# crypto.decode-calldata

Decode raw EVM transaction calldata. POST { data } (0x-prefixed hex). Resolves the 4-byte function selector to its human signature(s) via the openchain.xyz database, then ABI-decodes the parameters (address, uint/int, bool, bytesN, string, bytes, and elementary dynamic arrays). Returns selector, candidate signatures, d

Agent View of the PolicyLayer registry record for `crypto.decode-calldata`. HTML page: https://policylayer.com/tools/io-github-2s-io-mcp/crypto.decode-calldata

## Facts

- Tool: `crypto.decode-calldata`
- Server: Mcp (`@2sio/mcp`) — https://policylayer.com/tools/io-github-2s-io-mcp.md
- Install: `npx -y @2sio/mcp`
- Homepage: https://github.com/2s-io/sdk
- 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": "crypto.decode-calldata",
    "arguments": {}
  }
}
```

## Why crypto.decode-calldata is rated Low

This tool performs decoding and analysis of blockchain transaction data without modifying state, executing transactions, or moving funds. It is purely informational—taking encoded calldata as input and returning human-readable function signatures and decoded parameters. No side effects, no irreversible changes, no code execution triggered. This is a Read operation typical of blockchain analysis and auditing tools.

From the tool's own definition: "Decode raw EVM transaction calldata. POST { data } (0x-prefixed hex). Resolves the 4-byte function selector to its openchain.xyz database, then ABI-decodes the parameters..."

## Use case

AI agents call crypto.decode-calldata to retrieve information from Mcp 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:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "crypto.decode-calldata": {}
  }
}
```

## Other tools on Mcp (571)

- `queue.ack` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/queue.ack.md
- `store.blob-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.blob-delete.md
- `store.doc-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.doc-delete.md
- `store.kv-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.kv-delete.md
- `store.vector-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.vector-delete.md
- `watchers.cancel` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.cancel.md
- `ai.council` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/ai.council.md
- `ai.screenshot` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/ai.screenshot.md
- `batch.run` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/batch.run.md
- `dev.preflight` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/dev.preflight.md
- `dev.regex-test` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/dev.regex-test.md
- `hash.compute` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/hash.compute.md
- `pubsub.subscribe` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/pubsub.subscribe.md
- `queue.lease` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/queue.lease.md
- `search.crawl` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/search.crawl.md
- `url.render` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/url.render.md
- `watchers.crypto-address-activity` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.crypto-address-activity.md
- `watchers.earthquake` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.earthquake.md
- `predict.crypto-updown` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/predict.crypto-updown.md
- `predict.wallet` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/predict.wallet.md
- `watchers.fear-greed` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.fear-greed.md
- `watchers.fx-rate` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.fx-rate.md
- `agent.knowledge-delta` — Other — https://policylayer.com/tools/io-github-2s-io-mcp/agent.knowledge-delta.md
- `agriculture.drought` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/agriculture.drought.md
- `agriculture.stats` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/agriculture.stats.md
- `ai.chat` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.chat.md
- `ai.classify` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.classify.md
- `ai.describe-image` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.describe-image.md
- `ai.entities` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.entities.md
- `ai.extract` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.extract.md
- …and 541 more: https://policylayer.com/tools/io-github-2s-io-mcp.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=io-github-2s-io-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-2s-io-mcp