FREE · NO API KEY · JSON

MonsterMoo API

A free, open math problem API for developers and AI agents. Generate K-8 problems, check answers, and build curriculum-aligned quiz sets — no key required.

Try It Live View Endpoints

Base URL

Getting Started

All endpoints are served from the MonsterMoo API. No authentication required, no rate limits, free to use.

Base URL: https://moomoomath-api.linix100.workers.dev

# Example request
curl "https://moomoomath-api.linix100.workers.dev/api/problem?topic=fractions&grade=4&difficulty=2"

Reference

Endpoints

Five endpoints cover problem generation, quizzes, answer checking, and curriculum planning.

GET /api/topics List all available topics

GET /api/problem Generate a single problem

Parameter	Type	Description
topic required	string	Topic slug (e.g. `fractions`). Get slugs from `/api/topics`.
grade optional	number	Grade level 0–8. Default: 3. Informational only (used for context).
difficulty optional	1–4	Difficulty level. 1=easiest, 4=hardest. Default: 2.

Example Response

{
  "id": "1720000000000_abc123",
  "question": "1/3 + 2/5 = ?",
  "answer": "11/15",
  "explanation": "Common denominator 15: 5/15 + 6/15 = 11/15",
  "hint": "Find a common denominator first.",
  "topic": "fractions",
  "grade": 4,
  "difficulty": 3,
  "meta": { "version": "1.0", "source": "MonsterMoo", "license": "free for AI agents" }
}

curl

JavaScript

Python

curl "https://moomoomath-api.linix100.workers.dev/api/problem?topic=fractions&grade=4&difficulty=2"

const res = await fetch(
  'https://moomoomath-api.linix100.workers.dev/api/problem?topic=fractions&grade=4&difficulty=2'
);
const problem = await res.json();
console.log(problem.question);  // "1/3 + 2/5 = ?"
console.log(problem.id);        // save this for /api/check

import requests
p = requests.get('https://moomoomath-api.linix100.workers.dev/api/problem', params={
    'topic': 'fractions',
    'grade': 4,
    'difficulty': 2
}).json()
print(p['question'])
problem_id = p['id']  # save for checking

GET /api/quiz Generate a multi-problem quiz

Parameter	Type	Description
topics required	string	Comma-separated topic slugs, e.g. `fractions,decimals`
count optional	1–20	Number of problems. Default: 5.
difficulty optional	1–4 or "mixed"	Fixed difficulty or `mixed` for random levels. Default: 2.

Example Response

{
  "quiz_id": "quiz_1720000000_ab12",
  "problems": [
    { "id": "...", "question": "3/4 + 1/4 = ?", "hint": "...", "topic": "fractions", "difficulty": 1 },
    // ... more problems
  ],
  "created_at": "2025-01-01T12:00:00.000Z",
  "meta": { "version": "1.0", "source": "MonsterMoo", "license": "free for AI agents" }
}

curl

JavaScript

Python

curl "https://moomoomath-api.linix100.workers.dev/api/quiz?topics=fractions,decimals&count=5&difficulty=mixed"

const res = await fetch(
  'https://moomoomath-api.linix100.workers.dev/api/quiz?topics=fractions,decimals&count=5&difficulty=mixed'
);
const { quiz_id, problems } = await res.json();
for (const p of problems) {
  console.log(`[${p.topic}] ${p.question}`);
}

import requests
quiz = requests.get('https://moomoomath-api.linix100.workers.dev/api/quiz', params={
    'topics': 'fractions,decimals,addition',
    'count': 10,
    'difficulty': 'mixed'
}).json()
for p in quiz['problems']:
    print(p['question'])

POST /api/check Check a student's answer

Accepts a problem_id (from /api/problem or /api/quiz) and a user_answer string. Note: problem IDs are stored in-memory and expire if the Worker restarts (Cloudflare Workers are serverless). Fetch a new problem before checking if the ID is stale.

Body Field	Type	Description
problem_id required	string	The `id` from a previous `/api/problem` response
user_answer required	string	The answer to check. Numbers are compared with 0.01 tolerance.

