session-health

session-health is a skill for Claude Code from AfterRealm/father-time. It costs 67 tokens per session (1,174 once invoked), scanned A, original, MIT.

A session health checker that reads the conversation transcript to report token usage, proximity to context compaction, session weight, and rate-limit status.

In plain words
What is it for?
Use it to inspect the current session, compare all active sessions, review a project, adjust the compaction threshold, or request structured results.
Why use it?
It replaces rough estimates with information from the current or selected sessions, helping you decide when to save progress or start a fresh session.

Skill for Claude Code

Written for Claude Code: ${CLAUDE_PLUGIN_ROOT} variable. Also seen: names the AskUserQuestion tool.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the father-time plugin — 9 skills, 1 agent, 2 hooks shipped together

Good fit Use it to inspect the current session, compare all active sessions, review a project, adjust the compaction threshold, or request structured results.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add AfterRealm/father-time
Claude Code
/plugin install father-time

Made for: Claude Code.

Or install father-time, the plugin that ships this one along with the rest of its 9 skills, 1 agent, 2 hooks.

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 session-health

README.md
[![agentmods](https://agentmods.dev/badge/skills/afterrealm/father-time/session-health/github.svg)](https://agentmods.dev/skills/afterrealm/father-time/session-health)
Your own site
<a href="https://agentmods.dev/skills/afterrealm/father-time/session-health"><img src="https://agentmods.dev/badge/skills/afterrealm/father-time/session-health/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 session-health

Your own site · 80×15
<a href="https://agentmods.dev/skills/afterrealm/father-time/session-health"><img src="https://agentmods.dev/badge/skills/afterrealm/father-time/session-health.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,174 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 $0.00067 $0.01174
Opus 5 $0.00034 $0.00587
Sonnet 5 $0.00013 $0.00235
Haiku 4.5 $0.00007 $0.00117

Measured 12d ago against content hash d1ae1ebc435d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

session-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 12d 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/session-health/SKILL.md · 120 lines

How it starts

The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Session Health Check

Show the user real session health data — not estimates. Parse actual token counts from the JSONL transcript.

How to Get Real Data

For current session only:

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" --current

For all sessions:

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py"

For a specific project:

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" "project-name-fragment"

When invoked directly (not via time-menu), ask the user first with AskUserQuestion: Question: "Which sessions?" Header: "Health" Options:

  1. Label: "Current Session" Description: "Just this session"
  2. Label: "All Sessions" Description: "All active projects"

To override the compaction threshold (default 1M):

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" --threshold 800000

Combined:

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" --threshold 800000 "project-name-fragment"

For structured output (programmatic consumption — preferred when you need to extract specific fields rather than display them):

python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" --format json --current

Run python "${CLAUDE_PLUGIN_ROOT}/scripts/session_health.py" --help for the full flag and exit-code reference.

The script parses JSONL transcripts and reads actual usage blocks from API responses to get:

  • Real context usageinput_tokens + cache_read_input_tokens + cache_creation_input_tokens from the last assistant turn = actual context window size
  • JSONL file size — total transcript weight
  • Compaction count — how many compact_boundary markers exist
  • Turn count — total assistant responses
  • Cache efficiency — cache read vs write tokens
  • Total tokens — cumulative input and output across the session

How Context Is Calculated

The JSONL contains usage data on every assistant message:

"usage": {
  "input_tokens": 42,
  "output_tokens": 1500,
  "cache_read_input_tokens": 450000,
  "cache_creation_input_tokens": 2000
}

Read the full file on GitHub · 120 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. 12d ago First seen · 120 lines · 67 tokens per session scan A d1ae1ebc435d

Subscribe to this mod's changes

session-health is a skill published in the GitHub repository AfterRealm/father-time (6 stars, last pushed 4mo ago), licensed MIT. It adds 67 tokens to every session and 1,174 once invoked, about $0.0003 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.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

chat-pet-sprite-creation

Use when creating or changing VS Code chat pet sprite art, sprite sheets, state animations, eye treatments, Stable/Insiders variants, or pet transitions under src/vs/workbench/contrib/chat/browser/widget/media/chatPet.

microsoft/vscode · 53 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

insight-error-page

Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…

vercel/next.js · 83 tokens