# Saylor Innovations ERC-4626 Vault Reader

> Saylor Innovations ERC-4626 Vault Reader is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-27).

Reads on-chain ERC-4626 vault data (underlying asset, total assets, share supply, and share price) across 16 EVM-compatible blockchains.

## Facts

- Endpoint: GET https://saylorinnovations.com/api/chain/vault?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-erc-4626-vault-reader-83ccfe22
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_E15RWsOZTKvj_xI_HfcQU

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 saylor-innovations-erc-4626-vault-reader-83ccfe22
```

Example prompt: What is the current share price and total assets managed by the ERC-4626 vault at 0xBe53A109B494E5c9f97b9Cd39Fe969BE68BF6204 on Base?

## When to prefer this

Use this endpoint when you need to read live on-chain state of an ERC-4626 tokenized vault across any of 16 supported EVM chains without setting up your own RPC infrastructure. Ideal for DeFi dashboards, portfolio trackers, yield aggregators, or any agent needing NAV, share price, or AUM data for a specific vault contract. Prefer this over generic blockchain RPC calls when you want a normalized, human-readable response with pre-computed share price and asset metadata.

## Known failure modes

- Invalid or unsupported chain name/ID returns an error
- Vault address is not a valid ERC-4626 contract — call reverts or returns empty data
- Contract at address does not implement required ERC-4626 interface methods
- Network RPC unavailable for the requested chain — timeout or connection error
- Malformed vault address (not a valid Ethereum address) returns validation error

## How this service works

ERC-4626 vault reader for 16 EVM chains: underlying asset, total assets, share supply and the current share price in asset units.

## Output

Returns a JSON object with the chain name, chain ID, vault address, underlying asset address, asset symbol, asset decimals, vault name, vault share symbol, share decimals, total assets under management (in asset units), total shares in circulation, current share price in asset units, a human-readable note summarizing the result, and a source field indicating how the data was retrieved.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "chain",
      "vault"
     ],
     "properties": {
      "chain": {
       "type": "string",
       "description": "chain name (ethereum, base, arbitrum, optimism, polygon, bsc, avalanche, gnosis, linea, scroll, mantle, blast, sonic, celo, berachain, unichain) or chain id"
      },
      "vault": {
       "type": "string",
       "description": "the ERC-4626 vault contract address"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "chain",
      "chain_id",
      "vault",
      "asset",
      "total_assets",
      "total_shares",
      "note",
      "source"
     ],
     "properties": {
      "name": {
       "type": [
        "string",
        "null"
       ],
       "description": "vault name"
      },
      "note": {
       "type": "string",
       "description": "plain-language reading of the result"
      },
      "asset": {
       "type": "string",
       "description": "underlying asset token address"
      },
      "chain": {
       "type": "string",
       "description": "the chain name that was queried"
      },
      "vault": {
       "type": "string",
       "description": "the ERC-4626 vault"
      },
      "source": {
       "type": "string",
       "description": "where the data was read from or how it was computed"
      },
      "symbol": {
       "type": [
        "string",
        "null"
       ],
       "description": "vault share symbol"
      },
      "chain_id": {
       "type": "number",
       "description": "EIP-155 chain id of that network"
      },
      "asset_symbol": {
       "type": [
        "string",
        "null"
       ],
       "description": "underlying asset symbol"
      },
      "total_assets": {
       "type": "string",
       "description": "assets managed by the vault, in asset units"
      },
      "total_shares": {
       "type": "string",
       
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-erc-4626-vault-reader-83ccfe22/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)