# SignalHarness ABI Function Decode

> SignalHarness ABI Function Decode is a paid API for AI agents from signalharness.ai, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-13).

Decodes a raw ABI-encoded Ethereum function call into a human-readable representation, including warnings about the decoded data.

## Facts

- Endpoint: POST https://signalharness.ai/api/agent/services/abi_function_decode/invoke
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signalharness-abi-function-decode-205edee9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z_KWfwwECZilpximvAnIa

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 signalharness-abi-function-decode-205edee9 -d '<json body>'
```

Example prompt: Can you decode this ABI-encoded Ethereum function call for me? Here's the calldata: 0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000002386f26fc10000

## When to prefer this

Choose this endpoint when you need to decode raw Ethereum ABI-encoded function calldata into a human-readable form, especially within an agent workflow that already uses x402 micropayments. It is particularly useful for blockchain analytics, transaction auditing, smart contract debugging, or any scenario where you need to interpret raw on-chain input data programmatically at low per-call cost ($0.01 USDC).

## Known failure modes

- Invalid or malformed ABI-encoded data returns an error or warnings in the warnings array
- Calldata that doesn't match any known ABI signature may return partial or ambiguous decode results
- Input too long (>65536 characters) will be rejected by schema validation
- Malformed hex strings or non-ABI data will fail to decode cleanly
- Payment failure via x402 protocol will prevent execution

## How this service works

Explore 330 pay-per-call x402 API services and 27 agent-native digital products, with Base USDC pricing, secure Polar checkout, and free discovery.

## Output

Returns a JSON object containing the decoded function call (function name and parameter values), any warnings about the data, the evidence scope indicating how the data was interpreted, plus a full receipt with payment confirmation, latency, result hash, and execution metadata.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "abi_function_decode_request": {
   "type": "string",
   "maxLength": 65536,
   "minLength": 2
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "replay": false,
  "result": {
   "warnings": [
    "Decoded values reflect only the supplied ABI and bytes."
   ],
   "service_id": "abi_function_decode",
   "evidence_scope": "caller_supplied_data",
   "decoded_function_call": "{\"args\":[\"0x0000000000000000000000000000000000000001\"],\"functionName\":\"balanceOf\"}"
  },
  "status": "succeeded",
  "receipt": {
   "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
   "usage": [],
   "status": "succeeded",
   "network": "eip155:8453",
   "artifacts": [],
   "endedAtMs": 0,
   "latencyMs": 0,
   "paymentId": "example-payment",
   "receiptId": "example-receipt",
   "requestId": "example-request",
   "serviceId": "abi_function_decode",
   "executionId": "example-execution",
   "startedAtMs": 0,
   "amountAtomic": "10000",
   "resultSha256": "c2309aa284a0852faed303b6b747a5d28e909d8a17831406be457670166f7988",
   "serviceVersion": "1.0.0",
   "settlementReference": "0x0000000000000000000000000000000000000000000000000000000000000000"
  },
  "artifacts": [],
  "requestId": "example-request",
  "executionId": "example-execution"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signalharness-abi-function-decode-205edee9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from signalharness.ai](https://www.zero.xyz/host/signalharness.ai/llms.txt)