# OceanEye Sentinel 2.0 — Vault and Rounding Verification

> OceanEye Sentinel 2.0 — Vault and Rounding Verification is a paid API for AI agents from sentinel.oceaneye-ai.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-11-04).

Formally verifies ERC-4626 vault share/asset rounding invariants by executing user-supplied deposit and redeem preview functions against symbolic or bounded inputs to detect counterexamples.

## Facts

- Endpoint: POST https://sentinel.oceaneye-ai.com/x402/verify-vault-and-rounding?utm_source=zero.xyz
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-11-04
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/oceaneye-sentinel-2-0-vault-and-rounding-verification-9f3a902d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_fQSx4i3BqpWBSYc_Va5xh

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 oceaneye-sentinel-2-0-vault-and-rounding-verification-9f3a902d -d '<json body>'
```

Example prompt: Can you verify my ERC-4626 vault's rounding invariants — here's my preview_redeem code and preview_deposit code — check up to 10000 assets and 10000 shares, and also enable the zero-share-mint check?

## When to prefer this

Use this endpoint when you need automated formal or bounded verification of ERC-4626 vault share/asset rounding invariants, especially before deploying vault contracts. Prefer it over manual unit testing when you want systematic counterexample search across a bounded input space. Best suited for DeFi developers needing quick, low-cost ($0.02 USDC) correctness checks on vault preview functions prior to audit or deployment.

## Known failure modes

- Invalid or unparseable Python/AST code in redeem_fn_code or deposit_fn_code returns an error message
- Solver timeout or resource exhaustion if bounds are very large
- Malicious or unsafe code in function arguments may be rejected
- Counterexample found — verification returns verified=false with counterexample details
- Network or payment authentication failure returns HTTP 402 or 500

## How this service works

OceanEye Sentinel 2.0 — Plataforma de Inteligencia Marítima Satelital con Radar SAR Sentinel-1, Segmentación SAM 3.1 (Puerta A + Control Negativo), Arena Multimodal Muse Wonder 1.0 vs Muse Spark 1.3 (n=30) y Cadena de Custodia Ed25519.

## Output

Returns a JSON object indicating whether the vault's rounding invariants are verified (boolean), the type of check performed, the solver mode used, and optionally a counterexample object showing the specific asset/share values that violate the invariant if one is found.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "max_assets": {
   "type": "integer",
   "default": 10000
  },
  "max_shares": {
   "type": "integer",
   "default": 10000
  },
  "redeem_fn_code": {
   "type": "string",
   "description": "Python/AST code for preview_redeem"
  },
  "deposit_fn_code": {
   "type": "string",
   "description": "Python/AST code for preview_deposit"
  },
  "check_zero_share_mint": {
   "type": "boolean",
   "default": false
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "message": {
   "type": "string"
  },
  "verified": {
   "type": "boolean"
  },
  "check_type": {
   "type": "string"
  },
  "solver_mode": {
   "type": "string"
  },
  "counterexample": {
   "type": [
    "object",
    "null"
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/oceaneye-sentinel-2-0-vault-and-rounding-verification-9f3a902d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from sentinel.oceaneye-ai.com](https://www.zero.xyz/host/sentinel.oceaneye-ai.com/llms.txt)