# ERC-4626 Vault Reader

> ERC-4626 Vault Reader is a paid API for AI agents from api.vextorium.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-18).

Reads on-chain ERC-4626 tokenized vault data (Morpho, Yearn v3, Euler, sDAI, etc.) returning underlying asset, total assets, shares, price per share, and approximate USD TVL.

## Facts

- Endpoint: POST https://api.vextorium.com/vault-4626-pago?utm_source=zero.xyz
- Price: $0.004/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc-4626-vault-reader-77d80dbb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_tlljd1l6b1uQQJAK14doT

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 erc-4626-vault-reader-77d80dbb -d '<json body>'
```

Example prompt: What's the current price per share and approximate TVL of the sDAI vault at 0x83F20F44975D03b1b09e64809B757c47f942BEeA on Ethereum?

## When to prefer this

Use this endpoint when you need real-time on-chain ERC-4626 vault metrics (TVL, price per share, shares, underlying asset) for any major ERC-4626-compatible protocol such as Morpho, Yearn v3, Euler, Fluid, or sDAI across Ethereum, Base, Arbitrum, Optimism, or Polygon. Prefer this over DeFi aggregator APIs when you need trustless, directly on-chain data for a specific vault contract address rather than aggregated or lagged protocol-level summaries.

## Known failure modes

- Invalid or non-ERC-4626 contract address returns null fields or an error
- Unsupported network (outside base, ethereum, arbitrum, optimism, polygon) causes validation failure
- Contract address on wrong network returns empty or incorrect data
- RPC node unavailability may cause transient fetch failures
- Vault with no liquidity or newly deployed vault may show zero total assets

## How this service works

Read any ERC-4626 tokenized vault (Morpho, Yearn v3, Euler, Fluid, sDAI...) on-chain: underlying asset, total assets, shares outstanding, price per share and approximate TVL in USD.

## Output

Returns a JSON object with the vault name, symbol, the underlying asset (address, symbol, decimals), total assets held, total shares outstanding, price per share (values above 1.0 indicate accrued yield), and an approximate TVL in USD, plus a note explaining the price-per-share interpretation.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "red": {
   "enum": [
    "base",
    "ethereum",
    "arbitrum",
    "optimism",
    "polygon"
   ],
   "type": "string"
  },
  "vault": {
   "type": "string",
   "description": "Vault contract address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "red": "ethereum",
  "nota": "Precio por participación > 1 = el vault ha generado rendimiento desde su creación (o empezó así).",
  "vault": "0x83F20F44975D03b1b09e64809B757c47f942BEeA",
  "activo": {
   "simbolo": "DAI",
   "decimales": 18,
   "direccion": "0x6B175474E89094C44Da98b954EedeAC495271d0F"
  },
  "nombre": "Savings Dai",
  "simbolo": "sDAI",
  "tvl_usd_aprox": 164442216,
  "activos_totales": 164505714.886556,
  "participaciones": 139264625.634588,
  "precio_por_participacion": 1.1812455183
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc-4626-vault-reader-77d80dbb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.vextorium.com](https://www.zero.xyz/host/api.vextorium.com/llms.txt)