prompt-test

prompt-test is a command for Claude Code from Benkapner/claude-code-basecamp. It costs 28 tokens per session (1,156 once invoked), scanned A, original, MIT.

A tool for trying language-model prompts against example inputs. A prompt is the instruction sent to an AI model to produce an answer.

In plain words
What is it for?
Use it to test a new prompt, compare two prompt versions, or check an edited prompt against sample data. It can use existing test inputs or create realistic examples when none are available.
Why use it?
It lets you inspect results and notice regressions, meaning worse results after a prompt is changed, before deploying the change.

Command for Claude Code

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 commands/benkapner/claude-code-basecamp/prompt-test
Clone the repo
git clone --depth 1 https://github.com/Benkapner/claude-code-basecamp

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 prompt-test

README.md
[![agentmods](https://agentmods.dev/badge/commands/benkapner/claude-code-basecamp/prompt-test.svg)](https://agentmods.dev/commands/benkapner/claude-code-basecamp/prompt-test)
Your own site
<a href="https://agentmods.dev/commands/benkapner/claude-code-basecamp/prompt-test"><img src="https://agentmods.dev/badge/commands/benkapner/claude-code-basecamp/prompt-test.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,156 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 $0.00028 $0.01156
Opus 5 $0.00014 $0.00578
Sonnet 5 $0.00006 $0.00231
Haiku 4.5 $0.00003 $0.00116

Measured 3d ago against content hash d7ff04a9c78d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

prompt-test 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 3d 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.

.claude/commands/prompt-test.md · 118 lines

How it starts

The opening of the file, as written. The whole thing — 118 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prompt Test

Test your LLM prompts before deploying them. Run a prompt against sample inputs, inspect the outputs, and catch regressions when you modify prompts.

When to Use

  • After editing a prompt template (e.g., prompts/person_prompts.py)
  • Before committing prompt changes to make sure outputs didn't degrade
  • When comparing two prompt versions side-by-side
  • When building a new prompt from scratch and iterating on quality

Instructions

1. Identify the Prompt

  • If $ARGUMENTS specifies a file, read it and find the prompt function(s)
  • If $ARGUMENTS is empty, search the current repo for prompt files (look in prompts/, or files with "prompt" in the name)
  • List the available prompt functions and ask the user which to test

2. Prepare Test Inputs

  • Look for existing test data in the repo (e.g., sample JSON files in data/, test fixtures in tests/)
  • If no test data exists, generate 2-3 realistic sample inputs based on the prompt's expected input format
  • Show the user the test inputs and ask if they want to modify them

3. Build and Run the Prompt

  • Call the prompt function with each test input to generate the actual prompt text
  • Display the rendered prompt for each input so the user can review what's being sent to the LLM
  • If the user wants to actually call the LLM (requires API key):
    • Run the prompt against the configured LLM (check .env for GOOGLE_API_KEY, OPENAI_API_KEY, etc.)
    • Show the raw LLM response for each input
    • If the pipeline has a parsing function (e.g., parse_person_summary), run it on the response and show the parsed result

4. Evaluate Output Quality

For each test output, check:

  • Completeness: Did the LLM fill all expected fields? Any empty or "Unknown" values that shouldn't be?
  • Format compliance: Does the output match the expected format (e.g., SUMMARY/PRODUCTS/TECHNOLOGIES/WORK_FOCUS)?
  • Grounding: Does the output reference specific details from the input, or is it generic/hallucinated?
  • Length: Is the output within expected bounds (not too short, not too long)?
  • Parseability: If there's a parsing function, does it successfully parse the output without falling back to defaults?

Read the full file on GitHub · 118 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. 3d ago First seen · 118 lines · 28 tokens per session scan A d7ff04a9c78d

Subscribe to this mod's changes

prompt-test is a command published in the GitHub repository Benkapner/claude-code-basecamp (16 stars, last pushed 14d ago), licensed MIT. It adds 28 tokens to every session and 1,156 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.