codspeed-optimize

A coding workflow for making programs run faster, using CodSpeed benchmarks and flamegraphs, which show where a program spends its time.

In plain words
What is it for?
Use it to optimize a function, module, or benchmark suite. It measures performance, analyzes the results, applies changes, and measures again.
Why use it?
It replaces guesswork with repeated measurements, helping identify performance bottlenecks and check whether changes actually improve speed, CPU use, or memory use.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/codspeedhq/codspeed/codspeed-optimize
Any agent
npx skills add CodSpeedHQ/codspeed --skill codspeed-optimize
Clone the repo
git clone --depth 1 https://github.com/CodSpeedHQ/codspeed

Made for: Claude Code, Codex.

Per session 113 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,655 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00113 $0.02655
Opus 5 $0.00056 $0.01327
Sonnet 5 $0.00023 $0.00531
Haiku 4.5 $0.00011 $0.00265

Measured 2d ago against content hash 01023deaa74c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codspeed-optimize scanned grade A with 0 findings 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 2d 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.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/codspeed-optimize/SKILL.md · 227 lines

How it starts

The opening of the file, as written. The whole thing — 227 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Optimize

You are an autonomous performance engineer. Your job is to iteratively optimize code using CodSpeed benchmarks and flamegraph analysis. You work in a loop: measure, analyze, change, re-measure, compare — and you keep going until there's nothing left to gain or the user tells you to stop.

All measurements must go through CodSpeed. Always use the CodSpeed CLI (codspeed run, codspeed exec) to run benchmarks — never run benchmarks directly (e.g., cargo bench, pytest-benchmark, go test -bench) outside of CodSpeed. The CodSpeed CLI and MCP tools are your single source of truth for all performance data. If you're unable to run benchmarks through CodSpeed (missing auth, unsupported setup, CLI errors), ask the user for help rather than falling back to raw benchmark execution. Results outside CodSpeed cannot be compared, tracked, or analyzed with flamegraphs.

Before you start

  1. Understand the target: What code does the user want to optimize? A specific function, a whole module, a benchmark suite? If unclear, ask.

  2. Understand the metric: CPU time (default), memory, walltime? The user might say "make it faster" (CPU/walltime), "reduce allocations" (memory), or be specific.

  3. Check for existing benchmarks: Look for benchmark files, codspeed.yml, or CI workflows. If no benchmarks exist, stop here and invoke the setup-harness skill to create them. You cannot optimize what you cannot measure — setting up benchmarks first is a hard prerequisite, not a suggestion.

  4. Check CodSpeed auth: Run codspeed auth login if needed. The CodSpeed CLI must be authenticated to upload results and use MCP tools.

The optimization loop

Step 1: Establish a baseline

Build and run the benchmarks to get a baseline measurement. Use simulation mode for fast iteration:

For projects with CodSpeed integrations (Rust/criterion, Python/pytest, Node.js/vitest, etc.):

# Build with CodSpeed instrumentation
cargo codspeed build -m simulation          # Rust
# or for other languages, benchmarks run directly

# Run benchmarks
codspeed run -m simulation -- <bench_command>

Read the full file on GitHub · 227 lines

Changes

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.

  1. 2d ago First seen · 227 lines · 113 tokens per session scan A 01023deaa74c

Subscribe to this mod's changes

codspeed-optimize is a skill published in the GitHub repository CodSpeedHQ/codspeed (280 stars, last pushed 4d ago), licensed Apache-2.0. It adds 113 tokens to every session and 2,655 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

hotpath_init

Configure hotpath profiling in a Rust project. Adds the hotpath dependency with feature-gated setup, instruments main with hotpath::main, functions with measure/measureall, and wraps channels, mutexes, rwlocks, streams, futures, reqwest clients, axum routers and byte-level I/O with hotpath macros. Use when the user…

pawurb/hotpath-rs · 88 tokens

syncmeta

Sync changes from hotpath and hotpath-macros crates to their meta counterparts (hotpath-meta and hotpath-macros-meta). Use when meta crates need to be updated with recent changes.

pawurb/hotpath-rs · 43 tokens

hotpath_bump

Bump the hotpath version number across the workspace and related files. Updates crate versions in Cargo.toml files (exact patch version) and version references in the backend middleware, hotpathinit skill, and README (major.minor only). Use when the user wants to bump, bump the version, or release a new hotpath…

pawurb/hotpath-rs · 73 tokens

http-load-profiler

Run stepped HTTP load tests with ab/wrk, ramping concurrency levels to collect p50/p90/p99 latency, detect performance inflection points, and recommend optimal concurrency. Triggered by requests like 'load test this URL', 'benchmark my API', 'find the max concurrency', or mentions of p99 latency, throughput…

zebbern/claude-code-guide · 76 tokens

performant-code

Writing efficient code that handles large data and tight constraints.

vstorm-co/pydantic-deepagents · 14 tokens

Artillery Load Testing

Write and run Artillery load tests with YAML phases and scenarios, CSV data payloads, the expect plugin for functional checks, and ensure thresholds that fail CI when latency or error budgets are breached.

PramodDutta/qaskills · 44 tokens