# getERC20Allowance

Get the amount of tokens approved for a spender to use from an owner

Agent View of the PolicyLayer registry record for `getERC20Allowance`. HTML page: https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/geterc20allowance

## Facts

- Tool: `getERC20Allowance`
- Server: MCP Ethers Wallet (`crazyrabbitltc/mcp-ethers-server`) — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server.md
- Homepage: https://github.com/crazyrabbitLTC/mcp-ethers-server
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "getERC20Allowance",
    "arguments": {}
  }
}
```

## Why getERC20Allowance is rated Low

This tool queries blockchain state to retrieve an ERC20 allowance value. It has no side effects and does not modify, execute, or delete anything. While it operates in a financial domain (ERC20 tokens), the tool itself performs no financial transaction or movement of value — it only reads approval metadata. Thus it is categorized as Read with low severity, as an agent cannot cause direct harm by calling this tool.

From the tool's own definition: "Tool description states 'Get the amount of tokens approved for a spender to use from an owner' — this retrieves existing allowance data without modifying state."

## Use case

AI agents call getERC20Allowance to retrieve information from MCP Ethers Wallet without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches MCP Ethers Wallet:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "getERC20Allowance": {}
  }
}
```

## Other tools on MCP Ethers Wallet (68)

- `contractCall` — Execute — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/contractcall.md
- `prepareContractTransaction` — Execute — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/preparecontracttransaction.md
- `prepareERC1155SetApprovalForAll` — Execute — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/prepareerc1155setapprovalforall.md
- `prepareERC721SetApprovalForAll` — Execute — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/prepareerc721setapprovalforall.md
- `signMessage` — Execute — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/signmessage.md
- `approveERC20` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/approveerc20.md
- `approveNFT` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/approvenft.md
- `ethSign` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/ethsign.md
- `prepareERC1155BatchTransfer` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/prepareerc1155batchtransfer.md
- `prepareERC20Approval` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/prepareerc20approval.md
- `prepareTransaction` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/preparetransaction.md
- `safeBatchTransferERC1155` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/safebatchtransfererc1155.md
- `safeTransferERC1155` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/safetransfererc1155.md
- `safeTransferERC721` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/safetransfererc721.md
- `sendSignedTransaction` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/sendsignedtransaction.md
- `sendTransaction` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/sendtransaction.md
- `sendTransactionWithOptions` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/sendtransactionwithoptions.md
- `transferERC20` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/transfererc20.md
- `transferERC721` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/transfererc721.md
- `transferFromERC20` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/transferfromerc20.md
- `transferNFT` — Financial — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/transfernft.md
- `loadWallet` — Other — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/loadwallet.md
- `checkWalletExists` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/checkwalletexists.md
- `erc1155_balanceOf` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc1155-balanceof.md
- `erc1155_balanceOfBatch` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc1155-balanceofbatch.md
- `erc1155_uri` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc1155-uri.md
- `erc20_balanceOf` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc20-balanceof.md
- `erc20_getTokenInfo` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc20-gettokeninfo.md
- `erc721_balanceOf` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc721-balanceof.md
- `erc721_tokenURI` — Read — https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server/erc721-tokenuri.md
- …and 38 more: https://policylayer.com/tools/crazyrabbitltc-mcp-ethers-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=crazyrabbitltc-mcp-ethers-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/crazyrabbitltc-mcp-ethers-server