agentmods.dev

nodejs-api-latency-and-throughput

nodejs-api-latency-and-throughput is a skill for Claude Code, Codex from andrewsrigom/agent-skills. It costs 62 tokens per session (501 once invoked), scanned A, original, MIT.

Guidance for improving the response time and capacity of Node.js web APIs under real request load. It focuses on repeated work, unnecessary input/output, concurrency, serialization, cancellation, and measurements such as p50 and p95 latency.

In plain words
What is it for?
Use it when an endpoint is slow, handles too few simultaneous requests, repeats setup for every request, performs avoidable data calls, or does heavy processing in the request path.
Why use it?
It helps find the work that slows actual requests instead of relying on isolated benchmarks or changes that increase load and reduce reliability.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

not rated 2repo 7mo ago A scan 62 tokens original MIT

Good fit Use it when an endpoint is slow, handles too few simultaneous requests, repeats setup for every request, performs avoidable data calls, or does heavy processing in the request path.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput
View source ↗ andrewsrigom/agent-skills andrewsrigom.github.io
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.

Any agent
npx skills add andrewsrigom/agent-skills --skill nodejs-api-latency-and-throughput
Clone the repo
git clone --depth 1 https://github.com/andrewsrigom/agent-skills

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for nodejs-api-latency-and-throughput

README.md
[![agentmods](https://agentmods.dev/badge/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput/github.svg)](https://agentmods.dev/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput)
Your own site
<a href="https://agentmods.dev/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput"><img src="https://agentmods.dev/badge/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput/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.

agentmods 80×15 button for nodejs-api-latency-and-throughput

Your own site · 80×15
<a href="https://agentmods.dev/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput"><img src="https://agentmods.dev/badge/skills/andrewsrigom/agent-skills/nodejs-api-latency-and-throughput.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 501 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00062 $0.00501
Opus 5.5 $0.00025 $0.00200
Sonnet 5.5 $0.00012 $0.00100
Haiku 4.5 $0.00006 $0.00050

Measured 2mo ago against content hash 28978880305d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

nodejs-api-latency-and-throughput 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 2mo 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.

nodejs/nodejs-api-latency-and-throughput/SKILL.md · 67 lines

How it starts

The opening of the file, as written. The whole thing — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Node.js API Latency And Throughput

Use this skill when the problem is API performance under real request load, not generic runtime style.

Scope

  • endpoint latency
  • throughput under concurrency
  • repeated per-request setup
  • I/O amplification
  • expensive serialization or CPU work in hot paths

Default path

  1. Pick the slow endpoint or request class.
  2. Measure p50 and p95 before changing code.
  3. Remove repeated per-request setup first:
    • config parsing
    • client construction
    • redundant auth or schema work
  4. Batch or collapse avoidable I/O.
  5. Keep concurrency bounded and intentional.
  6. Move CPU-heavy work off the hot request path only when measurement shows it dominates.

When to deviate

  • Favor p95 and p99 over throughput if the business pain is tail latency.
  • Trade some peak throughput for safer memory or better cancellation when the API is interactive.
  • Stream responses only when it reduces real wait time or memory pressure.

Guardrails

  • Tail latency usually matters more than one fast happy-path benchmark.
  • Reusing clients and connections is often higher leverage than clever code changes.
  • Promise.all is not a free win when it creates downstream pressure or burst load.
  • Keep request cancellation and timeouts in the design when external I/O is involved.

Avoid

  • building clients or pools inside the request handler
  • unbounded concurrency in a hot path
  • optimizing CPU when network or database dominates
  • reporting throughput gains while hiding worse tail latency or memory spikes

Verification checklist

  • endpoint and percentile metric are explicit
  • per-request setup was audited
  • concurrency shape is intentional
  • the dominant I/O or CPU bottleneck is named
  • p95 or user-visible latency improved, not just synthetic throughput

Official references

References

Read the full file on GitHub · 67 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2mo ago First seen · 67 lines · 62 tokens per session scan A 28978880305d

Subscribe to this mod's changes

nodejs-api-latency-and-throughput is a skill published in the GitHub repository andrewsrigom/agent-skills (2 stars, last pushed 7mo ago), licensed MIT. It adds 62 tokens to every session and 501 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.

Backend and APIs
Related

nodejs-api-latency-and-throughput compared with skills from other repositories

nodejs-api-latency-and-throughput next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
nodejs-api-latency-and-throughputandrewsrigom/agent-skillsSkill27mo agoMITA62Claude Code, Codex
mem0-oss-to-platformmem0ai/mem0Skill69kyesterdayApache-2.0A217Claude Code, Codex
azure-mgmt-botservice-dotnetmicrosoft/skillsSkill3.2kyesterdayMITA78Claude Code
fastapi-router-pymicrosoft/skillsSkill3.2kyesterdayMITA46Claude Code
dev-runtimelangwatch/langwatchSkill5.0ktodayApache-2.0A172Claude Code
api-designericrisco/rsc-harnessSkill5293d agoMITA105Claude Code, Codex
migrate-segw-to-raparc-mcp/arc-1Skill253todayMITA106Claude Code