. All macros are noops when the feature is off, so no cfg_attr wrapping is needed.
Documentation
The hotpath docs are the reference for every macro, cargo feature, parameter and caveat; this skill only holds the procedure. Every page of https://hotpath.rs is served as markdown when requested with an Accept: text/markdown header:
curl -sL -H 'Accept: text/markdown' https://hotpath.rs/functions
Before each step, fetch the pages it names and follow them instead of relying on memory. Keep -L (some pages redirect) and the header (there are no .md URLs). A #fragment is not sent to the server: fetch the whole page and find the heading. Fetch a page only when the project uses what it covers.
The site documents the latest hotpath release, which can be newer than the version the project uses. Never change the project's hotpath version because the docs show a newer one. If the docs describe something that version does not have, tell the user it needs a newer hotpath instead of working around it.
| Page | Covers |
|---|---|
| https://hotpath.rs/ | basic setup, example report |
| https://hotpath.rs/profiling_modes | #[hotpath::main] vs HotpathGuardBuilder, report options, TUI, optional vs non-optional dependency |
| https://hotpath.rs/functions | main, measure, measure_all, skip, measure_block!, allocation profiling, custom allocators |
| https://hotpath.rs/data_flow | channel!, stream!, future!: supported libraries and their cargo features, hotpath::wrap:: types, call-site aggregation, capacity |
| https://hotpath.rs/locks | mutex!, rw_lock!: supported libraries and their cargo features, wrapped types |
| https://hotpath.rs/io_tracing | io!, io_unwrap, measured layers, compression encoders |
| https://hotpath.rs/sql_tracing | sqlx, Diesel and Toasty query profiling |
| https://hotpath.rs/http_tracing | reqwest and ureq client profiling |
| https://hotpath.rs/axum_tracing | axum router profiling, route scoping of SQL and HTTP |
| https://hotpath.rs/tokio_runtime | tokio_runtime!() metrics |
| https://hotpath.rs/configuration | every environment variable |
| https://hotpath.rs/regression_policy | the policy file of step 7 |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago Changed · -44 lines d0aea020256d
- 17d ago Changed · +10 lines e5038843de22
- 19d ago Changed ad3eb63dae3f
- 21d ago Changed 7faf18763ee7
- 1mo ago Changed 876cdbdb633b
- 1mo ago Changed e83025d013b2
- 1mo ago Changed · -1 lines c874585786f9
- 1mo ago Changed · +1 lines 4d9e2d42a182
- 1mo ago First seen · 166 lines · 88 tokens per session scan A a3b5e92d8c57
hotpath_init is a skill published in the GitHub repository pawurb/hotpath-rs (1,895 stars, last pushed yesterday), licensed MIT. It adds 88 tokens to every session and 2,372 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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