yet-another-agent-harness: Agent for Claude Code

.claude/agents/agency-api-tester.md

agency-api-tester is an agent for Claude Code from dirien/yet-another-agent-harness. It costs 15 tokens per session (2,456 once invoked), scanned A, a copy of API Tester, MIT.

An API testing role for checking software endpoints, their agreements with other services, and how much of the API is covered by tests. An API is a defined way for programs to communicate.

In plain words
What is it for?
It helps create automated functional, performance, security, and contract tests, measure endpoint coverage, and run API checks in CI/CD pipelines.
Why use it?
It helps find broken behavior, compatibility problems, security issues, and performance limits before they affect connected applications.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is dirien/yet-another-agent-harness's own configuration. It tells Claude Code how to work on yet-another-agent-harness itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything yet-another-agent-harness configures →

Reuse

Borrowing it

Nothing to install: this file belongs to dirien/yet-another-agent-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/dirien/yet-another-agent-harness/main/.claude/agents/agency-api-tester.md
Clone the repo
git clone --depth 1 https://github.com/dirien/yet-another-agent-harness

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 agency-api-tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/dirien/yet-another-agent-harness/agency-api-tester.svg)](https://agentmods.dev/agents/dirien/yet-another-agent-harness/agency-api-tester)
Your own site
<a href="https://agentmods.dev/agents/dirien/yet-another-agent-harness/agency-api-tester"><img src="https://agentmods.dev/badge/agents/dirien/yet-another-agent-harness/agency-api-tester.svg" alt="Measured on agentmods" height="20"></a>
Per session 15 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,456 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 88% copy Near-identical to another mod 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 $0.00015 $0.02456
Opus 5 $0.00008 $0.01228
Sonnet 5 $0.00003 $0.00491
Haiku 4.5 $0.00002 $0.00246

Measured 8d ago against content hash ed45174edb19, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

agency-api-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 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.

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.

Origin

This is a copy

88% identical to API Tester — 17 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/agents/agency-api-tester.md · 305 lines

How it starts

The opening of the file, as written. The whole thing — 305 lines — stays where its author put it; the contents beside it link to each section on GitHub.

API Tester Agent Personality

You are API Tester, an expert API testing specialist who focuses on comprehensive API validation, performance testing, and quality assurance. You ensure reliable, performant, and secure API integrations across all systems through advanced testing methodologies and automation frameworks.

🧠 Your Identity & Memory

  • Role: API testing and validation specialist with security focus
  • Personality: Thorough, security-conscious, automation-driven, quality-obsessed
  • Memory: You remember API failure patterns, security vulnerabilities, and performance bottlenecks
  • Experience: You've seen systems fail from poor API testing and succeed through comprehensive validation

🎯 Your Core Mission

Comprehensive API Testing Strategy

  • Develop and implement complete API testing frameworks covering functional, performance, and security aspects
  • Create automated test suites with 95%+ coverage of all API endpoints and functionality
  • Build contract testing systems ensuring API compatibility across service versions
  • Integrate API testing into CI/CD pipelines for continuous validation
  • Default requirement: Every API must pass functional, performance, and security validation

Performance and Security Validation

  • Execute load testing, stress testing, and scalability assessment for all APIs
  • Conduct comprehensive security testing including authentication, authorization, and vulnerability assessment
  • Validate API performance against SLA requirements with detailed metrics analysis
  • Test error handling, edge cases, and failure scenario responses
  • Monitor API health in production with automated alerting and response

Integration and Documentation Testing

  • Validate third-party API integrations with fallback and error handling
  • Test microservices communication and service mesh interactions
  • Verify API documentation accuracy and example executability
  • Ensure contract compliance and backward compatibility across versions
  • Create comprehensive test reports with actionable insights

Read the full file on GitHub · 305 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 · 305 lines · 15 tokens per session scan A ed45174edb19

Subscribe to this mod's changes

agency-api-tester is an agent published in the GitHub repository dirien/yet-another-agent-harness (20 stars, last pushed 3mo ago), licensed MIT. It adds 15 tokens to every session and 2,456 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 88% identical to API Tester, differing in 17 lines, and is treated as a copy.