# Power Pack Email Scorer

> Power Pack Email Scorer is a paid API for AI agents from power-pack-x402.fly.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Scores an outreach email on multiple quality dimensions and returns improvement suggestions plus a rewritten subject line

## Facts

- Endpoint: POST https://power-pack-x402.fly.dev/api/score-email
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/power-pack-email-scorer-e2e8e1d8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_eXsYppEkA2yiApLYj2wbw

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability power-pack-email-scorer-e2e8e1d8 -d '<json body>'
```

Example prompt: Before I send this cold sales email, can you score it for me? Subject: 'Quick question about your Q4 pipeline' — Body: 'Hi Sarah, I noticed Acme Corp just expanded into EMEA. We help revenue teams like yours hit quota 30% faster. Worth a 15-min call this week?' I want scores on spam risk, open rate, CTA clarity, and your top 3 suggestions to make it better, plus a stronger subject line.

## When to prefer this

Choose this endpoint when you need a fast, affordable ($0.01 per call) pre-send QA check on individual outreach emails — especially in sales, marketing, or recruiting workflows where email quality directly affects response rates. Prefer this over generic LLM prompting because it uses a specialized senior-copywriter system prompt and returns structured scores with concrete improvement suggestions, making it easy to programmatically gate or improve emails before delivery.

## Known failure modes

- Missing or empty email content returns an error field with ok: false
- Extremely long email bodies may be truncated or rejected
- Payment not included or insufficient USDC triggers 402 payment required
- Malformed JSON input returns a validation error
- Claude API timeout on the backend returns a 500 error with ok: false

## How this service works

Score an outreach email on subject quality, body quality, predicted open rate, spam risk, tone, length, personalization, and CTA clarity. Returns top 3 specific improvement suggestions and a stronger rewritten subject line. Useful for sales/marketing/recruiting AI agents that need QA before sending. Powered by Claude Haiku 4.5 with senior-copywriter system prompt.

## Output

Returns an ok boolean plus a score object containing numeric/letter ratings for subject quality, body quality, predicted open rate, spam risk, tone, length, personalization, and CTA clarity, along with the top 3 specific actionable improvement suggestions and a rewritten stronger subject line.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "score": {
   "tone": "salesy",
   "verdict": "revise_then_send",
   "spam_risk": 3,
   "body_score": 71,
   "cta_clarity": 6,
   "subject_score": 62,
   "top_improvements": [
    {
     "fix": "Reference their specific company milestone",
     "area": "subject",
     "issue": "Generic 'Quick question'"
    },
    {
     "fix": "Open with the prospect-specific hook",
     "area": "opening",
     "issue": "Starts with 'I hope this finds you well'"
    },
    {
     "fix": "Propose a specific 15-min slot",
     "area": "cta",
     "issue": "Vague 'let me know'"
    }
   ],
   "length_assessment": "too_long",
   "rewritten_subject": "Saw your Q3 launch — one idea on the onboarding flow",
   "personalization_score": 4,
   "predicted_open_rate_pct": 28
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/power-pack-email-scorer-e2e8e1d8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from power-pack-x402.fly.dev](https://www.zero.xyz/host/power-pack-x402.fly.dev/llms.txt)