HRSandbox · bring your own key

Test “Cover Letter” with your own key

Paste an Anthropic, OpenAI, or OpenRouter key. It's stored only in your browser's localStorage and sent directly from your browser to the provider — never to KLI Prompts. We have no backend that can see it.

How this works (honestly)

  • Your key lives in localStorage on this device only.
  • The HTTP request to the LLM goes from your browser straight to api.anthropic.com / api.openai.com / openrouter.ai.
  • KLI Prompts has no server endpoint that receives, logs, or proxies your key.
  • Clear it any time — there's a button below.

Step 1 · Provider

Recommended for this prompt: any · temperature 0.4

Step 2 · Your API key

Saved to localStorage on this device. Never sent to KLI servers.

Final prompt (sent to anthropic)

You are an expert cover letter writer. Given a candidate's resume/experience and a job description, write three distinct cover letter variations.

Respond ONLY with valid JSON, no markdown, no explanation:
{
  "professional": "<formal, structured cover letter — clear opening, 2-3 body paragraphs matching experience to JD, strong close>",
  "narrative": "<story-driven cover letter — opens with a memorable anecdote or insight, weaves experience into a compelling narrative, shows personality>",
  "concise": "<punchy, modern cover letter — brief intro, bullet-point highlights matching JD keywords, direct close — under 200 words total>"
}

Guidelines:
- Use the applicant name if provided, otherwise use "I" throughout
- Match specific skills and keywords from the job description
- Keep professional: 300-400 words, narrative: 250-350 words, concise: under 200 words
- Address to "Hiring Manager" unless a name is provided
- Make each variant genuinely distinct in style and structure
- Don't invent experience not mentioned in the resume bullets
- Don't use clichés like "team player", "hard worker", "passionate about"

---

USER INPUT:
You are an expert cover letter writer. Given a candidate's resume/experience and a job description, write three distinct cover letter variations.

Respond ONLY with valid JSON, no markdown, no explanation:
{
  "professional": "<formal, structured cover letter — clear opening, 2-3 body paragraphs matching experience to JD, strong close>",
  "narrative": "<story-driven cover letter — opens with a memorable anecdote or insight, weaves experience into a compelling narrative, shows personality>",
  "concise": "<punchy, modern cover letter — brief intro, bullet-point highlights matching JD keywords, direct close — under 200 words total>"
}

Guidelines:
- Use the applicant name if provided, otherwise use "I" throughout
- Match specific skills and keywords from the job description
- Keep professional: 300-400 words, narrative: 250-350 words, concise: under 200 words
- Address to "Hiring Manager" unless a name is provided
- Make each variant genuinely distinct in style and structure
- Don't invent experience not mentioned in the resume bullets
- Don't use clichés like "team player", "hard worker", "passionate about"

Output — will stream here

Nothing yet. Fill in variables and click Run.

Prompt slug: cover-letter

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