api-health

api-health is a skill for Claude Code, Codex from vmkteam/claude-plugins. It costs 43 tokens per session (844 once invoked), scanned A, original, MIT.

A guide for checking JSON-RPC services, which are APIs that receive named method calls in a standard JSON format. It uses service metadata and test requests to check availability and collect response timings.

In plain words
What is it for?
Use it to query configured production or staging endpoints, test RPC methods, measure total response and first-byte times, and investigate unavailable health checks.
Why use it?
It helps diagnose whether an RPC endpoint is reachable and whether slow responses come from the service or its network path. It also documents common endpoint and firewall obstacles.

Skill for Claude CodeCodex

Part of the vmkteam-developer plugin — 35 skills shipped together

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/vmkteam/claude-plugins/api-health
Any agent
npx skills add vmkteam/claude-plugins --skill api-health
Clone the repo
git clone --depth 1 https://github.com/vmkteam/claude-plugins

Made for: Claude Code, Codex.

Or install vmkteam-developer, the plugin that ships this one along with the rest of its 35 skills.

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 api-health

README.md
[![agentmods](https://agentmods.dev/badge/skills/vmkteam/claude-plugins/api-health.svg)](https://agentmods.dev/skills/vmkteam/claude-plugins/api-health)
Your own site
<a href="https://agentmods.dev/skills/vmkteam/claude-plugins/api-health"><img src="https://agentmods.dev/badge/skills/vmkteam/claude-plugins/api-health.svg" alt="Measured on agentmods" height="20"></a>
Per session 43 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 844 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 $0.00043 $0.00844
Opus 5 $0.00022 $0.00422
Sonnet 5 $0.00009 $0.00169
Haiku 4.5 $0.00004 $0.00084

Measured 4d ago against content hash 71b689df308e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

api-health 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 4d 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.

plugins/developer/skills/api-health/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Health — проверка JSON-RPC сервисов

Проверка здоровья API и тестовые запросы к JSON-RPC (zenrpc) сервисам.

Подключение

Profile: @{api_prod_profile} (production), @{api_dev_profile} (staging)
API type: JSON-RPC 2.0 (zenrpc)
RPC endpoint: определяется при онбординге (может быть /rpc/, /v1/rpc/, /v3/rpc/ и т.д.)

ВАЖНО:

  • /status и /healthcheck обычно скрыты за firewall, недоступны снаружи
  • SMD (GET на RPC endpoint) может не работать через reverse proxy (фронтенд перехватывает GET)
  • RPC endpoint может быть версионирован: /v1/rpc/, /v3/rpc/ — уточнять при онбординге

Команды pcurl

JSON-RPC запрос

pcurl @{profile} https://{host}/{rpc_endpoint} -s -L -X POST \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"{namespace.method}","params":{params},"id":1}'

С таймингами

pcurl @{profile} https://{host}/{rpc_endpoint} -s -L -X POST \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"{namespace.method}","params":{params},"id":1}' \
  -w '\n---\nHTTP %{http_code} | Time: %{time_total}s | TTFB: %{time_starttransfer}s | Size: %{size_download}b\n'

Только тайминги

pcurl @{profile} https://{host}/{rpc_endpoint} -s -o /dev/null -X POST \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"{namespace.method}","params":{params},"id":1}' \
  -w 'HTTP %{http_code} | Total: %{time_total}s | TTFB: %{time_starttransfer}s\n'

SMD (Service Mapping Description)

# SMD доступен через ?smd query parameter
pcurl @{profile} 'https://{host}/{rpc_endpoint}?smd' -s -L

# SMDBox UI (документация в браузере)
# https://{host}/{rpc_endpoint}doc/

JSON-RPC 2.0 формат

Запрос:

{"jsonrpc": "2.0", "method": "namespace.method", "params": {"key": "value"}, "id": 1}

Успех:

{"jsonrpc": "2.0", "result": {...}, "id": 1}

Ошибка (HTTP 200, но error в body!):

{"jsonrpc": "2.0", "error": {"code": -32600, "message": "Invalid Request"}, "id": 1}

Read the full file on GitHub · 85 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. 4d ago First seen · 85 lines · 43 tokens per session scan A 71b689df308e

Subscribe to this mod's changes

api-health is a skill published in the GitHub repository vmkteam/claude-plugins (7 stars, last pushed 4mo ago), licensed MIT. It adds 43 tokens to every session and 844 once invoked, about $0.0002 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 2026-08-31.

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