# Pyfile Toolkit – Ethereum Function Signature Lookup

> Pyfile Toolkit – Ethereum Function Signature Lookup is a paid API for AI agents from pyfile-agent.taile3ff35.ts.net, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Resolves a 4-byte Ethereum function selector (e.g. 0xa9059cbb) to its human-readable ABI function signature

## Facts

- Endpoint: GET https://pyfile-agent.taile3ff35.ts.net/data/abi
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/pyfile-toolkit-ethereum-function-signature-lookup-41daf6fd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_O-jhBlbpPJANdRNlPHgal

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 pyfile-toolkit-ethereum-function-signature-lookup-41daf6fd
```

Example prompt: What Ethereum function signature corresponds to the selector 0xa9059cbb? Look it up in the ABI database.

## When to prefer this

Use this endpoint when you need to resolve a raw 4-byte Ethereum function selector to its ABI signature for calldata decoding, transaction analysis, or smart contract auditing. Prefer this over generic blockchain explorers when you need a lightweight, programmatic lookup without full node access.

## Known failure modes

- Unknown selector not found in the signature database — returns empty or not-found response
- Malformed selector (not a valid 4-byte hex string) causes an error
- Network unavailability of the Tailscale-hosted endpoint
- Selector has multiple possible matches (hash collision) — may return one or all

## How this service works

Ethereum function signature lookup. ?selector=0xa9059cbb

## Output

The endpoint returns the human-readable Ethereum function signature (e.g. 'transfer(address,uint256)') corresponding to the provided 4-byte selector, enabling decoding of raw EVM calldata.

## 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",
     "properties": {
      "selector": {
       "type": "string"
      }
     }
    }
   }
  },
  "output": {
   "type": "object"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/pyfile-toolkit-ethereum-function-signature-lookup-41daf6fd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
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