catastrophiser

catastrophiser is an agent for Claude Code from povvo/claudikins-kernel. It costs 315 tokens per session (2,329 once invoked), scanned B, original, MIT.

A verification agent that checks whether software actually works by running it and examining its output. It chooses checks suited to the project, such as screenshots for web apps, requests for APIs, or commands for command-line tools.

In plain words
What is it for?
Use it during verification to inspect web pages, API responses, command-line output, or other running software. It can capture screenshots, run test flows, call endpoints, and use fallback checks when needed.
Why use it?
Passing tests alone may not reveal what users see or what an endpoint returns. This agent gathers direct evidence and reports problems without changing the code.

Agent for Claude Code

Written for Claude Code: hooks in frontmatter. Also seen: model in frontmatter; mentions subagents; names the TodoWrite 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 claudikins-kernel plugin — 4 skills, 4 commands, 7 agents, 8 hooks shipped together

Good fit Use it during verification to inspect web pages, API responses, command-line output, or other running software. It can capture screenshots, run test flows, call endpoints, and use fallback checks when needed.

Compare 6 agents 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 povvo/claudikins-kernel
Claude Code
/plugin install claudikins-kernel

Made for: Claude Code.

Or install claudikins-kernel, the plugin that ships this one along with the rest of its 4 skills, 4 commands, 7 agents, 8 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 catastrophiser

README.md
[![agentmods](https://agentmods.dev/badge/agents/povvo/claudikins-kernel/catastrophiser.svg)](https://agentmods.dev/agents/povvo/claudikins-kernel/catastrophiser)
Your own site
<a href="https://agentmods.dev/agents/povvo/claudikins-kernel/catastrophiser"><img src="https://agentmods.dev/badge/agents/povvo/claudikins-kernel/catastrophiser.svg" alt="Measured on agentmods" height="20"></a>
Per session 315 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,329 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 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 $0.00315 $0.02329
Opus 5 $0.00158 $0.01164
Sonnet 5 $0.00063 $0.00466
Haiku 4.5 $0.00032 $0.00233

Measured 8d ago against content hash b831c378ac35, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade B, and why

catastrophiser scanned grade B with 2 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 8d 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

curl -s -X POST http://localhost:3000/api/auth -H "Content-Type: application/json" -d '{"test": true}'

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

assistant: "Spawning catastrophiser to curl the auth endpoints and verify response shapes"
agents/catastrophiser.md · 379 lines

How it starts

The opening of the file, as written. The whole thing — 379 lines — stays where its author put it; the contents beside it link to each section on GitHub.

catastrophiser

You verify that code WORKS by SEEING its output. This is the feedback loop that makes Claude's code actually work.

"Give Claude a tool to see the output of the code." - Boris

Core Principle

Evidence before assertions. Always.

Never claim code works without seeing it work. Tests passing is not enough. You must SEE the output.

What You DO

  • Detect project type (web, API, CLI, library, service)
  • Run the appropriate verification method
  • Capture evidence (screenshots, responses, output)
  • Report issues clearly with evidence
  • Use fallback methods when primary fails

What You DON'T Do

  • Modify any code (you observe, not change)
  • Create new files
  • Spawn sub-agents
  • Skip verification because "tests pass"
  • Fabricate evidence

Project Type Detection

Detect the project type to choose verification method:

Detection Pattern Project Type Primary Method
package.json + src/app or pages/ Web app Screenshot + test flows
package.json + src/routes or controllers/ API Curl endpoints
Cargo.toml + src/main.rs with clap CLI Run commands
pyproject.toml + main.py CLI Run commands
**/lib.rs or setup.py Library Run examples
Dockerfile or docker-compose.yml Service Health check + logs

Verification Methods

Web Applications

# 1. Start dev server
npm run dev &
SERVER_PID=$!

# 2. Wait for server (max 30s)
timeout 30 bash -c 'until nc -z localhost 3000; do sleep 1; done'

# 3. Take screenshots via tool-executor (Playwright)
# Use mcp__tool-executor__execute_code

# 4. Check browser console for errors

# 5. Test critical flows

# 6. Cleanup
kill $SERVER_PID

Evidence to capture:

  • Screenshots of key pages
  • Browser console errors (if any)
  • Network request failures (if any)

Read the full file on GitHub · 379 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. 8d ago First seen · 379 lines · 315 tokens per session scan B b831c378ac35

Subscribe to this mod's changes

catastrophiser is an agent published in the GitHub repository povvo/claudikins-kernel (126 stars, last pushed 4mo ago), licensed MIT. It adds 315 tokens to every session and 2,329 once invoked, about $0.0016 per session on Opus 5. A static security scan graded it B with 2 findings (sends data to an external url, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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