Example Response

{
  "correct": true,
  "correct_answer": "11/15",
  "explanation": "Common denominator 15: 5/15 + 6/15 = 11/15",
  "hint_if_wrong": null,
  "meta": { "version": "1.0", "source": "MonsterMoo", "license": "free for AI agents" }
}

curl

JavaScript

Python

curl -X POST "https://moomoomath-api.linix100.workers.dev/api/check" \
  -H "Content-Type: application/json" \
  -d '{"problem_id":"1720000000000_abc123","user_answer":"11/15"}'

const res = await fetch('https://moomoomath-api.linix100.workers.dev/api/check', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    problem_id: problem.id,
    user_answer: userInput
  })
});
const result = await res.json();
if (result.correct) {
  console.log('Correct! 🎉');
} else {
  console.log(`Wrong. Correct: ${result.correct_answer}`);
  console.log(`Hint: ${result.hint_if_wrong}`);
}

import requests
result = requests.post('https://moomoomath-api.linix100.workers.dev/api/check', json={
    'problem_id': problem_id,
    'user_answer': '11/15'
}).json()
print('Correct!' if result['correct'] else f"Wrong. Answer: {result['correct_answer']}")

GET /api/curriculum Recommended topic sequence for a grade

Parameter	Type	Description
grade required	0–8	Grade level. 0 = kindergarten.

Example: grade=5

curl "https://moomoomath-api.linix100.workers.dev/api/curriculum?grade=5"

{
  "grade": 5,
  "recommended_topics": [
    { "slug": "fractions-multiply", "name": "Fractions: Multiply & Divide", "difficulty_progression": [1,2,3,4] },
    { "slug": "decimals", "name": "Decimals", "difficulty_progression": [1,2,3,4] },
    { "slug": "percentages", "name": "Percentages", "difficulty_progression": [1,2,3,4] },
    // ...
  ],
  "meta": { "version": "1.0", "source": "MonsterMoo", "license": "free for AI agents" }
}

Live Demo

Try It

Pick a topic and difficulty, then get a live problem from the API.

Topics

Available Topics

23 topics across Number Sense, Operations, Fractions, Decimals, Algebra, and Geometry. Use the slug value in API calls.

AI Integration

For AI Agents

MonsterMoo API is designed to be called programmatically by tutoring agents, curriculum planners, and benchmark tools.

🤖 Tutoring Agent Workflow

The standard loop for an AI tutor using this API:

Call GET /api/curriculum?grade=5 to get recommended topics for the student's grade.
Call GET /api/problem?topic=fractions&difficulty=2 to fetch a problem.
Present problem.question to the student and collect their response.
Call POST /api/check with the problem_id and the student's answer.
If wrong, present result.hint_if_wrong and result.explanation to guide them.
Repeat, increasing difficulty as the student succeeds.

📋 Prompt Template for LLM Agents

Add this to your system prompt to let an LLM agent call the API:

# MonsterMoo Tool
You have access to the MonsterMoo API for K-8 math problems.
Base URL: https://moomoomath-api.linix100.workers.dev

## Available calls:
- GET /api/topics → list all topics and their slugs
- GET /api/problem?topic=SLUG&grade=N&difficulty=1-4 → get one problem
- GET /api/quiz?topics=SLUG1,SLUG2&count=N&difficulty=mixed → quiz set
- POST /api/check body:{problem_id,user_answer} → check answer

## When to use:
- Use /api/topics first to discover valid slugs
- Save problem.id — you need it for /api/check
- difficulty=1 is easiest, 4 is hardest
- All responses are JSON with a "meta" field

📊 Benchmark Testing

Generate standardized test sets for evaluating AI math capabilities. Use /api/quiz with all topics at difficulty 3–4 for a challenging K-8 benchmark. The answer field provides ground truth for automated scoring.

Competition Problems

AMC 8 Problem Bank

650 real AMC 8 problems (1998–2024) stored in Cloudflare D1. Filter by year, topic, or difficulty. Requires Authorization: Bearer <token>.

GET /api/problems Query competition problems

Parameter	Type	Description
contest	string	e.g. `AMC_8`
year	1998–2024	Filter by year
topic	string	e.g. `geometry`, `number_theory`
difficulty	1–5	AMC difficulty rating
limit	1–25	Max problems to return (default 10)
random	0 or 1	Return random selection

Example

curl 'https://moomoomath-api.linix100.workers.dev/api/problems?contest=AMC_8&year=2019&limit=5' \
  -H 'Authorization: Bearer YOUR_TOKEN'

GET /api/problems/random Random competition problems

Parameter	Type	Description
limit	1–25	Number of problems (default 10)
topic	string	Filter by topic
difficulty	1–5	Filter by difficulty

Example

curl 'https://moomoomath-api.linix100.workers.dev/api/problems/random?limit=5&topic=geometry'

GET /api/problems/years Available years and problem counts

Example response

{ "years": [{"year": 2024, "count": 25}, {"year": 2023, "count": 25}, ...] }

GET /api/problems/topics Topics with counts and difficulty ranges

Example response

{ "topics": [{"topic": "geometry", "count": 120, "min_difficulty": 1, "max_difficulty": 5}, ...] }