# Orders of Magnitude API – Namespace Index Build

> Orders of Magnitude API – Namespace Index Build is a paid API for AI agents from x402-api-production-5133.up.railway.app, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Builds or retrieves a namespace index entry for a given input string via a paid AI/data service

## Facts

- Endpoint: GET https://x402-api-production-5133.up.railway.app/ns/index/build
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/orders-of-magnitude-api-namespace-index-build-acd39e2f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qrPwew1Q9QTTlXQgPowRe

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 orders-of-magnitude-api-namespace-index-build-acd39e2f
```

Example prompt: Build a namespace index entry for 'orders_of_magnitude_v1' using the Orders of Magnitude API — I want to index that string and get back the resulting namespace build data.

## When to prefer this

Use this endpoint when you need to build or initialize a namespace index entry via the Orders of Magnitude AI/data platform using the x402 micropayment protocol. Prefer this over generic indexing services if you are already operating within the x402 payment ecosystem and need per-call, pay-as-you-go namespace indexing without a subscription.

## Known failure modes

- Missing or empty 'input' field returns a validation error
- Payment not accepted or insufficient USDC balance causes a 402 response
- Input string format not recognized may return an empty or error result
- Service unavailability on railway.app infrastructure returns 5xx errors
- Ambiguous or excessively long input strings may produce unexpected results

## How this service works

Data and AI services via x402 payment protocol

## Output

Returns a JSON object representing the result of the namespace index build operation for the provided input string. The exact fields are unspecified but likely include status, index metadata, or build confirmation data.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/orders-of-magnitude-api-namespace-index-build-acd39e2f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-api-production-5133.up.railway.app](https://www.zero.xyz/host/x402-api-production-5133.up.railway.app/llms.txt)