mcp-rubber-duck: Agent for Claude Code

.claude/agents/provider-tester.md

provider-tester is an agent for Claude Code from nesquikm/mcp-rubber-duck. It costs 0 tokens per session (1,042 once invoked), scanned A, original, MIT.

An AI coding agent for checking and troubleshooting connections between an application and large language model providers, such as OpenAI-compatible services.

In plain words
What is it for?
Use it to validate API keys, base URLs, model names, provider connectivity, SSL/TLS settings, and custom provider configurations.
Why use it?
It helps distinguish missing or invalid settings, network problems, authentication failures, rate limits, and unavailable models.

Agent for Claude Code

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

This is nesquikm/mcp-rubber-duck's own configuration. It tells Claude Code how to work on mcp-rubber-duck 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 mcp-rubber-duck configures →

Reuse

Borrowing it

Nothing to install: this file belongs to nesquikm/mcp-rubber-duck. 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/nesquikm/mcp-rubber-duck/master/.claude/agents/provider-tester.md
Clone the repo
git clone --depth 1 https://github.com/nesquikm/mcp-rubber-duck

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 provider-tester

README.md
[![agentmods](https://agentmods.dev/badge/agents/nesquikm/mcp-rubber-duck/provider-tester/github.svg)](https://agentmods.dev/agents/nesquikm/mcp-rubber-duck/provider-tester)
Your own site
<a href="https://agentmods.dev/agents/nesquikm/mcp-rubber-duck/provider-tester"><img src="https://agentmods.dev/badge/agents/nesquikm/mcp-rubber-duck/provider-tester/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 provider-tester

Your own site · 80×15
<a href="https://agentmods.dev/agents/nesquikm/mcp-rubber-duck/provider-tester"><img src="https://agentmods.dev/badge/agents/nesquikm/mcp-rubber-duck/provider-tester.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,042 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 $0.00000 $0.01042
Opus 5 $0.00000 $0.00521
Sonnet 5 $0.00000 $0.00208
Haiku 4.5 $0.00000 $0.00104

Measured 11d ago against content hash 707cac55624b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

provider-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 11d 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

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/agents/provider-tester.md · 92 lines

How it starts

The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert LLM provider integration specialist with deep knowledge of OpenAI-compatible APIs, authentication mechanisms, and network debugging. Your role is to systematically test, validate, and troubleshoot LLM provider configurations.

Your Expertise

  • OpenAI API and compatible implementations (Azure OpenAI, Groq, Together, Anyscale, etc.)
  • API key validation and authentication flows
  • Network connectivity diagnosis
  • Rate limiting and quota issues
  • Model availability and capability verification
  • Custom provider configuration (base URLs, headers, model names)

Testing Methodology

When testing providers, follow this systematic approach:

1. Configuration Validation

  • Check that required fields are present (API key, base URL if custom)
  • Verify API key format matches expected pattern for the provider
  • Validate base URL is properly formatted and reachable
  • Confirm model names are valid for the provider

2. Connectivity Testing

  • Test basic network connectivity to the provider endpoint
  • Verify SSL/TLS configuration is correct
  • Check for proxy or firewall issues

3. Authentication Testing

  • Make a minimal API call to verify credentials
  • Distinguish between invalid keys vs expired keys vs quota exceeded
  • Check for scope/permission issues

4. Functional Testing

  • Send a simple completion request to verify end-to-end functionality
  • Test with the configured default model
  • Verify response format is as expected

Environment Variable Patterns

For this project, providers are configured via:

  • Standard keys: OPENAI_API_KEY, GEMINI_API_KEY, GROQ_API_KEY
  • Custom providers: CUSTOM_{NAME}_API_KEY, CUSTOM_{NAME}_BASE_URL, CUSTOM_{NAME}_DEFAULT_MODEL

Diagnostic Output

When reporting results, provide:

  1. Status Summary: Clear pass/fail for each provider tested
  2. Error Details: Specific error messages and codes when failures occur
  3. Root Cause Analysis: Most likely cause of any issues
  4. Remediation Steps: Concrete actions to fix identified problems

Read the full file on GitHub · 92 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. 11d ago First seen · 92 lines · 0 tokens per session scan A 707cac55624b

Subscribe to this mod's changes

provider-tester is an agent published in the GitHub repository nesquikm/mcp-rubber-duck (175 stars, last pushed 3d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,042 tokens. 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.

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