# NovaPath Math Worked Example Retrieval

> NovaPath Math Worked Example Retrieval is a paid API for AI agents from instructional-decision-engine-x402.vercel.app, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-31).

Retrieves a math worked example with step-by-step explanation, final answer, and model specification for a selected lesson from the NovaPath free catalog.

## Facts

- Endpoint: POST https://instructional-decision-engine-x402.vercel.app/instruction/worked-example?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/novapath-math-worked-example-retrieval-d2cc08e2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_crrUFD78FrzuvUSbEOO0v

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 novapath-math-worked-example-retrieval-d2cc08e2 -d '<json body>'
```

Example prompt: Pull up the NovaPath worked example for lesson NPMR26-F03-07 — I need the full step-by-step explanation, the answer, and the model specification.

## When to prefer this

Choose this endpoint when you need a specific, pre-authored math worked example with structured explanation steps and an attested model answer from the NovaPath catalog — particularly when the lesson ID is already known from the /instruction/catalog. This is preferable over generative math solvers when you need a curated, owner-reviewed canonical solution rather than an on-the-fly AI-generated answer.

## Known failure modes

- Invalid lessonId format (must match ^NPMR26-F[0-9]{2}-[0-9]{2}$) returns a validation error
- Requested lessonId not found in catalog returns a not-found error
- Lesson not currently available or outside catalog scope causes availability validation failure before payment is processed
- Payment failure via x402 protocol prevents content delivery
- Service downtime on Vercel hosting causes timeout or 5xx error

## How this service works

Retrieve an existing NovaPath math worked example with explanation steps, answer and available model specification. Select a lesson from the free catalog; owner review attested.

## Output

Returns a math worked example from the NovaPath catalog including ordered explanation steps, the final answer, and the available model specification for the selected lesson. The lesson is drawn from the free catalog and has been owner-reviewed and attested.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "lessonId": {
   "type": "string",
   "pattern": "^NPMR26-F[0-9]{2}-[0-9]{2}$",
   "description": "Choose a supported lesson ID from /instruction/catalog. Availability is validated before payment."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/novapath-math-worked-example-retrieval-d2cc08e2/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from instructional-decision-engine-x402.vercel.app](https://www.zero.xyz/host/instructional-decision-engine-x402.vercel.app/llms.txt)