# evm_selector_decode

Decode EVM function selectors, calldata and event topics: looks up 4-byte selectors (or 32-byte event topics) in 4byte.directory plus a built-in table of well-known signatures, re-hashes every candidate with Keccak-256 to drop bad entries, and for full calldata ABI-decodes the arguments (address with EIP-55 checksum, uint/int as exact decimal strings, bool, bytes, string, arrays, tuples), ranking candidates that decode cleanly first. Also computes the selector/topic for a given signature. Price: $0.005 USDC per successful call (x402, Solana). Same tool over HTTPS: GET https://scorptech.it.com/api/x402/v1/evm-selector-decode

Agent View of the PolicyLayer registry record for `evm_selector_decode`. HTML page: https://policylayer.com/tools/com-it-scorptech-x402/evm-selector-decode

## Facts

- Tool: `evm_selector_decode`
- Server: ScorpTech x402 API (`https://scorptech.it.com/api/x402/mcp`) — https://policylayer.com/tools/com-it-scorptech-x402.md
- Homepage: https://github.com/https://scorptech.it.com/api/x402/mcp
- Risk category: Destructive (Critical risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server CORS policy: *
- Server rate-limited: no
- Parameters: 5
- Recommended policy verdict: Hidden

## Parameters

| Parameter | Type | Required | Description |
| --- | --- | --- | --- |
| `limit` | integer | no | Max candidates 1-50 (default 10) |
| `topic` | string | no | 32-byte event topic0 hash |
| `calldata` | string | no | Full transaction input data (0x...), decoded against the candidates |
| `selector` | string | no | 4-byte function selector, e.g. 0xa9059cbb |
| `signature` | string | no | A signature like transfer(address,uint256) to hash into its selector/topic |

Parameters from the server's own tool schema.

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

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

## Why evm_selector_decode is rated Critical

An AI agent that decides to call evm_selector_decode doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from ScorpTech x402 API is gone. There is no undo for destructive operations.

## Use case

AI agents call evm_selector_decode to permanently remove resources in ScorpTech x402 API, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.

## Recommended policy (PolicyLayer)

Verdict: **Hidden**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches ScorpTech x402 API:

```json
{
  "version": "1",
  "default": "deny",
  "hide": [
    "evm_selector_decode"
  ]
}
```

## Other tools on ScorpTech x402 API (1011)

- `collatz_drop` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/collatz-drop.md
- `dedupe_records` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/dedupe-records.md
- `frames_timecode` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/frames-timecode.md
- `ip_reputation` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/ip-reputation.md
- `led_resistor` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/led-resistor.md
- `ruler_odd` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/ruler-odd.md
- `sql_format` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/sql-format.md
- `timecode_diff` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/timecode-diff.md
- `timecode_duration` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/timecode-duration.md
- `timecode_frames` — Destructive — https://policylayer.com/tools/com-it-scorptech-x402/timecode-frames.md
- `abi_encode` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/abi-encode.md
- `apery_term` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/apery-term.md
- `ballot` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/ballot.md
- `baum_sweet` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/baum-sweet.md
- `binom` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/binom.md
- `bit_subset` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/bit-subset.md
- `biunitary_sigma` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/biunitary-sigma.md
- `champernowne_start` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/champernowne-start.md
- `clinical_trials` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/clinical-trials.md
- `coin_min` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/coin-min.md
- `coin_ways` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/coin-ways.md
- `color_palette` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/color-palette.md
- `compound_interest` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/compound-interest.md
- `cron_explain` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/cron-explain.md
- `curl_to_code` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/curl-to-code.md
- `date_calc` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/date-calc.md
- `delannoy` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/delannoy.md
- `delannoy_sum` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/delannoy-sum.md
- `dmarc_report_parse` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/dmarc-report-parse.md
- `dockerfile_lint` — Execute — https://policylayer.com/tools/com-it-scorptech-x402/dockerfile-lint.md
- …and 981 more: https://policylayer.com/tools/com-it-scorptech-x402.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=com-it-scorptech-x402 · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/com-it-scorptech-x402