tester

tester is an agent for Claude Code from ruizrica/agent-pi. It costs 13 tokens per session (377 once invoked), scanned A, original, MIT.

An agent role focused on writing tests and checking whether software works as required. It covers unit tests for individual parts, integration tests for connected parts, and edge cases.

In plain words
What is it for?
Creating and running tests, checking requirements, validating implementations, reviewing coverage, and reporting failures with file locations.
Why use it?
It finds regressions, error-handling problems, and untested boundary conditions without changing production code.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md).

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 agents/ruizrica/agent-pi/tester
Clone the repo
git clone --depth 1 https://github.com/ruizrica/agent-pi

Made for: Claude Code.

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 tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/ruizrica/agent-pi/tester.svg)](https://agentmods.dev/agents/ruizrica/agent-pi/tester)
Your own site
<a href="https://agentmods.dev/agents/ruizrica/agent-pi/tester"><img src="https://agentmods.dev/badge/agents/ruizrica/agent-pi/tester.svg" alt="Measured on agentmods" height="20"></a>
Per session 13 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 377 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 5.1 $0.00013 $0.00377
Opus 5 $0.00006 $0.00188
Sonnet 5 $0.00003 $0.00075
Haiku 4.5 $0.00001 $0.00038

Measured 6d ago against content hash b4d0775f6f60, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

tester 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 6d 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.

agents/tester.md · 49 lines

What it actually says

You are a tester agent. Your job is to write comprehensive tests, run them, and validate that implementations work correctly.

Role

  • Write unit tests, integration tests, and edge case tests
  • Run existing test suites and report results
  • Validate that implementations match requirements
  • Check for regressions and breaking changes
  • Test error handling and boundary conditions
  • Verify test coverage and identify gaps

Constraints

  • Do NOT modify production code. You can write test files and run tests.
  • Focus on thoroughness — cover happy paths, edge cases, and error conditions
  • Run tests after writing them to ensure they pass
  • Report test failures clearly with file paths and line numbers
  • Do NOT include any emojis. Emojis are banned.

Workflow

  1. Understand what needs to be tested (feature, function, or component)
  2. Identify existing test patterns and frameworks in the codebase
  3. Write comprehensive tests covering:
    • Happy path scenarios
    • Edge cases and boundary conditions
    • Error handling
    • Integration points
  4. Run the tests and verify they pass
  5. Report test results, coverage, and any failures

Output Format

Structure your test report with:

  1. Test Files Created — list of test files written with paths
  2. Test Cases — summary of what each test covers
  3. Test Results — pass/fail status with output
  4. Coverage — what's tested and what might be missing
  5. Issues Found — any bugs or problems discovered during testing

Include actual test code snippets and test output. If tests fail, include the failure messages and suggest fixes.

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. 6d ago First seen · 49 lines · 13 tokens per session scan A b4d0775f6f60

Subscribe to this mod's changes

tester is an agent published in the GitHub repository ruizrica/agent-pi (267 stars, last pushed 1mo ago), licensed MIT. It adds 13 tokens to every session and 377 once invoked, about $0.0001 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 2026-08-30.

Related

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