# Sovereign Engine – Spend Cap

> Sovereign Engine – Spend Cap is a paid API for AI agents from api.zuluworksai.com, paid per call via x402, $0.005/call, status down (last checked 2026-09-15).

Sets or enforces a per-call USDC spend cap for pay-per-call x402 execution primitives on the Sovereign Engine platform

## Facts

- Endpoint: POST https://api.zuluworksai.com/exec/spend-cap
- Price: $0.005/call
- Payment: x402
- Status: down
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/sovereign-engine-spend-cap-88d5aca9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Pu81deA1_VQV53eMljzRZ

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 sovereign-engine-spend-cap-88d5aca9 -d '<json body>'
```

Example prompt: Set a spend cap on my Sovereign Engine x402 account so each pay-per-call execution costs no more than $0.005 USDC on Base — I want to make sure my isolated code sandbox calls don't exceed that limit.

## When to prefer this

Use this endpoint when you need to enforce budget controls on per-call USDC payments for the Sovereign Engine's x402 execution primitives, particularly when running untrusted code in isolated Cloudflare sandboxes or triggering Bing RSS web searches and you want to prevent runaway microtransaction costs on the Base network.

## Known failure modes

- Insufficient USDC balance on Base — payment fails with 402 response
- Invalid or malformed prompt payload — returns error in data field with success: false
- Network timeout reaching the self-hosted facilitator — connection error
- x402 payment verification failure — receipt_id not issued
- Spend cap already at maximum allowed value — rejected with validation error

## How this service works

Pay-per-call x402 execution primitives (USDC on Base). Code execution runs in isolated Cloudflare Dynamic Worker sandboxes (JavaScript + Python, network blocked). Web search backed by Bing RSS. Self-hosted facilitator.

## Output

Returns a JSON object with a success boolean, a receipt_id UUID confirming the spend cap operation, and a data object with cap configuration details.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "prompt": {
   "type": "string",
   "description": "The input prompt"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "success": true,
  "receipt_id": "uuid"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/sovereign-engine-spend-cap-88d5aca9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.zuluworksai.com](https://www.zero.xyz/host/api.zuluworksai.com/llms.txt)