regression-watch

regression-watch is a skill for Claude Code, Codex from hoangsonww/Claude-Code-Agent-Monitor. It costs 82 tokens per session (1,006 once invoked), scanned A, original, MIT.

A monitoring tool that checks whether Claude Code usage is getting worse over time across errors, caching, context compaction, and cost per session.

In plain words
What is it for?
Use it to investigate regressions in errors, cache hit rate, compaction frequency, or session cost.
Why use it?
It compares recent activity with an earlier baseline so gradual quality or efficiency declines are easier to notice.

Skill for Claude CodeCodex

Written for Claude Code and Codex: $ARGUMENTS substitution, but also agents/openai.yaml present. Also seen: mentions Claude Code.

Part of the ccam-insights plugin — 6 skills, 3 commands, 2 agents shipped together

Good fit Use it to investigate regressions in errors, cache hit rate, compaction frequency, or session cost.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hoangsonww/claude-code-agent-monitor/regression-watch
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 hoangsonww/Claude-Code-Agent-Monitor --skill regression-watch
Clone the repo
git clone --depth 1 https://github.com/hoangsonww/Claude-Code-Agent-Monitor

Made for: Claude Code, Codex.

Or install ccam-insights, the plugin that ships this one along with the rest of its 6 skills, 3 commands, 2 agents.

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 regression-watch

README.md
[![agentmods](https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/regression-watch/github.svg)](https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/regression-watch)
Your own site
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/regression-watch"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/regression-watch/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 regression-watch

Your own site · 80×15
<a href="https://agentmods.dev/skills/hoangsonww/claude-code-agent-monitor/regression-watch"><img src="https://agentmods.dev/badge/skills/hoangsonww/claude-code-agent-monitor/regression-watch.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 82 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,006 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00082 $0.01006
Opus 5 $0.00041 $0.00503
Sonnet 5 $0.00016 $0.00201
Haiku 4.5 $0.00008 $0.00101

Measured 9d ago against content hash c73b0aa098d2, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

regression-watch 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 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.

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/ccam-insights/skills/regression-watch/SKILL.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Regression Watch

Detect whether Claude Code sessions are getting worse over time across quality and efficiency metrics, using Agent Monitor data.

Input

The user provides: $ARGUMENTS

This may be:

  • empty or "all" — check every regression metric (default)
  • "errors" — error-rate regression only
  • "cache" — cache hit-rate regression only
  • "compaction" — compaction-frequency regression only
  • "cost" — cost-per-session regression only
  • A window like "last 30d" or "30 vs 90" — set the recent vs baseline window sizes

Data Sources

Endpoint Returns
GET /api/analytics daily_events (365d), daily_sessions (365d), event_types, tokens (total_input, total_output, total_cache_read, total_cache_write — baselines pre-summed), avg_events_per_session
GET /api/events?session_id=X Event stream incl. APIError, Compaction, PreToolUse/PostToolUse — used to localize regressions to specific sessions
GET /api/pricing/cost { total_cost, breakdown[...] } — total cost to derive cost-per-session
GET /api/pricing/cost/{sessionId} Per-session cost — used to compare recent vs baseline session cost
GET /api/workflows/{sessionId} compaction (impact), errorPropagation (by depth), effectiveness — per-session quality signals
GET /api/sessions?limit=N Sessions with started_at, cost, metadata — to bucket sessions into time windows

Report Sections

1. Windowing

Split history into a baseline window (older) and a recent window (newer). Default: recent = last 30 days, baseline = the 30–90 day range before it. Use daily_events/daily_sessions for series metrics and GET /api/sessions?limit=N to assign sessions to each window by started_at.

2. Error Rate Regression

  • Recent error rate = APIError count / total events in the recent window (from event_types and daily_events, or per-session GET /api/events).
  • Compare to the baseline rate. Flag if recent is higher.
  • Report the absolute and relative change and which sessions contributed most APIError events.

Read the full file on GitHub · 84 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. 9d ago First seen · 84 lines · 82 tokens per session scan A c73b0aa098d2

Subscribe to this mod's changes

regression-watch is a skill published in the GitHub repository hoangsonww/Claude-Code-Agent-Monitor (991 stars, last pushed 3d ago), licensed MIT. It adds 82 tokens to every session and 1,006 once invoked, about $0.0004 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 2026-09-03.