API Reference

Use the PromptGen API to generate expert AI prompts programmatically from any language or platform.

Base URL: https://getpromptgen.com/api/v1
All requests must include your API key in the Authorization header.

Authentication

All API requests are authenticated using an API key passed as a Bearer token.

Authorization: Bearer sb_live_YOUR_API_KEY

Generate your API key in Settings → Developer. Keys start with sb_live_ and are shown only once at creation.

Rate Limits

Plan	Calls / day	Max keys
Free	10	5
Pro	500	5

When you exceed the limit, the API returns 429 Too Many Requests. Limits reset at midnight UTC.

Each response includes calls_remaining_today so you can track usage programmatically.

Generate a Prompt

POST /api/v1/generate

Generates a structured, expert-quality prompt for any task.

Request Body

Field	Type	Description
taskrequired	string	What you want the prompt to accomplish
domain	string	Domain hint: `auto`, `software`, `business`, `creative`, `education`, `research`, `data`. Default: `auto`
technique	string	Prompting technique: `auto`, `chain_of_thought`, `few_shot`, `role_play`, `step_by_step`. Default: `auto`
target_ai	string	Model to optimise for: `general`, `claude`, `gpt4`, `gemini`. Default: `general`
provider	string	Which LLM generates the prompt: `anthropic`, `openai`, `gemini`. Default: `anthropic`
context	string	Optional extra context for the prompt

Response

Field	Type	Description
prompt	string	The generated, ready-to-use prompt
quality_score	float	Quality score 1–10
quality_reasoning	string	One-line explanation of the score
domain	string	Domain used
technique	string	Technique used
model_used	string	Exact model ID that generated the prompt
provider	string	Provider used
latency_ms	integer	Generation time in milliseconds
calls_remaining_today	integer	Remaining API calls for today

Example Request

curl -X POST https://getpromptgen.com/api/v1/generate \
  -H "Authorization: Bearer sb_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "task": "Write a blog post about the future of AI",
    "domain": "creative",
    "provider": "anthropic"
  }'

Example Response

{
  "prompt": "You are an expert technology writer with 10 years...",
  "quality_score": 9.2,
  "quality_reasoning": "Clear persona, structured output, and specific constraints.",
  "domain": "creative",
  "technique": "chain_of_thought",
  "model_used": "claude-sonnet-4-6",
  "provider": "anthropic",
  "latency_ms": 1842,
  "calls_remaining_today": 9
}

Get API Identity

GET /api/v1/me

Returns information about the API key and its owner. Useful for verifying a key works.

curl https://getpromptgen.com/api/v1/me \
  -H "Authorization: Bearer sb_live_YOUR_KEY"

{
  "user_email": "you@example.com",
  "plan": "free",
  "key_prefix": "sb_live_a8f3",
  "calls_today": 1,
  "daily_limit": 10,
  "calls_remaining": 9
}

Error Codes

Status	Meaning
400	Bad request — missing or invalid fields
401	Invalid or missing API key
403	Account inactive or no access
429	Daily rate limit exceeded
502	Upstream LLM provider error

All errors return JSON: {"detail": "Human-readable message"}

Code Examples

Python

import requests

resp = requests.post(
    "https://getpromptgen.com/api/v1/generate",
    headers={"Authorization": "Bearer sb_live_YOUR_KEY"},
    json={"task": "Summarise this document", "domain": "business"}
)
data = resp.json()
print(data["prompt"])

JavaScript / Node

const res = await fetch("https://getpromptgen.com/api/v1/generate", {
  method: "POST",
  headers: {
    "Authorization": "Bearer sb_live_YOUR_KEY",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({ task: "Write unit tests for my auth module" })
});
const { prompt } = await res.json();
console.log(prompt);

PHP

$ch = curl_init("https://getpromptgen.com/api/v1/generate");
curl_setopt_array($ch, [
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_POST => true,
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer sb_live_YOUR_KEY",
    "Content-Type: application/json"
  ],
  CURLOPT_POSTFIELDS => json_encode(["task" => "Create a marketing email"])
]);
$data = json_decode(curl_exec($ch), true);
echo $data["prompt"];